@article{proctor_stadler_cortes_brodsky_poisson_gerdts_smirnov_smirnova_barua_leahy_et al._2024, title={A TriAdj-Adjuvanted <i>Chlamydia trachomatis</i> CPAF Protein Vaccine Is Highly Immunogenic in Pigs}, url={https://www.mdpi.com/2076-393X/12/4/423}, DOI={10.3390/vaccines12040423}, abstractNote={Chlamydia trachomatis (Ct) infections are the most common sexually transmitted infection (STI). Despite effective antibiotics for Ct, undetected infections or delayed treatment can lead to infertility, ectopic pregnancies, and chronic pelvic pain. Besides humans, chlamydia poses similar health challenges in animals such as C. suis (Cs) in pigs. Based on the similarities between humans and pigs, as well as their chlamydia species, we use pigs as a large biomedical animal model for chlamydia research. In this study, we used the pig model to develop a vaccine candidate against Ct. The vaccine candidate consists of TriAdj-adjuvanted chlamydial-protease-like activity factor (CPAF) protein. We tested two weekly administration options—twice intranasal (IN) followed by twice intramuscular (IM) and twice IM followed by twice IN. We assessed the humoral immune response in both serum using CPAF-specific IgG (including antibody avidity determination) and also in cervical and rectal swabs using CPAF-specific IgG and IgA ELISAs. The systemic T-cell response was analyzed following in vitro CPAF restimulation via IFN-γ and IL-17 ELISpots, as well as intracellular cytokine staining flow cytometry. Our data demonstrate that while the IN/IM vaccination mainly led to non-significant systemic immune responses, the vaccine candidate is highly immunogenic if administered IM/IN. This vaccination strategy induced high serum anti-CPAF IgG levels with strong avidity, as well as high IgA and IgG levels in vaginal and rectal swabs and in uterine horn flushes. In addition, this vaccination strategy prompted a pronounced cellular immune response. Besides inducing IL-17 production, the vaccine candidate induced a strong IFN-γ response with CD4 T cells. In IM/IN-vaccinated pigs, these cells also significantly downregulated their CCR7 expression, a sign of differentiation into peripheral-tissue-homing effector/memory cells. Conclusively, this study demonstrates the strong immunogenicity of the IM/IN-administered TriAdj-adjuvanted Ct CPAF vaccine candidate. Future studies will test the vaccine efficacy of this promising Ct vaccine candidate. In addition, this project demonstrates the suitability of the Cs pre-exposed outbred pig model for Ct vaccine development. Thereby, we aim to open the bottleneck of large animal models to facilitate the progression of Ct vaccine candidates into clinical trials.}, journal={Vaccines}, author={Proctor, Jessica and Stadler, Maria and Cortes, Lizette M. and Brodsky, David and Poisson, Lydia and Gerdts, Volker and Smirnov, Alex I. and Smirnova, Tatyana I. and Barua, Subarna and Leahy, Darren and et al.}, year={2024}, month={Apr} }
 @article{kick_grete_crisci_almond_käser_2023, title={Testable Candidate Immune Correlates of Protection for Porcine Reproductive and Respiratory Syndrome Virus Vaccination}, volume={11}, ISSN={2076-393X}, url={http://dx.doi.org/10.3390/vaccines11030594}, DOI={10.3390/vaccines11030594}, abstractNote={Porcine reproductive and respiratory syndrome virus (PRRSV) is an on-going problem for the worldwide pig industry. Commercial and experimental vaccinations often demonstrate reduced pathology and improved growth performance; however, specific immune correlates of protection (CoP) for PRRSV vaccination have not been quantified or even definitively postulated: proposing CoP for evaluation during vaccination and challenge studies will benefit our collective efforts towards achieving protective immunity. Applying the breadth of work on human diseases and CoP to PRRSV research, we advocate four hypotheses for peer review and evaluation as appropriate testable CoP: (i) effective class-switching to systemic IgG and mucosal IgA neutralizing antibodies is required for protective immunity; (ii) vaccination should induce virus-specific peripheral blood CD4+ T-cell proliferation and IFN-γ production with central memory and effector memory phenotypes; cytotoxic T-lymphocytes (CTL) proliferation and IFN-γ production with a CCR7- phenotype that should migrate to the lung; (iii) nursery, finishing, and adult pigs will have different CoP; (iv) neutralizing antibodies provide protection and are rather strain specific; T cells confer disease prevention/reduction and possess greater heterologous recognition. We believe proposing these four CoP for PRRSV can direct future vaccine design and improve vaccine candidate evaluation.}, number={3}, journal={Vaccines}, publisher={MDPI AG}, author={Kick, Andrew R. and Grete, Alicyn F. and Crisci, Elisa and Almond, Glen W. and Käser, Tobias}, year={2023}, month={Mar}, pages={594} }
 @article{sper_proctor_lascina_guo_polkoff_kaeser_simpson_borst_gleason_zhang_et al._2022, title={Allogeneic and xenogeneic lymphoid reconstitution in a RAG2(-/-)IL2RG(y/-) severe combined immunodeficient pig: A preclinical model for intrauterine hematopoietic transplantation}, volume={9}, ISSN={["2297-1769"]}, DOI={10.3389/fvets.2022.965316}, abstractNote={Mice with severe combined immunodeficiency are commonly used as hosts of human cells. Size, longevity, and physiology, however, limit the extent to which immunodeficient mice can model human systems. To address these limitations, we generated RAG2−/−IL2RGy/− immunodeficient pigs and demonstrate successful engraftment of SLA mismatched allogeneic D42 fetal liver cells, tagged with pH2B-eGFP, and human CD34+ hematopoietic stem cells after in utero cell transplantation. Following intrauterine injection at day 42–45 of gestation, fetuses were allowed to gestate to term and analyzed postnatally for the presence of pig (allogeneic) and human (xenogeneic) B cells, T-cells and NK cells in peripheral blood and other lymphoid tissues. Engraftment of allogeneic hematopoietic cells was detected based on co-expression of pH2B-eGFP and various markers of differentiation. Analysis of spleen revealed robust generation and engraftment of pH2B-eGFP mature B cells (and IgH recombination) and mature T-cells (and TCR-β recombination), T helper (CD3+CD4+) and T cytotoxic (CD3+CD8+) cells. The thymus revealed engraftment of pH2B-eGFP double negative precursors (CD4−CD8−) as well as double positive (CD4+, CD8+) precursors and single positive T-cells. After intrauterine administration of human CD34+ hematopoietic stem cells, analysis of peripheral blood and lymphoid tissues revealed the presence of human T-cells (CD3+CD4+ and CD3+CD8+) but no detectable B cells or NK cells. The frequency of human CD45+ cells in the circulation decreased rapidly and were undetectable within 2 weeks of age. The frequency of human CD45+ cells in the spleen also decreased rapidly, becoming undetectable at 3 weeks. In contrast, human CD45+CD3+T-cells comprised >70% of cells in the pig thymus at birth and persisted at the same frequency at 3 weeks. Most human CD3+ cells in the pig's thymus expressed CD4 or CD8, but few cells were double positive (CD4+ CD8+). In addition, human CD3+ cells in the pig thymus contained human T-cell excision circles (TREC), suggesting de novo development. Our data shows that the pig thymus provides a microenvironment conducive to engraftment, survival and development of human T-cells and provide evidence that the developing T-cell compartment can be populated to a significant extent by human cells in large animals.}, journal={FRONTIERS IN VETERINARY SCIENCE}, author={Sper, Renan B. and Proctor, Jessica and Lascina, Odessa and Guo, Ling and Polkoff, Kathryn and Kaeser, Tobias and Simpson, Sean and Borst, Luke and Gleason, Katherine and Zhang, Xia and et al.}, year={2022}, month={Oct} }
 @article{proctor_wolf_brodsky_cortes_frias-de-diego_almond_crisci_negrão watanabe_hammer_käser_2022, title={Heterologous vaccine immunogenicity, efficacy, and immune correlates of protection of a modified-live virus porcine reproductive and respiratory syndrome virus vaccine}, volume={13}, ISSN={1664-302X}, url={http://dx.doi.org/10.3389/fmicb.2022.977796}, DOI={10.3389/fmicb.2022.977796}, abstractNote={Although porcine reproductive and respiratory syndrome virus (PRRSV) vaccines have been available in North America for almost 30 years, many vaccines face a significant hurdle: they must provide cross-protection against the highly diverse PRRSV strains. This cross-protection, or heterologous vaccine efficacy, relies greatly on the vaccine’s ability to induce a strong immune response against various strains—heterologous immunogenicity. Thus, this study investigated vaccine efficacy and immunogenicity of a modified live virus (MLV) against four heterologous type 2 PRRSV (PRRSV-2) strains. In this study, 60 pigs were divided into 10 groups. Half were MOCK-vaccinated, and the other half vaccinated with the Prevacent® PRRS MLV vaccine. Four weeks after vaccination, groups were challenged with either MOCK, or four PRRSV-2 strains from three different lineages—NC174 or NADC30 (both lineage 1), VR2332 (lineage 5), or NADC20 (lineage 8). Pre-and post-challenge, lung pathology, viral loads in both nasal swabs and sera, anti-PRRSV IgA/G, neutralizing antibodies, and the PRRSV-2 strain-specific T-cell response were evaluated. At necropsy, the lung samples were collected to assess viral loads, macroscopical and histopathological findings, and IgA levels in bronchoalveolar lavage. Lung lesions were only induced by NC174, NADC20, and NADC30; within these, vaccination resulted in lower gross and microscopic lung lesion scores of the NADC20 and NADC30 strains. All pigs became viremic and vaccinated pigs had decreased viremia upon challenge with NADC20, NADC30, and VR2332. Regarding vaccine immunogenicity, vaccination induced a strong systemic IgG response and boosted the post-challenge serum IgG levels for all strains. Furthermore, vaccination increased the number of animals with neutralizing antibodies against three of the four challenge strains—NADC20, NADC30, and VR2332. The heterologous T-cell response was also improved by vaccination: Not only did vaccination increase the induction of heterologous effector/memory CD4 T cells, but it also improved the heterologous CD4 and CD8 proliferative and/or IFN-γ response against all strains. Importantly, correlation analyses revealed that the (non-PRRSV strain-specific) serum IgG levels and the PRRSV strain-specific CD4 T-cell response were the best immune correlates of protection. Overall, the Prevacent elicited various degrees of efficacy and immunogenicity against four heterologous and phylogenetically distant strains of PRRSV-2.}, journal={Frontiers in Microbiology}, publisher={Frontiers Media SA}, author={Proctor, Jessica and Wolf, Iman and Brodsky, David and Cortes, Lizette M. and Frias-De-Diego, Alba and Almond, Glen W. and Crisci, Elisa and Negrão Watanabe, Tatiane Terumi and Hammer, James M. and Käser, Tobias}, year={2022}, month={Sep} }
 @article{cortes_brodsky_chen_pridgen_odle_snider_cruse_putikova_masuda_doyle_et al._2022, title={Immunologic and pathologic characterization of a novel swine biomedical research model for eosinophilic esophagitis}, volume={3}, ISSN={["2673-6101"]}, DOI={10.3389/falgy.2022.1029184}, abstractNote={Eosinophilic esophagitis (EoE) is a chronic allergy-mediated condition with an increasing incidence in both children and adults. Despite EoE's strong impact on human health and welfare, there is a large unmet need for treatments with only one recently FDA-approved medication for EoE. The goal of this study was to establish swine as a relevant large animal model for translational biomedical research in EoE with the potential to facilitate development of therapeutics. We recently showed that after intraperitoneal sensitization and oral challenge with the food allergen hen egg white protein (HEWP), swine develop esophageal eosinophilia—a hallmark of human EoE. Herein, we used a similar sensitization and challenge treatment and evaluated immunological and pathological markers associated with human EoE. Our data demonstrate that the incorporated sensitization and challenge treatment induces (i) a systemic T-helper 2 and IgE response, (ii) a local expression of eotaxin-1 and other allergy-related immune markers, (iii) esophageal eosinophilia (>15 eosinophils/0.24 mm2), and (iv) esophageal endoscopic findings including linear furrows and white exudates. Thereby, we demonstrate that our sensitization and oral challenge protocol not only induces the underlying immune markers but also the micro- and macro-pathological hallmarks of human EoE. This swine model for EoE represents a novel relevant large animal model that can drive translational biomedical research to develop urgently needed treatment strategies for EoE.}, journal={FRONTIERS IN ALLERGY}, author={Cortes, Lizette M. and Brodsky, David and Chen, Celine and Pridgen, Tiffany and Odle, Jack and Snider, Douglas B. and Cruse, Glenn and Putikova, Arina and Masuda, Mia Y. and Doyle, Alfred D. and et al.}, year={2022}, month={Nov} }
 @article{amaral_mcqueen_bellingham-johnstun_poston_darville_nagarajan_laplante_kaser_2021, title={Host-Pathogen Interactions of Chlamydia trachomatis in Porcine Oviduct Epithelial Cells}, volume={10}, ISSN={["2076-0817"]}, url={https://www.mdpi.com/2076-0817/10/10/1270}, DOI={10.3390/pathogens10101270}, abstractNote={Chlamydia trachomatis (Ct) causes the most prevalent bacterial sexually transmitted disease leading to ectopic pregnancy and infertility. Swine not only have many similarities to humans, but they are also susceptible to Ct. Despite these benefits and the ease of access to primary tissue from this food animal, in vitro research in swine has been underutilized. This study will provide basic understanding of the Ct host–pathogen interactions in porcine oviduct epithelial cells (pOECs)—the counterparts of human Fallopian tube epithelial cells. Using NanoString technology, flow cytometry, and confocal and transmission-electron microscopy, we studied the Ct developmental cycle in pOECs, the cellular immune response, and the expression and location of the tight junction protein claudin-4. We show that Ct productively completes its developmental cycle in pOECs and induces an immune response to Ct similar to human cells: Ct mainly induced the upregulation of interferon regulated genes and T-cell attracting chemokines. Furthermore, Ct infection induced an accumulation of claudin-4 in the Ct inclusion with a coinciding reduction of membrane-bound claudin-4. Downstream effects of the reduced membrane-bound claudin-4 expression could potentially include a reduction in tight-junction expression, impaired epithelial barrier function as well as increased susceptibility to co-infections. Thereby, this study justifies the investigation of the effect of Ct on tight junctions and the mucosal epithelial barrier function. Taken together, this study demonstrates that primary pOECs represent an excellent in vitro model for research into Ct pathogenesis, cell biology and immunity.}, number={10}, journal={PATHOGENS}, publisher={MDPI AG}, author={Amaral, Amanda F. and McQueen, Bryan E. and Bellingham-Johnstun, Kimberly and Poston, Taylor B. and Darville, Toni and Nagarajan, Uma M. and Laplante, Caroline and Kaser, Tobias}, year={2021}, month={Oct} }
 @article{kick_wolfe_amaral_cortes_almond_crisci_gauger_pittman_kaeser_2021, title={Maternal Autogenous Inactivated Virus Vaccination Boosts Immunity to PRRSV in Piglets}, volume={9}, ISSN={["2076-393X"]}, url={https://doi.org/10.3390/vaccines9020106}, DOI={10.3390/vaccines9020106}, abstractNote={Maternal-derived immunity is a critical component for the survival and success of offspring in pigs to protect from circulating pathogens such as Type 2 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV-2). The purpose of this study is to investigate the transfer of anti-PRRSV immunity to piglets from gilts that received modified-live virus (MLV) alone (treatment (TRT) 0), or in combination with one of two autogenous inactivated vaccines (AIVs, TRT 1+2). Piglets from these gilts were challenged with the autogenous PRRSV-2 strain at two weeks of age and their adaptive immune response (IR) was evaluated until 4 weeks post inoculation (wpi). The systemic humoral and cellular IR was analyzed in the pre-farrow gilts, and in piglets, pre-inoculation, and at 2 and 4 wpi. Both AIVs partially protected the piglets with reduced lung pathology and increased weight gain; TRT 1 also lowered piglet viremia, best explained by the AIV-induced production of neutralizing antibodies in gilts and their transfer to the piglets. In piglets, pre-inoculation, the main systemic IFN-γ producers were CD21α+ B cells. From 0 to 4 wpi, the role of these B cells declined and CD4 T cells became the primary systemic IFN-γ producers. In the lungs, CD8 T cells were the primary and CD4 T cells were the secondary IFN-γ producers, including a novel subset of porcine CD8α−CCR7− CD4 T cells, potentially terminally differentiated CD4 TEMRA cells. In summary, this study demonstrates that maternal AIV vaccination can improve protection of pre-weaning piglets against PRRSV-2; it shows the importance of transferring neutralizing antibodies to piglets, and it introduces two novel immune cell subsets in pigs—IFN-γ producing CD21α+ B cells and CD8α−CCR7− CD4 T cells.}, number={2}, journal={VACCINES}, publisher={MDPI AG}, author={Kick, Andrew R. and Wolfe, Zoe C. and Amaral, Amanda E. and Cortes, Lizette M. and Almond, Glen W. and Crisci, Elisa and Gauger, Phillip C. and Pittman, Jeremy and Kaeser, Tobias}, year={2021}, month={Feb} }
 @article{kaser_2021, title={Swine as biomedical animal model for T-cell research-Success and potential for transmittable and non-transmittable human diseases}, volume={135}, ISSN={["1872-9142"]}, url={https://doi.org/10.1016/j.molimm.2021.04.004}, DOI={10.1016/j.molimm.2021.04.004}, abstractNote={Swine is biologically one of the most relevant large animal models for biomedical research. With its use as food animal that can be exploited as a free cell and tissue source for research and its high susceptibility to human diseases, swine additionally represent an excellent option for both the 3R principle and One Health research. One of the previously most limiting factors of the pig model was its arguably limited immunological toolbox. Yet, in the last decade, this toolbox has vastly improved including the ability to study porcine T-cells. This review summarizes the swine model for biomedical research with focus on T cells. It first contrasts the swine model to the more commonly used mouse and non-human primate model before describing the current capabilities to characterize and extend our knowledge on porcine T cells. Thereafter, it not only reflects on previous biomedical T-cell research but also extends into areas in which more in-depth T-cell analyses could strongly benefit biomedical research. While the former should inform on the successes of biomedical T-cell research in swine, the latter shall inspire swine T-cell researchers to find collaborations with researchers working in other areas – such as nutrition, allergy, cancer, transplantation, infectious diseases, or vaccine development.}, journal={MOLECULAR IMMUNOLOGY}, publisher={Elsevier BV}, author={Kaser, Tobias}, year={2021}, month={Jul}, pages={95–115} }
 @article{kick_wolfe_amaral_cortes_almond_crisci_gauger_pittman_käser_2020, title={Maternal Autogenous Inactivated Virus Vaccination Boosts the Piglet Humoral and Cell-Mediated Immunity to PRRSV via Transfer of Neutralizing Antibodies and Interferon-Gamma Producing B Cells}, volume={12}, url={https://doi.org/10.20944/preprints202012.0074.v1}, DOI={10.20944/preprints202012.0074.v1}, abstractNote={Maternal-derived immunity is a critical component for survival and success of offspring in pigs to protect from circulating pathogens like Type 2 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV-2). The purpose of this study was to investigate the transfer of anti-PRRSV immunity to piglets from gilts that received modified-live virus (MLV) alone (TRT 0), or in combination with one of two autogenous inactivated vaccines (AIVs, TRT 1+2). Piglets from these gilts were challenged with the autogenous PRRSV-2 strain at two weeks of age and their adaptive immune response (IR) was evaluated until 4 weeks post inoculation (wpi). The systemic humoral and cellular IR was analyzed in the pre-farrow gilts, and in piglets, pre-inoculation, and at 2- and 4-wpi. Both AIVs partially protected the piglets with reduced lung pathology and increased weight gain; TRT 1 also lowered piglet viremia best explained by the AIV-induced production of neutralizing antibodies in gilts and their transfer to the piglets. In piglets, pre-inoculation, the main systemic IFN-&gamma; producers were CD21&alpha;+ B cells. From 0 to 4 wpi, the role of these B cells declined and CD4 T cells became the primary systemic IFN-&gamma; producers. In lungs, CD8 T cells were the primary and CD4 T cells the secondary IFN-&gamma; producers including a novel subset of porcine CD8&alpha;-CCR7- CD4 T cells, potentially terminally differentiated CD4 TEMRA cells. In summary, this study demonstrates that maternal AIV vaccination can improve protection of pre-weaning piglets against PRRSV-2; it shows the importance of transferring neutralizing antibodies to piglets; and it introduces two novel immune cell subsets in pigs &ndash; IFN-&gamma; producing CD21&alpha;+ B cells and CD8&alpha;-CCR7- CD4 T cells.}, publisher={MDPI AG}, author={Kick, Andrew R. and Wolfe, Zoe C. and Amaral, Amanda F. and Cortes, Lizette M. and Almond, Glen W. and Crisci, Elisa and Gauger, Phillip C. and Pittman, Jeremy and Käser, Tobias}, year={2020}, month={Dec} }
 @article{amaral_rahman_kick_cortes_robertson_kaltenboeck_gerdts_o'connell_poston_zheng_et al._2020, title={Mucosal Vaccination with UV-Inactivated <i>Chlamydia suis</i> in Pre-Exposed Outbred Pigs Decreases Pathogen Load and Induces CD4 T-Cell Maturation into IFN-γ<sup>+</sup> Effector Memory Cells}, volume={8}, url={https://www.mdpi.com/2076-393X/8/3/353}, DOI={10.3390/vaccines8030353}, abstractNote={Chlamydia trachomatis (Ct) infections are the most frequent bacterial sexually transmitted disease, and they can lead to ectopic pregnancy and infertility. Despite these detrimental long-term sequelae, a vaccine is not available. Success in preclinical animal studies is essential for vaccines to move to human clinical trials. Pigs are the natural host to Chlamydia suis (Cs)—a chlamydia species closely related to Ct, and are susceptible to Ct, making them a valuable animal model for Ct vaccine development. Before making it onto market, Ct vaccine candidates must show efficacy in a high-risk human population. The high prevalence of human Ct infection combined with the fact that natural infection does not result in sterilizing immunity, results in people at risk likely having been pre-exposed, and thus having some level of underlying non-protective immunity. Like human Ct, Cs is highly prevalent in outbred pigs. Therefore, the goal of this study was to model a trial in pre-exposed humans, and to determine the immunogenicity and efficacy of intranasal Cs vaccination in pre-exposed outbred pigs. The vaccine candidates consisted of UV-inactivated Cs particles in the presence or absence of an adjuvant (TriAdj). In this study, both groups of vaccinated pigs had a lower Cs burden compared to the non-vaccinated group; especially the TriAdj group induced the differentiation of CD4+ cells into tissue-trafficking CCR7- IFN-γ-producing effector memory T cells. These results indicate that Cs vaccination of pre-exposed pigs effectively boosts a non-protective immune response induced by natural infection; moreover, they suggest that a similar approach could be applied to human vaccine trials.}, number={3}, journal={Vaccines}, publisher={MDPI AG}, author={Amaral, Amanda F. and Rahman, Khondaker S. and Kick, Andrew R. and Cortes, Lizette M. and Robertson, James and Kaltenboeck, Bernhard and Gerdts, Volker and O'Connell, Catherine and Poston, Taylor B. and Zheng, Xiaojing and et al.}, year={2020}, month={Jul}, pages={353} }
 @article{rodriguez-gomez_talker_kaeser_stadler_reiter_ladinig_milburn_hammer_mair_saalmueller_et al._2019, title={Expression of T-Bet, Eomesodermin, and GATA-3 Correlates With Distinct Phenotypes and Functional Properties in Porcine gamma delta T Cells}, volume={10}, ISSN={["1664-3224"]}, DOI={10.3389/fimmu.2019.00396}, abstractNote={Unlike mice and humans, porcine γδ T cells represent a prominent subset of T cells in blood and secondary lymphatic organs. GATA-3, T-bet and Eomesodermin (Eomes) are transcription factors with crucial functions in T-cell development and functional differentiation, but their expression has not been investigated in porcine γδ T cells so far. We analyzed the expression of these transcription factors in γδ thymocytes, mature γδ T cells from blood, spleen, lymph nodes, and lung tissue as well as in vitro stimulated γδ T cells on the protein level by flow cytometry. GATA-3 was present in more than 80% of all γδ-thymocytes. Extra-thymic CD2− γδ T cells expressed high levels of GATA-3 in all investigated organs and had a CD8α−/dimCD27+perforin− phenotype. T-bet expression was mainly found in a subset of CD2+ γδ T cells with an opposing CD8αhighCD27dim/−perforin+ phenotype. Eomes+ γδ T cells were also found within CD2+ γδ T cells but were heterogeneous in regard to expression of CD8α, CD27, and perforin. Eomes+ γδ T cells frequently co-expressed T-bet and dominated in the spleen. During aging, CD2−GATA-3+ γδ T cells strongly prevailed in young pigs up to an age of about 2 years but declined in older animals where CD2+T-bet+ γδ T cells became more prominent. Despite high GATA-3 expression levels, IL-4 production could not be found in γδ T cells by intracellular cytokine staining. Experiments with sorted and ConA + IL-2 + IL-12 + IL-18-stimulated CD2− γδ T cells showed that proliferating cells start expressing CD2 and T-bet, produce IFN-γ, but retain GATA-3 expression. In summary, our data suggest a role for GATA-3 in the development of γδ-thymocytes and in the function of peripheral CD2−CD8α−/dimCD27+perforin− γδ T cells. In contrast, T-bet expression appears to be restricted to terminal differentiation stages of CD2+ γδ T cells, frequently coinciding with perforin expression. The functional relevance of high GATA-3 expression levels in extra-thymic CD2− γδ T cells awaits further clarification. However, their unique phenotype suggests that they represent a thymus-derived separate lineage of γδ T cells in the pig for which currently no direct counterpart in rodents or humans has been described.}, journal={FRONTIERS IN IMMUNOLOGY}, author={Rodriguez-Gomez, Irene M. and Talker, Stephanie C. and Kaeser, Tobias and Stadler, Maria and Reiter, Lisa and Ladinig, Andrea and Milburn, Jemma V and Hammer, Sabine E. and Mair, Kerstin H. and Saalmueller, Rmin and et al.}, year={2019}, month={Mar} }
 @article{kick_amaral_cortes_fogle_crisci_almond_käser_2019, title={The T-Cell Response to Type 2 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV)}, volume={11}, url={https://doi.org/10.3390/v11090796}, DOI={10.3390/v11090796}, abstractNote={Porcine reproductive and respiratory syndrome virus (PRRSV) continues to cause severe reproductive and respiratory pathologies resulting in immense monetary and welfare costs for the swine industry. The vaccines against PRRSV are available; but they struggle with providing protection against the plethora of heterologous PRRSV strains. To improve PRRSV vaccine development, the aim of this study was to provide an in-depth analysis of the crucial heterologous T-cell response to type-2 PRRSV. Following PRRSV modified live virus (MLV) vaccination or infection using one high- or one low-pathogenic PRRSV-strain, this nine-week study evaluated the T-cell response to different PRRSV strains. Our results demonstrate an important role for T cells in this homo- and heterologous response. Specifically, the T-helper cells were the main responders during viremia. Their peak response at 28 dpi correlated with a reduction in viremia, and their homing receptor expression indicated the additional importance for the anti-PRRSV response in the lymphatic and lung tissue. The cytotoxic T lymphocyte (CTL) response was the strongest at the site of infection—the lung and bronchoalveolar lavage. The TCR-γδ T cells were the main responders post viremia and PRRSV induced their expression of the lymph node homing the chemokine receptor, CCR7: This indicates a crucial role for TCR-γδ T cells in the anti-PRRSV response in the lymphatic system.}, number={9}, journal={Viruses}, publisher={MDPI AG}, author={Kick, Andrew and Amaral, Amanda and Cortes, Lizette and Fogle, Jonathan and Crisci, Elisa and Almond, Glen and Käser, Tobias}, year={2019}, month={Aug}, pages={796} }
 @article{käser_renois_wilson_cnudde_gerdts_dillon_jungersen_agerholm_meurens_2018, title={Contribution of the swine model in the study of human sexually transmitted infections}, volume={66}, url={https://doi.org/10.1016/j.meegid.2017.11.022}, DOI={10.1016/j.meegid.2017.11.022}, abstractNote={The pig has garnered more and more interest as a model animal to study various conditions in humans. The growing success of the pig as an experimental animal model is explained by its similarities with humans in terms of anatomy, genetics, immunology, and physiology, by their manageable behavior and size, and by the general public acceptance of using pigs for experimental purposes. In addition, the immunological toolbox of pigs has grown substantially in the last decade. This development led to a boost in the use of pigs as a preclinical model for various human infections including sexually transmitted diseases (STIs) like Chlamydia trachomatis. In the current review, we discuss the use of animal models for biomedical research on the major human STIs. We summarize results obtained in the most common animal models and focus on the contributions of the pig model towards the understanding of pathogenesis and the host immune response. In addition, we present the main features of the porcine model that are particularly relevant for the study of pathogens affecting human female and male genital tracts. We also inform on the technological advancements in the porcine toolbox to facilitate new discoveries in this biologically important animal model. There is a continued need for improvements in animal modeling for biomedical research inclusive STI research. With all its advantages and the highly improved toolbox, the porcine model can play a crucial role in STI research and open the door to new exciting discoveries.}, journal={Infection, Genetics and Evolution}, publisher={Elsevier BV}, author={Käser, Tobias and Renois, Fanny and Wilson, Heather L. and Cnudde, Thomas and Gerdts, Volker and Dillon, Jo-Anne R. and Jungersen, Gregers and Agerholm, Jørgen S. and Meurens, François}, year={2018}, month={Dec}, pages={346–360} }
 @article{hamonic_pasternak_forsberg_käser_wilson_2018, title={Expression of pattern recognition receptors in porcine uterine epithelial cells in vivo and in culture}, volume={202}, ISSN={0165-2427}, url={http://dx.doi.org/10.1016/J.VETIMM.2018.06.006}, DOI={10.1016/J.VETIMM.2018.06.006}, abstractNote={Preservation of a pathogen free uterine environment is critical for maintaining healthy swine herds with high reproductive performance. Considering that uterine epithelial cells are the most numerous and thus likely point of cellular contact for pathogens in the uterus, we hypothesize that these cells may be critical for activating the immune system to clear uterine infections. Although uterine epithelial cells have not been well characterized in pigs, studies in several other species have shown that these cells express several pattern recognition receptors (PRR) and thus may act as sentinels for the uterine immune response. To characterize PRR expression in the porcine uterine epithelia, we used laser-capture microdissection to isolate epithelial cells lining the porcine uterus to quantify in vivo mRNA expression levels for select PRRs. As well, primary uterine epithelial cells (UECs) were isolated, cultured, polarized and PRR expression was quantified. Immunohistofluorescence and immunofluorescence were used to determine subcellular localization of TLR3, TLR4 and TLR9 in both uterine tissue and in polarized primary UECs. Finally, polarized primary UECs were stimulated with ligands for TLR3, TLR4, TLR9 and NOD2 to determine their functional innate immune response. Uterine epithelial cells (in vivo and in vitro) were shown to express TLR1-7, TLR9, NOD1, NOD2, NLRP3, NLRP6, NLRX1, RIG1, MDA5 and LGP2. Subcellular localization of in vivo and polarized primary UECs exhibited TLR3 and TLR9 localized to the apical cell surface whereas TLR4 was localized to the intracellular space. Polarized primary UECs stimulated with TLR3, TLR4 and TLR9 ligands showed induced secretion of IL-6, IL-13 and IL-10, respectively indicating that these receptors were functional. These results indicate that pig uterine epithelial cells are functional innate immune cells that may act as sentinels to protect against uterine infection.}, journal={Veterinary Immunology and Immunopathology}, publisher={Elsevier BV}, author={Hamonic, Glenn and Pasternak, J. Alex and Forsberg, Nikki M. and Käser, Tobias and Wilson, Heather L.}, year={2018}, month={Aug}, pages={1–10} }
 @article{bauer_sipos_stark_kaeser_knecht_brunthaler_saalmueller_hofmann_ehling-schulz_2018, title={First Insights Into Within Host Translocation of the Bacillus cereus Toxin Cereulide Using a Porcine Model}, volume={9}, DOI={10.3389/fmicb.2018.02652}, abstractNote={Bacillus cereus is a gram-positive pathogen mainly known to evoke two types of foodborne poisonings. The diarrheal syndrome is caused by enterotoxins produced during growth in the intestine. In contrast, the emetic type is caused by the dodecadepsipeptide cereulide pre-formed in food. Usually, both diseases are self-limiting but occasionally more severe forms, including fatal ones, are reported. Since the mechanisms of cereulide toxin uptake and translocation within the body as well as the mechanism of its toxic action are still unknown, we used a porcine model to investigate the uptake, routes of excretion and distribution of cereulide within the host. Pigs were orally challenged with cereulide using single doses of 10–150 μg cereulide kg-1 body weight to study acute effects or using daily doses of 10 μg cereulide kg-1 body weight administered for 7 days to investigate effects of longtime, chronic exposure. Our study showed that part of cereulide ingested with food is rapidly excreted with feces while part of the cereulide toxin is absorbed, passes through membranes and is distributed within the body. Results from the chronic trial indicate bioaccumulation of cereulide in certain tissues and organs, such as kidney, liver, muscles and fat tissues. Beside its detection in various tissues and organs, our study also demonstrated that cereulide is able to cross the blood–brain–barrier, which may partially explain the cerebral effects reported from human intoxication cases. The neurobehavioral symptoms, such as seizures and lethargy, observed in our porcine model resemble those reported from human food borne intoxications. The rapid onset of these symptoms indicates direct effects of cereulide on the central nervous system (CNS), which warrant further research. The porcine model presented here might be useful to study the specific neurobiological effect in detail. Furthermore, our study revealed that typical diagnostic specimens used in human medicine, such as blood samples and urine, are not suitable for diagnostics of food borne cereulide intoxications. Instead, screening of fecal samples by SIDA-LC-MS may represent a simple and non-invasive method for detection of cereulide intoxications in clinical settings as well as in foodborne outbreak situations.}, journal={FRONTIERS IN MICROBIOLOGY}, author={Bauer, Tobias and Sipos, Wolfgang and Stark, Timo D. and Kaeser, Tobias and Knecht, Christian and Brunthaler, Rene and Saalmueller, Armin and Hofmann, Thomas and Ehling-Schulz, Monika}, year={2018} }
 @article{käser_2017, title={Challenges and efforts in vaccine development and distribution}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85026673860&partnerID=MN8TOARS}, DOI={10.1016/j.vaccine.2017.07.091}, journal={Vaccine}, author={Käser, T.}, year={2017} }
 @article{käser_pasternak_delgado-ortega_hamonic_lai_erickson_walker_dillon_gerdts_meurens_2017, title={Chlamydia suis and Chlamydia trachomatis induce multifunctional CD4 T cells in pigs}, volume={35}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84999648395&partnerID=MN8TOARS}, DOI={10.1016/j.vaccine.2016.11.050}, abstractNote={Chlamydia trachomatis infections are the most prominent bacterial sexually-transmitted disease world-wide and a lot of effort is put into the development of an effective vaccine. Pigs have been shown to be a valuable animal model for C. trachomatis vaccine development. The aim of this study was to decipher the T-cell-mediated immune response to chlamydial infections including C. trachomatis and C. suis, the chlamydia species naturally infecting pigs with a demonstrated zoonotic potential. Vaginal infection of pigs with C. suis and C. trachomatis lasted from 3 to 21days and intra-uterine infection was still present after 21days in 3 out of 5 C. suis- and 4 out of 5 C. trachomatis-inoculated animals and caused severe pathological changes. Humoral immune responses including neutralizing antibodies were found predominantly in response to C. suis starting at 14days post inoculation. The T-cell-mediated immune responses to C. trachomatis and C. suis-infections started at 7days post inoculation and consisted mainly of CD4+ T cells which were either IFN-γ single cytokine-producing or IFN-γ/TNF-α double cytokine-producing T-helper 1 cells. IL-17-producing CD4+ T cells were rare or completely absent. The T-cell-mediated immune responses were triggered by both homologous or heterologous re-stimulation indicating that cross-protection between the two chlamydia species is possible. Thus, having access to a working genital C. suis and C. trachomatis infection model, efficient monitoring of the host-pathogen interactions, and being able to accurately assess the responses to infection makes the pig an excellent animal model for vaccine development which also could bridge the gap to the clinical phase for C. trachomatis vaccine research.}, number={1}, journal={Vaccine}, author={Käser, T. and Pasternak, J.A. and Delgado-Ortega, M. and Hamonic, G. and Lai, K. and Erickson, J. and Walker, S. and Dillon, J.R. and Gerdts, V. and Meurens, F.}, year={2017}, pages={91–100} }
 @article{rodríguez-gómez_talker_käser_stadler_hammer_saalmüller_gerner_2016, title={Expression of T-bet, Eomesodermin and GATA-3 in porcine αβ T cells}, volume={60}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84959510124&partnerID=MN8TOARS}, DOI={10.1016/j.dci.2016.02.022}, abstractNote={The transcription factors GATA-3, T-bet and Eomesodermin play important roles in T-cell development, differentiation and memory formation. However, their expression has not been studied in great detail in porcine T cells. We report on protein expression at the single cell-level of these transcription factors in thymocytes and mature αβ T cells. GATA-3 expression was found in γδ(-) thymocytes, with decreasing expression from the CD4(-)CD8α(-) stage towards single-positive stages. Extra-thymic CD4(+) T cells but not CD8β(+) T cells expressed low levels of GATA-3, which decreased with age. CD4(+) and CD8β(+) T-bet(+) cells mainly displayed a CD8α(+)CD27(-) and perforin(+)CD27(dim/-) phenotype, respectively and had the capacity for IFN-γ production; indicative of an effector/effector memory phenotype. Eomesodermin(+) αβ T cells had mixed phenotypes in regard to CD8α, CD27 and perforin expression. In conclusion, our data so far support the hitherto reported roles for GATA-3 in T-cell development and T-bet for Th1 effector-differentiation, but question the role of Eomesodermin for memory formation of porcine T-cells.}, journal={Developmental and Comparative Immunology}, author={Rodríguez-Gómez, I.M. and Talker, S.C. and Käser, T. and Stadler, M. and Hammer, S.E. and Saalmüller, A. and Gerner, W.}, year={2016}, pages={115–126} }
 @article{hamonic_pasternak_käser_meurens_wilson_2016, title={Extended semen for artificial insemination in swine as a potential transmission mechanism for infectious Chlamydia suis}, volume={86}, ISSN={0093-691X}, url={http://dx.doi.org/10.1016/j.theriogenology.2016.03.018}, DOI={10.1016/j.theriogenology.2016.03.018}, abstractNote={Although typically unnoticed, Chlamydia infections in swine have been shown to be both widespread and may impact production characteristics and reproductive performance in swine. Serum titers suggest Chlamydia infection within boar studs is common, and infected boars are known to shed chlamydia in their ejaculates. Although the transmission of viruses in chilled extended semen (ES) is well established, the inclusion of antibiotics in commercially available extender is generally believed to limit or preclude the transmission of infectious bacteria. The objective of this study was to evaluate the potential of ES used in artificial insemination to support transmission of the obligate intracellular bacteria Chlamydia suis (C suis) under standard industry conditions. First, the effect of C suis on sperm quality during storage was assessed by flow cytometry. Only concentrations above 5 × 105 viable C suis/mL caused significant spermicidal effects which only became evident after 7 days of storage at 17 °C. No significant effect on acrosome reaction was observed using any chlamydial concentration. Next, an in vitro infection model of swine testicular fibroblast cells was established and used to evaluate the effect of chilled storage on C suis viability under variable conditions. Storage in Androhep ES reduced viability by 34.4% at a multiplicity of infection of 1.25, an effect which increased to 53.3% when the multiplicity of infection decreased to 0.1. Interestingly, storage in semen extender alone (SE) or ES with additional antibiotics had no effect on bacterial viability. To rule out a secondary effect on extender resulting from metabolically active sperm, C suis was stored in fresh and expended SE and again no significant effect on bacterial viability was observed. Fluorescent microscopy of C suis in ES shows an association between bacteria and the remaining gel fraction after storage suggesting that the apparent reduction of bacterial viability in the presence of semen is due to adherence to gel fraction. Taken together, the results of this study suggest that C suis remains viable and infectious during chilled storage and is globally unaffected by antibiotics in extender. Thus, ES used in artificial insemination may act as a viable transmission mechanism for C suis in swine.}, number={4}, journal={Theriogenology}, publisher={Elsevier BV}, author={Hamonic, G. and Pasternak, J.A. and Käser, T. and Meurens, F. and Wilson, H.L.}, year={2016}, month={Sep}, pages={949–956} }
 @article{käser_pasternak_hamonic_rieder_lai_delgado-ortega_gerdts_meurens_2016, title={Flow cytometry as an improved method for the titration of Chlamydiaceae and other intracellular bacteria}, volume={89}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84977648249&partnerID=MN8TOARS}, DOI={10.1002/cyto.a.22822}, abstractNote={Abstract}, number={5}, journal={Cytometry Part A}, author={Käser, T. and Pasternak, J.A. and Hamonic, G. and Rieder, M. and Lai, K. and Delgado-Ortega, M. and Gerdts, V. and Meurens, F.}, year={2016}, pages={451–460} }
 @article{bähr_käser_kemter_gerner_kurome_baars_herbach_witter_wünsch_talker_et al._2016, title={Ubiquitous LEA29Y Expression Blocks T Cell Co-Stimulation but Permits Sexual Reproduction in Genetically Modified Pigs}, volume={11}, ISSN={1932-6203}, url={http://dx.doi.org/10.1371/journal.pone.0155676}, DOI={10.1371/journal.pone.0155676}, abstractNote={We have successfully established and characterized a genetically modified pig line with ubiquitous expression of LEA29Y, a human CTLA4-Ig derivate. LEA29Y binds human B7.1/CD80 and B7.2/CD86 with high affinity and is thus a potent inhibitor of T cell co-stimulation via this pathway. We have characterized the expression pattern and the biological function of the transgene as well as its impact on the porcine immune system and have evaluated the potential of these transgenic pigs to propagate via assisted breeding methods. The analysis of LEA29Y expression in serum and multiple organs of CAG-LEA transgenic pigs revealed that these animals produce a biologically active transgenic product at a considerable level. They present with an immune system affected by transgene expression, but can be maintained until sexual maturity and propagated by assisted reproduction techniques. Based on previous experience with pancreatic islets expressing LEA29Y, tissues from CAG-LEA29Y transgenic pigs should be protected against rejection by human T cells. Furthermore, their immune-compromised phenotype makes CAG-LEA29Y transgenic pigs an interesting large animal model for testing human cell therapies and will provide an important tool for further clarifying the LEA29Y mode of action.}, number={5}, journal={PLOS ONE}, publisher={Public Library of Science (PLoS)}, author={Bähr, Andrea and Käser, Tobias and Kemter, Elisabeth and Gerner, Wilhelm and Kurome, Mayuko and Baars, Wiebke and Herbach, Nadja and Witter, Kirsti and Wünsch, Annegret and Talker, Stephanie C. and et al.}, editor={Câmara, Niels Olsen SaraivaEditor}, year={2016}, month={May}, pages={e0155676} }
 @article{käser_mair_hammer_gerner_saalmüller_2015, title={Natural and inducible Tregs in swine: Helios expression and functional properties}, volume={49}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84964227423&partnerID=MN8TOARS}, DOI={10.1016/j.dci.2014.12.005}, abstractNote={Within the population of regulatory T cells (Tregs) natural Tregs (nTregs) and inducible Tregs (iTregs) can be distinguished. Although information about Tregs in swine exists, porcine iTregs were not under investigation yet. In this study, Foxp3+ iTregs were generated from CD4+Foxp3− T cells by in vitro stimulation in the presence of IL-2 and TGF-β. In comparison to ex vivo Tregs these iTregs had a similar suppressive capacity on the proliferation of CD3-stimulated PBMC, caused higher levels of IL-10 in PBMC/Treg co-cultures, but did not suppress IFN-γ levels. The Ikaros family member Helios is currently discussed to distinguish iTregs and nTregs or to serve as an activation marker of Tregs. In this study, we demonstrate the cross-reactivity of an anti-mouse/human Helios mAb with porcine Helios. Flow cytometric analyses with this antibody showed that porcine iTregs do not express Helios after in vitro iTreg induction. Nevertheless, thymic Foxp3+ T cells, which arise at the CD4/CD8α single-positive stage of T-cell development and are defined as nTregs, entirely expressed Helios. Although this might suggest the suitability of Helios as an nTreg–iTreg differentiation marker we also found that Helios− Tregs displayed a phenotype of naive CD4+ T cells in vivo. Since iTregs are by definition activated/differentiated Tregs, this finding precludes that all Helios− Tregs are iTregs and thus also the use of Helios as a selection marker for porcine nTregs. Furthermore, Helios+ Tregs displayed a more differentiated phenotype indicating that Helios might rather serve as a Treg activation/differentiation marker.}, number={2}, journal={Developmental and Comparative Immunology}, author={Käser, T. and Mair, K.H. and Hammer, S.E. and Gerner, W. and Saalmüller, A.}, year={2015}, pages={323–331} }
 @article{rodríguez-gómez_käser_gómez-laguna_lamp_sinn_rümenapf_carrasco_saalmüller_gerner_2015, title={PRRSV-infected monocyte-derived dendritic cells express high levels of SLA-DR and CD80/86 but do not stimulate PRRSV-naïve regulatory T cells to proliferate}, volume={46}, ISSN={1297-9716}, url={http://dx.doi.org/10.1186/s13567-015-0186-z}, DOI={10.1186/s13567-015-0186-z}, abstractNote={In vitro generated monocyte-derived dendritic cells (moDCs) have frequently been used to study the influence of porcine reproductive and respiratory syndrome virus (PRRSV) infection on antigen presenting cells. However, obtained results have often been conflicting in regard to expression of co-stimulatory molecules and interaction with T cells. In this study we performed a detailed phenotypic characterisation of PRRSV-infected moDCs and non-infected moDCs. For CD163 and CD169, which are involved in PRRSV-entry into host cells, our results show that prior to infection porcine moDCs express high levels of CD163 but only very low levels for CD169. Following infection with either PRRSV-1 or PRRSV-2 strains after 24 h, PRRSV-nucleoprotein (N-protein)+ and N-protein− moDCs derived from the same microculture were analyzed for expression of swine leukocyte antigen-DR (SLA-DR) and CD80/86. N-protein+ moDCs consistently expressed higher levels of SLA-DR and CD80/86 compared to N-protein− moDCs. We also investigated the influence of PRRSV-infected moDCs on proliferation and frequency of Foxp3+ regulatory T cells present within CD4+ T cells in in vitro co-cultures. Neither CD3-stimulated nor unstimulated CD4+ T cells showed differences in regard to proliferation and frequency of Foxp3+ T cells following co-cultivation with either PRRSV-1 or PRRSV-2 infected moDCs. Our results suggest that a more detailed characterisation of PRRSV-infected moDCs will lead to more consistent results across different laboratories and PRRSV strains as indicated by the major differences in SLA-DR and CD80/86 expression between PRRSV-infected and non-infected moDCs present in the same microculture.}, number={1}, journal={Veterinary Research}, publisher={Springer Nature}, author={Rodríguez-Gómez, Irene M and Käser, Tobias and Gómez-Laguna, Jaime and Lamp, Benjamin and Sinn, Leonie and Rümenapf, Till and Carrasco, Librado and Saalmüller, Armin and Gerner, Wilhelm}, year={2015}, month={May} }
 @article{käser_cnudde_hamonic_rieder_pasternak_lai_tikoo_wilson_meurens_2015, title={Porcine retinal cell line VIDO R1 and Chlamydia suis to modelize ocular chlamydiosis}, volume={166}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84938741130&partnerID=MN8TOARS}, DOI={10.1016/j.vetimm.2015.06.003}, abstractNote={Human ocular Chlamydia trachomatis infections can lead to trachoma, the major cause of infectious blindness worldwide. Trachoma control strategies are very helpful but logistically challenging, and a trachoma vaccine is needed but not available. Pigs are a valuable large animal model for various immunological questions and could facilitate the study of human ocular chlamydial infections. In addition, a recent study identified the zoonotic potential of Chlamydia suis, the natural pathogen of pigs. In terms of the One Health Initiative, understanding the host-pathogen-interactions and finding a vaccine for porcine chlamydia infections would also benefit human health. Thus, we infected the porcine retinal cell line VIDO R1 with C. suis and analyzed the chlamydial life cycle and the innate immune response of the infected cells. Our results indicate that C. suis completes its life cycle in VIDO R1 cells within 48 h, comparable to C. trachomatis in humans. C. suis infection of VIDO R1 cells led to increased levels of various innate immune mediators like pathogen recognition receptors, cytokines and chemokines including IL6, TNFα, and MMP9, also most relevant in human C. trachomatis infections. These results illustrate the first steps in the host-pathogen-interactions of ocular C. suis infections in pigs and show their similarity to C. trachomatis infections in humans, justifying further testing of pigs as an animal model for human trachoma.}, number={3-4}, journal={Veterinary Immunology and Immunopathology}, author={Käser, T. and Cnudde, T. and Hamonic, G. and Rieder, M. and Pasternak, J.A. and Lai, K. and Tikoo, S.K. and Wilson, H.L. and Meurens, F.}, year={2015}, pages={95–107} }
 @article{paudel_hess_wernsdorf_käser_meitz_jensen-jarolim_hess_liebhart_2015, title={The systemic multiplication of Gallibacterium anatis in experimentally infected chickens is promoted by immunosuppressive drugs which have a less specific effect on the depletion of leukocytes}, volume={166}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84930087105&partnerID=MN8TOARS}, DOI={10.1016/j.vetimm.2015.05.001}, abstractNote={The progression of Gallibacterium anatis infection in immunosuppressed versus immunocompetent chickens was investigated. Before experimental infection, birds were treated with corticosterone for general immunosuppression, or 5-fluorouracil, cyclosporine-A, cyclophosphamide for depletion of specific leukocyte populations. Necropsy and sampling were performed at 0, 3, 7, 10 and 28 days post infection. The used drugs did not cause selected depletion of B cells, T cells, heterophils and monocytes/macrophages, as determined by quantification of leukocytes in blood and lymphoid organs using different technologies. Bacterial re-isolation and counts of colony forming units (CFU) showed that G. anatis colonization pattern in various organs, and the numbers of bacteria in trachea were not affected by immunosuppression. However, the treatments acutely increased CFU counts derived from the spleen, which demonstrates that chemically induced immunosuppression intensifies systemic multiplication of G. anatis in chickens.}, number={1-2}, journal={Veterinary Immunology and Immunopathology}, author={Paudel, S. and Hess, C. and Wernsdorf, P. and Käser, T. and Meitz, S. and Jensen-Jarolim, E. and Hess, M. and Liebhart, D.}, year={2015}, pages={22–32} }
 @article{mair_sedlak_käser_pasternak_levast_gerner_saalmüller_summerfield_gerdts_wilson_et al._2014, title={The porcine innate immune system: An update}, volume={45}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84899134882&partnerID=MN8TOARS}, DOI={10.1016/j.dci.2014.03.022}, abstractNote={Over the last few years, we have seen an increasing interest and demand for pigs in biomedical research. Domestic pigs (Sus scrofa domesticus) are closely related to humans in terms of their anatomy, genetics, and physiology, and often are the model of choice for the assessment of novel vaccines and therapeutics in a preclinical stage. However, the pig as a model has much more to offer, and can serve as a model for many biomedical applications including aging research, medical imaging, and pharmaceutical studies to name a few. In this review, we will provide an overview of the innate immune system in pigs, describe its anatomical and physiological key features, and discuss the key players involved. In particular, we compare the porcine innate immune system to that of humans, and emphasize on the importance of the pig as model for human disease.}, number={2}, journal={Developmental and Comparative Immunology}, author={Mair, K.H. and Sedlak, C. and Käser, T. and Pasternak, A. and Levast, B. and Gerner, W. and Saalmüller, A. and Summerfield, A. and Gerdts, V. and Wilson, H.L. and et al.}, year={2014}, pages={321–343} }
 @article{rodríguez-gómez_burgara-estrella_mateu_gómez-laguna_carrasco_saalmüller_käser_2013, title={Effect of Two Strains of PRRSV on the Expression of Differentiation Antigens of Monocyte-derived Dendritic Cells}, volume={148}, ISSN={0021-9975}, url={http://dx.doi.org/10.1016/j.jcpa.2012.11.026}, DOI={10.1016/j.jcpa.2012.11.026}, number={1}, journal={Journal of Comparative Pathology}, publisher={Elsevier BV}, author={Rodríguez-Gómez, I.M. and Burgara-Estrella, A.J. and Mateu, E. and Gómez-Laguna, J. and Carrasco, L. and Saalmüller, A. and Käser, T.}, year={2013}, month={Jan}, pages={51} }
 @article{balmayor_flicker_käser_saalmüller_erben_2013, title={Human Placental Alkaline Phosphatase as a Tracking Marker for Bone Marrow Mesenchymal Stem Cells}, volume={2}, ISSN={2164-7860 2164-7860}, url={http://dx.doi.org/10.1089/biores.2013.0027}, DOI={10.1089/biores.2013.0027}, abstractNote={Abstract Currently, adult mesenchymal stem cells (MSCs) are being evaluated for a wide variety of therapeutic approaches. It has been suggested that MSCs possess regenerative properties when implanted or injected into damaged tissue. However, the efficacy of MSCs in several of the proposed treatments is still controversial. To further explore the therapeutic potential of these cells, it is necessary to trace the fate of individual donor or manipulated cells in the host organism. Recent studies from our lab showed that human placental alkaline phosphatase (hPLAP) is a marker with great potential for cell tracking. However, a potential concern related to this marker is its enzymatic activity, which might alter cell behavior and differentiation by hydrolyzing substrates in the extracellular space and thereby changing the cellular microenvironment. Therefore, the aim of this study was to characterize bone marrow MSCs (BMSCs) derived from hPLAP-transgenic inbred F344 rats (hPLAP-tg) in comparison to wild type (wt) BMSCs. Here, we show that BMSCs from wt and hPLAP-tg donors are indistinguishable in terms of cell morphology, viability, adhesion, immune phenotype, and proliferation as well as in their differentiation capacity over six passages. The expression of the hPLAP marker enzyme was not impaired by extensive in vitro cultivation, osteogenic, adipogenic, or chondrogenic differentiation, or seeding onto two- or three-dimensional biomaterials. Thus, our study underscores the utility of genetically labeled BMSCs isolated from hPLAP-tg donors for long-term tracking of the fate of transplanted MSCs in regenerative therapies.}, number={5}, journal={BioResearch Open Access}, publisher={Mary Ann Liebert Inc}, author={Balmayor, Elizabeth Rosado and Flicker, Magdalena and Käser, Tobias and Saalmüller, Armin and Erben, Reinhold G.}, year={2013}, month={Oct}, pages={346–355} }
 @article{balka_ladinig_ritzmann_saalmüller_gerner_käser_jakab_rusvai_weißenböck_2013, title={Immunohistochemical characterization of type II pneumocyte proliferation after challenge with type I porcine reproductive and respiratory syndrome virus}, volume={149}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84881084731&partnerID=MN8TOARS}, DOI={10.1016/j.jcpa.2012.12.006}, abstractNote={The aim of this study was to characterize histologically and immunohistochemically the lung lesions developing in growing pigs, 10 and 21 days after experimental challenge with a field strain of porcine reproductive and respiratory syndrome virus (PRRSV). Lung lesions were scored for (1) pneumocyte hypertrophy and hyperplasia, (2) septal mononuclear infiltration, (3) intra-alveolar necrotic debris, (4) intra-alveolar inflammatory cell accumulation and (5) perivascular inflammatory cell accumulation. Immunohistochemistry was performed using antibodies specific for cytokeratin, Ki67, thyroid transcription factor (TTF)-1, the myelomonocytic marker MAC387 and PRRSV. Anti-TTF-1 identified type II pneumocytes and there was marked proliferation of these cells compared with control lung (P <0.05). Anti-cytokeratin labelled type I and II pneumocytes as well as bronchial epithelial cells; however, this labelling was not suitable for cell counting purposes. There was a correlation between lesion severity and the number of cells expressing Ki67 (P <0.05).}, number={2-3}, journal={Journal of Comparative Pathology}, author={Balka, G. and Ladinig, A. and Ritzmann, M. and Saalmüller, A. and Gerner, W. and Käser, T. and Jakab, C. and Rusvai, M. and Weißenböck, H.}, year={2013}, pages={322–330} }
 @article{talker_käser_reutner_sedlak_mair_koinig_graage_viehmann_klingler_ladinig_et al._2013, title={Phenotypic maturation of porcine NK- and T-cell subsets}, volume={40}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84875633332&partnerID=MN8TOARS}, DOI={10.1016/j.dci.2013.01.003}, abstractNote={Detailed information concerning the development of the immune system in young pigs is still rudimental. In the present study, we analyzed changes in phenotype and absolute numbers of natural killer cells, γδ T cells, T helper cells, regulatory T cells and cytolytic T cells in the blood of pigs from birth to six months of age. For each lymphocyte subpopulation, a combination of lineage and differentiation markers was investigated by six-color flow cytometry. Major findings were: (i) absolute numbers of γδ T cells strongly increased from birth until 19–25 weeks of age, indicating an important role for these cells during adolescence; (ii) phenotype of T helper cells changed over time from CD8α−SLA-DR−CD27+ towards CD8α+SLA-DR+CD27− but CD45RC− T helper cells were found immediately after birth, therefore questioning the role of this marker for the identification of T-helper memory cells; (iii) for cytolytic T cells, putative phenotypes for early effector (CD3+CD8αβ+perforin+CD27dim) and late effector or memory cells (CD3+CD8αβ+perforin+CD27−) could be identified.}, number={1}, journal={Developmental and Comparative Immunology}, author={Talker, S.C. and Käser, T. and Reutner, K. and Sedlak, C. and Mair, K.H. and Koinig, H. and Graage, R. and Viehmann, M. and Klingler, E. and Ladinig, A. and et al.}, year={2013}, pages={51–68} }
 @article{käser_gerner_mair_hammer_patzl_saalmüller_2012, title={Current knowledge on porcine regulatory T cells}, volume={148}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84864137049&partnerID=MN8TOARS}, DOI={10.1016/j.vetimm.2011.05.035}, abstractNote={Regulatory T cells (Tregs) are known in humans and mice from last 15 years, and several studies led to a detailed knowledge on their phenotype, functions, and role in various immune reactions. In swine, the existence of Tregs was first demonstrated in 2008 and research is still at the beginning. Nevertheless, basic information regarding phenotype, mechanisms and targets of suppression, as well as implications in transplantation and some diseases are available. Purpose of this review is to give a brief summary of the current knowledge about porcine Tregs.}, number={1-2}, journal={Veterinary Immunology and Immunopathology}, author={Käser, T. and Gerner, W. and Mair, K. and Hammer, S.E. and Patzl, M. and Saalmüller, A.}, year={2012}, pages={136–138} }
 @article{käser_müllebner_hartl_essler_saalmüller_catharina duvigneau_2012, title={Porcine T-helper and regulatory T cells exhibit versatile mRNA expression capabilities for cytokines and co-stimulatory molecules}, volume={60}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84866755421&partnerID=MN8TOARS}, DOI={10.1016/j.cyto.2012.07.007}, abstractNote={T-helper (TH) and regulatory T cells (Tregs) are important modulators of immune responses. Aim of this study was to analyse their expression potential for cytokines and other immune-relevant molecules. Therefore, porcine PBMC, CD4(-) cells, CD4(+)CD25(-) resting, CD4(+)CD25(dim) activated TH cells, and CD4(+)CD25(high) Tregs were analysed on their mRNA expression potential ex vivo or after in vitro stimulation with CD3 and IL-2 by RT-qPCR. In vitro stimulation led to an increased production of pro-inflammatory (IL-6, TNFα) and TH (IL-2, IL-4, IL-17, IFN-γ) cytokines and a diverse production of immunosuppressive cytokines (IL-10 and TGF-β) in PBMC, CD4(-), and CD4(+) cells. Resting and activated TH cells showed an increased expression of various immune-modulatory molecules indicating that porcine TH cells possess distinct immunological skills in order to react on the actual immune situation. In contrast, Tregs appear to fulfil mainly immunosuppressive functions characterized by increased production of IL-10, IL-35, CD40L, and CD25.}, number={2}, journal={Cytokine}, author={Käser, T. and Müllebner, A. and Hartl, R.T. and Essler, S.E. and Saalmüller, A. and Catharina Duvigneau, J.}, year={2012}, pages={400–409} }
 @article{käser_gerner_saalmüller_2011, title={Porcine regulatory T cells: Mechanisms and T-cell targets of suppression}, volume={35}, ISSN={0145-305X}, url={http://dx.doi.org/10.1016/j.dci.2011.04.006}, DOI={10.1016/j.dci.2011.04.006}, abstractNote={Tregs are known for their suppressive capacity on various immune reactions. In swine, existence as well as suppressive activity of Foxp3+ Tregs could be demonstrated but detailed functional investigations are lacking. Therefore, we analysed the functional properties of porcine Tregs. We observed that besides TCR stimulation Tregs require IL-2 for activation. Furthermore, we investigated the following mechanisms of suppression: (i) cell–cell contact dependency, (ii) production of soluble suppressive factors and (iii) competition for growth factors. Our experiments revealed that suppression by porcine Tregs is abrogated by blocking cell–cell contact or by supplementing excessive amounts of IL-2. Additionally it could be shown that porcine Tregs produce immunosuppressive IL-10. Thereby, we demonstrated that porcine Tregs can use all main mechanisms of suppression mentioned above. Further investigations on the suppressive activity of Tregs using CFSE proliferation assays demonstrated that suppression affects T-helper cells as well as cytotoxic T lymphocytes and TCR-γδ T cells.}, number={11}, journal={Developmental & Comparative Immunology}, publisher={Elsevier BV}, author={Käser, Tobias and Gerner, Wilhelm and Saalmüller, Armin}, year={2011}, month={Nov}, pages={1166–1172} }
 @article{gerner_hammer_käser_diny_pintaric_saalmüller_2009, title={Characterization of CD79α+CD21− B cells in swine}, volume={128}, ISSN={0165-2427}, url={http://dx.doi.org/10.1016/j.vetimm.2008.10.137}, DOI={10.1016/j.vetimm.2008.10.137}, number={1-3}, journal={Veterinary Immunology and Immunopathology}, publisher={Elsevier BV}, author={Gerner, Wilhelm and Hammer, Sabine and Käser, Tobias and Diny, Nicola and Pintaric, Maša and Saalmüller, Armin}, year={2009}, month={Mar}, pages={274} }
 @article{bolzer_käser_saalmüller_hammer_2009, title={Molecular characterisation of porcine Forkhead-box p3 (Foxp3)}, volume={132}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-70449526431&partnerID=MN8TOARS}, DOI={10.1016/j.vetimm.2009.05.014}, abstractNote={In swine the phenotypical identification of regulatory T cells (Tregs) was limited so far to the surface expression of CD4 and CD25. However, with the discovery of the Treg-specific transcription factor forkhead-box p3 (Foxp3) in mice and humans a powerful marker for the identification of Tregs is available. Recently, we published data on a murine anti-mouse/rat Foxp3 antibody (FJK-16s) showing cross-reactivity with the putative porcine Foxp3 protein in lymphoid cells but the final proof for the specific cross-reactivity of this antibody was missing. By performing RACE-experiments, we have sequenced the entire porcine Foxp3 cDNA which is 1296 nucleotides in length and codes for a polypeptide of 432 amino acids. The porcine Foxp3 nucleotide and amino acid sequences show high homology to all known orthologues from other mammals, with the greatest homology with the bovine sequence. To demonstrate the specificity of the FJK-16s antibody for the porcine Foxp3 protein, HEK293T cells were transfected with porcine Foxp3 containing the FJK-16s-specific binding region and the expression of the epitope was identified by immuno-staining. In conclusion, this study represents the final proof for the specificity of the murine FJK-16s antibody for the porcine Foxp3 homologue and therefore strengthens future work on porcine Tregs.}, number={2-4}, journal={Veterinary Immunology and Immunopathology}, author={Bolzer, K. and Käser, T. and Saalmüller, A. and Hammer, S.E.}, year={2009}, pages={275–281} }
 @article{gerner_käser_saalmüller_2009, title={Porcine T lymphocytes and NK cells - An update}, volume={33}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-57149108489&partnerID=MN8TOARS}, DOI={10.1016/j.dci.2008.06.003}, abstractNote={Natural killer (NK) cells represent an important cell population of the innate immune system with the ability to attack spontaneously pathogen-infected and malignant body cells as well as to produce immune-regulatory cytokines. T lymphocytes belong to the adaptive immune system and perform a wide array of functions in immune regulation, inflammation and protective immune responses. In this review we summarize the current knowledge about the phenotype and functional characteristics of these two cell populations in swine. Porcine NK cells can be distinguished from T cells by the complex phenotype perforin+ CD3(-)CD4(-)CD5(-)CD6(-)CD8alpha+CD8beta(-)CD11b+CD16+. Investigations so far show that these cells have the capacity to lyse virus-infected target cells and respond to various regulatory cytokines. Such cytokines can induce interferon-gamma (IFN-gamma) production in porcine NK cells, as well as the up-regulation of effector/activation molecules like perforin and CD25. Porcine T cells can be divided into a number of subpopulations, including a prominent fraction of T cells expressing T-cell receptors (TCR) with gammadelta-chains. Like TCR-alphabeta T cells, these TCR-gammadelta T cells can express CD8alpha and MHC class II, two molecules which in swine seem to be correlated with an activation status of T cells. Functional properties of these cells seem to include cytolytic activity as well as antigen presentation; however, both aspects require further investigation. Like in other species, TCR-alphabeta T cells in swine comprise MHC class-I restricted cytolytic T cells, T-helper cells and recently identified regulatory T cells. We summarize data on the phenotype and function of these cells including memory cell formation. Current knowledge suggests that MHC class-I restricted cytolytic T cells can be identified by the expression of CD8alphabeta heterodimers. T-helper cells express CD4 as well as other activation-related markers, including CD8alpha, MHC class II and CD45RC. Porcine regulatory T cells have a phenotype similar to that of mouse and humans: CD4+CD25+Foxp3+. First results indicate that these cells can suppress proliferation of other T cells and produce IL-10. Finally, the abundant expression of swine-specific activation markers CD8alpha and MHC class II on T cells and NK cells is discussed in more detail.}, number={3}, journal={Developmental and Comparative Immunology}, author={Gerner, W. and Käser, T. and Saalmüller, A.}, year={2009}, pages={310–320} }
 @article{käser_gerner_hammer_patzl_saalmüller_2008, title={Detection of Foxp3 protein expression in porcine T lymphocytes}, volume={125}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-49049112196&partnerID=MN8TOARS}, DOI={10.1016/j.vetimm.2008.05.007}, abstractNote={Regulatory T cells (Tregs) are potent regulators of various immune reactions. Due to the lack of Treg-specific markers their analysis had often been challenging until the discovery of the transcription factor Forkhead-box p3 (Foxp3) which serves as this highly demanded marker. So far, antibodies staining human and murine Foxp3 have been developed. This study describes the analysis of four commercially available anti-Foxp3 antibodies for reactivity with their specific antigen in cells derived from porcine lymphoid tissues. One out of the four antibodies showed selective reactivity with porcine CD25(+) T lymphocytes. The intracellular antigen was expressed on a small subset of CD25(dim) cells and the majority of the CD25(high) positive T-cell subpopulation. Intracellular antigen positive cells showed a heterogeneous expression of other leukocyte differentiation antigens. The majority belonged to the CD4(+)CD8(+) T-lymphocyte subpopulation, but were also found in the CD4(+)CD8(-) subpopulation. Another small minority was included in the CD4(-)CD8(+) T-lymphocyte subpopulation. Additionally, a small fraction of the putative Foxp3(+) cells showed an expression of MHC-II molecules. These staining patterns in three and four colour flow cytometry analyses indicated that the cells detected by a rat anti-mouse/rat-Foxp3 antibody expressed the porcine Foxp3. The expression of the putative Foxp3 protein in distinct leukocyte subsets was confirmed by molecular analysis of Foxp3 mRNA expression. Using Western blot analysis specific protein bands could only be detected in fractions that also exhibited the corresponding Foxp3 mRNA expression. These experiments also revealed that the antibody recognized a single chain protein with a molecular mass of about 45kDA similar to Foxp3 described for other species. In summary, these data strongly indicate the reactivity of this antibody with porcine Foxp3. Thereby, this rat anti-mouse/rat Foxp3 antibody presents a powerful tool for the identification of porcine regulatory T cells.}, number={1-2}, journal={Veterinary Immunology and Immunopathology}, author={Käser, T. and Gerner, W. and Hammer, S.E. and Patzl, M. and Saalmüller, A.}, year={2008}, pages={92–101} }
 @article{detection of intracellular antigens in porcine pbmc by flow cytometry: a comparison of fixation and permeabilisation reagents_2008, volume={121}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-38549177571&partnerID=MN8TOARS}, DOI={10.1016/j.vetimm.2007.09.019}, abstractNote={The staining of intracellular antigens is a standard method in flow cytometry but still only occasionally used for immunologic studies in veterinary species. In order to improve information about suitable fixation/permeabilisation protocols in porcine lymphocytes we tested six fixation/permeabilisation variants for the staining of different intracellular antigens: CD79α, perforin, interferon-γ and the cell cycle associated protein Ki-67. For the fixation/permeabilisation procedure, four commercial kits from BD Biosciences, ADG Bio Research, Dako and AbD Serotec were tested in comparison to non-commercial fixation solutions of formaldehyde together with either saponin or Tween-20 for permeabilisation. Perforin and Ki-67 expressing cells were optimally stained only with permeabilisation reagents containing saponin, which includes the BD kit. In contrast, labelling of CD79α and IFN-γ was possible with all investigated fixation/permeabilisation variants; however, here saponin and Tween protocols induced a higher degree of unspecific binding. Also, scatter properties of cells treated with saponin were worse compared to samples prepared with the kits from ADG, Dako and Serotec. Simultaneous staining of cell surface antigens was not negatively affected by any of the fixation/permeabilisation variants. A universal recommendation for a single fixation/permeabilisation strategy could not be deduced from our data but our work provides a useful guideline for optimal staining of common intracellular antigens analyzed in swine lymphocytes.}, number={3-4}, journal={Veterinary Immunology and Immunopathology}, year={2008}, pages={251–259} }
 @article{käser_gerner_hammer_patzl_saalmüller_2008, title={Phenotypic and functional characterisation of porcine CD4+CD25high regulatory T cells}, volume={122}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-39449127746&partnerID=MN8TOARS}, DOI={10.1016/j.vetimm.2007.08.002}, abstractNote={Over the last years regulatory T cells (Tregs) were defined as CD4(+)CD25(+) T lymphocytes expressing the transcription factor Foxp3 (Forkhead Box P3) with the ability to downregulate various immune responses. In swine the existence of CD4(+)CD25(+) T lymphocytes was described before but nothing is known about the function of this minor cell population to date. Therefore, we studied porcine CD4(+)CD25(+) T cells with regard to major attributes of murine and human Tregs: their phenotype concerning the expression of several T-cell specific antigens, including Foxp3, their IL-10 production and their suppressive capacity. Our results revealed that porcine CD4(+)CD25(+) T cells with high CD25 expression count for about 2-9% of the CD4(+) T-cell subset. They demonstrate a strong Foxp3 expression, a heterogeneous CD45RC-, CD8alpha- and MHC-II-defined phenotype and a moderate IL-10 production. Co-cultivation of increasing numbers of CD4(+)CD25(high) T cells with a constant number of CD4(+)CD25(-) responder-T cells caused a decrease in proliferation of the entire culture. This demonstrates the suppressive capacity of the CD4(+)CD25(high) T-cell subset and - together with their Foxp3 expression - the existence of porcine Tregs.}, number={1-2}, journal={Veterinary Immunology and Immunopathology}, author={Käser, T. and Gerner, W. and Hammer, S.E. and Patzl, M. and Saalmüller, A.}, year={2008}, pages={153–158} }
 @unpublished{a triadj-adjuvanted <em>chlamydia trachomatis </em>cpaf protein vaccine is highly immunogenic in pigs., DOI={10.20944/preprints202403.0298.v1}, abstractNote={Chlamydia trachomatis (Ct) infections are the most common sexually-transmitted infection (STI). Despite effective antibiotics for Ct, undetected infections or delayed treatment can lead to infertility, ectopic pregnancies, and chronic pelvic pain. Besides humans, chlamydia poses similar health challenges in animals such as C. suis (Cs) in pigs. Based on the similarities between humans and pigs as well as their chlamydia species, we use pigs as a large biomedical animal model for chlamydia research. In this study, we use the pig model to develop a vaccine candidate against Ct. The vaccine candidate consists of TriAdj-adjuvanted chlamydial protease-like activity factor (CPAF) protein. We tested two weekly administration options – twice intranasal (IN) followed by twice intramuscular (IM), or twice IM followed by twice IN. We assessed the humoral immune response not only in serum by CPAF-specific IgG including antibody avidity determination but also in cervical and rectal swabs by CPAF-specific IgG and IgA ELISAs. The systemic T-cell response was analyzed upon in vitro CPAF-restimulation via IFN-γ and IL-17 ELISpots as well as intracellular cytokine staining flow cytometry. Our data demonstrate that while the IN/IM vaccination mainly led to non-significant systemic immune responses, the vaccine candidate is highly immunogenic if administered IM/IN. This vaccination strategy induced high serum anti-CPAF IgG levels with strong avidity as well as high IgA and IgG levels in vaginal and rectal swabs and in uterine horn flushes. In addition, this vaccination strategy prompted a pronounced cellular immune response: Besides inducing IL-17 production, the vaccine candidate induced a strong IFN-γ response by CD4 T cells. In the IM/IN vaccinated pigs, these cells also significantly downregulated their CCR7 expression – a sign for differentiation into peripheral tissue homing effector/ memory cells. Conclusively, this study demonstrates strong immunogenicity of the IM/IN administered TriAdj-adjuvanted Ct CPAF vaccine candidate. Future studies will test vaccine efficacy of this promising Ct vaccine candidate. In addition, this project demonstrates suitability of the Cs pre-exposed outbred pig model for Ct vaccine development. Thereby, we aim to open the bottleneck of large animal models to facilitate the progression of Ct vaccine candidates into clinical trials.} }
 @article{pasternak_hon ng_käser_meurens_wilson, title={Grouping Pig-Specific Responses to Mitogen with Similar Responder Animals may Facilitate the Interpretation of Results Obtained in an Out-Bred Animal Model}, volume={5}, journal={Journal of Vaccines and Vaccination}, author={Pasternak, J.A. and Hon Ng, S.L. and Käser, T. and Meurens, F. and Wilson, H.L}, pages={1–9} }