@article{levy_liang_ritchey_davidson_tompkins_tompkins_2004, title={Failure of FIV-infected cats to control Toxoplasma gondii correlates with reduced IL2, IL6, and IL12 and elevated IL10 expression by lymph node T cells}, volume={98}, ISSN={["0165-2427"]}, DOI={10.1016/j.vetimm.2003.11.002}, abstractNote={Increased susceptibility to intracellular pathogens in HIV-infected individuals and FIV-infected cats is attributed to a defective T-helper 1 (Th1) immune response. However, little is known about specific cytokine responses to secondary pathogens. To address this question, control and FIV-infected cats were challenged with Toxoplasma gondii, and lymph node cells analyzed for cytokine mRNA expression. Twenty-four weeks post-FIV infection, prior to T. gondii challenge, IL2 and IL12 mRNAs were depressed, whereas IL10 and IFNγ mRNAs were increased in CD4+ and CD8+ subsets. Following T. gondii challenge, control cats showed increased expression of IL2, IFNγ, IL10, IL12, and IL6 mRNAs. In contrast, IL2, IL6, IFNγ, and IL12 mRNAs were suppressed in FIV–T. gondii co-infected cats, whereas IL10 remained at the high prechallenge levels. IFNγ and IL10 mRNAs were produced by both CD4+ and CD8+ cells in FIV–T. gondii cats. Elevated IL10 may suppress a Th1 cytokine response to T. gondii challenge.}, number={1-2}, journal={VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY}, author={Levy, JK and Liang, YH and Ritchey, JW and Davidson, MG and Tompkins, WA and Tompkins, MB}, year={2004}, month={Mar}, pages={101–111} }
 @article{bragg_hudson_liang_tompkins_fernandes_meeker_2002, title={Choroid plexus macrophages proliferate and release toxic factors in response to feline immunodeficiency virus}, volume={8}, ISSN={["1355-0284"]}, DOI={10.1080/13550280290049679}, abstractNote={Recent observations have suggested that lentiviruses stimulate the proliferation and activation of microglia. A similar effect within the dense macrophage population of the choroid plexus could have significant implications for trafficking of virus and inflammatory cells into the brain. To explore this possibility, we cultured fetal feline macrophages and examined their response to feline immunodeficiency virus (FIV) or the T-cell-derived protein, recombinant human CD40-ligand trimer (rhuCD40-L). The rhCD40-L was the most potent stimulus for macrophage proliferation, often inducing a dramatic increase in macrophage density. Exposure to FIV resulted in a small increase in the number of macrophages and macrophage nuclei labeled with bromodeoxyuridine. The increase in macrophage density after FIV infection also correlated with an increase in neurotoxic activity of the macrophage-conditione d medium. Starting at 16–18 weeks postinfection, well after the peak of viremia, a similar toxic activity was detected in cerebrospinal fluid (CSF) from FIV-infected cats. Toxicity in the CSF increased over time and was paralleled by strong CD18 staining of macrophages/microglia in the choroid plexus and adjacent parenchyma. These results suggest that lentiviral infection of the choroid plexus can induce a toxic inflammatory response that is fueled by local macrophage proliferation. Together with the observation of increasing toxic activity in the CSF and increased CD18 staining in vivo, these observations suggest that choroid plexus macrophages may contribute to an inflammatory cascade in the brain that progresses independently of systemic and CSF viral load.}, number={3}, journal={JOURNAL OF NEUROVIROLOGY}, author={Bragg, DC and Hudson, LC and Liang, YH and Tompkins, MB and Fernandes, A and Meeker, RB}, year={2002}, month={Jun}, pages={225–239} }
 @article{liang_hudson_levy_ritchey_tompkins_tompkins_2000, title={T cells overexpressing interferon-gamma and interleukin-10 are found in both the thymus and secondary lymphoid tissues of feline immunodeficiency virus-infected cats}, volume={181}, ISSN={["0022-1899"]}, DOI={10.1086/315226}, abstractNote={Similar to human immunodeficiency virus type 1, feline immunodeficiency virus (FIV) replicates in the thymus of infected animals, causing marked alteration in thymic lymphocyte subpopulations. The immune phenotype and cytokine patterns in the thymus and secondary lymphoid tissues of FIV-infected cats were investigated. FIV infection caused an acute-stage transient reduction in CD4CD8 double-positive thymocytes, a marked increase in CD8 single-positive thymocytes, and formation of thymic B cell lymphoid follicles. Interferon (IFN)-gamma and interleukin (IL)-10 mRNA were up-regulated in both the thymus and lymph nodes of FIV-infected cats. Analysis of purified CD4 and CD8 cells revealed that CD4 cells produced most of the IL-10, whereas IFN-gamma was produced by both subsets. Quantitative-competitive reverse-transcription polymerase chain reaction analysis revealed that thymocytes, especially CD4CD8 thymocytes, had much greater levels of gag mRNA than did lymph node T cells. Thus, overexpression of IFN-gamma and IL-10 is a feature of the thymus and secondary lymphoid tissues of FIV-infected cats.}, number={2}, journal={JOURNAL OF INFECTIOUS DISEASES}, author={Liang, YH and Hudson, LC and Levy, JK and Ritchey, JW and Tompkins, WAF and Tompkins, MB}, year={2000}, month={Feb}, pages={564–575} }
 @article{jordan_liang_hudson_tompkins_1999, title={Shedding of feline immunodeficiency virus in semen of domestic cats during acute infection}, volume={60}, number={2}, journal={American Journal of Veterinary Research}, author={Jordan, H. L. and Liang, Y. H. and Hudson, L. C. and Tompkins, W. A.}, year={1999}, pages={211–215} }
 @article{levy_ritchey_rottman_davidson_liang_jordan_tompkins_tompkins_1998, title={Elevated interleukin-10-to-interleukin-12 ratio in feline immunodeficiency virus-infected cats predicts loss of type 1 immunity to Toxoplasma gondii}, volume={178}, ISSN={["0022-1899"]}, DOI={10.1086/515632}, abstractNote={Similar to human immunodeficiency virus, feline immunodeficiency virus (FIV) induces immunodeficiency and enhanced susceptibility to secondary pathogens. To explore cytokine alterations in lentivirus immunodeficiency, constitutive mRNA expression was measured in lymph nodes of healthy and FIV-infected cats before and after challenge with Toxoplasma gondii. Cytokine mRNA expression was similar in control and FIV-infected cats during the first 10 weeks after infection. At 16 weeks, interferon (IFN)-gamma, tumor necrosis factor-alpha, and interleukin (IL)-10 mRNA were increased in FIV-infected cats. Challenge with T. gondii induced an increase in IL-2, IFN-gamma, and IL-12 in the lymph nodes of control cats, whereas IFN-gamma and IL-10 but not IL-2 or IL-12 increased in the lymph nodes of FIV-T. gondii coinfected cats. These results indicate that FIV immunodeficiency may derive from a failure to generate an IL-12-dependent type 1 response and that an elevated level of IL-10 mRNA expression is a predictor of lentivirus immunodeficiency.}, number={2}, journal={JOURNAL OF INFECTIOUS DISEASES}, author={Levy, JK and Ritchey, JW and Rottman, JB and Davidson, MG and Liang, YH and Jordan, HL and Tompkins, WA and Tompkins, MB}, year={1998}, month={Aug}, pages={503–511} }