@article{conley_brown_westerman_elfenbein_sheats_2024, title={MARCKS Inhibition Alters Bovine Neutrophil Responses to <i>Salmonella</i> Typhimurium}, volume={12}, ISSN={["2227-9059"]}, url={https://www.mdpi.com/2227-9059/12/2/442}, DOI={10.3390/biomedicines12020442}, abstractNote={Neutrophils are innate immune cells that respond quickly to sites of bacterial infection and play an essential role in host defense. Interestingly, some bacterial pathogens benefit from exuberant neutrophil inflammation. Salmonella is one such pathogen that can utilize the toxic mediators released by neutrophils to colonize the intestine and cause enterocolitis. Because neutrophils can aid gut colonization during Salmonella infection, neutrophils represent a potential host-directed therapeutic target. Myristoylated alanine-rich C-kinase substrate (MARCKS) is an actin-binding protein that plays an essential role in many neutrophil effector responses. We hypothesized that inhibition of MARCKS protein would alter bovine neutrophil responses to Salmonella Typhimurium (STm) ex vivo. We used a MARCKS inhibitor peptide to investigate the role of MARCKS in neutrophil responses to STm. This study demonstrates that MARCKS inhibition attenuated STm-induced neutrophil adhesion and chemotaxis. Interestingly, MARCKS inhibition also enhanced neutrophil phagocytosis and respiratory burst in response to STm. This is the first report describing the role of MARCKS protein in neutrophil antibacterial responses.}, number={2}, journal={BIOMEDICINES}, author={Conley, Haleigh E. and Brown, Chalise F. and Westerman, Trina L. and Elfenbein, Johanna R. and Sheats, M. Katie}, year={2024}, month={Feb} }
 @article{conley_till_berglund_jones_sheats_2023, title={A myristoylated alanine-rich C-kinase substrate (MARCKS) inhibitor peptide attenuates neutrophil outside-in & beta;(2)-integrin activation and signaling}, volume={17}, ISSN={["1933-6926"]}, url={https://doi.org/10.1080/19336918.2023.2233204}, DOI={10.1080/19336918.2023.2233204}, abstractNote={ABSTRACT MARCKS is an actin and PIP2-binding protein that plays an essential role in neutrophil migration and adhesion; however, the molecular details regarding MARCKS function in these processes remains unclear. Neutrophil adhesion and migration also require the cell surface receptors β2-integrins. We hypothesized that MARCKS inhibition would alter neutrophil β2-integrin activation and signaling. We utilized a MARCKS-targeting peptide to inhibit MARCKS in inside-out and outside-in β2-integrin activation in neutrophils. MANS-mediated MARCKS inhibition had no significant effect on inside-out β2-integrin activation. MANS treatment significantly attenuated ICAM-1/Mn2+-stimulated static adhesion, cell spreading and β2-integrin clustering, suggesting a role for MARCKS function in outside-in β2-integrin activation. Additional work is needed to better understand the molecular mechanisms of MARCKS role in outside-in β2-integrin activation and signaling.}, number={1}, journal={CELL ADHESION & MIGRATION}, author={Conley, Haleigh and Till, Rebecca L. and Berglund, Alix K. and Jones, Samuel L. and Sheats, M. Katie}, year={2023}, month={Dec}, pages={1–16} }
 @article{phelps_palekar_conley_ferrero_driggers_linder_kullman_reif_sheats_dewitt_et al._2023, title={Legacy and emerging per- and polyfluoroalkyl substances suppress the neutrophil respiratory burst}, volume={20}, ISSN={["1547-6901"]}, url={https://doi.org/10.1080/1547691X.2023.2176953}, DOI={10.1080/1547691X.2023.2176953}, abstractNote={Abstract Per- and polyfluoroalkyl substances (PFASs) are used in a multitude of processes and products, including nonstick coatings, food wrappers, and fire-fighting foams. These chemicals are environmentally-persistent, ubiquitous, and can be detected in the serum of 98% of Americans. Despite evidence that PFASs alter adaptive immunity, few studies have investigated their effects on innate immunity. The report here presents results of studies that investigated the impact of nine environmentally-relevant PFASs [e.g. perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid potassium salt (PFOS-K), perfluorononanoic acid (PFNA), perfluorohexanoic acid (PFHxA), perfluorohexane sulfonic acid (PFHxS), perfluorobutane sulfonic acid (PFBS), ammonium perfluoro(2-methyl-3-oxahexanoate) (GenX), 7H-perfluoro-4-methyl-3,6-dioxa-octane sulfonic acid (Nafion byproduct 2), and perfluoromethoxyacetic acid sodium salt (PFMOAA-Na)] on one component of the innate immune response, the neutrophil respiratory burst. The respiratory burst is a key innate immune process by which microbicidal reactive oxygen species (ROS) are rapidly induced by neutrophils in response to pathogens; defects in the respiratory burst can increase susceptibility to infection. The study here utilized larval zebrafish, a human neutrophil-like cell line, and primary human neutrophils to ascertain whether PFAS exposure inhibits ROS production in the respiratory burst. It was observed that exposure to PFHxA and GenX suppresses the respiratory burst in zebrafish larvae and a human neutrophil-like cell line. GenX also suppressed the respiratory burst in primary human neutrophils. This report is the first to demonstrate that these PFASs suppress neutrophil function and support the utility of employing zebrafish larvae and a human cell line as screening tools to identify chemicals that may suppress human immune function.}, number={1}, journal={JOURNAL OF IMMUNOTOXICOLOGY}, author={Phelps, Drake W. and Palekar, Anika I. and Conley, Haleigh E. and Ferrero, Giuliano and Driggers, Jacob H. and Linder, Keith E. and Kullman, Seth W. and Reif, David M. and Sheats, M. Katie and DeWitt, Jamie C. and et al.}, year={2023}, month={Dec} }
 @misc{conley_sheats_2023, title={Targeting Neutrophil beta(2)-Integrins: A Review of Relevant Resources, Tools, and Methods}, volume={13}, ISSN={["2218-273X"]}, url={https://doi.org/10.3390/biom13060892}, DOI={10.3390/biom13060892}, abstractNote={Neutrophils are important innate immune cells that respond during inflammation and infection. These migratory cells utilize β2-integrin cell surface receptors to move out of the vasculature into inflamed tissues and to perform various anti-inflammatory responses. Although critical for fighting off infection, neutrophil responses can also become dysregulated and contribute to disease pathophysiology. In order to limit neutrophil-mediated damage, investigators have focused on β2-integrins as potential therapeutic targets, but so far these strategies have failed in clinical trials. As the field continues to move forward, a better understanding of β2-integrin function and signaling will aid the design of future therapeutics. Here, we provide a detailed review of resources, tools, experimental methods, and in vivo models that have been and will continue to be utilized to investigate the vitally important cell surface receptors, neutrophil β2-integrins.}, number={6}, journal={BIOMOLECULES}, author={Conley, Haleigh E. and Sheats, M. Katie}, year={2023}, month={Jun} }
 @article{pollara_tay_edwards_goodman_crowley_edwards_easterhoff_conley_hoxie_gurley_et al._2021, title={Functional Homology for Antibody-Dependent Phagocytosis Across Humans and Rhesus Macaques}, volume={12}, ISSN={["1664-3224"]}, DOI={10.3389/fimmu.2021.678511}, abstractNote={Analyses of human clinical HIV-1 vaccine trials and preclinical vaccine studies performed in rhesus macaque (RM) models have identified associations between non-neutralizing Fc Receptor (FcR)-dependent antibody effector functions and reduced risk of infection. Specifically, antibody-dependent phagocytosis (ADP) has emerged as a common correlate of reduced infection risk in multiple RM studies and the human HVTN505 trial. This recurrent finding suggests that antibody responses with the capability to mediate ADP are most likely a desirable component of vaccine responses aimed at protecting against HIV-1 acquisition. As use of RM models is essential for development of the next generation of candidate HIV-1 vaccines, there is a need to determine how effectively ADP activity observed in RMs translates to activity in humans. In this study we compared ADP activity of human and RM monocytes and polymorphonuclear leukocytes (PMN) to bridge this gap in knowledge. We observed considerable variability in the magnitude of monocyte and PMN ADP activity across individual humans and RM that was not dependent on FcR alleles, and only modestly impacted by cell-surface levels of FcRs. Importantly, we found that for both human and RM phagocytes, ADP activity of antibodies targeting the CD4 binding site was greatest when mediated by human IgG3, followed by RM and human IgG1. These results demonstrate that there is functional homology between antibody and FcRs from these two species for ADP. We also used novel RM IgG1 monoclonal antibodies engineered with elongated hinge regions to show that hinge elongation augments RM ADP activity. The RM IgGs with engineered hinge regions can achieve ADP activity comparable to that observed with human IgG3. These novel modified antibodies will have utility in passive immunization studies aimed at defining the role of IgG3 and ADP in protection from virus challenge or control of disease in RM models. Our results contribute to a better translation of human and macaque antibody and FcR biology, and may help to improve testing accuracy and evaluations of future active and passive prevention strategies.}, journal={FRONTIERS IN IMMUNOLOGY}, author={Pollara, Justin and Tay, Matthew Zirui and Edwards, R. Whitney and Goodman, Derrick and Crowley, Andrew R. and Edwards, Robert J. and Easterhoff, David and Conley, Haleigh E. and Hoxie, Taylor and Gurley, Thaddeus and et al.}, year={2021}, month={May} }