@article{smithberg_fogle_mexas_reckling_lankford_tompkins_dean_2008, title={In vivo depletion of CD4(+)CD25(+) regulatory T cells in cats}, volume={329}, ISSN={["0022-1759"]}, DOI={10.1016/j.jim.2007.09.015}, abstractNote={To establish a characterized model of regulatory T cell (Treg) depletion in the cat we assessed the kinetics of depletion and rebound in peripheral and central lymphoid compartments after treatment with anti-CD25 antibody as determined by cell surface markers and FOXP3 mRNA expression. An 82% decrease in circulating CD4+CD25+ Tregs was observed by day 11 after treatment. CD4+CD25+ cells were also reduced in the thymus (69%), secondary lymphoid tissues (66%), and gut (67%). Although CD4+CD25+ cells rebound by day 35 post-treatment, FOXP3 levels remain depressed suggesting anti-CD25 antibody treatment has a sustainable diminutive effect on the Treg population. To determine whether CD25+ Treg depletion strategies also deplete activated CD25+ effector cells, cats were immunized with feline immunodeficiency virus (FIV) p24-GST recombinant protein, allowing them to develop a measurable memory response, prior to depletion with anti-CD25 antibody. Anti-FIV p24-GST effector cell activity in peripheral blood after depletion was sustained as determined by antigen-specific T cell proliferation and humoral responses against FIV p24-GST with an ELISA for antigen-specific feline IgG. Furthermore, development of an anti-mouse response in Treg-depleted cats was similar to control levels indicating the retained capacity to respond to a novel antigen. We conclude that despite alterations in CD25+ cell levels during depletion, the feline immune system remains functional. We demonstrate here a model for the study of disease pathogenesis in the context of reduced numbers of immunosuppressive CD4+CD25+ Tregs throughout the feline immune system.}, number={1-2}, journal={JOURNAL OF IMMUNOLOGICAL METHODS}, author={Smithberg, S. Rochelle and Fogle, Jonathan E. and Mexas, Angela M. and Reckling, Stacie K. and Lankford, Susan M. and Tompkins, Mary B. and Dean, Gregg A.}, year={2008}, month={Jan}, pages={81–91} }