AUTHOR=Mair Iris , Zandee Stephanie E. J. , Toor Iqbal S. , Saul Louise , McPherson Rhoanne C. , Leech Melanie D. , Smyth Danielle J. , O’Connor Richard A. , Henderson Neil C. , Anderton Stephen M. TITLE=A Context-Dependent Role for αv Integrins in Regulatory T Cell Accumulation at Sites of Inflammation JOURNAL=Frontiers in Immunology VOLUME=9 YEAR=2018 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2018.00264 DOI=10.3389/fimmu.2018.00264 ISSN=1664-3224 ABSTRACT=
Several inflammatory diseases including multiple sclerosis and inflammatory bowel disease have been associated with dysfunctional and/or reduced numbers of Foxp3+ regulatory T cells (Treg). While numerous mechanisms of action have been discovered by which Treg can exert their function, disease-specific Treg requirements remain largely unknown. We found that the integrin αv, which can pair with several β subunits including β8, is highly upregulated in Treg at sites of inflammation. Using mice that lacked αv expression or β8 expression specifically in Treg, we demonstrate that there was no deficit in Treg accumulation in the central nervous system during experimental autoimmune encephalomyelitis and no difference in the resolution of disease compared to control mice. In contrast, during a curative T cell transfer model of colitis, Treg lacking all αv integrins were found at reduced proportions and numbers in the inflamed gut. This led to a quantitative impairment in the ability of αv-deficient Treg to reverse disease when Treg numbers in the inflamed colon were below a threshold. Increase of the number of curative Treg injected was able to rescue this phenotype, indicating that αv integrins were not required for the immunosuppressive function of Treg