@article{BarahonadeBritoPatra2022, author = {Barahona de Brito, Carlotta and Patra, Amiya Kumar}, title = {NFAT factors are dispensable for the development but are critical for the maintenance of Foxp3\(^+\) regulatory T cells}, series = {Cells}, volume = {11}, journal = {Cells}, number = {9}, issn = {2073-4409}, doi = {10.3390/cells11091397}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270668}, year = {2022}, abstract = {The transcription factors of the nuclear factor of activated T cell (NFAT) family play a crucial role in multiple aspects of T cell function. It has recently been reported that NFATs play an important role in the suppressive function of CD4\(^+\)CD25\(^+\)Foxp3\(^+\) regulatory T (T\(_{reg}\)) cells. In this study, we have investigated the role of NFATs in the thymic development of T\(_{reg}\) cells in mice. We show that NFAT factors are dispensable for the development of Foxp3\(^+\) T\(_{reg}\) cells in the thymus but are critical for the maintenance of both the phenotype and survival of T\(_{reg}\) cells in the thymus as well as in peripheral lymphoid organs. Specifically, the homeostasis of CD4\(^+\)CD25\(^+\)Foxp3\(^+\) but not the CD4\(^+\)CD25\(^-\)Foxp3\(^+\) fraction is severely perturbed when NFAT signaling is blocked, leading to a strongly reduced T\(_{reg}\) population. We underscored this intriguing effect of NFAT on CD4\(^+\)CD25\(^+\)Foxp3\(^+\) T\(_{reg}\) cells to the disruption of survival signals provided by interleukin 2 (IL-2). Accordingly, blocking T\(_{reg}\) cell death by abolishing the activity of pro-apoptotic Bcl-2 family member Bim, compensated for the survival defects induced due to a lack of NFAT-IL-2-IL-2R signaling. Inhibition of NFAT activity led to a strong reduction in the number of Foxp3\(^+\) T\(_{reg}\) cells; however, it did not influence the level of Foxp3 expression on an individual cell basis. In addition, we show a differential effect of IL-2 and IL-7 signaling on Foxp3\(^+\) T\(_{reg}\) versus CD4\(^+\)CD25\(^-\) T cell development, again underlining the dispensability of NFAT signaling in the development, but not in the maintenance of Foxp3\(^+\) T\(_{reg}\) cells.}, language = {en} }