Congratulations to Dr. Ann Griffith and her trainees for their paper showing that oxidative stress is not always bad.\u00a0 It is required by thymic stromal cells for the clonal deletion of autoreactive T Cells.<\/p>\n
From the article: Thymic stromal cells impose T cell self-tolerance by presenting self-antigens to developing T cells and inducing apoptosis in strongly self-reactive cells, a process known as clonal deletion. Self-antigen presentation is facilitated by particularly high levels of basal autophagy in thymic stromal cells, but the mechanisms regulating this constitutive autophagy have not been clear. Here, we find that high basal autophagy in thymic stromal cells depends on conspicuously low expression of the hydrogen peroxide\u2013quenching enzyme catalase and that the highly oxidative redox status of thymic stromal cells promotes T cell clonal deletion and self-tolerance in an autophagy-dependent manner. These studies suggest that tightly regulated catalase expression promotes thymic stromal cell autophagy and central T cell tolerance.<\/p>\n
Semwal MK, Hester AK, Xiao Y, Udeaja C, Cepeda S, Verschelde JS, Jones N, Wedemeyer SA, Emtage S, Wimberly K, Griffith AV. Redox status regulates autophagy in thymic stromal cells and promotes T cell tolerance. PNAS. 2022. Sept. 26 119 (40) e2204296119 PMID:\u00a036161925<\/p>\n