Breakdown in repression of IFN-gamma mRNA leads to accumulation of self-reactive effector CD8+ T cells
Tight regulation of virus-induced cytotoxic effector CD8(+) T cells is essential to prevent immunopathology. Naturally occurring effector CD8(+) T cells, with a KLRG1(hi) CD62L(lo) phenotype typical of short-lived effector CD8(+) T cells (SLECs), can be found in increased numbers in autoimmune-prone mice, most notably in mice homozygous for the san allele of Roquin. These SLEC-like cells were able to trigger autoimmune diabetes in a susceptible background. When Roquin is mutated (Roquin(san)), effector CD8(+) T cells accumulate in a cell-autonomous manner, most prominently as SLEC-like effectors. Excessive IFN-gamma promotes the accumulation of SLEC-like cells, increases their T-bet expression, and enhances their granzyme B production in vivo. We show that overexpression of IFN-gamma was caused by failed posttranscriptional repression of Ifng mRNA. This study identifies a novel mechanism that prevents accumulation of self-reactive cytotoxic effectors, highlighting the importance of regulating Ifng mRNA stability to maintain CD8(+) T cell homeostasis and prevent CD8-mediated autoimmunity.
|Authors||Chang, P. P.; Lee, S. K.; Hu, X.; Davey, G.; Duan, G.; Cho, J. H.; Karupiah, G.; Sprent, J.; Heath, W. R.; Bertram, E. M.; Vinuesa, C. G.|
|Publisher Name||JOURNAL OF IMMUNOLOGY|
|DOI||jimmunol.1102432 [pii] 10.4049/jimmunol.1102432|
|URL link to publisher's version||http://www.ncbi.nlm.nih.gov/pubmed/22685317|
|OpenAccess link to author's accepted manuscript version||https://publications.gimr.garvan.org.au/open-access/11434|