Abstract
STAT3 regulates CD4+ T cell survival and differentiation. However, its effects on CD8+ T cells are not well understood. Here, we show that in comparison to WT CD8+ T cells, STAT3-deficient CD8+ T cells exhibit a preactivated memory-like phenotype, produce more IL-2, proliferate faster, and are more sensitive to activation-induced cell death (AICD). The enhanced proliferation and sensitivity to AICD correlated with downregulation of class-O forkhead transcription factors (FoxO1, FoxO3A), p21(waf1), p27(KIP1), Bcl-2, OX-40, and upregulation of FasL, Bax, and Bad. We examined whether STAT3-deficient CD8+ T cells can mount effective response during herpes simplex virus (HSV-1) infection and experimental autoimmune uveitis (EAU). Compared to WT mice, HSV-1-infected STAT3-deficient mice (STAT3KO) produced less IFN-γ and virus-specific KLRG-1+ CD8+ T cells. STAT3KO mice are also resistant to EAU and produced less IL-17-producing Tc17 cells. Resistance of STAT3KO to EAU correlated with marked expansion of IL-10-producing regulatory CD8+ T cells (CD8-Treg) implicated in recovery from autoimmune encephalomyelitis. Thus, increases of IL-6-induced STAT3 activation observed during inflammation may inhibit expansion of CD8-Tregs, thereby impeding recovery from uveitis. These results suggest that STAT3 is a potential therapeutic target for upregulating CD8+ T cell-mediated responses to viruses and suggest the successful therapeutic targeting of STAT3 as treatment for uveitis, derived, in part, from promoting CD8-Treg expansion.
Original language | English |
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Article number | 359674 |
Journal | Mediators of Inflammation |
Volume | 2013 |
DOIs | |
Publication status | Published - 2013 |
Keywords
- Animals
- Apoptosis
- Autoimmune Diseases/immunology
- CD8-Positive T-Lymphocytes/cytology
- Cell Proliferation
- Cell Separation
- Flow Cytometry
- Gene Expression Regulation
- Herpes Simplex/metabolism
- Herpesvirus 1, Human
- Inflammation
- Interleukin-10/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Phenotype
- STAT3 Transcription Factor/genetics
- Up-Regulation
- Uveitis/immunology