Negative Regulation of Type I IFN Expression by OASL1 Permits Chronic Viral Infection and CD8+ T-Cell Exhaustion
Figure 2
Phenotypic change of virus-specific CD8+ T cells in tissues of Oasl1 KO mice during late phase of chronic LCMV infection.
(A–D) Lymphocytes were isolated from the spleen (SP), lung (LG), and liver (LV) of LCMV CL-13-infected WT and Oasl1 KO mice at 75 d p.i. and analyzed by flow cytometry. (A) Representative data showing the frequency of GP33 and GP276–286 (GP276) tetramer-positive cells among CD8+ T cells. (B) Absolute numbers of the tetramer-positive CD8+ T cells in the indicated tissues. (C, D) PD-1 and CD127 expression levels on virus-specific CD8+ T cells in the spleen of WT and KO mice. Numbers in the plots indicate PD-1 MFI value (C) on GP33 and GP276 tetramer-positive CD8+ T cells and CD127+ cell percentage (D) among the tetramer-positive cells. Blue vertical lines in the plots of (D) divide CD127+ and CD127− tetramer-positive CD8+ T cells. The PD-1 MFI values and CD127+ cell frequencies in the indicated tissues are also summarized in the graphs. (E) Co-expression pattern of CD127 and CD62L on virus-specific CD8+ T cells ex vivo. Splenocytes isolated from LCMV CL-13-infected WT and KO mice at 75 d p.i. (top) and 130 d p.i. (bottom) were analyzed by flow cytometry. GP33 and GP276 tetramer-positive CD8+ T cells were plotted: the numbers in the plots indicate percentages of CD127+CD62L+ (central memory) and CD127+CD62L− (effector memory). All bar graphs show mean + SD. Data are representative of at least two independent experiments (n = 3–4 per group in each experiment). ns, not significant; *, P<0.05; **, P<0.01; ***, P<0.001.