Figure 6. Type I IFN synergizes with TCR to promote CD69 expression and suppress T cell egress.

(A) Immunoblot analysis of RICTOR, p-AKT₄₇₃, AKT (pan), p-STAT1 and p-S6RP in CD4⁺ T cells from B6 and Cd4^creRictor^fl/fl mice stimulated with or without anti-CD3/anti-CD28 in the presence or absence of IFNα for 1 and 6 hours. Right, summaries of the relative p-AKT₄₇₃ expression (normalized to total AKT and then compared with baseline B6 CD4⁺ T cells) stimulated for 6 hours. (B) Flow cytometry analysis of p-AKT₄₇₃ expression in CD4⁺ T cells treated with IFNα alone, or in combination with anti-CD3/anti-CD28 overnight. Right, summary of the relative pAKT₄₇₃ expression (normalized to that in B6 CD4⁺ T cells without any stimulation). (C) Immunoblot analysis of p-AKT₄₇₃, AKT (pan), and p-STAT1 in human CD4⁺ T cells with or without anti-CD3/anti-CD28 activation in presence or absence of human IFNα for 3 hours. Right, summary of the relative p-AKT₄₇₃ expression normalized to total AKT and then compared with baseline. (D) and (E) B6 and Cd4^creRictor^fl/fl mice were administered with poly(I:C) intraperitoneally. (D) Expression of CD69 in blood CD4⁺ T cells from B6 and Cd4^creRictor^fl/fl mice after poly(I:C) administration. Numbers indicate the percentages of CD69⁺CD4⁺ T cells. Right, summary of CD69⁺ percentage in CD4⁺ T cells at baseline or treated with poly(I:C) for 16 h and 40 h. (E) Blood CD4⁺ T cell counts were determined before and after poly(I:C) treatment. (F) Expression of CD69 in CD4⁺ T cells from B6, Lpr and Lpr.Rictor T-KO mice. Right, summary of CD69⁺ percentages among pLN CD4⁺ T cells. (G) Blood CD4⁺ T cell counts were determined in 4–6 months old B6, Lpr and Lpr.Rictor T-KO mice. NS, not significant; * P < 0.05, ** P < 0.01, *** P < 0.001, **** P < 0.0001 (A, B, D and E, unpaired Student’s t test, C, F and G, one-way ANOVA). Results were presentative of 4 (A, C), or pooled from at least 3 (A-G) independent experiments. Error bars represent SEM.