Figure 6.

P2X7-mediated control of PSGL-1 down-regulation and IFN-γ secretion in pristane-treated mice. (A) Frequency of PNA⁺Fas⁺ GC splenic B cells (untreated WT, n = 3; P2rx7^−/−, n = 3; and Icos^−/−P2rx7^−/−, n = 3; pristane-treated WT, n = 9; P2rx7^−/−, n = 9; and Icos^−/−P2rx7^−/−, n = 5). (B) Serum ANA IgG detection by ELISA (MRL/lpr, n = 2; untreated WT, n = 4; P2rx7^−/−, n = 4; and Icos^−/−P2rx7^−/−, n = 5; pristane-treated WT, n = 9; P2rx7^−/−, n = 10; and Icos^−/−P2rx7^−/−, n = 10). (C) Proteinuria score (untreated WT, n = 3; P2rx7^−/−, n = 3; and Icos^−/−P2rx7^−/−, n = 4; pristane-treated WT, n = 8; P2rx7^−/−, n = 8; and Icos^−/−P2rx7^−/−, n = 8) in the indicated mice at 33 wk after pristane injection. Each dot represents an individual mouse, and horizontal lines represent median values. (D) Representative contour plots for PSGL-1 and CD62L on splenic CD4⁺ T cells, frequency and absolute number (mean ± SEM) of PSGL1^lo/−CD62L⁻ cells from untreated WT (n = 12), P2rx7^−/− (n = 10), Icos^−/−P2rx7^−/− (n = 5), treated WT (n = 38), P2rx7^−/− (n = 37), and Icos^−/−P2rx7^−/− (n = 8) mice. (E) Contour plots show representative intracellular staining for IL-21, IL-17, and IFN-γ on gated CD4⁺ICOS⁺PSGL1^lo/− cells from spleens of treated WT and P2rx7^−/− mice. Statistics from three independent experiments are shown (mean ± SEM, untreated mice, n ≥ 4; treated mice, n ≥ 8). Two-tailed Mann–Whitney U test. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001. ns, not significant.