Figure 2. Cellular, chemokine and cytokine requirements of IL21+ CD4 T cells.
(A) FACS plots of VFP+CD4 T cells in PBL from 4 wk old WT, Ighm−/−, Cxcr5−/− and Icos−/− IL21-VFP mice. Also shows co-expression of CD44, ICOS, CXCR5 and PD1 (n=12). (B) Frequencies of VFP+CD4 T cells in PBL from Ighm−/−, Cxcr5−/−, and Icos−/− and WT IL21- VFP mice (n=12). (C) MFI of VFP by CD4+ T cells; pooled data from PBL of 4 wk old Ighm−/− (n=13), WT (n=28) Cxcr5−/− (n=12), and Icos−/− (n=8) IL21-VFP mice. (D) Frequencies of VFP+ CD4 T cells in 5–6 wk old WT (n=14), Il10−/− IL21-VFP (n=8) and Ifnar−/− IL21-VFP mice. (E) Frequencies of VFP+ CD4 T cells in 4–6 wk old WT (n=15), Il6−/− IL21-VFP (n=9), Il21r−/− IL21-VFP (n=5) and Il6−/− Il21r−/− (n=4) IL21-VFP mice. Representative of two to four independent experiments. * P ≤0.05; ** P ≤0.01; *** P≤0.001; n.s, not significant. Mean ± SD is indicated.