Figure 7. Anti-CD28 cannot sustain an increase in CD4⁺CXCR5⁺ T cells (T_FH) in the absence of ICOS.

After sensitization with S. mansoni, ICOS^+/+ and ICOS^−/− mice injected i.p. on day 0 with anti-CD28 or HIg were sacrificed on the days indicated. A, Percentage of spleen CD4⁺CXCR5⁺ T cells in αCD28 or HIg treated ICOS^+/+ mice or ICOS^−/− mice. Significance determined by two way ANOVA as indicated in figure. B, Number of CD4⁺CXCR5⁺ T cells found in the spleen on Day 14.