Figure 6.

CD86 is the dominant CD28 ligand in early antigen-specific CD4⁺ cell proliferation in the renal draining LN. Illustrative single-parameter histograms (A) show that 72 h after intrarenal OVA injection, substantial proliferation of OT-II cells is seen in mice given control Ab. Proliferation is diminished after inhibition of CD86 but not CD80, quantified in the total numbers of OT-II cells (B) and the number of cells in each division (C). Compared with combined CD80 and CD86 neutralization, individual blockade of either CD80 or CD86 did not alter the proportion of OT-II cells in each division, suggesting that time to onset of proliferation is similar in all three groups (D). Experiments were conduced at the same time as simultaneous CD80 and CD86 blockade; the control Ab data are shown again in this figure for clarity. The dotted vertical lines in the single-parameter histograms (A) represent the degree of CFSE intensity of nonproliferating cells. (B and C) □, Mice injected with control Ab; ▪, mice injected with anti-CD80 Ab; ▒, mice injected with anti-CD86 Ab.