Activating and inhibitory IgG Fc receptors on human DCs mediate opposing functions
J. Clin. Invest. Adam M. Boruchov, et al. 115:2914 doi:10.1172/JCI24772 [Go to this article.]

Figure 4
Ligation of CD32a or CD32b on immature moDCs has opposing effects on maturation phenotype. (A–E) MoDCs were cultured on plates with immobilized (Imm.) human IgG to ligate FcγRs (filled histograms). CD32a (A) or CD32b (B) was specifically ligated by first incubating moDCs with blocking antibodies against either CD32b or CD32a, respectively. CD32a and CD32b were ligated simultaneously (C) by preincubating moDCs without blocking antibodies. DCs with or without blocking antibodies were also cultured on untreated plates as negative controls (open histograms). Cells were harvested at 48 hours, and DC phenotype was assessed by flow cytometry. Histograms from 1 representative experiment of 8 that used CD32a₁₃₁HH or -HR samples are shown in A–C. Immature IFN-γ–treated moDCs (D) and soluble IgG–treated moDCs (E) were washed to remove these factors and recultured with (filled histograms) or without (open histograms) immobilized human IgG. Cells were harvested at 24–48 hours and phenotype was assessed by flow cytometry. Representative histograms from 1 of 5 separate experiments are shown. (F) In contrast to results obtained from CD32a₁₃₁HH or -HR samples (C, filled histograms), CD32a₁₃₁RR samples were not matured to the same extent after coculture with immobilized human IgG (F, filled histograms; n = 4 experiments). Immobilized mouse IgG1 (F, open histograms), which ligates CD32a but not CD32b in CD32a₁₃₁RR individuals (10), led to maturation that was similar to conditions specifically targeting CD32a on CD32a₁₃₁HH or -HR samples (A, filled histograms). Averaged changes in CD83 and CD86 expression are summarized in Table 1.