Figure 7.

Lipid-depleting treatments affect Fcγ receptor–mediated signaling.A, macrophages (MH-S) were mock treated (control) or treated with bacterial sphingomyelinase (bSMase) and subsequently stimulated with bovine serum albumin (BSA)–IgG immune complex (IC) for 5 min. Fc receptor γ chain (FcRγ) was immunoprecipitated (IP) and evaluated for phosphorylation of the tyrosine residues. IP samples were probed for FcRγ or phosphotyrosine (p-Tyr). Representative immunoblots are shown. B, immunoblots were quantified using ImageJ software; p-Tyr was normalized by FcRγ (n = 3 experiments). Error bars represent the SEM, and statistical significance was determined using one-way ANOVA with Tukey's multiple comparisons test. ∗p < 0.05. All p values were adjusted for multiplicity using Bonferroni's correction. C, MH-S cells were mock treated (control) or treated with methyl-beta-cyclodextrin (MβCD) and subsequently stimulated with BSA–IgG IC for 5 min. FcRγ was IP and evaluated for phosphorylation of the tyrosine residue. IP samples were probed for FcRγ or p-Tyr. Representative immunoblots are shown. D, immunoblots were quantified using ImageJ software; p-Tyr was normalized by FcRγ (n = 3). Error bars represent the SEM, and statistical significance was determined using one-way ANOVA with Tukey's multiple comparisons test compared with the control. ∗p < 0.05. All p values were adjusted for multiplicity.