Inability of IVIg-DCs to conduct DC-to-PLT modulation in Selp^−/−, Fcgr2b^−/−, and Fcgr3^−/− mice. (A-D) IVIg treatments could not ameliorate MWReg30-induced ITP in Selp^−/− mice (A) compared with WT mice (B). As shown in experiment outline in Figure 3A, after the adoptive transfer of WT vehicle/IVIg-primed DCs and the induction of ITP, the PLT counts of Selp^−/−, Fcgr2b^−/−, and Fcgr3^−/− recipients were analyzed (C). In PLT-CD14⁺ LC engagements, 2 combinations of recipient PLTs plus control LCs (untreated naive mice, UN-mice) (D), and recipient LCs plus control PLTs (UN-mice; E) were analyzed. PLT-CD14⁺ LC engagement levels of control PLTs plus control LCs were normalized to 100% (D-E, gray columns). D: donor; R: recipient; Control: untreated naive-mice. *P < .05 represents significant amelioration, versus respective vehicle groups. n = 6 (3 experiments with 2 replicates). Data are mean ± SD. Naive: without cell transfer. Untreated: without ITP induction and vehicle/IVIg treatments.