DCIR-mediated enhancing effect on HIV-1 binding/entry requires Src and Syk family members. Experimental procedures used here are similar to those described for Figure 2 except that the following inhibitors and oligonucleotides were tested: (A) Src inhibitor PP2 (10μM), (B) oligonucleotides specific for Src, (C) BTK inhibitor LFM-A13 (2.5μM), (D) Syk inhibitor piceatannol (10μM), (E) oligonucleotides specific for Syk, and (F) PI3K inhibitor wortmannin (50nM). Data shown correspond to the means ± SD of triplicate samples from 3 combined independent experiments. The statistical significance of differences between untreated and treated cells or nontransfected and Raji-CD4-DCIR transfected with antisense oligonucleotides is denoted by asterisks: *P < .05; **P < .01; ***P < .001. After gene silencing, the diminution of the targeted protein was verified by Western blotting and actin was used as a loading control marker (provided as inserts for each graph). Vertical lines have been inserted to indicate repositioned gel lanes.