DCIR-mediated enhancing effect on HIV-1 binding/entry involves SHP-1 and SHP-2. (A) Raji-CD4 and Raji-CD4-DCIR cells were either left untreated or treated with SSG (100 μg/mL) for 10 minutes at 37°C. Thereafter, cells were pulsed with NL4-3 for 60 minutes. After 3 washes with PBS to remove nonadsorbed virus, cell-associated virus was quantified by measuring the p24 content. Data shown correspond to the means ± SD of triplicate samples from 3 combined independent experiments. The statistical significance of differences between untreated and treated Raji-CD4-DCIR is denoted by asterisks: *P < .05; **P < .01. (B) Cells were either left untransfected or transfected with sense or antisense oligonucleotides specific for the signaling protein of interest. Next, cells were pulsed with NL4-3 for 60 minutes. After 3 washes with PBS to eliminate unbound virus, cell-associated virus was quantified by measuring the p24 content. Data shown correspond to the means ± SD of triplicate samples from 3 combined independent experiments. The statistical significance of differences between nontransfected and Raji-CD4-DCIR transfected with antisense oligonucleotides is denoted by an asterisk: *P < .05. 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).