FIG. 5.

CLEC-2 contributes to HIV-1 capture by platelets. (A) Platelets were incubated with phosphate-buffered saline (PBS), control serum, or anti-CLEC-2 serum and pulsed with HIV-1 NL4-3 Luc generated in 293T cells. After unbound virus was removed, CEMx174 R5 target cells were added and luciferase activities in culture lysates determined 3 days after cocultivation. The averages of seven independent experiments are shown. Error bars indicate standard errors of the means. (B) The transmission experiment was performed as described for panel A, but NL4-3 Luc generated in CEMx174 R5 cells (left panel) or PBMCs (right panel) was employed. The results of representative experiments performed in triplicate are presented, and error bars indicate standard deviations. Similar results were obtained in an independent experiment. (C) HIV-1 capture was assessed as described for panel A, using the indicated primary HIV-1 isolates generated in CEMx174 R5 cells. A representative experiment is shown. The results were confirmed in an independent experiment with a different platelet preparation. Error bars indicate standard deviations. P values were determined using a two-sided (A) independent- or (B and C) dependent-sample t test. IgG, immunoglobulin G; c.p.s., counts per second.