Fig 1: HCV replication was increased by CD36.(A) High expression of CD36 increased HCV infection and replication (n = 3). (B) Silence of CD36 decreased HCV infection and replication (n = 3). Huh7.5 cells were transfected with 0.2 μg CD36-HA plasmid (A) or with 150 pmol siRNA for CD36 (B) for 48 hrs, and then were washed and infected with HCV (150 IU/cell) for 2 hrs, followed by washing and continuously incubating. Intracellular HCV RNA and proteins were detected in 96 hrs, and the cytotoxicity of siRNAs was measured in 96-wells plate with a MTT assay in B. (C) High sCD36 in supernatants increased HCV infection (n = 3 for RNA, n = 4 for protein). (D) Low sCD36 in supernatants decreased HCV infection (n = 3 for RNA and cytotoxicity, n = 4 for protein). Huh7.5 cells were incubated with culture supernatants of Huh7.5 cells transfected with 0.2 μg CD36-HA plasmid (C) or with 150 pmol siRNA for CD36 (D) for 48 hrs, and infected with HCV (150 IU/cell) for 2 hrs, followed by washing and continuously culturing. Intracellular HCV RNA and proteins were detected in 72 hrs, and cytotoxicity was measured with a MTT assay accordingly in D. The pcDAN3.1(+) vector was used as plasmid control in A and C. The SR-BI siRNA (sc-44753) was used as positive control and siRNA-A as negative control in (B). *P < 0.05 and **P < 0.01, vs control; #P < 0.05, vs CD36 siRNA. (E) CD36 mAbs neutralized HCV infection in a dose-dependent manner (concentrations of ab17044 were 0.2, 1, and 5 μg/mL) (n = 3). (F) CD36 mAbs synergistically inhibited HCV infection with SR-BI antibody (n = 4). Huh7.5 cells were incubated with 5 μg/mL mAb for 1 hr and then infected with HCV (150 IU/cell) for 2 hrs, followed by washing and culturing. Intracellular HCV RNA was detected in 72 hrs (E,F). *P < 0.05 and **P < 0.01, vs IgG group; #,P < 0.05, vs monotherapy with ab23680 or SR-BI antibody. The mAbs code was from Abcam, Co. Ltd. (G) Cross-silencing test of CD36 and SR-BI (sc-44752), and cytotoxicity was measured with a MTT assay (n = 3 for RNA and cytotoxicity, n = 6 for protein). The protein bands presented in the figure showed the results of a representative experiment. Presented are mean ± standard deviation. Student’s t-test was used in (A–G).