FIG 5.

HCV and GBV-B pseudoparticle cross-entry into human and small primate cells. (A) HCV and GBV-B glycoprotein incorporation at the surface of pseudoparticles. Aliquots of the indicated pseudoparticle (pp) stocks were analyzed by SDS-PAGE followed by immunoblotting with anti-E2^GB polyclonal antibodies (left) and a mixture of anti-E1^H77 and anti-E2^H77 monoclonal antibodies (right). (B) Primary marmoset hepatocyte (PMH) cultures are susceptible to GBV-B infection. PMH cultures derived from the liver of marmoset CJ507 were infected with tamarin-derived GBV-B or with UV-inactivated GBV-B at an MOI of 10 genome equivalents (ge) per cell. Virus production was evaluated by RT-qPCR quantification of GBV-B RNA extracted from culture supernatants at 72 h p.i. (mean results ± standard deviations from 5 experiments). (C, D) Analysis of HCV-pp and GBV-B-pp entry into human and small primate cells. Human (Huh7.5) and tamarin (TH1-14S) hepatic cell lines were infected with high doses (15 μl, black bars) and 5-fold-lower doses (3 μl, gray bars) of the indicated untreated or heat-inactivated pp stocks with MLV cores (C), and PMH cultures were infected with 100 μl (black bars) of untreated or heat-inactivated pp stocks with lentivirus cores (D). Mean log₁₀ values ± standard deviations of the ratios of firefly luciferase (FLuc) activities obtained 72 h after infection with the untreated and heat-inactivated pp in 3 independent experiments are shown. The dashed line represents the threshold below which entry is not considered to be specific with respect to the FLuc ratio obtained for pseudoparticles devoid of envelope glycoprotein (no env-pp).