Fig. 4. Polymorphisms that protect HCV from NAbs also increase the need for SR-BI to mediate subsequent CD81 interactions.

(A to C) Receptor blocking of the entry of indicated HCV recombinants using a dilution series of antibody against CD81 (A), LDLr (B), and SR-BI (C). (D) Receptor blocking of the entry of indicated recombinants pre- and postviral attachment. (E) Neutralization of the indicated H77 recombinants with a dilution series of sCD81-LEL. (F) IC₅₀ values against sCD81-LEL for the indicated H77 recombinants plotted against SR-BI entry dependency calculated as outlined in (C) (Bmax). The data were analyzed as described in Fig. 1 to estimate maximum attainable effect, Bmax (C), or to calculate IC₅₀ values (E). (G) R² values from IC₅₀ values for the indicated monoclonal NAbs against H77 recombinants from (A) to (F) plotted against their corresponding SR-BI entry dependency calculated as outlined in (C) (Bmax) (see fig. S4B for correlation plots). All error bars represent SD. *Receptor blocking or neutralization sensitivity of the HCV recombinant was statistically significantly different from H77-FL.