Human Anti-HCV E2 Recombinant Antibody (clone #37) (CAT#: FAMAB-0586WJ)

Figure 1 Isotyping revealed that #37 and #55 were IgG1/kappa and IgG1/lambda, respectively.

Huh7 cells expressing the HCV E2 (aa 384-661) derived from strain H77 were incubated with #37 or #55, washed, and stained with fluoresceinated anti-human IgG1, anti-human lambda, or anti-human kappa.

Shimizu, Y. K., Hijikata, M., Oshima, M., Shimizu, K., Alter, H. J., Purcell, R. H., ... & Hotta, H. (2013). Isolation of human monoclonal antibodies to the envelope e2 protein of hepatitis C virus and their characterization. PloS one, 8(2), e55874.

Figure 2 Epitope mapping revealed that #37 and #55 recognized the regions aa 429 to 652 and aa 508 to 607 of the E2 protein, respectively.

IF-reactions of #37 and #55 against the cells expressing aa 429-652 and aa 508-607.

Shimizu, Y. K., Hijikata, M., Oshima, M., Shimizu, K., Alter, H. J., Purcell, R. H., ... & Hotta, H. (2013). Isolation of human monoclonal antibodies to the envelope e2 protein of hepatitis C virus and their characterization. PloS one, 8(2), e55874.

Figure 3 Different pattern of IF-staining by #37 and #55 in the HCV-infected Huh7.5 cells.

#37 gave granular IF-reactions scattered in the cytoplasm. #55 gave diffuse staining throughout the cytoplasm. The control antibody (human IgG) gave negative staining. #37, #55, and the control antibody were not reactive with uninfected Huh7.5 cells.

Shimizu, Y. K., Hijikata, M., Oshima, M., Shimizu, K., Alter, H. J., Purcell, R. H., ... & Hotta, H. (2013). Isolation of human monoclonal antibodies to the envelope e2 protein of hepatitis C virus and their characterization. PloS one, 8(2), e55874.

Figure 4 Immuno-gold EM demonstrated that both #37 and #55 recognized HCV intact particles.

(A). Equilibrium SDG centrifugation. ♦, HCV RNA copies measured by RT-qPCR; Δ, buoyant densities. (B). The ratio of infectivity titer (FFU) to HCV RNA copies of fractions 3 and 6. (C). Immuno-gold EM. Viral particles in fraction 3 were treated with #37 (a, b), #55 (c), or a control antibody (d) followed by anti-human IgG conjugated with colloidal gold particles, and examined under an electron microscope. HCV-like particles in the sample treated with #37 and #55 were observed with specific labeling of gold particles indicating that the antibodies are capable of binding to viral particles. Bar = 50 nm.

Shimizu, Y. K., Hijikata, M., Oshima, M., Shimizu, K., Alter, H. J., Purcell, R. H., ... & Hotta, H. (2013). Isolation of human monoclonal antibodies to the envelope e2 protein of hepatitis C virus and their characterization. PloS one, 8(2), e55874.

Figure 5 Neutralization assay by FFU reduction.

The mean numbers of positive foci are shown for viruses H77/C3 (A), Con1/C3 (B), and J6/C3 (C). Compared to the results obtained with an irrelevant control antibody, #55 inhibited the viral infection in dose-dependent manner for all of the 3 samples tested. Inhibition by #37 was not observed. ♦, control; ▪, #55; ▴, #37.

Shimizu, Y. K., Hijikata, M., Oshima, M., Shimizu, K., Alter, H. J., Purcell, R. H., ... & Hotta, H. (2013). Isolation of human monoclonal antibodies to the envelope e2 protein of hepatitis C virus and their characterization. PloS one, 8(2), e55874.

Figure 6 Blocking of viral adsorption by #55

Blocking of viral adsorption measured by RT-qPCR. Compared to the control antibody (human IgG), #55 inhibited viral adsorption in dose-dependent manner. Inhibition by #37 was not observed but rather slightly enhanced at a concentration of 50 µg/ml.

Shimizu, Y. K., Hijikata, M., Oshima, M., Shimizu, K., Alter, H. J., Purcell, R. H., ... & Hotta, H. (2013). Isolation of human monoclonal antibodies to the envelope e2 protein of hepatitis C virus and their characterization. PloS one, 8(2), e55874.