Figure 3.

Anti–glycoprotein D (gD) antibodies are predominantly immunoglobulin (Ig) G1 subclass and do not bind to C1q. A, Anti-gD IgG1, IgG1, and IgG3 were quantified by means of enzyme-linked immunosorbent assay (ELISA) using plates coated with gD-2 protein (1:10 000 dilution for IgG and 1:1000 for IgG1 and IgG3). ***P < .001 (t test comparing gD/AS04 vaccine vs acute infection). Abbreviation: OD₄₅₀, optical density at 450 nm. B, gD-specific C1q-binding antibodies were measured by ELISA, with 5 samples from each group at dilutions of 1:5, 1:25, and 1:125. Abbreviation: HIV⁻, human immunodeficiency virus (HIV) uninfected; HIV⁺, HIV infected. Results are means with standard deviation C, Western blots were performed with 10 µg of herpes simplex virus (HSV) 2 (4674)–infected Vero cell lysates (HSV) or 5 μg of gD-2 protein (gD) per lane as the antigen and probed with pooled immune serum (n = 3) containing 10 μg/mL of IgG from gD/ASO4 vaccine recipients or participants with acute infection using anti-IgG1 or anti-IgG3 secondary antibodies.