Fig. 1: Fc variant EFTAE enhances complement-mediated functions of bNAb 10E8v4.
a C’-mediated lysis of HIVBaL virions incubated with a panel of bNAbs in normal serum. Data shown are mean ± SD of two replicates. Lysis was measured by flow cytometric quantification of supernatant p27 with complete lysis determined by incubation with detergent instead of antibody. b Comparative ADCC activity of bNAbs against SHIVSF162P3-infected target cells expressing luciferase reporter, with greater activity corresponding to a decrease in relative light units (RLU). Data shown are mean only. c Site visualization of Fc point mutations inserted into each IgG1 CH2 domain. Each mutation is shown on only one arm for clarity. d 10E8v4-unmodified and Fc-modified Fab-mediated binding to MPER determined by ELISA and e neutralization of SHIVSF162P3 replication-competent challenge virus (single round infection in TZM-bl cells) and SHIVSF162P3 pseudovirus in the TZM-bl assay. Values shown are mean ± SD among 10E8v4-unmodified and variants. f C1q binding and g ADCD assessed as C3b deposition to antibody complexed with MPER-coated beads measured by SPR. h Complement-mediated lysis of transduced Raji B cells resulting in either intermediate or high levels of HIVYU2 Env surface expression. Antibody plus cells were incubated with normal (left) or heat-inactivated (right) serum and percent lysed cells determined by flow cytometry. Results are reported as the percentage of dead cells above that in wells without antibody, with biological replicates from three independent serum donors. i C’-mediated lysis of SHIVSF162P3 virions incubated with 10E8v4 variants in normal serum. Data and analysis are derived from n = 6 animals per group. Analyzed data shown in a, d, f–i are mean ± SD and are representative of at least two independent experiments. Source data are provided in the Source Data file associated with this manuscript. The color key is shown and colors are consistent throughout the manuscript. ADCML antibody-dependent complement-mediated lysis, ADCP antibody-dependent cellular phagocytosis, ADCC antibody-dependent cellular cytotoxicity, ADCD antibody-dependent complement deposition.
