Fig 7. gO peptides 20 and 26 deplete neutralizing Abs from human serum.

(A) Pooled HCMV seropositive serum was diluted to (NT₁₀₀) titers then incubated with either no protein, 1μg of soluble trimer, or gO peptides (with biotin): 20, 26, 32 or 33 (each at 0.5 mM) for 1 h at 37°C. Peptide 22, which did not bind substantial IgG, served as a negative control. The trimer was removed using nickel-agarose and peptides removed using streptavidin-agarose. The remaining Abs were tested in neutralization assays involving HCMV (BADrUL131) and ARPE-19 epithelial cells. The relative infectivity of HCMV after incubation with these sera was determined by counting GFP+ (infected) cells after 24 h of infection and compared to the numbers of infected cells following incubation of HCMV with similarly diluted sera from HCMV seronegative donors (sero-neg) Data was collected from three separate wells for each condition. (B and C) Two panels of 8 a.a. peptides with 7 a.a. overlap were derived from peptide 20 (B) or peptide 26 (C). These peptides were tested in depletion assays as in panel A. The relative infectivity of HCMV (BADrUL131) on ARPE-19 epithelial cells was determined and normalized to the level of HCMV infectivity with depletions performed with soluble trimer. Data was collected from a randomly selected field of the same surface area from each well.