ADCC Develops Over Time during Persistent Infection with Live-Attenuated SIV and Is Associated with Complete Protection against SIVmac251 Challenge
Figure 1
Development of neutralizing antibody and ADCC titers in macaques inoculated with SIVmac239Δnef.
Plasma collected from 10 animals at 0, 3, 5, 7, 13 or 15, and 21 weeks after inoculation with SIVmac239Δnef was evaluated for its capacity to neutralize SIVmac239 (A) and to direct ADCC against SIVmac239-infected cells (B). The loss of relative light units (RLU) indicates the loss of virus-infected cells during an 8-hour incubation in the presence of plasma and an NK cell line. Target cells infected by SHIVSF162P3 served as a negative control for all ADCC assays (gray). Dashed lines indicate 50% activity. Neutralizing antibody titers were compared with 50% ADCC titers (C), and with AUC values for ADCC (D). An odds ratio (OR) for the probability of detecting neutralization per log10 increase in 50% ADCC titer, or per 1 AUC unit increase in ADCC activity, was estimated by logistic regression.