Neutralizing activities of antibodies to the gp41 N-HR domain are potentiated by α-defensin.

TZM-bl cells were allowed to bind HXB2 (A, C, E) or BaL (B, D, F) pseudoviruses in the cold, overlaid with medium containing neutralizing mAbs, 8k8 (A, B), D5 (C, D) or bF-3674 (E, F) in the absence (black symbols) or in the presence (red symbols) of 7.3 µM HNP-1. See Table 2 for the respective IC50 values. In control experiments, titration with 8k8 was done in the presence of 7.5 µM of the inactive linearized HNP-1 mutant Abu-HNP (inverted black triangles). Data points are means and SEM from one (bF-3674 and 8k8/BaL) or two (D5 and 8k8 for HXB2) experiments performed in triplicate.