FIG 2.

Relative levels of resistance to neutralizing HIV-1 patient IgG (HIVIG) in HIV-1 cell-to-cell transmission. (A) Single-round neutralization experiments using the two HIV-1 T/F Envs, laboratory-adapted NL4-3 Env, and chronic R5-tropic JR-FL Env NLCI constructs with pooled HIV-1-positive patient IgG (HIVIG) in cell-free infection (closed circle with solid lines) and cell-to-cell infection (open triangles with dotted lines). HIVIG was serially 3-fold diluted starting from 50 μg/ml. (B) NLCI_QH0692 (top), NLCI_RHPA (middle), and NLCI_NL4-3 (bottom) were tested for cell-free and cell-to-cell neutralization sensitivity to single-patient IgG isolated from plasma from three chronically infected HIV-1 patients. Single-patient IgG was purified by the use of protein AG beads and serially diluted 1:3 starting from 1 mg/ml.