Human immunodeficiency virus type-1 (HIV-1) evades antibody-dependent phagocytosis
Fig 5
Fluorescence correlation spectroscopy reveals quantitative differences in virion aggregation.
(A) Normalized experimental average ACFs recovered for native virus opsonized with anti-gp41 mAbs or HIVIG (A-gp41) or with anti-gp120 mAbs or HIVIG (A-gp120), gp41-coated virus opsonized with anti-gp41 mAbs or HIVIG (B-gp41) or with anti-gp120 mAbs or HIVIG (B-gp120), aggregated virus opsonized with anti-gp41 mAbs or HIVIG (C-gp41) or with anti-gp120 mAbs or HIVIG (C-gp120). (B) Normalized experimental average ACFs recovered for control groups consisting of the same virus preparations as in (A) but with no antibody or anti-dengue mAb. In both panels (A) and (B), only half of the total data points is shown for the sake of visual clarity, and the ACFs global fit to eq. S.4 (S1 Text) is shown with red continuous lines (all best-fit parameters are reported in S1 Table). (C) Hydrodynamic radius R2 of the aggregate population recovered for each group. Radii were computed based on the Stokes-Einstein equation (S1 Text) from the best-fit estimates of the diffusion coefficient D2. Thick error bars correspond to the standard deviations quantified by the rigorous error analysis of the ACF global fit as described in Materials and Methods. The same rigorous error analysis has also been exploited to yield, for each hydrodynamic radius, the minimum and maximum allowed values (thin error bars) compatible with one standard deviation of the ACF’s global-fit chi-square value. Results of the one-way ANOVA statistical analysis on the recovered radii are reported in S2 Table. All FCS experiments were conducted twice.