FIG. 2.

Viral propagations in HI-infected/immunotherapy-treated mice versus HI-infected/nontreated animals. A total of 54 newborn mice were used per group of HI-infected/667 MAb-treated and HI-infected/nontreated mice (two animals per time point in three different experiments), and a total of 36 newborn mice were used for each of the other groups (two animals per time point in two different experiments). Viral propagation was monitored using three criteria: spleen infectious centers, Env-expressing splenocytes, and serum viremia. (A, D, and F) SIC assays. Spleen cells from simply infected mice or from infected mice treated with either the 667 MAb, the 667 F(ab′)₂ fragment, or the 672 MAb were isolated and plated onto indicator Mus dunni cells. SICs corresponded to the number of infectious centers scored in focal immunofluorescence assays after 3 days of coculture, as described in Materials and Methods. % SICs on the y axis indicates the percentage of infectious splenocytes versus the total number of splenocytes used in the experiment. (B, E, and G) Assay of Env-expressing splenocytes. Splenocytes were purified from the various mice, and Env expression at their surface was quantified by flow cytometry, as described in Materials and Methods. The percentage of Env-expressing splenocytes is indicated on the y axis. (C and H) Serum viremia assay. Viremia was assayed in a focal immunofluorescence assay, as indicated in Materials and Methods. Error bars indicate standard deviations. Statistical significance between the groups was established using the Mann and Whitney test. **, P < 0.01; *, P < 0.05.