B cell responses after the immunization by HIV-1 Env gp120 and W427S mutant.

<p>(A–B) Specific binding antibodies in immunized mouse sera to Bal gp120 (A) and HIV-1 06044 gp120 (B) were detected by ELISA and shown as OD450 values at reciprocal serum dilutions. (C–E) HIV-1 Env-specific antibody-secreting cells (ASCs) and total IgG-secreting cells (SCs) were detected by B cell ELISPOT assay. The BM cells were isolated at day 14 after final immunization and added as duplicate in 96-well plate. Biotin-labeled HIV-1 Bal gp120 protein and biotin-labeled anti-mouse IgG antibodies were used for detection of specific ASC and total IgG SCs, respectively. (F) Total IgG levels in immunized mouse sera were measured by quantitative ELISA. WT, wild-type gp120. Data were shown as mean ± SEM. Asterisks indicate statistical significance (* <i>P</i><0.05, *** <i>P</i><0.001).