FIG 2.

Isolation and screening of preS1-specific memory B cells. (A) Splenocytes derived from mice immunized with the indicated plasmids were subjected to flow cytometric analysis. Upper panels show representative data for the gating strategy. Lower panels show representative flow data for preS1/2–47-binding memory B cells. (B) Detection of antibodies to the preS1/2–47 peptide in memory B cell culture supernatants. Culture supernatants of isolated memory B cells were diluted 5-fold and added to ELISA microtiter wells containing preS1/2–47. Antibody binding was detected using HRP-conjugated anti-mouse IgG secondary antibody. OD, optical density. (C) Neutralizing activities of memory B cell culture supernatants. HBV/NL derived from genotype C was preincubated with culture supernatants (1:1) for 1 h and then used to infect G2/NT-18 cells. Luciferase activity of the cells was determined 7 days postinfection and is expressed relative to activity without supernatant. Data are averages of quadruplicate values, with error bars showing standard deviations.