Memory B-cell responses to HIV and non-HIV antigens in early and chronic HIV-infected individuals. The frequencies of antibody-secreting cells (ASCs) against immobilized (A-B) and soluble (C-D) forms of monomeric HIV-1 gp120 envelope and against seasonal influenza (E-F) were measured by elispot after 4 days of culture. Responses were measured in 6 early (A,C,E) and 6 chronic (B,D,F) HIV-infected individuals before (M0) and 12 months after (M12) initiation of ART. While the majority of ASCs were of the IgG isotype, data represent total IgG, IgA, and IgM ASCs for each antigen. See supplemental Figure 1 for distribution of switched and unswitched isotypes and supplemental Figure 2 for total Ig ASC frequencies.