B6.NZMc1|c7 B cells produce IgG ANAs. Total splenocytes from 9- to 12-month-old mice (10⁶ cells in 200 μL media per well) were cultured for 7 days. At the end of the culture period, the culture supernatants were assayed by ELISA for total IgG (a) and IgG ANAs specific for dsDNA, or for H2A/H2B/DNA (b). Each bar represents the mean (± SEM) levels of IgG antibodies (total or antigen specific) present in triplicate splenocyte cultures from the respective strains. B6.NZMc1|c7 splenocytes produced significantly more total IgG (P < 0.02), IgG anti-dsDNA (P < 0.01), and IgG anti-H2A/H2B/DNA (P < 0.006) compared with B6 or B6.NZMc7 splenocytes. Compared with B6.NZMc1 splenocytes, B6.NZMc1|c7 splenocytes secreted significantly increased amounts of anti-dsDNA (P < 0.01), but not anti-H2A/H2B/DNA ANAs, in culture. (c) B6.NZMc1|c7 B cells, FACS-sorted from 9-month-old spleens, were cultured with or without FACS-sorted syngeneic splenic CD4⁺ or CD8⁺ T cells, or LPS (10 μg/mL). 5 × 10⁵ cells of each type were added per well in 200-μL culture volumes. Each bar represents the triplicate mean (± SEM) IgG anti-dsDNA ANAs secreted in culture after 7 days of culture. B cells cocultured with CD4⁺ T cells produced significantly higher levels of ANAs compared with the cultures without T cells or with CD8⁺ T cells (P < 0.03). Cultures with CD4⁺ or CD8⁺ T cells alone typically exhibited ANA levels of <2 U/mL. Data are representative of 3 independent experiments.