Fig. 4

Antibodies produced by pre-naïve B cells are autoreactive. a Sorted pre-naïve and naïve B cells were cultured with irradiated CD4⁺ T cells in anti-CD3 pre-coated microtiter wells and, after 11 days of culture, were assessed for CD38^highCD27⁺IgD⁻ plasma cells. Numbers represent percentage of CD27⁺CD38^high B cells and CD27⁺CD38^highIgD⁻ B cells. b Reactivity of antibodies produced by pre-naïve and naïve B cells. Culture supernatants from experiment described in (a) from pre-naïve B cells (●) and naïve B cells (○) were analyzed for reactivity with indicated antigens, histone, dsDNA, and ssDNA by enzyme-linked immunosorbent assay. Values indicate results from individual donors of a total of 15 tested. c Sorted pre-naïve and naïve B cells were stimulated with anti-CD40 2 μg/ml and interleukin-21 (IL-21) 200 ng/ml in the presence and absence of anti-IL-10 monoclonal antibodies 10 μg/ml and assessed for frequencies of CD27⁺CD38^highIgD⁻ plasma cells at days 3, 6, and 8. Numbers represent percentage of cells. A.U. arbitary units, dsDNA double-stranded DNA, PC plasma cells, ssDNA, single-stranded DNA