Proliferation of GC B cells cultured with cytokine combinations. GC B cells were cultured in microtiter plates for 10 days with CD32-L cells, CD40 MoAb, G28-5, and various cytokine combinations (A through E) or culture medium alone (F ). Cultures were seeded at 105 per well and cells were recovered from 3 triplicate wells and pooled for counts at the times shown. Viable cell numbers are represented by open symbols and nonviable cells by the closed symbols. Tritiated thymidine incorporation (broken line, second ordinate) was measured in parallel cultures after the intervals shown as described for Fig 1. Data are representative of three experiments. (A) IL-10+IL-1β+IL-2; (B) IL-10+IL-1β+IL-3; (C) IL-10+IL-3+IL-6; (D) IL-10+IL-3+IL-7; (E) IL-10+IL-4+IL-7.
