Figure 4.

Anti-κ chain treatment induces λ-chain expression, but not apoptosis in cultures of normal, non-Tg B cells. B10.D2 BM depleted of IgM⁺ cells was cultured in the presence or absence of anti-κ mAb 187 for 6 days and analyzed for expression of CD23 (A) and surface light chain (B). In all cultures, IL-7 was withdrawn 24 hr before analysis. Representative results from three experiments are shown. For CD23 expression, gates were set to include all CD23⁺ cells that were then analyzed for expression of λ light chain. Cells positive for CD23 but negative for λ were considered as κ.