Analysis of in vitro immunoglobulin isotype switching in splenic B cells.

(A) LPS stimulation induced IgG3 expression on B220⁺ B cells obtained from normal γc⁺, untreated Δγc⁺-XSCID (XSCID), and gene-corrected Δγc⁺-XSCID (mγc-BMT) mice. (B) LPS alone failed to induce IgG1 expression, whereas in combination with IL-4, IgG1-expressing B220⁺ cells developed in samples from normal and mγc-BMT mice but not from untreated Δγc⁺-XSCID mice. Shown are representative results of 2 independent experiments.