Development of B cells in scid mice with immunoglobulin transgenes: implications for the control of V(D)J recombination.

The inability of scid pro-B cells to progress to the pre-B and B cell stages is believed to be caused by a defective recombinase activity that fails to resolve chromosomal breaks resulting from attempted V(D)J recombination. In support of this model, we report that certain immunoglobulin transgenes, specifically those which strongly inhibit endogenous VH-to-DJH and V kappa-to-J kappa rearrangement in wild-type mice, allow scid pro-B cells to progress to the pre-B and B cell stages. This rescue of scid B cell differentiation is associated with a dramatic reduction in expression of the recombination activation genes, RAG1 and RAG2, and with reduced transcription of the kappa locus.