Immunoglobulin heavy-chain expression and class switching in a murine leukaemia cell line

Abstract

A cell line that switches from .mu. to .gamma.2b synthesis during growth in culture uses the same VH region for both H chains but retains 2 copies of the C.mu. gene. This suggests that the .mu. to .gamma.2b class switch can occur, at least in part, by an RNA processing mechanism. Regulatory variants of this cell line lose constitutive .mu.-chain synthesis but simultaneously acquire lipopolysaccharide (LPS)-inducible synthesis of that chain. This co-variation is allele-specific and is correlated to a large deletion of DNA in the JH.sbd.C.mu. intron.