Surrogate light chain expression is required to establish immunoglobulin heavy chain allelic exclusion during early B cell development.
Allelic exclusion at the IgH locus was examined in B lineage cells of wild-type mice and mice unable to express the surrogate light chain molecule lambda 5 using a single-cell PCR approach. By analyzing B precursor cells containing two VHDHJH rearrangements, we found that in wild-type animals, cells are allelically excluded as soon as mu chains are expressed. Furthermore, we provide evidence that in cells expressing D mu proteins VH-->DHJH rearrangement is inhibited. In contrast, in the absence of lambda 5 protein, B precursor cells were allelically "included", indicating that allelic exclusion at the IgH locus requires expression of the pre-B cell receptor either containing a mu chain or a D mu chain. However, although mu chain double-producing B precursor cells are generated in lambda 5-deficient mice, such cells were not detected among surface immunoglobulin positive B cells.
Löffert
D
D
Institute for Genetics, University of Cologne, Federal Republic of Germany.
Ehlich
A
A
Müller
W
W
Rajewsky
K
K
D000483:Alleles; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D001483:Base Sequence; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D015322:Gene Rearrangement, B-Lymphocyte / Q000276:immunology; D005803:Genes, Immunoglobulin / Q000276:immunology*; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007147:Immunoglobulin Light Chains / Q000235:genetics*; D054444:Immunoglobulin Light Chains, Surrogate; D008562:Membrane Glycoproteins / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction
D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D054444:Immunoglobulin Light Chains, Surrogate; D008562:Membrane Glycoproteins