Rearrangement of mouse immunoglobulin kappa deleting element recombining sequence promotes immune tolerance and lambda B cell production.
The recombining sequence (RS) of mouse and its human equivalent, the immunoglobulin (Ig) kappa deleting element (IGKDE), are sequences found at the 3' end of the Ig kappa locus (Igk) that rearrange to inactivate Igk in developing B cells. RS recombination correlates with Ig lambda (Iglambda) light (L) chain expression and likely plays a role in receptor editing by eliminating Igk genes encoding autoantibodies. A mouse strain was generated in which the recombination signal of RS was removed, blocking RS-mediated Igk inactivation. In RS mutant mice, receptor editing and self-tolerance were impaired, in some cases leading to autoantibody formation. Surprisingly, mutant mice also made fewer B cells expressing lambda chain, whereas lambda versus kappa isotype exclusion was only modestly affected. These results provide insight into the mechanism of L chain isotype exclusion and indicate that RS has a physiological role in promoting the formation of lambda L chain-expressing B cells.
Vela
José Luis
JL
Department of Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA.
Aït-Azzouzene
Djemel
D
Duong
Bao Hoa
BH
Ota
Takayuki
T
Nemazee
David
D
D000818:Animals; D000974:Antibodies, Antinuclear / Q000097:blood; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D015328:Gene Rearrangement, B-Lymphocyte, Light Chain / Q000235:genetics* / Q000276:immunology; D005803:Genes, Immunoglobulin; D006825:Hybridomas; D007108:Immune Tolerance; D007145:Immunoglobulin kappa-Chains / Q000235:genetics* / Q000276:immunology*; D007146:Immunoglobulin lambda-Chains / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D008822:Mice, Transgenic; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2; D011995:Recombination, Genetic
D000974:Antibodies, Antinuclear; D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; C052617:Bcl2 protein, mouse