Secondary V(D)J rearrangements and B cell receptor-mediated down-regulation of recombination activating gene-2 expression in a murine B cell line.
It has recently become clear that recombination of Ig genes is not restricted to B cell precursors but that secondary rearrangements can also occur under certain conditions in phenotypically immature bone marrow and peripheral B cells. However, the nature of these cells and the regulation of secondary V(D)J recombination in response to B cell receptor (BCR) stimulation remain controversial. In the present study, we have analyzed secondary light chain gene rearrangements and recombination activating gene (RAG) expression in the surface IgM+, IgD- murine B cell line, 38C-13, which has previously been found to undergo kappa light chain replacement. We find that 38C-13 cells undergo spontaneous secondary Vkappa-Jkappa and RS rearrangements in culture, with recombination occurring on both productive and nonproductive alleles. Both 38C-13 cells and the Id-negative variants express the RAG genes, indicating that the presence of RAG does not depend on activation via the 38C-13 BCR. Moreover, BCR cross-linking in 38C-13 cells leads to a rapid and reversible down-regulation of RAG2 mRNA. Therefore, 38C-13 cells resemble peripheral IgM+, IgD- B cells undergoing light chain gene rearrangement and provide a possible in vitro model for studying peripheral V(D)J recombination.
Maës
J
J
Unité de Génétique et Biochimie du Développement, Department of Immunology, Institut Pasteur, Paris, France.
Caspi
Y
Y
Rougeon
F
F
Haimovich
J
J
Goodhardt
M
M
D000818:Animals; D000916:Antibody Diversity / Q000235:genetics; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics*; D015536:Down-Regulation / Q000235:genetics / Q000276:immunology*; D005786:Gene Expression Regulation / Q000276:immunology*; D015328:Gene Rearrangement, B-Lymphocyte, Light Chain; D014644:Genetic Variation / Q000276:immunology; D007130:Immunoglobulin Idiotypes / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D007133:Immunoglobulin Joining Region / Q000096:biosynthesis / Q000235:genetics*; D007135:Immunoglobulin Variable Region / Q000096:biosynthesis / Q000235:genetics*; D007145:Immunoglobulin kappa-Chains / Q000096:biosynthesis / Q000235:genetics; D051379:Mice; D011947:Receptors, Antigen, B-Cell / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D014158:Transcription, Genetic / Q000276:immunology; D019895:Transposases / Q000235:genetics
D004268:DNA-Binding Proteins; D007130:Immunoglobulin Idiotypes; D007133:Immunoglobulin Joining Region; D007135:Immunoglobulin Variable Region; D007145:Immunoglobulin kappa-Chains; C499308:Rag2 protein, mouse; D011947:Receptors, Antigen, B-Cell; C064655:V(D)J recombination activating protein 2; D019895:Transposases