title: Directed Ig class switch recombination in activated murine B cells.
abstract: Immunoglobulin class switch recombination occurs at frequencies of up to 10%/cell/generation in activated murine B-lymphocytes. We analysed cH gene rearrangements and switch recombinations from active and inactive IgH loci of B-cells activated in various ways and immortalized by cell fusion. Although about half of the IgM+ cells show rearrangement of c mu genes, the deletion of c mu is a rare event. Half of the IgG3+ and IgG1+ cells show rearrangement of c mu genes on the inactive IgH locus and the other half of the IgG+ cells have deleted c mu from both IgH loci by switch recombination. This recombination is directed to the same switch regions on both IgH loci in 60-80% of all cases. Interleukin 4 may play a critical role in programming murine B-lymphocytes for specific switch recombination.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D001483:Base Sequence; D004262:DNA Restriction Enzymes; D005796:Genes; D007074:Immunoglobulin G / Q000235:genetics; D007075:Immunoglobulin M / Q000235:genetics; D007136:Immunoglobulins / Q000235:genetics*; D008213:Lymphocyte Activation; D051379:Mice; D008815:Mice, Inbred Strains
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins; D004262:DNA Restriction Enzymes