V(D)J recombination in peritoneal B cells of leaky scid mice
Autor: | Norman R. Ruetsch, D B Kotloff, Melvin J. Bosma |
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Rok vydání: | 1993 |
Předmět: |
Aging
T cell Molecular Sequence Data Immunology Gene Rearrangement B-Lymphocyte Heavy Chain Immunoglobulin Variable Region Mice SCID Autoantigens Germline Mice medicine Animals Immunology and Allergy Peritoneal Cavity B cell Autoantibodies DNA Primers Genetics B-Lymphocytes Mice Inbred BALB C Severe combined immunodeficiency Hybridomas Recombinase activity Base Sequence Genes Immunoglobulin biology V(D)J recombination Articles Gene rearrangement medicine.disease Molecular biology medicine.anatomical_structure Immunoglobulin M biology.protein Antibody Immunoglobulin Heavy Chains |
Zdroj: | The Journal of Experimental Medicine |
ISSN: | 1540-9538 0022-1007 |
DOI: | 10.1084/jem.178.6.1981 |
Popis: | Developing lymphocytes in immune-deficient severe combined immunodeficient (scid) mice express a defective recombinase activity and rarely succeed in making an antigen receptor; those cells that do succeed account for the known B and T cell leakiness in this mutant mouse strain. To gain more insight into the nature of the scid defect, we assessed the status of heavy (H) and light (L)k, chain genes in immunoglobulin (Ig)Mk-secreting B cells from the peritoneal cavity of old leaky scid mice, the only lymphoid site where scid B cells have been routinely detected. We found these cells to be unusual in that their nonexpressed H chain alleles were either abnormally rearranged or in germline configuration (wild-type B cells generally show normal rearrangements at both H chain alleles). The VDJH junctions of the expressed alleles showed little or no nontemplated (N) addition, similar to neonatal B cells from wild-type mice. About half of the V(D)J junctions lacking N additions contained nucleotides that could have been encoded by either of the participating coding elements (VDH, DJH, or VJk), indicating that the recombination occurred between short stretches of homology. Unusually long templated (P) additions were seen in both VDJH and VJK junctions, and many recombinations appeared to involve P-based homologies. These findings suggest that: (a) B cell leakiness results from a low frequency of coding joint formation in cells expressing the defective scid recombinase activity; (b) joining of scid coding ends is facilitated when the ends contain short stretches of sequence homology, where in many cases, one of the homologous sequences results from a P addition; and (c) scid peritoneal B cells may arise early in ontogeny. |
Databáze: | OpenAIRE |
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