Class-Switch Recombination Occurs Infrequently in Germinal Centers

onychomadesis in a patient with immunoglobulin class switch recombination deficiency

immunoglobulin class switch recombination deficiencies (ig csr deficiencies) or hyper igm syndromes (higm) are a group of primary immunodeficiency diseases, characterized by defective cd40 signaling of b cells resulting into a csr and a somatic hypermutation. the affected patients are characterized with reduced serum levels of igg and iga, and normal or elevated level of igm, which lead to incr...

Interallelic Class Switch Recombination

PP4 Is Essential for Germinal Center Formation and Class Switch Recombination in Mice

PP4 is a serine/threonine phosphatase required for immunoglobulin (Ig) VDJ recombination and pro-B/pre-B cell development in mice. To elucidate the role of PP4 in mature B cells, we ablated the catalytic subunit of murine PP4 in vivo utilizing the CD23 promoter and cre-loxP recombination and generated CD23(cre)PP4(F/F) mice. The development of follicular and marginal zone B cells was unaffected...

Immunoglobulin class-switch recombination deficiencies

Immunoglobulin class-switch recombination deficiencies (Ig-CSR-Ds) are rare primary immunodeficiencies characterized by defective switched isotype (IgG/IgA/IgE) production. Depending on the molecular defect in question, the Ig-CSR-D may be combined with an impairment in somatic hypermutation (SHM). Some of the mechanisms underlying Ig-CSR and SHM have been described by studying natural mutants ...

Nibrin functions in Ig class-switch recombination.

Nijmegen breakage syndrome (NBS) is a rare autosomal recessive disorder characterized by predisposition to hematopoietic malignancy, cell-cycle checkpoint defects, and ionizing radiation sensitivity. NBS is caused by a hypomorphic mutation of the NBS1 gene, encoding nibrin, which forms a protein complex with Mre11 and Rad50, both involved in DNA repair. Nibrin localizes to chromosomal sites of ...