title: Affinity maturation of antibodies requires integrity of the adult thymus.
abstract: The generation of B-cell responses to proteins requires a functional thymus to produce CD4(+)  T cells which helps in the activation and differentiation of B cells. Because the mature T-cell repertoire has abundant cells with the helper phenotype, one might predict that in mature individuals, the generation of B-cell memory would proceed independently of the thymus. Contrary to that prediction, we show here that the removal of the thymus after the establishment of the T-cell compartment or sham surgery without removal of the thymus impairs the affinity maturation of antibodies. Because removal or manipulation of the thymus did not decrease the frequency of mutation of the Ig variable heavy chain exons encoding antigen-specific antibodies, we conclude that the thymus controls affinity maturation of antibodies in the mature individual by facilitating the selection of B cells with high-affinity antibodies.
authors: Department of Surgery, Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109-2200, USA.
authors: Mouhammed
authors: M
authors: AbuAttieh
authors: Diane
authors: D
authors: Bender
authors: Esther
authors: E
authors: Liu
authors: Peter
authors: P
authors: Wettstein
authors: Jeffrey L
authors: JL
authors: Platt
authors: Marilia
authors: M
authors: Cascalho
mesh_terms: D000818:Animals; D000915:Antibody Affinity / Q000235:genetics; D000917:Antibody Formation / Q000235:genetics; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D002454:Cell Differentiation / Q000235:genetics; D002478:Cells, Cultured; D060966:Clonal Selection, Antigen-Mediated; D007143:Immunoglobulin Heavy Chains / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D007156:Immunologic Memory; D008213:Lymphocyte Activation / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D013934:Thymectomy; D013950:Thymus Gland / Q000166:cytology* / Q000196:embryology / Q000254:growth & development / Q000601:surgery
chemical_list: D007143:Immunoglobulin Heavy Chains