title: Maintenance of peritoneal B-1a lymphocytes in the absence of the spleen.
abstract: Positive selection by autoantigens is believed to play an important role in the generation/maintenance of B-1a cells. Recently, it has been described that splenectomy results in the loss of an already established B-1a cell pool. To elucidate whether the spleen influences the peritoneal B-1a repertoire, we have analyzed the consequences of splenectomy in the recently established IgL-transgenic L2 mouse model. L2 mice are characterized by a severe block of B-2 development and predominance of B-1a cells, which exhibit a pronounced IgH oligoclonality, presumably due to positive selection by autoantigens. In this study, we show that, in striking contrast to splenectomized normal mice, L2 mice exhibit unchanged frequencies of peritoneal B-1a cells. The IgH repertoire of these B-1a cells, however, was severely perturbed in that the previously described predominant B-1a H chains were no longer present. The repertoire changes were partial since phosphatidylcholine-specific B-1a cells were present in similar numbers before and after splenectomy. Thus, splenic Ags appear to act as "survival factors" for major subsets of peritoneal B cells. The loss of B-1a cells in the absence of such factors is compensated by repertoire changes among B-1a cells in B cell lymphopenic L2 but not normal mice.
authors.affiliation: Molecular Immunology, Gesellschaft für Biotechnologische Forschung, German Research Centre for Biotechnology, Braunschweig, Germany. Karsten_Kretschmer@dfci.harvard.edu
authors.forename: Karsten
authors.initials: K
authors.lastname: Kretschmer
authors.forename: Jana
authors.initials: J
authors.lastname: Stopkowicz
authors.forename: Stephan
authors.initials: S
authors.lastname: Scheffer
authors.forename: Tim F
authors.initials: TF
authors.lastname: Greten
authors.forename: Siegfried
authors.initials: S
authors.lastname: Weiss
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016175:B-Lymphocyte Subsets / Q000502:physiology*; D001483:Base Sequence; D002465:Cell Movement; D022801:Complementarity Determining Regions / Q000737:chemistry; D018398:Homeodomain Proteins / Q000502:physiology; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010529:Peritoneal Cavity / Q000166:cytology; D013154:Spleen / Q000502:physiology*
chemical_list: D022801:Complementarity Determining Regions; D018398:Homeodomain Proteins; D007143:Immunoglobulin Heavy Chains; D007135:Immunoglobulin Variable Region; C064658:RAG-1 protein