title: Self-renewal of B-1 lymphocytes is dependent on CD19.
abstract: The B-1 subset of B lymphocytes is maintained by self-renewal of mature cells, and this process may involve signaling through membrane immunoglobulin (mIg). We determined whether CD19, a membrane protein that co-stimulates B cells by mIg, has a role in this process. Pre-natal treatment of mice with 1D3, a rat anti-mouse CD19 monoclonal antibody, down-regulated CD19 expression and reduced by sixfold the number of B-1a cells at birth; B-2 cells were relatively unaffected. Prolonged treatment of adult mice with 1D3 caused the loss of approximately 2% per day of peritoneal B-1a cells, without diminishing the recovery of splenic B-2 cells. The loss of B-1a cells was associated with inhibition of their replication rather than with accelerated turnover. Therefore, CD19 is involved in the development and self-renewal of B-1a cells, perhaps through its ability to amplify signaling through mIgM.
authors.affiliation: Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, USA.
authors.forename: I
authors.initials: I
authors.lastname: Krop
authors.forename: A R
authors.initials: AR
authors.lastname: de Fougerolles
authors.forename: R R
authors.initials: RR
authors.lastname: Hardy
authors.forename: M
authors.initials: M
authors.lastname: Allison
authors.forename: M S
authors.initials: MS
authors.lastname: Schlissel
authors.forename: D T
authors.initials: DT
authors.lastname: Fearon
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D018941:Antigens, CD19 / Q000737:chemistry / Q000276:immunology / Q000502:physiology*; D016175:B-Lymphocyte Subsets / Q000166:cytology* / Q000187:drug effects / Q000276:immunology; D001483:Base Sequence; D002454:Cell Differentiation / Q000276:immunology*; D005314:Embryonic and Fetal Development / Q000276:immunology; D005260:Female; D007166:Immunosuppressive Agents / Q000494:pharmacology; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008969:Molecular Sequence Data; D011247:Pregnancy; D051381:Rats; D011917:Rats, Inbred Lew
chemical_list: D000911:Antibodies, Monoclonal; D018941:Antigens, CD19; D007166:Immunosuppressive Agents