All T15 Id-positive antibodies (but not the majority of VHT15+ antibodies) are produced by peritoneal CD5+ B lymphocytes.
After adult irradiation and reconstitution with autologous bone marrow, BALB/c and C.B20 mice no longer utilize the T15 Id in response to phosphorylcholine. T15 Id expression can be restored by transfers of peritoneal B cells or by FACS-purified CD5+ IgM+ lymphocytes (but not by T lymphocytes) from syngeneic donors. Using bone marrow and peritoneal cell donors that are congeneic for heavy and light chain allotypes, the exclusive origin of the T15 Id in peritoneal B cells was ascertained. These conclusions have been essentially confirmed by immunization with either anti-T15 Id or anti-VHT15 antibodies conjugated to lipopolysaccharide. Thus, the production of VHT15-positive antibodies continues at control levels in bone marrow-reconstituted animals while no T15 Id production can be stimulated even in this protocol of direct B cell stimulation. These results constitute the first formal demonstration of the exclusive production of and Id by CD5+ B-cells.
Masmoudi
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H
Département d'Immunologie (Université Pierre & Marie Curie and UA CNRS 359), Institut Pasteur, Paris, France.
Mota-Santos
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T
Huetz
F
F
Coutinho
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A
Cazenave
P A
PA
D000818:Animals; D000943:Antigens, Differentiation; D001402:B-Lymphocytes / Q000276:immunology*; D001853:Bone Marrow / Q000276:immunology; D001854:Bone Marrow Cells; D018956:CD5 Antigens; D007130:Immunoglobulin Idiotypes / Q000096:biosynthesis*; D051379:Mice; D008815:Mice, Inbred Strains; D010529:Peritoneal Cavity / Q000166:cytology; D010767:Phosphorylcholine / Q000276:immunology; D011828:Radiation Chimera
D000943:Antigens, Differentiation; D018956:CD5 Antigens; D007130:Immunoglobulin Idiotypes; D010767:Phosphorylcholine