title: B lymphocyte development in rabbit: progenitor B cells and waning of B lymphopoiesis.
abstract: In mammals that use gut-associated lymphoid tissues for expansion and somatic diversification of the B cell repertoire, B lymphopoiesis occurs early in ontogeny and does not appear to continue throughout life. In these species, including sheep, rabbit, and cattle, little is known about the pathway of B cell development and the time at which B lymphopoiesis wanes. We examined rabbit bone marrow by immunofluorescence with anti-CD79a and anti-mu and identified both proB and preB cells. The proB cells represent the vast majority of B-lineage cells in the bone marrow at birth and by incorporation of 5-bromo-2'-deoxyuridine, they appear to be a dynamic population. PreB cells reach maximum levels in the bone marrow at 3 wk of age, and B cells begin to accumulate at 7 wk of age. We cloned two VpreB and one lambda5 gene and demonstrated that they are expressed within B-lineage cells in bone marrow. VpreB and lambda5 coimmunoprecipitated with the mu-chain in lysates of 293T cells transfected with VpreB, lambda5, and mu, indicating that VpreB, lambda5, and mu-chains associate in a preB cell receptor-like complex. By 16 wk of age, essentially no proB or preB cells are found in bone marrow and by PCR amplification, B cell recombination excision circles were reduced 200-fold. By 18 mo of age, B cell recombination excision circles were reduced 500- to 1000-fold. We suggest that B cell development in the rabbit occurs primarily through the classical, or ordered, pathway and show that B lymphopoiesis is reduced over 99% by 16 wk of age.
authors.affiliation: Department of Microbiology and Immunology, Loyola University Chicago, Maywood, IL 60153, USA.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Jasper
authors.forename: Shi-Kang
authors.initials: SK
authors.lastname: Zhai
authors.forename: Susan L
authors.initials: SL
authors.lastname: Kalis
authors.forename: Mae
authors.initials: M
authors.lastname: Kingzette
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Knight
mesh_terms: D000375:Aging / Q000235:genetics / Q000276:immunology; D000595:Amino Acid Sequence; D000818:Animals; D000831:Animals, Newborn; D016175:B-Lymphocyte Subsets / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D001483:Base Sequence; D001854:Bone Marrow Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D001973:Bromodeoxyuridine / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D015328:Gene Rearrangement, B-Lymphocyte, Light Chain; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007147:Immunoglobulin Light Chains; D054444:Immunoglobulin Light Chains, Surrogate; D007135:Immunoglobulin Variable Region / Q000096:biosynthesis / Q000235:genetics; D007146:Immunoglobulin lambda-Chains / Q000096:biosynthesis / Q000235:genetics; D038041:Lymphopoiesis / Q000235:genetics / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D054420:Pre-B Cell Receptors; D011817:Rabbits / Q000235:genetics / Q000276:immunology*; D011947:Receptors, Antigen, B-Cell; D017386:Sequence Homology, Amino Acid
chemical_list: D007147:Immunoglobulin Light Chains; D054444:Immunoglobulin Light Chains, Surrogate; D007135:Immunoglobulin Variable Region; D007146:Immunoglobulin lambda-Chains; D008562:Membrane Glycoproteins; D054420:Pre-B Cell Receptors; D011947:Receptors, Antigen, B-Cell; D001973:Bromodeoxyuridine