title: B-cell development in bovine fetuses proceeds via a pre-B like cell in bone marrow and lymph nodes.
abstract: The production of B cells and the primary antibody repertoire in mammalian species other than rodents or man appears to depend on gut-associated lymphoid tissue. Bovine B cells are generated in ileal Peyer's patch from late gestational to juvenile age. However, little is known about where and when the bona fide B lymphopoiesis takes place. We analyzed bovine fetuses for signs of ongoing B lymphopoiesis using a combination of immunohistochemistry, flow cytometry, real-time quantitative PCR and RNA in situ hybridization. In fetal bone marrow and lymph node, we could demonstrate pre-B like cells positive for intracellular Ig mu but negative for membrane IgM. Strong expression of immunoglobulin lambda-like polypeptide 1 and recombination activating genes was also detected in the same tissues. Similar analyses did not reveal pre-B like cells in the corresponding adult tissues. These results suggest that bovine fetal bone marrow and lymph node support B lymphopoiesis via a pre-B cell like stage before and in parallel to the development of the ileal Peyer's patch.
authors.affiliation: Department of Veterinary Biosciences, University of Helsinki, Finland.
authors.forename: Anna
authors.initials: A
authors.lastname: Ekman
authors.forename: Tiina
authors.initials: T
authors.lastname: Pessa-Morikawa
authors.forename: Jenni
authors.initials: J
authors.lastname: Liljavirta
authors.forename: Mikael
authors.initials: M
authors.lastname: Niku
authors.forename: Antti
authors.initials: A
authors.lastname: Iivanainen
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D001853:Bone Marrow / Q000196:embryology / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D002417:Cattle; D004622:Embryo, Mammalian; D018507:Gene Expression Regulation, Developmental / Q000276:immunology; D016654:Genes, RAG-1 / Q000276:immunology; D054444:Immunoglobulin Light Chains, Surrogate / Q000235:genetics / Q000378:metabolism*; D007075:Immunoglobulin M / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000196:embryology / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D038041:Lymphopoiesis; D054448:Precursor Cells, B-Lymphoid / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D054444:Immunoglobulin Light Chains, Surrogate; D007075:Immunoglobulin M