title: Comparative analyses of B cell populations in trout kidney and mouse bone marrow: establishing "B cell signatures".
abstract: This study aimed to identify the frequency and distribution of developing B cell populations in the kidney of the rainbow trout, using four molecular B cell markers that are highly conserved between species, including two transcription factors, Pax5 and EBF1, recombination-activating gene RAG1, and the immunoglobulin heavy chain mu. Three distinct B cell stages were defined: early developing B cells (CLP, pro-B, and early pre-B cells), late developing B cell (late pre-B, immature B, and mature B cells), and IgM-secreting cells. Developmental stage-specific, combinatorial expression of Pax5, EBF1, RAG1 and immunoglobulin mu was determined in trout anterior kidney cells by flow cytometry. Trout staining patterns were compared to a well-defined primary immune tissue, mouse bone marrow, and using mouse surface markers B220 and CD43. A remarkable level of similarity was uncovered between the primary immune tissues of both species. Subsequent analysis of the entire trout kidney, divided into five contiguous segments K1-K5, revealed a complex pattern of early developing, late developing, and IgM-secreting B cells. Patterns in anterior kidney segment K1 were most similar to those of mouse bone marrow, while the most posterior part of the kidney, K5, had many IgM-secreting cells, but lacked early developing B cells. A potential second B lymphopoiesis site was uncovered in segment K4 of the kidney. The B cell patterns, or "B cell signatures" described here provide information on the relative abundance of distinct developing B cell populations in the trout kidney, and can be used in future studies on B cell development in other vertebrate species.
authors: Department of Biology, The College of William and Mary, Williamsburg, VA 23188, United States. pxzwol@wm.edu
authors: Patty
authors: P
authors: Zwollo
authors: Katrina
authors: K
authors: Mott
authors: Maggie
authors: M
authors: Barr
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis; D015153:Blotting, Western; D001853:Bone Marrow / Q000276:immunology*; D002454:Cell Differentiation; D005434:Flow Cytometry; D015870:Gene Expression; D018398:Homeodomain Proteins / Q000032:analysis; D007143:Immunoglobulin Heavy Chains / Q000032:analysis; D007148:Immunoglobulin mu-Chains / Q000032:analysis; D007668:Kidney / Q000276:immunology*; D017493:Leukocyte Common Antigens / Q000032:analysis; D051917:Leukosialin / Q000032:analysis; D038041:Lymphopoiesis; D051379:Mice; D051757:PAX5 Transcription Factor / Q000032:analysis; D054448:Precursor Cells, B-Lymphoid; D015534:Trans-Activators / Q000032:analysis; D014157:Transcription Factors / Q000235:genetics; D014337:Trout / Q000235:genetics / Q000276:immunology*
chemical_list: D015415:Biomarkers; C489921:Ebf1 protein, mouse; D018398:Homeodomain Proteins; D007143:Immunoglobulin Heavy Chains; D007148:Immunoglobulin mu-Chains; D051917:Leukosialin; D051757:PAX5 Transcription Factor; C497282:Pax5 protein, mouse; D015534:Trans-Activators; D014157:Transcription Factors; C064658:RAG-1 protein; D017493:Leukocyte Common Antigens