title: Cell surface immunoglobulin regulated checkpoints in chicken B cell development.
abstract: The bursa of Fabricius is critical for the normal development of B lymphocytes in avian species. Productive colonization of bursal follicles by B cell precursors requires surface immunoglobulin expression. We have shown using retroviral gene transfer that expression of chimeric receptors containing the extracellular and transmembrane domains of murine CD8alpha and CD8beta fused to the cytoplasmic domains of chicken Igalpha and Igbeta can support productive bursal colonization in the chicken embryo in bursal cells lacking the expression of endogenous sIgM. We show here that chimeric receptor expression does not support continued bursal cell development after hatch. However intrabursal administration of anti-CD8 antibodies that ligate the CD8alpha:Igalpha chimeric receptor results in maintained numbers of bursal cells that express the chimeric receptor in the absence of endogenous sIgM. These results support a model in which sIgM receptor expression is required for productive bursal colonization in the chick embryo but sIgM receptor ligation is required to support later B cell development after hatch.
authors.affiliation: Department of Immunology, University of Toronto, 1 King's College Circle, Toronto, Ont., Canada M5S 1A8.
authors.forename: Parinaz
authors.initials: P
authors.lastname: Aliahmad
authors.forename: Kelly A
authors.initials: KA
authors.lastname: Pike
authors.forename: Michael J H
authors.initials: MJ
authors.lastname: Ratcliffe
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002060:Bursa of Fabricius / Q000166:cytology / Q000254:growth & development / Q000276:immunology; D016827:CD8 Antigens / Q000235:genetics; D002454:Cell Differentiation; D002642:Chick Embryo; D002645:Chickens / Q000235:genetics / Q000254:growth & development / Q000276:immunology*; D002678:Chimera / Q000276:immunology; D051379:Mice; D011947:Receptors, Antigen, B-Cell / Q000235:genetics / Q000378:metabolism*
chemical_list: D016827:CD8 Antigens; D011947:Receptors, Antigen, B-Cell