title: T cell-mediated elimination of B7.2 transgenic B cells.
abstract: Transgenic mice were generated to explore the effects on lymphoid development and immune function of constitutive expression of murine B7.2 on B and T cells. The number of B lymphocytes in primary and secondary lymphoid tissues is normal in B7.2 transgenic lines expressing low levels of B7.2 on B cells, but markedly reduced in transgenic lines expressing moderate to high levels of the transgene on B cells. This reduction is not due to an intrinsic abnormality of the transgenic B cells, but is rather the consequence of an elimination by an immune mechanism requiring the engagement of CD28 on T cells. Interestingly, during cognate antigen-specific interaction with T cells in vivo, B7.2 transgenic B cells are not eliminated, but proliferate and differentiate normally. Our findings suggest that, in the absence of high affinity ligand for the TCR, the CD28-B7.2 system participates in the regulation of B cell homeostasis.
authors.affiliation: Department of Molecular and Cellular Biology, University of California at Berkeley, 94720, USA.
authors.forename: S
authors.initials: S
authors.lastname: Fournier
authors.forename: J C
authors.initials: JC
authors.lastname: Rathmell
authors.forename: C C
authors.initials: CC
authors.lastname: Goodnow
authors.forename: J P
authors.initials: JP
authors.lastname: Allison
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis / Q000235:genetics*; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D051940:B7-2 Antigen; D018106:CD28 Antigens / Q000096:biosynthesis; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D017637:Clonal Deletion / Q000235:genetics*; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000235:genetics; D018655:Lymphocyte Count; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008822:Mice, Transgenic; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D019014:fas Receptor / Q000276:immunology / Q000502:physiology
chemical_list: D015703:Antigens, CD; D051940:B7-2 Antigen; D018106:CD28 Antigens; C497965:Cd86 protein, mouse; D008562:Membrane Glycoproteins; D019014:fas Receptor