title: Germinal center formation in mice lacking alpha beta T cells.
abstract: T cells are essential for inducing clonal B cell expansion in germinal centers during T cell-dependent antibody responses. However, class-switched antibodies are readily detectable in TCR alpha-deficient mice that congenitally lack alpha beta T cells, including those such as IgG1 that are considered to be dependent on collaboration between B cells and alpha beta T cells. This observation suggests that a novel form of B:T collaboration may be evident in TCR alpha-/- mice. We report that germinal centers develop spontaneously in mice lacking T cell receptor alpha genes (TCR alpha-/-), despite the absence of alpha beta T cells. They are not seen in TCR beta-/- mice kept in similar conditions. Both strains of mice have gamma delta T cells, but it is a subset of T cells expressing TCR beta and CD4 that is dominant in the germinal centers of TCR alpha-/- mice. Exceptionally, germinal centers were associated with CD4+ gamma delta T cells. The expression of CD4 seems to be important, for few extrafollicular T cells have CD4 and CD4 is largely absent from TCR beta-/- T cells. The CD4+ TCR beta cells may help B cells produce autoantibodies that have been identified in TCR alpha-/- mice.
authors.affiliation: Imperial Cancer Research Fund, London, GB.
authors.forename: L
authors.initials: L
authors.lastname: Dianda
authors.forename: A
authors.initials: A
authors.lastname: Gulbranson-Judge
authors.forename: W
authors.initials: W
authors.lastname: Pao
authors.forename: A C
authors.initials: AC
authors.lastname: Hayday
authors.forename: I C
authors.initials: IC
authors.lastname: MacLennan
authors.forename: M J
authors.initials: MJ
authors.lastname: Owen
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000737:chemistry / Q000166:cytology / Q000276:immunology; D002999:Clone Cells / Q000737:chemistry / Q000166:cytology / Q000276:immunology; D018858:Germinal Center / Q000737:chemistry / Q000166:cytology / Q000276:immunology*; D008211:Lymphocyte Cooperation / Q000235:genetics; D051379:Mice; D008817:Mice, Mutant Strains; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000172:deficiency* / Q000235:genetics*; D016176:T-Lymphocyte Subsets / Q000737:chemistry / Q000166:cytology / Q000276:immunology*
chemical_list: D016693:Receptors, Antigen, T-Cell, alpha-beta