title: Gamma delta T cell help of B cells is induced by repeated parasitic infection, in the absence of other T cells.
abstract: BACKGROUND
  gamma delta T cells, like alpha beta T cells, are components of all well-studied vertebrate immune systems. Yet, the contribution of gamma delta T cells to immune responses is poorly characterized. In particular, it has not been resolved whether gamma delta cells, independent of any other T cells, can help B cells produce immunoglobulin and form germinal centers, anatomical foci of specialized T cell-B cell collaboration.
  
  
  RESULTS
  TCR beta-/- mice, which lack all T cells except gamma delta T cells, routinely displayed higher levels of antibody than fully T cell-deficient mice. Repeated parasitic infection of TCR beta-/- mice, but not of T cell-deficient mice, increased antibody levels and induced germinal centers that contained B cells and monoclonal gamma delta cells in close juxtaposition. However, antibody specificities were more commonly against self than against the challenging pathogen. gamma delta T cell-B cell help was not induced by repeated inoculation of TCR beta-/- mice with mycobacterial antigens.
  
  
  CONCLUSIONS
  In the absence of any other T cells, gamma delta T cell-B cell collaboration can be significantly enhanced by repeated infection. However, the lack of obvious enrichment for antibodies against the challenging pathogen distinguishes gamma delta T cell help from alpha beta T cell help induced under analogous circumstances. The increased production of generalized antibodies may be particularly relevant to the development of autoimmunity, which commonly occurs in patients suffering from alpha beta T cell deficiencies, such as AIDS.
authors.affiliation: Department of Biology, Yale University, New Haven, Connecticut 06520, USA.
authors.forename: W
authors.initials: W
authors.lastname: Pao
authors.forename: L
authors.initials: L
authors.lastname: Wen
authors.forename: A L
authors.initials: AL
authors.lastname: Smith
authors.forename: A
authors.initials: A
authors.lastname: Gulbranson-Judge
authors.forename: B
authors.initials: B
authors.lastname: Zheng
authors.forename: G
authors.initials: G
authors.lastname: Kelsoe
authors.forename: I C
authors.initials: IC
authors.lastname: MacLennan
authors.forename: M J
authors.initials: MJ
authors.lastname: Owen
authors.forename: A C
authors.initials: AC
authors.lastname: Hayday
mesh_terms: D000818:Animals; D000974:Antibodies, Antinuclear / Q000097:blood*; D000913:Antibodies, Protozoan / Q000097:blood*; D001402:B-Lymphocytes / Q000276:immunology*; D015704:CD4 Antigens / Q000032:analysis; D003048:Coccidiosis / Q000276:immunology; D004539:Eimeria / Q000276:immunology; D015334:Gene Rearrangement, gamma-Chain T-Cell Antigen Receptor; D018858:Germinal Center / Q000276:immunology; D007111:Immunity, Cellular; D007074:Immunoglobulin G / Q000097:blood; D051379:Mice; D008817:Mice, Mutant Strains; D016692:Receptors, Antigen, T-Cell, gamma-delta; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D000974:Antibodies, Antinuclear; D000913:Antibodies, Protozoan; D015704:CD4 Antigens; D007074:Immunoglobulin G; D016692:Receptors, Antigen, T-Cell, gamma-delta