title: Different composition of the human and the mouse gammadelta T cell receptor explains different phenotypes of CD3gamma and CD3delta immunodeficiencies.
abstract: The gammadelta T cell receptor for antigen (TCR) comprises the clonotypic TCRgammadelta, the CD3 (CD3gammaepsilon and/or CD3deltaepsilon), and the zetazeta dimers. gammadelta T cells do not develop in CD3gamma-deficient mice, whereas human patients lacking CD3gamma have abundant peripheral blood gammadelta T cells expressing high gammadelta TCR levels. In an attempt to identify the molecular basis for these discordant phenotypes, we determined the stoichiometries of mouse and human gammadelta TCRs using blue native polyacrylamide gel electrophoresis and anti-TCR-specific antibodies. The gammadelta TCR isolated in digitonin from primary and cultured human gammadelta T cells includes CD3delta, with a TCRgammadeltaCD3epsilon(2)deltagammazeta(2) stoichiometry. In CD3gamma-deficient patients, this may allow substitution of CD3gamma by the CD3delta chain and thereby support gammadelta T cell development. In contrast, the mouse gammadelta TCR does not incorporate CD3delta and has a TCRgammadeltaCD3epsilon(2)gamma(2)zeta(2) stoichiometry. CD3gamma-deficient mice exhibit a block in gammadelta T cell development. A human, but not a mouse, CD3delta transgene rescues gammadelta T cell development in mice lacking both mouse CD3delta and CD3gamma chains. This suggests important structural and/or functional differences between human and mouse CD3delta chains during gammadelta T cell development. Collectively, our results indicate that the different gammadelta T cell phenotypes between CD3gamma-deficient humans and mice can be explained by differences in their gammadelta TCR composition.
authors.affiliation: Max-Planck-Institute of Immunobiology and University of Freiburg, 79108 Freiburg, Germany.
authors.forename: Gabrielle M
authors.initials: GM
authors.lastname: Siegers
authors.forename: Mahima
authors.initials: M
authors.lastname: Swamy
authors.forename: Edgar
authors.initials: E
authors.lastname: Fernández-Malavé
authors.forename: Susana
authors.initials: S
authors.lastname: Minguet
authors.forename: Sylvia
authors.initials: S
authors.lastname: Rathmann
authors.forename: Alberto C
authors.initials: AC
authors.lastname: Guardo
authors.forename: Verónica
authors.initials: V
authors.lastname: Pérez-Flores
authors.forename: Jose R
authors.initials: JR
authors.lastname: Regueiro
authors.forename: Balbino
authors.initials: B
authors.lastname: Alarcón
authors.forename: Paul
authors.initials: P
authors.lastname: Fisch
authors.forename: Wolfgang W A
authors.initials: WW
authors.lastname: Schamel
mesh_terms: D000328:Adult; D000818:Animals; D017252:CD3 Complex / Q000235:genetics*; D002999:Clone Cells; D006801:Humans; D018655:Lymphocyte Count; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000097:blood / Q000235:genetics*; D012016:Reference Values; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D017252:CD3 Complex; C452842:CD3 antigen, gamma chain; C472562:CD3delta antigen; D016692:Receptors, Antigen, T-Cell, gamma-delta