title: Qa-1 restricted recognition of foreign antigen by a gamma delta T-cell hybridoma.
abstract: Distinct T-lymphocyte subsets recognize antigens in conjunction with different classes of major histocompatibility complex (MHC) glycoproteins using the T-cell receptor (TCR), a disulphide-linked heterodimer associated with the CD3 complex on the cell surface. In general, class I and class II MHC products provide a context for the recognition of foreign antigens by CD8+ and CD4+ T cells, respectively. This recognition seems to be largely dependent on alpha beta TCR heterodimers, whereas the function of the second gamma delta TCR, present on a minor subpopulation of cells, is still unknown. In the mouse, the existence of six cell-surface MHC class I products (K, D, L, Qa-1, Qa-2 and Tla) has been firmly established by serological, biochemical and genetic evidence. So far, only the most polymorphic of them, K, D and L ('classical' class I) have been reported as restriction elements for T-cell recognition of foreign antigens. The function of the relatively invariant Qa and Tla molecules remains unknown. We have made a T-helper cell hybridoma clone (DGT3) that recognizes synthetic copolymer poly(Glu50Tyr50) in the context of Qa-1 cell surface product, and has a CD4-CD8- phenotype. Our studies indicate that DGT3 cells express the gamma delta TCR on the cell surface, implicating its role in Qa-1-restricted antigen recognition. This is the first evidence that T cells can recognize foreign antigen in association with self Qa product, confirming that Qa molecules not only topologically, but also functionally, belong to the MHC.
authors.affiliation: Basel Institute for Immunology, Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: Vidović
authors.forename: M
authors.initials: M
authors.lastname: Roglić
authors.forename: K
authors.initials: K
authors.lastname: McKune
authors.forename: S
authors.initials: S
authors.lastname: Guerder
authors.forename: C
authors.initials: C
authors.lastname: MacKay
authors.forename: Z
authors.initials: Z
authors.lastname: Dembić
mesh_terms: D000818:Animals; D000937:Antigen-Antibody Reactions; D000941:Antigens / Q000276:immunology; D015152:Blotting, Northern; D015395:Histocompatibility Antigens Class I / Q000502:physiology*; D036341:Intercellular Signaling Peptides and Proteins; D007376:Interleukin-2 / Q000096:biosynthesis; D051379:Mice; D010455:Peptides / Q000276:immunology; D012333:RNA, Messenger / Q000235:genetics; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000502:physiology*; D016692:Receptors, Antigen, T-Cell, gamma-delta; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D000941:Antigens; D015395:Histocompatibility Antigens Class I; D036341:Intercellular Signaling Peptides and Proteins; D007376:Interleukin-2; D010455:Peptides; C032907:Q surface antigens; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; D016692:Receptors, Antigen, T-Cell, gamma-delta; C027606:L-glutamic acid-L-tyrosine copolymer