title: Clonal specificity of human gamma delta T cells: V gamma 9+ T-cell clones frequently recognize Plasmodium falciparum merozoites, Mycobacterium tuberculosis, and group-A streptococci.
abstract: Peripheral blood gamma delta T cells expressing a V gamma 9/V delta 2 T-cell receptor are stimulated by killed bacteria including Mycobacterium tuberculosis (m.tb.) and group-A streptococci (strep A). In addition, recent data indicate that V gamma 9/V delta 2 T cells from unexposed individuals also respond to Plasmodium falciparum (P. falcip.) merozoites. Here we analyzed the reactivity to these ligands of 23 V gamma 9/V delta 2, 3 V gamma 9/V delta 1, and 4 V gamma 9-/V delta 1 clones derived from 8 healthy individuals after phytohemagglutinin stimulation of cell sorter-selected gamma delta T cells. Upon restimulation in the presence of irradiated antigen-presenting cells, the majority of V gamma 9/V delta 2 clones recognized m.tb. and strep A (but not strep D), and about one third of the clones also recognized P. falcip. Some clones, however, recognized only one or two of the tested ligands, and 4 V gamma 9/V delta 2 clones did not react at all. Interestingly, 2 of 3 V gamma 9/V delta 1 clones proliferated in response to m.tb., P. falcip., strep A and strep D, while V gamma 9-/V delta 1 clones were not activated by any of the tested ligands. Nucleotide sequence analysis indicated a broad diversity of V gamma 9 N regions in V gamma 9/V delta 2 clones. At the clonal level, our results demonstrate that individual V gamma 9/V delta 2 T cells can recognize m.tb., strep A, as well as P. falcip.-infected erythrocytes, with no influence of the expressed V gamma 9 N region.
authors.affiliation: Institut für Immunologie, Universität Heidelberg, BRD.
authors.forename: A
authors.initials: A
authors.lastname: Bender
authors.forename: B
authors.initials: B
authors.lastname: Heckl-Ostreicher
authors.forename: E J
authors.initials: EJ
authors.lastname: Grondal
authors.forename: D
authors.initials: D
authors.lastname: Kabelitz
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D000918:Antibody Specificity; D001483:Base Sequence; D002999:Clone Cells / Q000276:immunology; D000939:Epitopes; D006801:Humans; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000276:immunology / Q000502:physiology / Q000648:ultrastructure*; D010963:Plasmodium falciparum / Q000276:immunology / Q000502:physiology / Q000648:ultrastructure*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000737:chemistry / Q000502:physiology*; D012689:Sequence Homology, Nucleic Acid; D013297:Streptococcus pyogenes / Q000276:immunology / Q000648:ultrastructure*
chemical_list: D000907:Antibodies, Bacterial; D000939:Epitopes; D016692:Receptors, Antigen, T-Cell, gamma-delta