title: Functional and morphologic characterization of human T lymphocytes expressing the TCR gamma/delta.
abstract: A minor subset of T lymphocytes express a TCR composed of gamma and delta chains. This subset differs from conventional T cells for a number of phenotypic and functional characteristics. TCR gamma/delta+ cells simultaneously lack both CD4 and CD8 antigens. Cloning of CD4-8- peripheral blood lymphocytes, under limiting dilution conditions, revealed that they are homogeneously composed of cytolytic cells which efficiently lyse tumor target cells. Formal proofs have been provided that TCR gamma/delta+ cells are able to recognize antigens. For example, they proliferated in response to allogeneic mixed lymphocyte culture (MLC); in addition, MLC-derived TCR gamma/delta+ cells specifically lysed PHA-induced blast cells bearing the stimulating alloantigens. The selection of monoclonal antibodies specific for TCR gamma/delta molecules allowed to identify two distinct subsets of TCR gamma/delta+ cells. Both of these mABs, termed BB3 and delta TCS-1 respectively, induced specific activation of cloned cells expressing the corresponding antigenic determinants (as assessed by measurements of intracellular Ca++ and/or lymphokine production or cytolytic activity). Analysis of the distribution of subsets expressing different forms of TCR gamma/delta, showed that the BB3-reactive form is prevalent in the peripheral blood. In contrast, delta-TCS-1-reactive cells are relatively infrequent in peripheral blood but represent the majority of TCR gamma/delta+ cells in tissues.
authors.affiliation: Istituto di Anatomia Umana, Genova, Italy.
authors.forename: C E
authors.initials: CE
authors.lastname: Grossi
authors.forename: E
authors.initials: E
authors.lastname: Ciccone
authors.forename: J
authors.initials: J
authors.lastname: Zeromski
authors.forename: A
authors.initials: A
authors.lastname: Moretta
authors.forename: L
authors.initials: L
authors.lastname: Moretta
mesh_terms: D006801:Humans; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics / Q000502:physiology*; D013601:T-Lymphocytes / Q000166:cytology / Q000502:physiology*
chemical_list: D016692:Receptors, Antigen, T-Cell, gamma-delta