title: Growth requirements for avian gamma delta T cells include exogenous cytokines, receptor ligation and in vivo priming.
abstract: These studies analyze growth requirements for the normal gamma delta T cell population in peripheral lymphoid tissues. Avian gamma delta T cells can respond well to T cell mitogens in the presence of alpha beta T cells, but our studies indicate that they do not grow well alone. Exogenous growth factors were required in order for gamma delta T cells to proliferate in response to receptor ligation by anti-T cell receptor antibodies or other T cell mitogens. Interleukin-2 was implicated as one of the necessary growth factors that the gamma delta cells cannot produce adequately on their own. The response to dual stimulation (receptor ligation plus exogenous T cell factors) was attributable to a discrete subpopulation of gamma delta T cells that could be identified by their cell surface CD8, major histocompatibility complex class II expression and relative increase in cell size. Conversely, non-responsive gamma delta T cells did not exhibit these activation markers. These observations suggest a physiological basis for the relatively late appearance of gamma delta T cells in inflammatory responses and their failure as a population to match the growth potential of alpha beta T cells. More importantly, the results imply that the biological role of gamma delta T cells must be understood within the context of their interaction with alpha beta T cells.
authors.affiliation: Department of Medicine, University of Alabama at Birmingham 35294-3300.
authors.forename: Y
authors.initials: Y
authors.lastname: Kasahara
authors.forename: C H
authors.initials: CH
authors.lastname: Chen
authors.forename: M D
authors.initials: MD
authors.lastname: Cooper
mesh_terms: D000818:Animals; D016827:CD8 Antigens / Q000032:analysis; D002478:Cells, Cultured; D002645:Chickens; D016207:Cytokines / Q000494:pharmacology; D006133:Growth Substances / Q000494:pharmacology*; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000096:biosynthesis; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis* / Q000502:physiology; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology / Q000502:physiology*
chemical_list: D016827:CD8 Antigens; D016207:Cytokines; D006133:Growth Substances; D008222:Lymphokines; D016692:Receptors, Antigen, T-Cell, gamma-delta