Bovine gamma/delta TcR+ T lymphocytes are stimulated to proliferate by autologous Theileria annulata-infected cells in the presence of interleukin-2.
An in vitro model system has been developed in which freshly isolated resting WC1+ gamma/delta TcR+ T cells proliferate in response to cells transformed by the protozoan parasite Theileria annulata, providing a strategy in which the basis of activation of naive gamma/delta T cells can be investigated. Irradiated parasite-transformed cells stimulate the proliferation, but not cytolytic activity, of autologous peripheral blood mononuclear cells (PBMC) from non-immune animals. The proliferating cells are mainly WC1+ gamma/delta T cells. The majority of WC1+ gamma/delta T cells in freshly isolated PBMC express CD25 at a low level that increases when stimulated with T. annulata-infected cells. Purified WC1+ gamma/delta T cells fail to proliferate when cultured with irradiated T. annulata-infected cells and produce a small proliferative response to IL-2, but proliferate strongly to irradiated or lightly fixed Theileria-infected cells in combination with IL-2. The Theileria-infected cells express cytokine transcripts encoding IL-1 alpha, IL-1 beta, IL-6 and IL-10, but not IFN gamma, IL-2, IL-4 and IL-7. Purified WC1+ gamma/delta T cells stimulated with T. annulata-infected cells with or without IL-2 fail to produce IL-2 transcripts, but do produce those for TNF alpha. These experiments show that WC1+ gamma/delta T cells recognize a surface determinant on T. annulata-infected cells, that together with a second signal, which can be provided by exogenous IL-2, stimulates their proliferation.
Collins
R A
RA
Division of Immunology and Pathology, Institute for Animal Health, Compton, Newbury, UK.
Sopp
P
P
Gelder
K I
KI
Morrison
W I
WI
Howard
C J
CJ
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics; D005786:Gene Expression Regulation; D005856:Germ-Free Life; D007376:Interleukin-2 / Q000494:pharmacology*; D007963:Leukocytes, Mononuclear / Q000469:parasitology*; D008213:Lymphocyte Activation / Q000187:drug effects*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis*; D018123:Receptors, Interleukin / Q000096:biosynthesis / Q000235:genetics; D053707:Receptors, Interleukin-12; D015398:Signal Transduction; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology*; D016796:Theileria annulata / Q000276:immunology*; D013801:Theileriasis / Q000276:immunology* / Q000473:pathology
D016207:Cytokines; D007376:Interleukin-2; D016692:Receptors, Antigen, T-Cell, gamma-delta; D018123:Receptors, Interleukin; D053707:Receptors, Interleukin-12