HUMAN T-CELLS IN HU-PBL-SCID MICE PROLIFERATE IN RESPONSE TO DAUDI LYMPHOMA AND CONFER ANTITUMOR IMMUNITY

In vitro culture of human peripheral blood lymphocytes (PBL) with Daud i (Burkitt lymphoma) cells results in selective proliferation of Vgamm a9/Vdelta2 T cells with high cytotoxicity against Daudi cells. After a doptive transfer into severe combined immunodeficient (SCID) mice, the se cells exert specific anti-tumour activity against Daudi lymphoma. T o test whether cytotoxic Vy9/Vdelta2 T cells are induced in SCID mice, human PBL injected intraperitoneally were stimulated with irradiated Daudi cells (PBL/Daudi-SCID). After 7-14 days, PBL/Daudi-SCID had a si gnificantly higher percentage of human gammadelta T cells in their per itoneal cavity, lymph nodes and blood than controls (PBL-SCID). DNA co ntent analysis of T cell subsets from PBL/Daudi-SCID showed a signific antly higher percentage of cells in S+G2+M phases of the cell cycle in the TCR-gammadelta-1+ than in CD3+ cell population. Human cells recov ered from PBL/Daudi-SCID showed specific cytotoxicity against Daudi ce lls. PBL/Daudi-SCID inoculated with a lethal dose of Daudi lymphoma su rvived significantly longer than controls. This protection was specifi c for Daudi cells and was not mediated by murine natural killer (NK) c ells. Thus human peripheral blood T cells grafted in SCID mice prolife rate in response to antigen and confer specific immunity.