Tumor formation suppressed in gamma delta T knock-out mice

Tumor formation was examined in mice in which the beta -chain gene of alpha betaT was knocked out (alpha betaT-KO mice) or the delta -chain gene of ga mma deltaT was knocked out (gamma deltaT-KO mice). Development of Hepa 1-6 cell hepatoma was observed in six of six alpha betaT-KO mice, in four of si x wild-type mice. and in only one of six gamma deltaT-KO mice. These result s imply that gamma deltaT cells play a role in suppression of killer cell a ctivity in tumor-bearing mice. (C) 2000 Elsevier Science Ireland Ltd. All r ights reserved.