[Cellular immunity and its suppressor mechanisms in cervical cancer]

The generation of cytotoxic T cells specific for subtle alterations in autologous cell surfaces accompanied by malignant change is an important effector mechanism in tumor immunity. In 58 patients with cervical cancer, proliferative and cytotoxic responses of T cells were tested after in vitro priming and boosting with trinitrophenyl-modified autologous cells (TNP-self) as a model of tumor cells. The activity of Con A-induced suppressor T cells was also examined in those responses to TNP-self. The results were as follows: 1) Proliferative and cytotoxic responses of T cells significantly decreased in stage II and III. 2) The activity of Con A-induced suppressor T (Ts) cells tended to increase in the advanced stage. 3) Those abnormalities gradually improved after surgical removal of tumor. 4) The generation of TNP-self-specific cytotoxic T (Tc) cells depends on proliferative response, therefore, TNP-self-specific proliferative T cells are presumably helper T (Th) cells. These findings suggest that activated Ts cells may undermine effective Th function, with resulting the depression of Tc function as a tumoricidal immune effector mechanism, and enhance tumor growth.