Effector mechanisms against Rous sarcomas in quail.

The inhibitory effect on tumor growth of thymus-derived cells in the avian virus system has been demonstrated by several investigators. Here we report two kinds of experiments performed to test the role of various potential effector cells in the immune response against Rous sarcomas. In vivo experiments in Japanese quail using the antimacrophage agent silica implicate the macrophage as a further mechanism in the defense against Rous sarcoma virus-induced tumors. Induction of a nonspecific inflammation at the site of tumor development led to reduced tumor growth.