Demonstration of cellular and humoral immunity to transplantable carcinomas derived from the respiratory tract of rats

Abstract

Previous studies with respiratory tract tumors in mice have suggested that such tumors are not immunogenic or are only weakly so. To determine whether this is a general characteristic of neoplasias found in the airways of rodents, we investigated seven transplantable carcinomas in rats, six of which originated from tracheal epithelium and one of which orginated from the distal lung. These carcinomas were all of the squamous type and were induced by three different carcinogenic polycyclic hydrocarbons. All of the tumors were shown to be immunogenic, capable of mobilizing cellular and humoral immune responses in isogenic hosts upon immunization. This was demonstrated by induction of transplantation resistance, by Winn's neutralization test, and by the detection of antibodies in the sera of tumor-immune hosts by two independent methods (antibody-dependent cytotoxicity and antibody-binding test). The degree of immunogenicity varied among the tumor lines. The most metastatic tumor was clearly the least immunogenic. The relationship between carcinogenic insult and immunogenicity, as well as the possible nature of the tumor-associated antigens involved, is discussed.