Cytokine production by lymphoreticular cells from mammary tumor bearing mice: the role of tumor-derived factors.

Mammary tumor development has multiple effects on the T cell, B cell and macrophage compartments of the hosts as evidenced by the alterations in their phenotype and functions. Cytokines are known to modulate the immune system, thus a study of the production of these factors has great relevance to tumor immunity. Here we present evidence that tumor progression causes a profound dysregulation of the cytokine production by various lymphoreticular cells. Furthermore, the tumors themselves are capable of secreting factors that can directly or indirectly affect the cells of the immune system, thereby resulting in the immunosuppressive and other deleterious effects that favor the progress of the neoplastic disease.