Immunobiology of Visualizable Brain Tumor Cells: Gamma Interferon Induces Changes in the Immune Environment in Each Compartment of Brain Tumor Spread

Abstract

We have developed a rat model system that allows study of the cellular immune response to individual, visualizable brain tumor cells. The identifiable tumor cells grow and spread in ways that mimic the spread of human brain tumors. A single focal injection of a moderate dose of gamma interferon (IFN-g) was shown to change the immune environment in each anatomic compartment where tumor spread is seen: IFN-g increases entry of inflammatory cells across brain blood vessels. In addition, IFN-g increases expression of major histocompatibility complex (MHC) antigens by cells of the blood vessel walls, in the ependymal lining of the ventricles, and within the parenchyma proper. These effects of IFN-g were defined in tumor-free rats. Studies in progress are defining the effects of IFN-g on tumor growth in each anatomic compartment.