The purpose of this investigation is to characterize the phenotypes and function of intestinal lamina propria lymphocytes in non-human primates both in normal animals and in animals having intestinal inflammation. Initially, methods were developed to isolate lymphocytes from the intestinal lamina propria, characterize them with a variety of monoclonal antibodies, and characterize their immunoregulatory and cytotoxic function. In animals having intestinal inflammation caused by the human pathogen Lymphogranuloma venereum (LGV) we found that isolated lymphocytes were phenotypically and functionally predominantly helper T cells. Lymphocytes with the phenotype of cytolytic T cells were present, but natural killer cells were rare. These results are comparable to studies of human intestinal inflammation in diseases such as Crohn's disease. This animal model system will be used to investigate mechanisms of regulation of intestinal inflammation and the effect of pharmacologic agents.