The acquired immunodeficiency syndrome (AIDS) is probably the most serious challenge currently facing biomedicine and the health-care professions. The syndrome and allied conditions produce a wide range of serious oral lesions which are, as yet, poorly understood. This program project integrates the activities of clinical and laboratory investigators in a broadly-based long-term interdisciplinary study of the oral manifestations of AIDS and associated diseases. The program project proposal is new, but the key investigators have worked together effectively for several years. The program is organized as a core and four separate but interrelated research projects. The first of these involves studies of the epidemiology of the oral manifestations of AIDS-virus infection utilizing eight cohorts which are the subjects of investigation in San Francisco. The second project concentrates on the etiology, pathogenesis and clinical aspects of the oral soft-tissue disease manifestations of AIDS-virus disease. The third project will study the pathogenesis and host responses of the periodontal disease manifestations, while the fourth project will involve investigations of the oral features of simian AIDS. The overall goal is to enable the several investigator groups to work individually and together in order to broaden knowledge of the prevalence, incidence, clinical features and mechanisms of the oral consequences of AIDS-virus infection. The ultimate intention is to bring such investigations to clinical application in the prevention and treatment of these diseases.