V. Evaluation of Cross-Immunity against Type 1 Dengue Fever in Human Subjects Convalescent from Subclinical Natural Japanese Encephalitis Virus Infection and Vaccinated with 17D Strain Yellow Fever Vaccine
Centro de Pesquisas “Rene Rachou,” Caixa Postal 1743, 30.000 Belo Horizonte, Veterans Administration Medical Center and the Department of Microbiology, Vanderbilt University School of Medicine, Nashville, Tennessee 37203, Brazil
The proliferative responses of peripheral blood mononuclear cells from patients with Schistosoma mansoni infections were studied in response to heterogeneous schistosomal antigenic preparations derived from whole adult worms, cercariae or schistosomula, and soluble tegumental preparations from adult worms or schistosomula. The use of these preparations was standardized with a Brazilian patient population, and comparisons were made between previously used and newly, variously prepared antigenic preparations. Responses of cells from these intestinal/ambulatory patients were generally strong to whole adult worm antigens and low to moderate to whole cercarial or schistosomular materials. Although most patients responded well to whole worm extracts, they were not stimulated by the soluble adult tegumental preparation. In contrast, the responses to the soluble schistosomular tegumental material were vigorous. These responses were usually much higher than to whole schistosomula-derived materials. Thus it appears, using these particular preparations, that human schistosomal patient lymphocytes recognize and are stimulated by schistosomular tegumental antigens but they do not demonstrate good reactivity when exposed to an adult worm tegumental preparation.