Onchocerca volvulus: Comparative analysis of antibody responses to recombinant antigens in two animal models of onchocerciasis

Onchocerca volvulus: Comparative analysis of antibody responses to recombin ant antigens in two animal models of onchocerciasis. Experimental Parasitol ogy 94, 158-162. Experimental infections of chimpanzees with Onchocerca vol vulus and cattle with Onchocerca ochengi provide model systems for research in human onchocerciasis. These infections share many similarities from the standpoint of parasite biology, but little is known about the comparabilit y of immune responses in the two systems. To make a direct comparison betwe en the models in terms of immune responsiveness to defined parasite product s, three recombinant antigens of O. volvulus (Ov7, Ov103, and B20) were use d to analyze the kinetics of antibody production following experimental inf ection. Each of the antigens was derived from adult cDNA libraries followin g immunoscreening with sera from chimpanzees (Ov7, Ov103) or cattle (B20). All chimpanzees (n = 12) and cattle (n = 8) displayed responses to Ov7 and Ov103, and all cattle, but only 33% of chimpanzees, showed responses to B20 . The dynamics of the response to individual antigens showed further simila rities between the chimpanzees and the cattle, with responses to Ov7 and Ov 103 peaking after, and B20 before, the onset of patent infections. We concl ude that there is good preliminary evidence of concordance in the kinetics of serological responses in the two models. However, individual antigens ma ny be more or less immunogenic in the two systems, making it inadvisable to extrapolate between models concerning the relative immunodominance of spec ific parasite products. (C) 2000 Academic Press.