Behavior of Biozzi high and low responder mice upon infection with Schistosoma mansoni

Abstract

Mice genetically selected for high (Ab/H) or low (Ab/L) humoral antibody responses were infected with Schistosoma mansoni in order to assess the role of antibodies in innate and acquired immunity to this parasite. Ab/H mice produced higher levels of humoral antibodies to schistosome antigens, but were more susceptible to infection than Ab/L mice. This was shown by the higher number of parasites recovered from Ab/H mice, by the larger size of the parasites themselves, by the number of schistosome eggs and their rate of deposition in the host liver. In addition, Ab/L mice could develop an acquired resistance to schistosome re-infection which was as good as, or possibly even better than the resistance developed by Ab/H mice. These findings suggest that humoral antibodies per se may not play a critical role in schistosome immunity, and at the same time call attention to the possible importance of macrophages in determining the results observed.