Cross-resistance between Taenia taeniaeformis and Hymenolepis nana infections in C3H/HE mice

Abstract

C3H/He male mice harboring cysticerci of Taenia taeniaeformis in their liver and non-infected control mice were challenged with either eggs or cysticercoids of Hymenolepis nana. Prior infection with T. taeniaeformis resulted in a 40% reduction in recovery of H. nana tissue cysticercoids from the intestinal wall 4 days after the challenge infection with eggs. In contrast, prior infection with T. taeniaeformis conferred no resistance to challenge infection with H. nana cysticercoids so that neither the number of adult tapeworms nor the fresh worm biomass assessed 10 days after cysticercoid challenge were decreased compared to controls. Mice which experienced only the tissue phase of H. nana infection (by treatment with praziquantel 6 days after egg inoculation) demonstrated substantial resistance to challenge infection with eggs of T. taeniaeformis. There was approximately a 60% reduction in the total numbers of T. taeniaeformis cysticerci, a 70% reduction in the proportion that were cystic and a 40% decrease in the liver weights compared with control mice. These results showed clearly that cross-immunity exists between the tissue stages of these two species of cestode in the mouse host, but that lumenal stages of H. nana were not affected by prior infection with T. taeniaeformis.