Effect of an intraperitoneal injection with activated Hymenolepis nana and H. diminuta cysticercoids on homologous challenge.
The intraperitoneal injection of excysted-activated cysticercoids of Hymenolepis nana and H. diminuta stimulates a protective immunity in mice and rats against an oral homologous challenge with different levels of effectiveness. The immunizing dose reduced only worm growth in the natural host (i.e. H. nana/mouse and H. diminuta/rat models), while in the unnatural host (i.e. H. diminuta/mouse model) expulsion of the worms from the intestine was accelerated. In mice infected with H. nana the effect appeared about 20 days after injection, but a greater effect was found in both models 40 days later even at low dose (1 cysticercoid). In rats the effect appeared 40 days after injection when a large inoculum (50 or 100 cysticercoids) was used. The induced immunity was slow in developing and only partially effective: this was probably related to host difficulties in processing somatic worm antigens, or to the slow production of metabolites by the worms in the peritoneal cavity.
Gabriele
F
F
Istituto di Patologia Sperimentale, Facoltà di Medicina e Chirurgia, Università degli Studi di Cagliari.
Bortoletti
G
G
Conchedda
M
M
Palmas
C
C
D000818:Animals; D006925:Hymenolepiasis / Q000469:parasitology / Q000628:therapy*; D006926:Hymenolepis / Q000254:growth & development / Q000276:immunology*; D016233:Immunotherapy, Active; D007274:Injections, Intraperitoneal; D007411:Intestinal Diseases, Parasitic / Q000469:parasitology / Q000628:therapy*; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D051381:Rats; D017208:Rats, Wistar