Immunity to adult cestodes: basic knowledge and vaccination problems. A review

Area of Science:

• Immunology
• Parasitology
• Mammalian Host-Parasite Interactions

Background:

• Intestinal cestode infections in mammals are modeled using Hymenolepis tapeworms in rats and mice.
• Primary infections can persist, but higher doses lead to worm expulsion.
• Concomitant immunity, resistance to superimposed infection, is observed in rodent models and suggested for human Taenia infections.

Purpose of the Study:

• To review and synthesize current knowledge on mammalian immunity to intestinal cestodes.
• To explore mechanisms of immunity, worm counter-responses, and potential vaccination strategies.

Main Methods:

• Review of existing literature on rodent models (Hymenolepis diminuta, H. microstoma, H. nana) and human cestode infections (Taenia spp.).
• Analysis of studies on primary and secondary infection dynamics, immunological memory, and antibody-mediated responses.
• In vitro studies using peritoneal exudate cells and passive transfer experiments with lymph node cells.

Main Results:

• Concomitant immunity and immunity to secondary infections occur, but immunological memory is short-lived.
• Serum antibodies show in vitro precipitation, but in vivo roles and interactions with host cells remain unclear.
• Peritoneal exudate cells can kill H. diminuta in vitro; tapeworm tegumental glycoconjugates and secretory bodies are potential immune evasion mechanisms.
• Passive transfer of immunity is successful only with specific cells from H. nana infected mice.

Conclusions:

• Mammalian immunity to intestinal cestodes is complex, involving both worm expulsion and resistance.
• Mechanisms of tapeworm immune evasion require further investigation.
• Vaccination strategies, particularly for zoonotic cestodes like Echinococcus granulosus, present challenges and require further development.