Triggering immunological memory against the tapeworm Hymenolepis diminuta to protect against colitis

Infection with parasitic helminths can ameliorate the severity of concomitant inflammatory disease. To use the tapeworm, Hymenolepis diminuta, and to extend this concept by assessing whether triggering a memory response against the worm inhibits dinitrobenzene sulphonic acid (DNBS)-induced colitis in Balb/c mice. Initial studies revealed that oral infection with 1, 3 or 5 H. diminuta cysticercoids 8 days before intrarectal administration of DNBS (3 mg) resulted in less severe inflammation and that infected mice displayed an increased propensity for T helper-2 immunity. A 1 mg dose of a PBS-soluble extract of the worm (HdAg) delivered intraperitoneally concomitant with DNBS was anticolitic as determined by macroscopic and histological disease scores 72 hour post-DNBS. Mice infected 28 days previously had a memory response as determined by HdAg-evoked increases in interleukin (IL)-4 and IL-10 from in vitro stimulated splenocytes and serum anti-H. diminuta IgG. Moreover, mice infected with 5 H. diminuta 28 days previously were protected from DNBS-induced colitis by secondary infection or 100 μg HdAg (ip.) at the time of DNBS treatment. An additional approach to managing inflammatory disease could be infection with H. diminuta followed by eliciting antiworm recall responses.