Immunological mechanisms involved in the protection against intestinal taeniosis elicited by oral immunization with Taenia solium calreticulin

Oral immunization with functional recombinant Taenia solium calreticulin (rTsCRT) induces 37% reduction in tapeworm burden in the experimental model of intestinal taeniosis in hamsters. Furthermore, tapeworms recovered from vaccinated animals exhibit diminished length, being frequently found in more posterior parts of the small intestine. The aim of this study was to analyze the immunological mechanisms involved in protection in response to rTsCRT oral immunization. Hamsters were orally immunized with rTsCRT using cholera toxin (CT) as adjuvant, weekly for 4 weeks. Fifteen days after the last boost animals were challenged with four T. solium cysticerci. Reduction in the adult worm recovery and increased transcription of mRNA for IL-4 and IFN-gamma in the mucosa of rTsCRT + CT immunized animals were observed. Immunization also induced goblet cell hyperplasia in the mucosa surrounding the implantation site of the parasite. Specific IgG and IgA antibodies in serum and fecal supernatants were detected after the second immunization, being more pronounced after challenge. Our data suggest that oral vaccination with rTsCRT + CT regulates a local expression of IL-4 and IFN-gamma, stimulating secretion of IgA that, together with the increase of goblet cells and mucin production, could result in an unfavorable environment for T. sollum promoting an impaired tapeworm development. (c) 2012 Elsevier Inc. All rights reserved.