CYSTICERCOSIS - IDENTIFICATION AND CLONING OF PROTECTIVE RECOMBINANT ANTIGENS

We describe the cloning and the evaluation of the protective capacity of 5 recombinant antigens expressed during the cysticercus stage of bo th Taenia crassiceps and Taenia solium. A cDNA library was constructed in bacteriophage lambda ZAP using mRNA isolated from larvae of T. cra ssiceps of the ORF strain. The recombinant phage library was screened with polyclonal antibodies against 56- and 74-kDa protective antigen f ractions. This screening identified 13 recombinant clones, 5 of which were also strongly recognized by pooled sera from pigs experimentally infected with T. solium. The native antigens are proteins of 56 (clone s KETc1, 4, 7) and 74 and 78 kDa (clones KETc11, 12) of T. crassiceps cysticerci. Vaccination experiments using these 5 recombinant clones a gainst murine cysticercosis point to the relevance of KETc1, 4, 7, and 12 in host protection, whereas immunization with the clone KETc11 doe s not modify the parasite load in females and facilitates the parasito sis in males. We report here the DNA and the deduced amino acid sequen ce (100 amino acids) of the first protective antigen (KETc7) of potent ial interest for T. solium pig cysticercosis prevention.