Antimicrobial peptides (Temporin A and Iseganan IB-367): effect on the cysticerci of Taenia crassiceps

Taenia solium infections continue being a health problem in undeveloped countries, and few effective control measures against this Parasite are being applied. Antimicrobial Peptides (AMPs) belong to the innate immune response and capable of destroying pathogens. We tested the ability of two AMPs, Temporin A (TA) and Iseganan IB-367 (IB-367) to damage T. crassiceps cysticerci in vitro. Doses of 200 and 400 microg/ml of TA and IB-367 caused cysticerci to shrink, lose motility, the formation of macrovesicles in the tegument, as well as decreased evagination properties. These changes were observed as early as 3-6h and became more pronounced over 24h, when the morphological changes of the bladders became evident by both LIGHT and electron microscopy. Electron micrographs of cysticerci exposed to Peptides showed initial changes as collapsed microvesicles in the tegument, with formation of large vesicles and extrusion of tegumentary tissues into the surrounding media, which led to complete loss of the tegument as well as shrinkage and complete loss of structure of parenchymal tissue after 24h. Peptides administered to cysticercotic mice one month post-infection in a single intraperitoneal dose of 200 or 400 microg, reduced the Parasite load by 25% for IB-367, and 50% for TA. The humoral response of infected mice does not appear capable of killing surviving cysticerci. Our studies show that in vitro, AMPs severely damage the tegument and the scolex, and open a new pathway for biological drug design or the development of transgenic Animals that over express these Peptides capable of killing the cysticerci in vivo.