Comparative analysis of excretory-secretory antigens of Trichinella spiralis and Trichinella britovi muscle larvae by two-dimensional difference gel electrophoresis and immunoblotting

Background: trichinellosis is a zoonotic disease in humans caused by trichinella spp. the present study was undertaken to discover excretory-secretory (e-s) proteins from t. spiralis and t. britovi muscle larvae (ml) that hold promise for species-specific diagnostics. to that end,the purified e-s proteins were analyzed by fluorescent two-dimensional difference gel electrophoresis (2-d dige) coupled with protein identification by liquid chromatography-tandem mass spectrometry (lc-ms/ms). to search for immunoreactive proteins that are specifically recognized by host antibodies the e-s proteins were subjected to two-dimensional (2-de) immunoblotting with antisera derived from pigs experimentally infected with t. spiralis or t. britovi.results: according to 2-d dige analysis,a total of twenty-two proteins including potentially immunogenic proteins and proteins produced only by one of the two trichinella species were subjected to lc-ms/ms for protein identification. from these proteins seventeen could be identified,of which many were identified in multiple spots,suggesting that they have undergone post-translational modification,possibly involving glycosylation and/or proteolysis. these proteins included 5'-nucleotidase,serine-type protease/proteinase,and p43 glycoprotein (gp43) as well as 49 kda e-s protein (p49). our findings also suggest that some of the commonly identified proteins were post-translationally modified to different extents,which in certain cases seemed to result in species-specific modification. both commonly and specifically recognized immunoreactive proteins were identified by 2-de immunoblotting; shared antigens were identified as gp43 and different protease variants,whereas those specific to t. britovi included multiple isoforms of the 5'-nucleotidase.conclusions: both 2-d dige and 2-de immunoblotting approaches indicate that t. spiralis and t. britovi produce somewhat distinctive antigen profiles,which contain e-s antigens with potential as species-specific diagnostic markers for trichinella. our results also demonstrate the value of 2-d dige as a versatile tool to compare secretomes of different trichinella species for pinpointing factors contributing to the interaction with the host. © 2012 bien et al; biomed central ltd.