Proteomic analysis and immunodetection of antigens from early developmental stages of Trichinella spiralis

Trichinella spiralis is an ubiquitous parasitic nematode that lives in muscle tissue of many hosts and causes trichinellosis in humans. Numerous efforts have been directed at specific detection of this infection and strategies for its control. TSL-1 and other antigens, mainly from muscle larvae (ML), have been used to induce partial protection in rodents. An improvement in protective immunity may be achieved by using antigens from other parasite stages. Further, identification of other parasite antigens may provide insights into their role in the host-parasite interaction. In this study, T. spiralis antigens from early developmental parasite stages, namely ML and pre-adult (PA) obtained at 6 h, 18 h and 30 h post-infection, were identified by proteomic and mass spectrometry analyses. Our findings showed a differential expression of several proteins with molecular weights in the range of 13-224 kDa and pI range of 4.54-9.89. Bioinformatic analyses revealed a wide diversity of functions in the identified proteins, which include structural, antioxidant, actin binding, peptidyl prolyl cis-trans isomerase, motor, hydrolase, ATP binding, magnesium and calcium binding, isomerase and translation elongation factor. This, together with the differential recognition of antigens from these parasite stages by antibodies present in intestinal fluid, in supernatants from intestinal explants, and in serum samples from mice infected with T. spiralis or re-infected with this parasite, provides information that may lead to alternatives in the design of vaccines against this parasite or for modulation of immune responses.