RESUMO
The expression of heat shock proteins (HSPs) and their immunogenic role in host parasite relationship has been studied in T. spiralis infection in mice. Two groups of infective stage larvae were incubated at 37 degrees C or at 43 degrees C for 3 hours in a nutrient medium. Crude somatic extracts and excretory/secretory (E/S) products were obtained. Quantitative estimation and in vitro translation of mRNA were carried out. Crude somatic extracts, E/S products and in vitro translated proteins were all subjected to SDS-PAGE and immunoelectrophoresis against a monoclonal antibody to HSP70. They were further used to immunize mice which were then infected with T. spiralis. The degree of immunization was assessed by counting adult worms, muscle larvae and estimating total gamma globulins of mice. SDS-PAGE revealed intense peaks of 71 KDa and 81 KDa in all proteins obtained from heat shocked larvae. These proteins have been proved to involve HSP70 as manifested by their strong reactivity with anti-HSP70. In vitro translated products of heat shocked larvae (at 43 degrees C) proved to be strongly immunogenic as evidenced by the lower adult worm, muscle larval counts and higher total gamma globulins in sera of mice in comparison with the control non immunized group as well as to other larval antigens incubated at 37 degrees C. So, exposure to heat, can induce the synthesis of heat shock proteins which can defend the organism against environmental stress. Meanwhile, these heat shock proteins can render the host more refractory to reinfection.