Isolation of Poly A(+) RNA from Schistosoma mansoni and Immunoprecipitation of Its In vitro Translation Products

Abstract

Total RNA was extracted from S. mansoni by homogenization in 4 M guanidine thiocyanate followed by centrifugation through cesium chloride. Poly A(+) RNA was isolated by oligo(dT)-cellulose chromatography. The recovered poly A(+) RNA was subsequently shown to stimulate protein synthesis in a cell-free, rabbit reticulocyte system. Among the translation products were polypeptides with molecular weights of 18, 20, 26, 39, 42, and 50 kilodaltons that were recognized by rabbit anti-schistosome-denuded body IgG. Human infection serum IgG precipitated polypeptides with molecular weights of 16, 18, 30, 35, 37, and 42 kilodaltons. These results identify several mRNA's that may provide useful templates for preparation of cDNA for eventual cloning or as probes in various related experiments.

Isolation of cDNA clones for differentially expressed genes of the human parasite Schistosoma mansoni.

“…Immunologically, differentiation ofparasite stages has been demonstrated using monoclonal antibodies developed against stage-specific proteins (24)(25)(26)(27). Recently, immunoprecipitation of in vitro translation products of S. mansoni mRNA using polyclonal antisera suggested that there are several adult worm-and schistosomula-specific polypeptides (28)(29)(30)(31)(32). Previous reports concerning cloning of S. mansoni antigens (33,34) did not describe RNA analyses which would have allowed comparisons to the cDNAs described in the present study.…”