Studies on physiologically active substances produced by plerocercoids of Spirometra erinaceieuropaei.

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1.The rule of a growth hormone-like factor and molecular cloning of the gene encoding it's factor produced by plerocercoids of Spirometra Erinaceieuropaei.A 1085 bp cDNA encoding a growth hormone-like factor (PGF) was cloned from a plerocercoid cDNA library. The amino acid sequence predicted from the cDNA has 65% homology with that of mouse cathepsin-L. Its fusion protein specifically reacted with anti-PGF antibody, but this fusion protein brought from E.coli XL-1 blue was not solublized with the buffer. The gene was characterized by Northern and Southern blot analysis, showing that PGF is stage specifically expressed. On the other hand, PGF had trypsin inhibitory activity, when the trypsin inhibitor was purified from the plerocercoid extract.2.Effects of excretory/secretory (ES) products of plerocercoids on murine peritoneal macrophages.ES products from plerocercoids reduced iNOS, chemokine and TNF-α mRNA levels in murine peritoneal macrophages stimulated with cytokines and/or LPS, analyzing with Northern blot. These suppressive factors were found in void fractions when ES products were separated by gel filtration. Then, macrophages obtained from plerocercoid-infected mice showed lower expression of TNF-α mRNA levels than those of uninfected controls. The suppressive effect of ES products was not depend on the prostaglandin E2 and IL-10.