A protein secreted in vivo by Echinococcus granulosus inhibits elastase activity and neutrophil chemotaxis

摘要: Abstract A cDNA encoding the carboxy-terminal of 12-kDa subunit antigen B Echinococcus granulosus has been cloned and sequenced. In addition, an amino acid sequence generated for amino-terminal which is tentatively contiguous with open reading frame DNA-derived sequence. Comparison inferred other known sequences indicated a limited similarity to α-1 antitrypsin. functional assays, gel-purified native from natural infections inhibited elastase but not trypsin or chymotrypsin, providing further evidence that this parasite protease inhibitor. Possibly unrelated its anti-protease activity potentially important function was ability inhibit recruitment neutrophils. These functions may be viability in face host immune response. match between protein imperfect, some residues having, according sequencing, two alternatives aaproximately equal concentrations, four failing at all. The expressed as isoforms polymorphic gene and, far we are aware, observed polymorphism not, date, described any flatworm antigen.