title: A novel cDNA clone encoding a specific excretory/secretory antigen of larval Trichinella pseudospiralis.
abstract: A cDNA library for Trichinella pseudospiralis was constructed to study the expression of specific antigens. Four positive clones were identified using antibodies against the excretory/secretory (ES) products of the nematode as probe. Sequence analysis showed that they contained identical cDNA inserts of 606 bp, including a 5' non-translated region of 96 bp, a core translated segment of 408 bp and a poly(A)+ 3' terminus. It encoded a novel 136-amino-acid polypeptide. Southern blot analysis indicated that the cDNA did not cross-hybridize to the genomic digests of T. spiralis, mouse, or rat. A single copy only of its complementary sequence was found in the genome of T. pseudospiralis. Using the lambda ZAP expression system, the cDNA was induced to express a 23-kDa beta-galactosidase-fusion protein which did not cross-react with polyclonal and monoclonal antibodies against T. spiralis, heat shock proteins, or four heterologous species of nematodes. The antiserum against the fusion protein recognized a 15-kDa band from the ES products of T. pseudospiralis in immunoblotting. Immunocytolocalization demonstrated that the anti-fusion protein serum only recognized an epitope in the stichosome of T. pseudospiralis and not in T. spiralis. The protein can therefore serve as a specific antigen for the differential diagnosis of trichinellosis.
authors.affiliation: Department of Zoology, The University of Hong Kong, China.
authors.forename: Y Y
authors.initials: YY
authors.lastname: Chung
authors.forename: R C
authors.initials: RC
authors.lastname: Ko
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000947:Antigens, Helminth / Q000235:genetics*; D001483:Base Sequence; D015139:Blotting, Southern; D003001:Cloning, Molecular; D018509:DNA, Helminth; D015723:Gene Library; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008969:Molecular Sequence Data; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D017422:Sequence Analysis, DNA; D013552:Swine; D014234:Trichinella / Q000235:genetics* / Q000276:immunology
chemical_list: D000947:Antigens, Helminth; D018509:DNA, Helminth