Sequence and immunogenicity of the Taenia saginata homologue of the major surface antigen of Echinococcus spp.
A clone (R-Tso18) was isolated from a Taenia saginata oncosphere cDNA library by screening with sera from rabbits immunised with oncosphere extract. It contained a full-length cDNA sequence of 1893 bp with an open reading frame of 1680 bp, corresponding to 559 amino acids with a deduced molecular mass of 65.173 kDa and an isoelectric point of 6.08. The R-Tso18 protein showed 80-84% nucleotide identity with the major protoscolex surface antigens of Echinococcus multilocularis (EM10) and E. granulosus (EG10). Preliminary immunogenicity studies employing the radiolabeled R-Tso18 protein in immune co-precipitation assays indicated sero-positivity for T. saginata-infected calf sera (6/13), T. solium cysticercosis human (7/22) and pig (2/2) sera and E. multilocularis (6/10)- and E. granulosus (1/12)-infected human sera, whereas other helminth-infection sera were negative. As immuno-precipitation is a relatively insensitive assay, it was concluded that further studies on the diagnostic potential of the purified recombinant R-Tso18 antigen, or its peptides, are merited.
Benitez
L
L
Ministerio de Sanidad y Consumo, Instituto de Salud Carlos III, CNM, Madrid, Spain.
Harrison
L J
LJ
Parkhouse
R M
RM
Gonzalez
L M
LM
Gottstein
B
B
Garate
T
T
D000595:Amino Acid Sequence; D000818:Animals; D000947:Antigens, Helminth / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D000954:Antigens, Surface / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D003001:Cloning, Molecular; D003551:Cysticercosis / Q000276:immunology / Q000662:veterinary; D018076:DNA, Complementary; D004446:Echinococcus / Q000276:immunology*; D006801:Humans; D008969:Molecular Sequence Data; D011233:Precipitin Tests; D014176:Protein Biosynthesis; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013621:Taenia / Q000737:chemistry / Q000235:genetics* / Q000276:immunology*; D014158:Transcription, Genetic
D000947:Antigens, Helminth; D000954:Antigens, Surface; D018076:DNA, Complementary; C072149:Elp protein, Echinococcus multilocularis; C113105:R Tso18 protein, Taenia saginata; D011994:Recombinant Proteins