Teladorsagia circumcincta: activation-associated secreted proteins in excretory/secretory products of fourth stage larvae are targets of early IgA responses in infected sheep.
A detailed proteomic analysis of excreted/secretory (ES) proteins derived from fourth stage larvae (L4) of Teladorsagia circumcincta identified a number of components, including N-type and C-type single domain activation-associated secreted proteins (ASPs). Immunoblotting of L4 ES extracts with abomasal mucus derived from infected, immune sheep demonstrated the immunogenicity of some of these components, including an N-type single-domain ASP, designated Tci-ASP-1. The full-length cDNA encoding this protein was isolated and sequenced. Homology searches using the inferred amino acid sequence of Tci-ASP-1 showed that it had highest identity (75% over 231 residues) to, a N-type, single-domain ASP from Ostertagia ostertagi. Phylogenetic analysis confirmed the relationship of Tci-ASP-1 with other N-type ASPs. Reverse-transcriptase (RT)-PCR experiments demonstrated the presence of transcript encoding Tci-ASP-1 in L4 and adult stage T. circumcincta but not in pre-parasitic stages such as eggs and third stage larvae. A recombinant version of Tci-ASP-1 was expressed in Escherichia coli and the purified protein was reactive with IgA present in abomasal mucus derived from immune sheep.
Nisbet
A J
AJ
Parasitology Division, Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, UK.
Smith
S K
SK
Armstrong
S
S
Meikle
L I
LI
Wildblood
L A
LA
Beynon
R J
RJ
Matthews
J B
JB
D000595:Amino Acid Sequence; D000818:Animals; D000909:Antibodies, Helminth / Q000096:biosynthesis; D015180:Electrophoresis, Gel, Two-Dimensional / Q000662:veterinary; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D005753:Gastric Mucosa / Q000276:immunology; D015801:Helminth Proteins / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D015151:Immunoblotting / Q000662:veterinary; D007071:Immunoglobulin A, Secretory / Q000096:biosynthesis*; D007814:Larva / Q000276:immunology / Q000378:metabolism; D013058:Mass Spectrometry / Q000662:veterinary; D010802:Phylogeny; D040901:Proteomics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment / Q000662:veterinary; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology* / Q000469:parasitology; D014251:Trichostrongyloidea / Q000145:classification / Q000276:immunology* / Q000378:metabolism; D014252:Trichostrongyloidiasis / Q000276:immunology / Q000662:veterinary*
D000909:Antibodies, Helminth; D015801:Helminth Proteins; D007071:Immunoglobulin A, Secretory