Teladorsagia circumcincta: Activation-associated secreted proteins in excretory/secretory products of fourth stage larvae are targets of early IgA responses in infected sheep

A. J. Nisbet, S. K. Smith, S. Armstrong, L. I. Meikle, L. A. Wildblood, R. J. Beynon, J. B. Matthews

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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 colt and the purified protein was reactive with IgA present in abomasal mucus derived from immune sheep. (C) 2010 Elsevier Inc. All rights reserved.

Original languageEnglish
Pages (from-to)329-337
Number of pages9
JournalExperimental Parasitology
Issue number4
Publication statusPublished - Aug 2010

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