Eimeria tenella sporozoites and merozoites differentially express glycosylphosphatidylinositol-anchored variant surface proteins

Enrique Tabarés, David Ferguson, Julie Clark, Puay Eng Soon, Kiew Lian Wan, Fiona Tomley

Research output: Contribution to journalArticle

41 Citations (Scopus)

Abstract

Little is known about glycosylphosphatidylinositol (GPI)-linked surface proteins in the coccidian parasite Eimeria tenella. Examination of 28,550 EST sequences from the sporozoite and second merozoite developmental stages of the parasite led to the identification of 37 potential GPI-linked variant surface proteins, termed EtSAGs. Analysis of the complete nucleotide sequences of 23 EtSAG genes separated them into two multi-gene families. All the predicted EtSAG proteins (which vary in length from 228 to 271 residues) have an N-terminal hydrophobic signal peptide, a C-terminal hydrophobic GPI signal-anchor peptide and an extracellular domain organised around six cysteine residues, the positions of which are conserved within each family. Using specific antibodies against a small number of recombinant-expressed EtSAGs, the surface localisation and GPI-anchorage of members of both families was confirmed experimentally. Expression of EtSAGs is differentially regulated between the oocyst/sporozoite and second generation merozoite stages, with only one expressed specifically in the sporozoite, a small number expressed in both stages and the majority expressed specifically in the second generation merozoite. Preliminary data support a model in which multiple variant surface antigens are co-expressed on individual parasites, rather than a model of antigenic switching. The biological role(s) of EtSAGs and the effect(s) that expression of a complex repertoire of variant surface antigens by the second generation merozoite has on host adapted immunity are unknown.

Original languageEnglish
Pages (from-to)123-132
Number of pages10
JournalMolecular and Biochemical Parasitology
Volume135
Issue number1
DOIs
Publication statusPublished - May 2004

Fingerprint

Eimeria tenella
Merozoites
Sporozoites
Glycosylphosphatidylinositols
Membrane Proteins
Parasites
Surface Antigens
Protein Sorting Signals
GPI-Linked Proteins
Antigenic Variation
Oocysts
Expressed Sequence Tags
Genes
Cysteine
Immunity
Antibodies
Proteins

Keywords

  • Differential expression
  • Eimeria tenella
  • Eimeria tenella surface antigen
  • EtSAG
  • Glycosylphosphatidylinositol
  • GPI
  • GPI-linked
  • Merozoite
  • Sporozoite
  • Surface protein

ASJC Scopus subject areas

  • Molecular Biology
  • Parasitology

Cite this

Eimeria tenella sporozoites and merozoites differentially express glycosylphosphatidylinositol-anchored variant surface proteins. / Tabarés, Enrique; Ferguson, David; Clark, Julie; Soon, Puay Eng; Wan, Kiew Lian; Tomley, Fiona.

In: Molecular and Biochemical Parasitology, Vol. 135, No. 1, 05.2004, p. 123-132.

Research output: Contribution to journalArticle

Tabarés, Enrique ; Ferguson, David ; Clark, Julie ; Soon, Puay Eng ; Wan, Kiew Lian ; Tomley, Fiona. / Eimeria tenella sporozoites and merozoites differentially express glycosylphosphatidylinositol-anchored variant surface proteins. In: Molecular and Biochemical Parasitology. 2004 ; Vol. 135, No. 1. pp. 123-132.
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