Analysis of structures and epitopes of surface antigen glycoproteins expressed in bradyzoites of Toxoplasma gondii

Biomed Res Int. 2013:2013:165342. doi: 10.1155/2013/165342. Epub 2013 Mar 21.

Abstract

Toxoplasma gondii is a protozoan parasite capable of infecting humans and animals. Surface antigen glycoproteins, SAG2C, -2D, -2X, and -2Y, are expressed on the surface of bradyzoites. These antigens have been shown to protect bradyzoites against immune responses during chronic infections. We studied structures of SAG2C, -2D, -2X, and -2Y proteins using bioinformatics methods. The protein sequence alignment was performed by T-Coffee method. Secondary structural and functional domains were predicted using software PSIPRED v3.0 and SMART software, and 3D models of proteins were constructed and compared using the I-TASSER server, VMD, and SWISS-spdbv. Our results showed that SAG2C, -2D, -2X, and -2Y are highly homologous proteins. They share the same conserved peptides and HLA-I restricted epitopes. The similarity in structure and domains indicated putative common functions that might stimulate similar immune response in hosts. The conserved peptides and HLA-restricted epitopes could provide important insights on vaccine study and the diagnosis of this disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Protozoan / chemistry*
  • Antigens, Protozoan / immunology
  • Antigens, Surface* / chemistry
  • Antigens, Surface* / immunology
  • Epitopes / chemistry
  • Epitopes / immunology
  • Glycoproteins* / chemistry
  • Glycoproteins* / immunology
  • HLA Antigens / immunology
  • Humans
  • Peptides / immunology
  • Protozoan Proteins / chemistry*
  • Protozoan Proteins / immunology
  • Toxoplasma / chemistry*
  • Toxoplasma / immunology
  • Toxoplasma / pathogenicity
  • Toxoplasmosis / immunology
  • Toxoplasmosis / parasitology*

Substances

  • Antigens, Protozoan
  • Antigens, Surface
  • Epitopes
  • Glycoproteins
  • HLA Antigens
  • Peptides
  • Protozoan Proteins
  • surface antigen P22, Toxoplasma