Enhanced protective efficacy of a chimeric form of the schistosomiasis vaccine antigen Sm-TSP-2

PLoS Negl Trop Dis. 2012;6(3):e1564. doi: 10.1371/journal.pntd.0001564. Epub 2012 Mar 13.

Abstract

The large extracellular loop of the Schistosoma mansoni tetraspanin, Sm-TSP-2, when fused to a thioredoxin partner and formulated with Freund's adjuvants, has been shown to be an efficacious vaccine against murine schistosomiasis. Moreover, Sm-TSP-2 is uniquely recognised by IgG(1) and IgG(3) from putatively resistant individuals resident in S. mansoni endemic areas in Brazil. In the present study, we expressed Sm-TSP-2 at high yield and in soluble form in E. coli without the need for a solubility enhancing fusion partner. We also expressed in E. coli a chimera called Sm-TSP-2/5B, which consisted of Sm-TSP-2 fused to the immunogenic 5B region of the hookworm aspartic protease and vaccine antigen, Na-APR-1. Sm-TSP-2 formulated with alum/CpG showed significant reductions in adult worm and liver egg burdens in two separate murine schistosomiasis challenge studies. Sm-TSP-2/5B afforded significantly greater protection than Sm-TSP-2 alone when both antigens were formulated with alum/CpG. The enhanced protection obtained with the chimeric fusion protein was associated with increased production of anti-Sm-TSP-2 antibodies and IL-4, IL-10 and IFN-γ from spleen cells of vaccinated animals. Sera from 666 individuals from Brazil who were infected with S. mansoni were screened for potentially deleterious IgE responses to Sm-TSP-2. Anti-Sm-TSP-2 IgE to this protein was not detected (also shown previously for Na-APR-1), suggesting that the chimeric antigen Sm-TSP-2/5B could be used to safely and effectively vaccinate people in areas where schistosomes and hookworms are endemic.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic / administration & dosage
  • Adolescent
  • Adult
  • Aged
  • Alum Compounds / administration & dosage
  • Animals
  • Antibodies, Helminth / blood
  • Antigens, Helminth / administration & dosage
  • Antigens, Helminth / genetics
  • Antigens, Helminth / immunology*
  • Aspartic Acid Proteases / administration & dosage
  • Aspartic Acid Proteases / genetics
  • Aspartic Acid Proteases / immunology
  • Brazil
  • Child
  • Child, Preschool
  • Cytokines / metabolism
  • Disease Models, Animal
  • Escherichia coli / genetics
  • Female
  • Gene Expression
  • Humans
  • Immunoglobulin G / blood
  • Infant
  • Leukocytes, Mononuclear / immunology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Middle Aged
  • Oligodeoxyribonucleotides / administration & dosage
  • Recombinant Fusion Proteins / administration & dosage
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / immunology
  • Schistosomiasis / immunology
  • Schistosomiasis / prevention & control*
  • Spleen / immunology
  • Tetraspanins / administration & dosage
  • Tetraspanins / genetics
  • Tetraspanins / immunology*
  • Vaccines, Synthetic / administration & dosage
  • Vaccines, Synthetic / immunology
  • Young Adult

Substances

  • Adjuvants, Immunologic
  • Alum Compounds
  • Antibodies, Helminth
  • Antigens, Helminth
  • CPG-oligonucleotide
  • Cytokines
  • Immunoglobulin G
  • Oligodeoxyribonucleotides
  • Recombinant Fusion Proteins
  • Tetraspanins
  • Vaccines, Synthetic
  • aluminum sulfate
  • Aspartic Acid Proteases