SPARC (secreted protein acidic and rich in cysteine) of the intestinal nematode Strongyloides ratti is involved in mucosa-associated parasite-host interaction

Mol Biochem Parasitol. 2016 Jun;207(2):75-83. doi: 10.1016/j.molbiopara.2016.06.001. Epub 2016 Jun 3.

Abstract

The secreted protein acidic and rich in cysteine (SPARC), found in the excretory/secretory products of Strongyloides ratti, is most strongly expressed in parasitic females. Since SPARC proteins are involved in the modulation of cell-matrix interactions, a role of the secreted S. ratti SPARC (Sr-SPARC) in the manifestation of the parasite in the host's intestine is postulated. The full-length cDNA of Sr-SPARC was identified and the protein was recombinantly expressed. The purified protein was biologically active, able to bind calcium, and to attach to mucosa-associated human cells. Addition of Sr-SPARC to an in vitro mucosal three-dimensional-cell culture model led to a time-dependent release of the cytokines TNF-α, IL-22, IL-10 and TSLP. Of importance, exposure with Sr-SPARC fostered wound closure in an intestinal epithelial cell model. Here, we demonstrate for the first time that SPARC released from the nematode is a multifunctional protein affecting the mucosal immune system.

Keywords: 3D- cell culture; Excretory/secretory products; Immune response; SPARC; Strongyloides.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Calcium / metabolism
  • Cells, Cultured
  • Cytokines / metabolism
  • Helminth Proteins / chemistry
  • Helminth Proteins / metabolism*
  • Host-Parasite Interactions*
  • Humans
  • Intestinal Mucosa / immunology*
  • Intestinal Mucosa / metabolism
  • Leukocytes, Mononuclear / immunology
  • Leukocytes, Mononuclear / metabolism
  • Osteonectin / chemistry
  • Osteonectin / metabolism*
  • Rats
  • Rats, Wistar
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Sequence Alignment
  • Strongyloides ratti / physiology*
  • Strongyloidiasis / immunology*
  • Strongyloidiasis / parasitology
  • Wound Healing

Substances

  • Cytokines
  • Helminth Proteins
  • Osteonectin
  • Recombinant Proteins
  • Calcium