Filarial thioredoxin reductase exerts anti-inflammatory effects upon lipopolysaccharide induced inflammation in macrophages

Int J Biol Macromol. 2021 Dec 15;193(Pt B):1379-1390. doi: 10.1016/j.ijbiomac.2021.10.200. Epub 2021 Nov 10.

Abstract

Lymphatic filariasis and its associated health hazards have taken enormous tolls especially in the tropical and sub-tropical countries round the globe. Our present work contemplates the immunomodulatory role of filarial Thioredoxin reductase (TrxR) for the survival of the parasite inside the human host. For this, the protein TrxR was purified from the filarial parasite Setaria cervi and further substantiated through specific anti-TrxR antibody raised in mice. Both commercially available anti-TrxR antibody and laboratory raised antibody produced a single band with a molecular mass of ~80 kDa on western blot. The protein is optimally active at pH 7.0 and at temperature 37 °C. This protein contains both alpha helix and beta pleated sheet with selenocysteine at its active site. The Km was found to be 2.75 ± 0.49 mM. TrxR was found to downregulate lipopolysaccharide (LPS)-induced inflammation in macrophages due to inhibition of TLR4-NF-κB pathway. The result was further supported by the downregulation of inflammasome pathway and activation of alternatively activated macrophages upon TrxR treatment. Hence this study projects insights into the importance of filarial TrxR in host-parasite interface as well as it illustrates novel therapeutic strategy towards anti-filarial drug development.

Keywords: Anti-inflammatory milieu; Host-parasite interaction; Lymphatic filariasis; Protein purification; Thioredoxin reductase.

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / metabolism*
  • Anti-Inflammatory Agents / pharmacology*
  • Cell Line
  • Down-Regulation / drug effects
  • Helminth Proteins / metabolism
  • Inflammation / chemically induced
  • Inflammation / drug therapy*
  • Inflammation / metabolism*
  • Lipopolysaccharides / pharmacology
  • Macrophages / metabolism*
  • Mice
  • NF-kappa B / metabolism
  • Protein Conformation, alpha-Helical / drug effects
  • Protein Conformation, beta-Strand / drug effects
  • RAW 264.7 Cells
  • Setaria Nematode / drug effects
  • Thioredoxin-Disulfide Reductase / metabolism*
  • Thioredoxin-Disulfide Reductase / pharmacology*
  • Toll-Like Receptor 4 / metabolism

Substances

  • Anti-Inflammatory Agents
  • Helminth Proteins
  • Lipopolysaccharides
  • NF-kappa B
  • Toll-Like Receptor 4
  • Thioredoxin-Disulfide Reductase