Immunomodulation by Helminths: Intracellular Pathways and Extracellular Vesicles

Front Immunol. 2018 Oct 12;9:2349. doi: 10.3389/fimmu.2018.02349. eCollection 2018.


Helminth parasites are masters at manipulating host immune responses, using an array of sophisticated mechanisms. One of the major mechanisms enabling helminths to establish chronic infections is the targeting of pattern recognition receptors (PRRs) including toll-like receptors, C-type lectin receptors, and the inflammasome. Given the critical role of these receptors and their intracellular pathways in regulating innate inflammatory responses, and also directing adaptive immunity toward Th1 and Th2 responses, recognition of the pathways triggered and/or modulated by helminths and their products will provide detailed insights about how helminths are able to establish an immunoregulatory environment. However, helminths also target PRRs-independent mechanisms (and most likely other yet unknown mechanisms and pathways) underpinning the battery of different molecules helminths produce. Herein, the current knowledge on intracellular pathways in antigen presenting cells activated by helminth-derived biomolecules is reviewed. Furthermore, we discuss the importance of helminth-derived vesicles as a less-appreciated components released during infection, their role in activating these host intracellular pathways, and their implication in the development of new therapeutic approaches for inflammatory diseases and the possibility of designing a new generation of vaccines.

Keywords: extracellular vesicle; helminths; immunosuppression; intracellular pathways; pattern recognition receptors.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Biomarkers
  • Extracellular Vesicles / metabolism
  • Helminthiasis / immunology*
  • Helminthiasis / metabolism*
  • Helminthiasis / parasitology
  • Helminthiasis / prevention & control
  • Helminths / immunology*
  • Helminths / metabolism
  • Host-Parasite Interactions / immunology*
  • Humans
  • Immune System / cytology
  • Immune System / immunology
  • Immune System / metabolism
  • Immunomodulation*
  • Intracellular Space / metabolism
  • Protozoan Vaccines / immunology
  • Receptors, Pattern Recognition / metabolism
  • Secretory Vesicles / metabolism
  • Signal Transduction


  • Biomarkers
  • Protozoan Vaccines
  • Receptors, Pattern Recognition