The Phenotype of Circulating Neutrophils during Visceral Leishmaniasis

Am J Trop Med Hyg. 2017 Sep;97(3):767-770. doi: 10.4269/ajtmh.16-0722. Epub 2017 Aug 18.

Abstract

Visceral leishmaniasis (VL) is a chronic parasitic disease associated with suppressed T cell responses. Although parasites reside intracellularly in macrophages during chronic VL, neutrophils are the first host cell to infiltrate the infection site and phagocytose the parasite. Subsets of neutrophils with unusual characteristics have been documented in human VL, but whether the total neutrophil population is aberrant during disease is not known. Therefore, we examined phenotypic characteristics of unfractionated polymorphonuclear leukocyte (neutrophils) from subjects with active VL, and compared these with neutrophils from healthy controls or subjects who have been treated for VL. The data showed decreased mRNA and diminished amounts of the neutrophil chemoattractant CXCL8 (interleukin [IL]-8), increased IL-10 mRNA and protein, and elevated transcripts encoding arginase-1, which is involved in suppressing T cell responses. Neutrophils from VL subjects showed enhanced capacity to phagocytose Leishmania spp. promastigotes. The results suggest that neutrophils may contribute to immunosuppression in subjects with active VL.

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Cytokines / genetics
  • Cytokines / metabolism
  • Gene Expression Regulation
  • Humans
  • Leishmaniasis, Visceral / immunology*
  • Neutrophils / classification*
  • Transcriptome
  • Young Adult

Substances

  • Cytokines