Lipophosphoglycans from Leishmania amazonensis Strains Display Immunomodulatory Properties via TLR4 and Do Not Affect Sand Fly Infection

PLoS Negl Trop Dis. 2016 Aug 10;10(8):e0004848. doi: 10.1371/journal.pntd.0004848. eCollection 2016 Aug.

Abstract

The immunomodulatory properties of lipophosphoglycans (LPG) from New World species of Leishmania have been assessed in Leishmania infantum and Leishmania braziliensis, the causative agents of visceral and cutaneous leishmaniasis, respectively. This glycoconjugate is highly polymorphic among species with variation in sugars that branch off the conserved Gal(β1,4)Man(α1)-PO4 backbone of repeat units. Here, the immunomodulatory activity of LPGs from Leishmania amazonensis, the causative agent of diffuse cutaneous leishmaniasis, was evaluated in two strains from Brazil. One strain (PH8) was originally isolated from the sand fly and the other (Josefa) was isolated from a human case. The ability of purified LPGs from both strains was investigated during in vitro interaction with peritoneal murine macrophages and CHO cells and in vivo infection with Lutzomyia migonei. In peritoneal murine macrophages, the LPGs from both strains activated TLR4. Both LPGs equally activate MAPKs and the NF-κB inhibitor p-IκBα, but were not able to translocate NF-κB. In vivo experiments with sand flies showed that both stains were able to sustain infection in L. migonei. A preliminary biochemical analysis indicates intraspecies variation in the LPG sugar moieties. However, they did not result in different activation profiles of the innate immune system. Also those polymorphisms did not affect infectivity to the sand fly.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brazil
  • CHO Cells
  • Cricetulus
  • Cytokines / immunology
  • Glycosphingolipids / chemistry*
  • Glycosphingolipids / immunology*
  • Glycosphingolipids / isolation & purification
  • Host-Parasite Interactions* / immunology
  • Humans
  • Immunity, Innate / drug effects
  • Leishmania mexicana / chemistry*
  • Leishmaniasis, Cutaneous / parasitology
  • Macrophages, Peritoneal / immunology*
  • Mice
  • Mitogen-Activated Protein Kinase Kinases / drug effects
  • Psychodidae / parasitology*
  • Toll-Like Receptor 4 / genetics
  • Toll-Like Receptor 4 / immunology*

Substances

  • Cytokines
  • Glycosphingolipids
  • Tlr4 protein, mouse
  • Toll-Like Receptor 4
  • lipophosphonoglycan
  • Mitogen-Activated Protein Kinase Kinases

Grants and funding

This manuscript was mainly funded by Conselho Nacional de Pesquisa e Desenvolvimento of Brazil (CNPq PAPES VI 407438/2012-2; 407687/2012-2; 407743/2012; 168260/2014-0; and CNPq PROEP 401975/2012) and Fundação de Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG, PPM-00163-14); URLs: 1) www.cnpq.br 2) www.fapemig.br. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.