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The Influence of Low Oxygen on Macrophage Response to Leishmania Infection
Author(s) -
Degrossoli A.,
ArraisSilva W. W.,
Colhone M. C.,
Gadelha F. R.,
Joazeiro P. P.,
Giorgio S.
Publication year - 2011
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/j.1365-3083.2011.02566.x
Subject(s) - biology , hypoxia (environmental) , intracellular , leishmania , macrophage , reactive oxygen species , nitric oxide , microbiology and biotechnology , cutaneous leishmaniasis , intracellular parasite , immunology , leishmaniasis , chemistry , parasite hosting , oxygen , biochemistry , in vitro , organic chemistry , endocrinology , world wide web , computer science
Abstract Hypoxia (low oxygen tension) is a common feature of inflamed and infected tissues. The influence of hypoxia on macrophage responses to micro‐organisms has only recently been studied. This study demonstrates that hypoxia induced macrophages to control Leishmania amazonensis, an intracellular parasite that causes cutaneous and cutaneous metastatic lesions. The mechanisms that contribute to the control of macrophages against L. amazonensis infection under a hypoxic microenvironment are not known. Nitric oxide, TNF‐α, IL‐10 or IL‐12 is not responsible for the decrease in parasitism under hypoxia. Live L. amazonensis entry or exocytosis of internalized particles as well as energetic metabolism was not impaired in infected macrophages; no apoptosis‐like death was detected in intracellular parasites. Reactive oxygen species (ROS) is likely to be involved, because treatment with antioxidants N‐ acetylcysteine (NAC) and ebselen inhibits the leishmanicidal effect of macrophages under hypoxia. Leishmania amazonensis infection induces macrophages to express hypoxia‐inducible factor‐1 (HIF‐1α) and ‐2 (HIF‐2α). Data indicate that hypoxia affects the microbial activities and protein expression of macrophages leading to a different phenotype from that of the normoxic counterpart and that it plays a role in modulating Leishmania infection.