Modulation of human macrophage responses to mycobacterium tuberculosis by silver nanoparticles of different size and surface modification
Author(s)
Type
Journal Article
Abstract
Exposure to silver nanoparticles (AgNP) used in consumer products carries potential health risks including increased susceptibility to infectious pathogens. Systematic assessments of antimicrobial macrophage immune responses in the context of AgNP exposure are important because uptake of AgNP by macrophages may lead to alterations of innate immune cell functions. In this study we examined the effects of exposure to AgNP with different particle sizes (20 and 110 nm diameters) and surface chemistry (citrate or polyvinlypyrrolidone capping) on cellular toxicity and innate immune responses against Mycobacterium tuberculosis (M.tb) by human monocyte-derived macrophages (MDM). Exposures of MDM to AgNP significantly reduced cellular viability, increased IL8 and decreased IL10 mRNA expression. Exposure of M.tb-infected MDM to AgNP suppressed M.tb-induced expression of IL1B, IL10, and TNFA mRNA. Furthermore, M.tb-induced IL-1β, a cytokine critical for host resistance to M.tb, was inhibited by AgNP but not by carbon black particles indicating that the observed immunosuppressive effects of AgNP are particle specific. Suppressive effects of AgNP on the M.tb-induced host immune responses were in part due to AgNP-mediated interferences with the TLR signaling pathways that culminate in the activation of the transcription factor NF-κB. AgNP exposure suppressed M.tb-induced expression of a subset of NF-κB mediated genes (CSF2, CSF3, IFNG, IL1A, IL1B, IL6, IL10, TNFA, NFKB1A). In addition, AgNP exposure increased the expression of HSPA1A mRNA and the corresponding stress-induced Hsp72 protein. Up-regulation of Hsp72 by AgNP can suppress M.tb-induced NF-κB activation and host immune responses. The observed ability of AgNP to modulate infectious pathogen-induced immune responses has important public health implications.
Date Issued
2015-11-18
Date Acceptance
2015-10-31
Citation
PLOS One, 2015, 10 (11)
ISSN
1932-6203
Publisher
Public Library of Science
Journal / Book Title
PLOS One
Volume
10
Issue
11
Copyright Statement
© 2015 Sarkar et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
License URL
Sponsor
Medical Research Council (MRC)
Natural Environment Research Council (NERC)
National Institutes of Health
Grant Number
G0700926
NE/H012893/1
H50669
Subjects
Science & Technology
Multidisciplinary Sciences
Science & Technology - Other Topics
HEAT-SHOCK PROTEINS
DEPENDENT MECHANISM
NLRP3 INFLAMMASOME
OXIDATIVE STRESS
EPITHELIAL-CELLS
INNATE IMMUNITY
HOST-DEFENSE
A549 CELLS
RECEPTOR
EXPRESSION
General Science & Technology
MD Multidisciplinary
Publication Status
Published
Article Number
e0143077