Urban airborne particle exposure impairs human lung and blood Mycobacterium tuberculosis immunity.

Journal Article (Journal Article)


Associations between urban (outdoor) airborne particulate matter (PM) exposure and TB and potential biological mechanisms are poorly explored.


To examine whether in vivo exposure to urban outdoor PM in Mexico City and in vitro exposure to urban outdoor PM2.5 (< 2.5 µm median aerodynamic diameter) alters human host immune cell responses to Mycobacterium tuberculosis .


Cellular toxicity (flow cytometry, proliferation assay (MTS assay)), M. tuberculosis and PM2.5 phagocytosis (microscopy), cytokine-producing cells (Enzyme-linked immune absorbent spot (ELISPOT)), and signalling pathway markers (western blot) were examined in bronchoalveolar cells (BAC) and peripheral blood mononuclear cells (PBMC) from healthy, non-smoking, residents of Mexico City (n=35; 13 female, 22 male). In vivo-acquired PM burden in alveolar macrophages (AM) was measured by digital image analysis.

Measurements and main results

In vitro exposure of AM to PM2.5 did not affect M. tuberculosis phagocytosis. High in vivo-acquired AM PM burden reduced constitutive, M. tuberculosis and PM-induced interleukin-1β production in freshly isolated BAC but not in autologous PBMC while it reduced constitutive production of tumour necrosis factor-alpha in both BAC and PBMC. Further, PM burden was positively correlated with constitutive, PM, M. tuberculosis and purified protein derivative (PPD)-induced interferon gamma (IFN-γ) in BAC, and negatively correlated with PPD-induced IFN-γ in PBMC.


Inhalation exposure to urban air pollution PM impairs important components of the protective human lung and systemic immune response against M. tuberculosis . PM load in AM is correlated with altered M. tuberculosis -induced cytokine production in the lung and systemic compartments. Chronic PM exposure with high constitutive expression of proinflammatory cytokines results in relative cellular unresponsiveness.

Full Text

Duke Authors

Cited Authors

  • Torres, M; Carranza, C; Sarkar, S; Gonzalez, Y; Osornio Vargas, A; Black, K; Meng, Q; Quintana-Belmares, R; Hernandez, M; Angeles Garcia, JJF; Páramo-Figueroa, VH; Iñiguez-Garcia, MA; Flores, JL; Zhang, JJ; Gardner, CR; Ohman-Strickland, P; Schwander, S

Published Date

  • July 2019

Published In

Volume / Issue

  • 74 / 7

Start / End Page

  • 675 - 683

PubMed ID

  • 31036772

Pubmed Central ID

  • PMC7162557

Electronic International Standard Serial Number (EISSN)

  • 1468-3296

International Standard Serial Number (ISSN)

  • 0040-6376

Digital Object Identifier (DOI)

  • 10.1136/thoraxjnl-2018-212529


  • eng