Season and size of urban particulate matter differentially affect cytotoxicity and human immune responses to Mycobacterium tuberculosis

• DOI: 10.1371/journal.pone.0219122
• Publication Date: 2019-07-11T17:31:30Z
• Authors: Srijata Sarkar; César E. Rivas-Sa...; Olufunmilola A. I...; Claudia Carranza; Qingyu Meng; Álvaro Osornio-Va...; Junfeng Zhang; Martha Torres; Judith C. Chow; John G. Watson; Pamela Ohman-Stri...; Stephan Schwander
• Keywords: Adult; Cytotoxicity, Immunologic; Male; Adolescent; Science; Interleukin-1beta; In Vitro Techniques; Interferon-gamma; 03 medical and health sciences; 0302 clinical medicine; 11. Sustainability; Humans; Cities; Particle Size; Mexico; Aged; Air Pollutants; Host Microbial Interactions; Q; R; Environmental Exposure; Mycobacterium tuberculosis; Middle Aged; 3. Good health; 13. Climate action; Leukocytes, Mononuclear; Medicine; Female; Particulate Matter; Research Article

Exposure to air pollution particulate matter (PM) and tuberculosis (TB) are two of the leading global public health challenges affecting low middle income countries. An estimated 4.26 million premature deaths attributable household an additional 4.1 outdoor annually. Mycobacterium (M.tb) infects a large proportion world's population with risk for TB development increasing during immunosuppressing conditions. There is strong evidence that such immunosuppressive conditions develop exposure, which increases rates development. urban has been shown alter outcome therapy. Here we examined whether in vitro exposure PM alters human immune responses M.tb. PM2.5 PM10 (aerodynamic diameters <2.5μm, <10μm) were collected monthly from rainy, cold-dry warm-dry seasons Iztapalapa, highly populated TB-endemic municipality Mexico City elevated levels. We evaluated effects seasonality size on cytotoxicity antimycobacterial host immunity peripheral blood mononuclear cells (PBMC) interferon gamma (IFN-γ) release assay (IGRA)+ IGRA- healthy study subjects. induced highest PBMC. With exception season, pre-exposure all seasonal reduced M.tb phagocytosis by Furthermore, M.tb-induced IFN-γ production was suppressed PM10-pre-exposed PBMC IGRA+ This observation coincides expression T-bet, transcription factor regulating T cells. Pre-exposure compared led greater loss growth control. different differentially impairs immunity, suggesting biological mechanisms underlying altered infection treatment outcomes exposures.