Stephan Schwander
Associate Professor and Director
Environmental Health
Environmental and Occupational Health Sciences Institute
United States of America
Biography
The primary goal of my translational research is to improve the understanding of environmental effects on human health and human immunity during infections such as with Mycobacterium tuberculosis (M.tb), the bacterium that causes TB. For the past 15 years my lab, in collaboration with others, has spearheaded research on human lung immune responses to M.tb. Our findings helped to establish the concept of compartmentalization of immune responses to the lungs in human pulmonary TB. Recent studies from my lab with co-investigators at EOHSI and at the University of Southern California (USC), have shown that stimulation of peripheral blood mononuclear cells (PBMC) with diesel exhaust particles (DEPs) alter cytokine production and toll-like receptor-mediated M.tb-specific cell activation pathways. DEPs are major components of aerosolized urban ambient fine particulate matter (PM). We noted that the production of critical M.tb-induced pro-inflammatory cytokines such as IFN-gamma, TNF-alpha, IL-1 beta, and IL-6 was reduced in a DEP dose-dependent manner in PBMC. Furthermore, inhibition of expression of many NF-kB and IFN regulatory signaling pathway target genes was observed upon DEP stimulation in non-infected cells. These data suggest that DEPs downregulate M.tb-induced cytokine and gene expression responses thus significantly compromising antimycobacterial host immune responses.
Research Interest
Human antimycobacterial immunity; Human lung immunology during mycobacteriumtuberculosis infection and disease; Effects of particulate matter on antimycobacterial immunity
Publications
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Mukherjee, D, Porter, A, Ryan, M, Schwander, S, Chung, KF, Tetley, T, Zhang, J, Georgopoulos, P. Modeling In Vivo Interactions of Engineered Nanoparticles in the Pulmonary Alveolar Lining Fluid. Nanomaterials (Basel). 2015;5 (3):1223-1249. doi: 10.3390/nano5031223. PubMed PMID:26240755 PubMed Central PMC4521411
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Sarkar, S, Leo, BF, Carranza, C, Chen, S, Rivas-Santiago, C, Porter, AE, Ryan, MP, Gow, A, Chung, KF, Tetley, TD et al.. Modulation of Human Macrophage Responses to Mycobacterium tuberculosis by Silver Nanoparticles of Different Size and Surface Modification. PLoS ONE. 2015;10 (11):e0143077. doi: 10.1371/journal.pone.0143077. PubMed PMID:26580078 PubMed Central PMC4651328
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Sweeney, S, Leo, BF, Chen, S, Abraham-Thomas, N, Thorley, AJ, Gow, A, Schwander, S, Zhang, JJ, Shaffer, MSP, Chung, KF et al.. Pulmonary surfactant mitigates silver nanoparticle toxicity in human alveolar type-I-like epithelial cells. Colloids Surf B Biointerfaces. 2016;145 :167-175. doi: 10.1016/j.colsurfb.2016.04.040. PubMed PMID:27182651
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Theodorou, IG, Ruenraroengsak, P, Gow, A, Schwander, S, Zhang, JJ, Chung, KF, Tetley, TD, Ryan, MP, Porter, AE. Effect of pulmonary surfactant on the dissolution, stability and uptake of zinc oxide nanowires by human respiratory epithelial cells. Nanotoxicology. 2016;10 (9):1351-62. doi: 10.1080/17435390.2016.1214762. PubMed PMID:27441789 PubMed Central PMC5322737
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Zhang, JJ, Lee, KB, He, L, Seiffert, J, Subramaniam, P, Yang, L, Chen, S, Maguire, P, Mainelis, G, Schwander, S et al.. Effects of a nanoceria fuel additive on the physicochemical properties of diesel exhaust particles. Environ Sci Process Impacts. 2016;18 (10):1333-1342. doi: 10.1039/c6em00337k. PubMed PMID:27711787
