Title

PPARγ Deficiency in Carbon Nanotube-elicited Granulomatous Inflammation Promotes a Th17 Response to a Microbial Antigen

Authors

Victoria Sanderford, Program in Lung Cell Biology and Translational Research, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Brody School of Medicine, East Carolina University, Greenville, NC, USA.
Barbara P. Barna, Program in Lung Cell Biology and Translational Research, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Brody School of Medicine, East Carolina University, Greenville, NC, USA.
Robert A. Barrington, Department of Microbiology and Immunology, University of South Alabama, Mobile, AL, USA.
Anagha Malur, Program in Lung Cell Biology and Translational Research, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Brody School of Medicine, East Carolina University, Greenville, NC, USA.
Arjun Mohan, Program in Lung Cell Biology and Translational Research, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Brody School of Medicine, East Carolina University, Greenville, NC, USA.
Nancy Leffler, Program in Lung Cell Biology and Translational Research, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Brody School of Medicine, East Carolina University, Greenville, NC, USA.
Eman Soliman, Program in Lung Cell Biology and Translational Research, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Brody School of Medicine, East Carolina University, Greenville, NC, USA.
Mary Jane Thomassen, Program in Lung Cell Biology and Translational Research, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Brody School of Medicine, East Carolina University, Greenville, NC, USA.

Document Type

Article

Publication Title

Journal of nanomedicine & nanotechnology

Abstract

BACKGROUND: The pathological consequences of interaction between environmental carbon pollutants and microbial antigens have not been fully explored. We developed a murine model of multi-wall carbon nanotube (MWCNT)-elicited granulomatous disease which bears a striking resemblance to sarcoidosis, a human granulomatous disease. Because of reports describing lymphocyte reactivity to mycobacterial antigens in sarcoidosis patients, we hypothesized that addition of mycobacterial antigen (ESAT-6) to MWCNT might elicit activation in T cells. METHODS: Macrophage-specific peroxisome-proliferator-activated receptor gamma (PPARγ) knock out (KO) mice were studied along with wild-type mice because our previous report indicated PPARγ deficiency in sarcoidosis alveolar macrophages. MWCNT+ESAT-6 were instilled into mice. Controls received vehicle (surfactant-PBS) or ESAT-6 and were evaluated 60 days post-instillation. As noted in our recent publication, lung tissues from PPARγ KO mice instilled with MWCNT+ESAT-6 yielded more intensive pathophysiology, with elevated fibrosis. RESULTS: Inspection of mediastinal lymph nodes (MLN) revealed no granulomas but deposition of MWCNT. MLN cell counts were higher in PPARγ KO than in wild-type instilled with MWCNT+ESAT-6. Moreover, the CD4:CD8 T cell ratio, a major clinical metric for human disease, was increased in PPARγ KO mice. Bronchoalveolar lavage (BAL) cells from PPARγ KO mice instilled with MWCNT+ESAT-6 displayed increased Th17 cell markers (RORγt, IL-17A, CCR6) which associate with elevated fibrosis. CONCLUSION: These findings suggest that PPARγ deficiency in macrophages may promote ESAT-6-associated T cell activation in the lung, and that the MWCNT+ESAT-6 model may offer new insights into pathways of lymphocyte-mediated sarcoidosis histopathology.

DOI

10.35248/2157-7439.20.11.541

Publication Date

1-1-2020

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