title: Traffic-related PM2.5 induces cytosolic [Ca²⁺] increase regulated by Orai1, alters the CaN-NFAT signaling pathway, and affects IL-2 and TNF-α cytoplasmic levels in Jurkat T-cells.
abstract: The atmospheric particulate matter with a diameter less than or equal to 2.5 um (PM2.5) can result in increased immune system damage or diseases, however, the possible mechanism remains unclear. In this study, we used Jurkat T cells to determine the effects of PM2.5 on T cell-mediated adaptive immune response. Our results indicated that PM2.5 exposure increased intracellular calcium ion concentration [Ca(2+)]. In contrast, cytosolic free Ca(2+) concentration [Ca(2+)]i significantly decreased in Jurkat T cells transfected with Orai1siRNA. In addition, we detected the level of interleukin (IL)-2 and tumor-necrosis factor (TNF)-α as well as other signalling molecules, including calcineurin (CaN) and NFATc2, a gene on 20q13.2 that encodes a member of the nuclear factor of activated T cells (NFAT), in the supernatant of cells exposed to PM2.5. The expression of NFATc2 protein increased in a time-dependent manner after exposure to PM2.5, but the activity of CaN decreased. NFATc2 was not consistent with IL-2 accumulation, thus indicating the involvement of other signals in the suppression of IL-2 accumulation. Our findings demonstrate that PM2.5 exposure in immune cells results in locally increased [Ca(2+)]i generated by Orai1 and CaN-NFAT gene expression, TNF-α and IL-2 cytoplasmic concentrations may be altered.
authors.affiliation: Department of Environmental Health, School of Public Health, Shanxi Medical University, Taiyuan, The People's Republic of China.
authors.forename: Guo-Qiang
authors.initials: GQ
authors.lastname: Tong
authors.forename: Zhi-Hong
authors.initials: ZH
authors.lastname: Zhang
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhao
authors.forename: Jie-Jing
authors.initials: JJ
authors.lastname: Liu
authors.forename: Jian-Biao
authors.initials: JB
authors.lastname: Han
mesh_terms: D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism*; D015870:Gene Expression; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism*; D019169:Jurkat Cells; D050778:NFATC Transcription Factors / Q000378:metabolism; D000071740:ORAI1 Protein; D052638:Particulate Matter / Q000633:toxicity*; D013601:T-Lymphocytes; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D015220:Calcium Channels; D007376:Interleukin-2; D050778:NFATC Transcription Factors; D000071740:ORAI1 Protein; C510746:ORAI1 protein, human; D052638:Particulate Matter; D014409:Tumor Necrosis Factor-alpha; D002118:Calcium