Evaluation of an air–liquid interface cell culture model for studies on the inflammatory and cytotoxic responses to tobacco smoke aerosols

Abstract

In vitro toxicological studies for tobacco product assessment have traditionally been undertaken using the particulate phase of tobacco smoke. However, this does not truly reflect exposure conditions that occur in smokers. Thus in vitro cell culture systems are required in which cells are exposed to tobacco whole smoke (WS) at the air-liquid interface (ALI). In this study bronchial epithelial cells were cultured on semi-permeable membranes, transitioned to the ALI and the robustness and sensitivity of the cells to tobacco WS and vapour phase (VP) assessed. Although no effect of air exposure was observed on cell viability, IL-6 and IL-8 release was increased. Exposure to WS resulted in a significant dose dependent decrease in cell viability and a significant non-dose dependent increase in inflammatory mediator secretion. The VP was found to contribute approximately 90% of the total cytotoxicity derived from WS. The cell culture system was also able to differentiate between two smoking regimens and was sensitive to passage number with increased inflammatory mediator secretion and lower cell viability observed in cell cultures of low passage number following WS exposure. This simple cell culture system may facilitate studies on the toxicological impact of future tobacco products and nicotine delivery devices.

A Case Study for the Comparison ofIn VitroData Across Multiple Aerosol Exposure Studies with Extrapolation to Human Dose

“…Studies were selected on the basis of several key criteria: (1) data were generated solely from Kentucky 3R4F reference cigarettes; (2) International Organization for Standardization (ISO) guidelines for puffing regimens and cigarette conditioning [ISO, 1999, 2012] were used consistently throughout; (3) Azzopardi et al 2015 36 Neilson et al 2015 37 Bishop et al 2018 38…”

“…Cytotoxicity data from contrasting and independent whole smoke studies were analyzed and presented using a consistent measure of dose (lg/cm 2 deposited mass and mg nicotine). Data from four previously published studies [35][36][37][38] were reanalyzed and combined with a previously unpublished data set using a comparative study design. Cytotoxicity data were supplemented with newly measured deposited mass of undiluted cigarette smoke, specifically obtained for this study to characterize the dilution principle.…”

“…In brief, Studies 1-4 are reanalyzed data. [35][36][37][38] Study Five is previously unpublished data. All percentage mass deliveries and fold dilutions are based on newly obtained data ( Fig.…”

Smoking and female sex as key risk factors associated with severe arthralgia in acute and chronic phases of Chikungunya virus infection

“…Increased IL-6 levels are associated with increased severity and persistence of joint pain (4). Notably, cigarette smoke extract in non-cytotoxic doses is capable of increasing the levels of IL-6 in cell cultures (28) and in animal models (29). Additionally, smoking correlates with higher serum levels of IL-6 in apparently healthy individuals, the elderly and HIV-infected patients (30)(31)(32).…”

Assessment of AcuteIn VitroHuman Cellular Responses to Smoke Extracts from a Reduced Toxicant Prototype Cigarette

“…Literature shows that the vapor phase is primarily responsible for the cytotoxic effects observed in this assay. 25,[30][31][32] The RTP cigarette had significant reductions in acetaldehyde and acrolein ( Supplementary Table S3) compared with the CC cigarette, both of which have been shown to inhibit cell proliferation and/or induce cytotoxicity in vitro. 12,[33][34][35][36][37] This may explain why WS from RTP cigarettes induced significantly less cytotoxicity in lung epithelial cells versus the CC cigarettes.…”