Immunomodulatory effects of cigarette smoke condensate in mouse macrophage cell line

Comparative toxicological assessment of cigarettes and new category products via an in vitro multiplex proteomics platform

Cigarette smoking is a risk factor for several diseases such as cancer, cardiovascular disease (CVD), and chronic obstructive pulmonary diseases (COPD), however, the underlying mechanisms are not fully understood. Alternative nicotine products with reduced risk potential (RRPs) including tobacco heating products (THPs), and e-cigarettes have recently emerged as viable alternatives to cigarettes that may contribute to the overall strategy of tobacco harm reduction due to the significantly lower levels of toxicants in these products' emissions as compared to cigarette smoke. Assessing the effects of RRPs on biological responses is important to demonstrate the potential value of RRPs towards tobacco harm reduction. Here, we evaluated the inflammatory and signaling responses of human lung epithelial cells to aqueous aerosol extracts (AqE) generated from the 1R6F reference cigarette, the glo™ THP, and the Vype ePen 3.0 e-cigarette using multiplex analysis of 37 inflammatory and phosphoprotein markers. Cellular exposure to the different RRPs and 1R6F AqEs resulted in distinct response profiles with 1R6F being the most biologically active followed by glo™ and ePen 3.0. 1R6F activated stress-related and pro-survival markers c-JUN, CREB1, p38 MAPK and MEK1 and led to the release of IL-1α. glo™ activated MEK1 and decreased IL-1β levels, whilst ePen 3.0 affected IL-1β levels but had no effect on the signaling activity compared to untreated cells. Our results demonstrated the reduced biological effect of RRPs and suggest that targeted analysis of inflammatory and cell signaling mediators is a valuable tool for the routine assessment of RRPs.

Dual Exposure to E-Cigarette Vapour and Cigarette Smoke Results in Poorer Airway Cell, Monocyte, and Macrophage Function Than Single Exposure

E-cigarette users predominantly also continue to smoke cigarettes. These Dual Users either consume e-cigarettes in locations where smoking is not allowed, but vaping is, or to reduce their consumption of cigarettes, believing it will lead to harm reduction. Whilst it is known that e-cigarette vapour is chemically less complex than cigarette smoke, it has a distinct chemical profile, and very little is known about the health impacts of exposure to both chemical profiles vs. either alone. We simultaneously exposed cells in vitro to non-toxic levels of e-cigarette vapour extract (EVE) and cigarette smoke extract (CSE) to determine their effects on 16HBE14o- airway epithelial cell metabolism and inflammatory response, as well as immune cell (THP-1 cells and monocyte-derived macrophages (MDM) from healthy volunteers) migration, phagocytosis, and inflammatory response. We observed increased toxicity, reduced metabolism (a marker of proliferation) in airway epithelial cells, and reduced monocyte migration, macrophage phagocytosis, and altered chemokine production after exposure to either CSE or EVE. These cellular responses were greater after dual exposure to CSE and EVE. The airway epithelial cells from smokers showed reduced metabolism after EVE (the Switcher model) and dual CSE and EVE exposure. When EVE and CSE were allowed to interact, the chemicals were found to be altered, and new chemicals were also found compared to the CSE and EVE profiles. Dual exposure to e-cigarette vapour and cigarette smoke led to worse functional outcomes in cells compared to either single exposure alone, adding to limited data that dual use may be more dangerous than smoking only.

18-β-glycyrrhetinic acid-loaded polymeric nanoparticles attenuate cigarette smoke-induced markers of impaired antiviral response in vitro

Tobacco smoking is a leading cause of preventable mortality, and it is the major contributor to diseases such as COPD and lung cancer. Cigarette smoke compromises the pulmonary antiviral immune response, increasing susceptibility to viral infections. There is currently no therapy that specifically addresses the problem of impaired antiviral response in cigarette smokers and COPD patients, highlighting the necessity to develop novel treatment strategies. 18-β-glycyrrhetinic acid (18-β-gly) is a phytoceutical derived from licorice with promising anti-inflammatory, antioxidant, and antiviral activities whose clinical application is hampered by poor solubility. This study explores the therapeutic potential of an advanced drug delivery system encapsulating 18-β-gly in poly lactic-co-glycolic acid (PLGA) nanoparticles in addressing the impaired antiviral immunity observed in smokers and COPD patients. Exposure of BCi-NS1.1 human bronchial epithelial cells to cigarette smoke extract (CSE) resulted in reduced expression of critical antiviral chemokines (IP-10, I-TAC, MIP-1α/1β), mimicking what happens in smokers and COPD patients. Treatment with 18-β-gly-PLGA nanoparticles partially restored the expression of these chemokines, demonstrating promising therapeutic impact. The nanoparticles increased IP-10, I-TAC, and MIP-1α/1β levels, exhibiting potential in attenuating the negative effects of cigarette smoke on the antiviral response. This study provides a novel approach to address the impaired antiviral immune response in vulnerable populations, offering a foundation for further investigations and potential therapeutic interventions. Further studies, including a comprehensive in vitro characterization and in vivo testing, are warranted to validate the therapeutic efficacy of 18-β-gly-PLGA nanoparticles in respiratory disorders associated with compromised antiviral immunity.

Epidemiological survey of warts in Chinese military recruits: A cross-sectional and follow-up study

Background

Warts are very common in military personnel, either at war or during peace times. However, little is known about the prevalence and natural course of warts in military recruits in China.

Objective

To investigate the prevalence and natural course of warts in Chinese military recruits.

Methods

In this cross-sectional study, the head, face, neck, hands, and feet of 3093 Chinese military recruits aged 16-25 years in Shanghai were examined for the presence of warts upon enlistment medical examinations. Questionnaires were distributed to collect the general information of the participants before the survey. All the patients were followed up by telephone interview for 11-20 months.

Results

The prevalence rate of warts in Chinese military recruits was 2.49%. The diagnosis of most cases was common and plantar warts, which were usually less than 1 cm in diameter and with mild discomfort. Multivariate logistic regression analysis showed that smoking and sharing personal items with others were risk factors. Coming from southern China was a protective factor. Over 2/3 of patients recovered within 1 year and the type, number, and size of warts and treatment choice did not predict resolution.Study limitations and Conclusions This study demonstrated that warts had a relative lower morbidity and a higher spontaneous resolution rate in Chinese military recruits. The telephone interviews following the initial survey and the limitations of a cross-sectional study were the main drawbacks.

Tobacco Use and Response to Immune Checkpoint Inhibitor Therapy in Non-Small Cell Lung Cancer

Tobacco is a known risk factor for lung cancer, and continued tobacco use is associated with poorer outcomes across multiple lung cancer treatment modalities including surgery, chemotherapy and radiation therapy. Less is known about the association of tobacco use and outcomes with immune checkpoint inhibitors (ICIs), which are becoming an important part of the treatment landscape in lung cancer, both in metastatic and curative settings. We reviewed the literature on the association of tobacco and tumor biology as it relates to immunotherapy. We also reviewed the association of tobacco use on outcomes among phase III randomized clinical trials involving ICIs in non-small cell lung cancer (NSCLC). We identified that patients with a smoking history may have a greater benefit with ICI treatment compared to never smokers in both treatment-naïve (HR 0.82, 95% CI 0.69–0.97, vs. HR 1.06, 95% CI 0.81–1.38) and pre-treated (HR 0.79, 95% CI 0.70–0.90 vs. 1.03, 95% CI 0.74–1.43) settings. In trials where smoking status was further defined, ex-smokers appear to demonstrate greater benefit with ICI therapy compared to current smokers (HR 0.78, 95% CI 0.59–1.01 vs. 0.91, 95% CI 0.72–1.14). We conclude by offering our perspective on future directions in this area of research, including implementation of standardized collection and analysis of tobacco use in clinical trials involving ICI therapy in lung cancer and other disease sites, and also evaluating how tobacco may affect toxicities related to ICI therapy. Based on our review, we believe that a patient’s history of tobacco smoking does have a role to play in guiding treatment decision making in patients with lung cancer.

Cytotoxicity, oxidative stress, and inflammatory response of smokeless tobacco extracts and cytotoxicity of combustible cigarette whole smoke in a 3D oral organotypic buccal cell model

Oral disease is frequently associated with viral and environmental exposures and oral hygiene. The use of tobacco is a risk factor in the development of oral disease. Cytotoxicity, inflammatory response, and oxidative stress have been reported to have a role in the development of oral disease. These three endpoints were evaluated in a 3D human oral buccal model, EpiOral™, following exposure to CORESTA reference smokeless tobacco products (CRPs) and cigarette whole smoke. CRPs for Swedish style snus (CRP1), moist snuff (CRP2), and dry snuff (CRP3) were each extracted in complete artificial saliva (CAS) with a ratio of 300 mg CRP to 1 mL of CAS. Each of the CRP extracts (15-300 mg/ml) were applied to the apical side of a 3D organotypic buccal cell model for 24 or 48 h continuously, then cytotoxicity (LDH), oxidative stress (8-isoprostane), and inflammatory response (IP10, IL-1α, and IL-8) were measured. Experiments with 3R4F cigarettes were conducted by exposing the buccal tissues to whole smoke for a maximum of 2.5 h. Cytotoxicity (MTT) was measured 24 h post-exposure. Exposure of buccal tissues to whole smoke from a cigarette induced a dose-dependent cytotoxic response. In contrast, the CRP extracts elicited minimal cytotoxicity (<15%) when compared to CAS (vehicle control), but time- and dose-dependent effects on oxidative stress and inflammatory response were observed. Collectively, these data demonstrate that a 3D organotypic buccal human model may be used to assess biological mechanisms (MOAs) involved in the development of oral disease following exposure to smokeless tobacco products and may be applicable for differentiation between tobacco product categories.

Cigarette smoke alters inflammatory genes and the extracellular matrix - investigations on viable sections of peripheral human lungs

Chronic obstructive pulmonary disease (COPD) is a complex chronic respiratory disorder often caused by cigarette smoke. Cigarette smoke contains hundreds of toxic substances. In our study, we wanted to identify initial mechanisms of cigarette smoke induced changes in the distal lung. Viable slices of human lungs were exposed 24 h to cigarette smoke condensate, and the dose–response profile was analyzed. Non-toxic condensate concentrations and lipopolysaccharide were used for further experiments. COPD-related protein and gene expression was measured. Cigarette smoke condensate did not induce pro-inflammatory cytokines and most inflammation-associated genes. In contrast, lipopolysaccharide significantly induced IL-1α, IL-1β, TNF-α and IL-8 (proteins) and IL1B, IL6, and TNF (genes). Interestingly, cigarette smoke condensate induced metabolism- and extracellular matrix–associated proteins and genes, which were not influenced by lipopolysaccharide. Also, a significant regulation of CYP1A1 and CYP1B1, as well as MMP9 and MMP9/TIMP1 ratio, was observed which resembles typical findings in COPD. In conclusion, our data show that cigarette smoke and lipopolysaccharide induce significant responses in human lung tissue ex vivo, giving first hints that COPD starts early in smoking history.

Exposure to biomass smoke induces pulmonary Th17 cell differentiation by activating TLR2 on dendritic cells in a COPD rat model

Almost three billion people in developing countries are exposed to biomass smoke (BS), which predisposes them to developing chronic obstructive pulmonary disease (COPD). COPD is associated with abnormal innate and adaptive immune responses in the lungs and systemic circulation, but the mechanisms underlying BS-COPD development are uncertain. We investigated the role of dendritic cells (DCs) and interleukin (IL)-17A in BS-COPD. We investigated T helper cell responses in the BS-exposed COPD rat model by flow cytometry, quantitative PCR, and enzyme-linked immunosorbent assays. We conducted ex vivo experiments to determine which antigen-presenting cells induce Th17 cell responses. We evaluated the in vitro effects of BS-related particulate matter (BRPM) (2.5 μm) on the function of bone marrow-derived dendritic cells (BMDCs). We found that BS exposure enhanced Th17 responses in the lungs of the COPD-modelled rats, and the stimulated DCs (but not the macrophages) were sufficient to induce naïve CD4 + T cells to produce IL-17A in ex vivo experiments. BRPM significantly enhanced the maturation and activation of DCs through Toll-like receptor 2 (TLR2), but not TLR4, and induced Th17 responses. Therefore, BS activated lung DCs through TLR2, which led to Th17 responses and emphysema in the rats. This process is possibly therapeutically targetable.

Anti-HIV Activity of Cucurbitacin-D against Cigarette Smoke Condensate-Induced HIV Replication in the U1 Macrophages

Chemodietary agents are emerging as promising adjuvant therapies in treating various disease conditions. However, there are no adjuvant therapies available to minimize the neurotoxicity of currently existing antiretroviral drugs (ARVs). In this study, we investigated the anti-HIV effect of a chemodietary agent, Cucurbitacin-D (Cur-D), in HIV-infected macrophages using an in-vitro blood-brain barrier (BBB) model. Since tobacco smoking is prevalent in the HIV population, and it exacerbates HIV replication, we also tested the effect of Cur-D against cigarette smoke condensate (CSC)-induced HIV replication. Our results showed that Cur-D treatment reduces the viral load in a dose-dependent (0-1 μM) manner without causing significant toxicity at <1 μM concentration. Further, a daily dose of Cur-D (0.1 μM) not only reduced p24 in control conditions, but also reduced CSC (10 μg/mL)-induced p24 in U1 cells. Similarly, Cur-D (single dose of 0.4 μM) significantly reduced the CSC (single dose of 40 μg/mL)-induced HIV replication across the BBB model. In addition, treatment with Cur-D reduced the level of pro-inflammatory cytokine IL-1β. Therefore, Cur-D, as an adjuvant therapy, may be used not only to suppress HIV in the brain, but also to reduce the CNS toxicity of currently existing ARVs.

Effects of smokeless tobacco on cell viability, reactive oxygen species, apoptosis, and inflammatory cytokines in human umbilical vein endothelial cells

Smokeless tobacco products provide an alternative to cigarettes; however, smokeless tobacco is carcinogenic and harmful to human health. This study evaluated the toxicological effects of snus extracts and cigarette smoke total particulate matter (TPM) on human umbilical vein endothelial cells (HUVECs). Treated cells were examined for cell viability, reactive oxygen species (ROS), apoptosis, and inflammatory cytokines. Moreover, we explored the mechanism of programmed cell death induced by snus. The results showed that snus extracts significantly inhibited cell viability in a dose-dependent manner. ROS was significantly increased in treatment groups, and anti-oxidant treatment could not prevent snus extract-induced cell death. Snus extracts induced apoptosis, DNA damage, activation and cleavage of caspase-3 and caspase-8, pathway-related gene change, and interleukin (IL)-6 and IL-8 release in HUVECs. Snus extracts exposure may induce cytotoxicity, ROS generation, inflammatory cytokines release, and apoptosis or DNA damage through intrinsic and extrinsic pathways in HUVECs.

Tobacco extracts promote PD-L1 expression and enhance malignant biological differences via mTOR in gefitinib-resistant cell lines

BACKGROUND

The aim of this study was to investigate whether tobacco extracts could regulate PD-L1 expression and enhance malignant biological differences in gefitinib-resistant cell lines.

METHODS

We constructed gefitinib-resistant cells and observed the biological differences in gefitinib-resistant cells. The cells were stimulated with medium containing 5% volume of tobacco extract, and the change in PD-L1 expression and the mammalian target of rapamycin (mTOR) and p-mTOR expression in gefitinib-resistant cells treated with tobacco extracts was observed. We discussed the relationship between PD-L1 and mTOR.

RESULTS

Tobacco extracts could promote PD-L1 expression in the cell line. Western blot analysis showed that mTOR and p-mTOR were significantly enhanced in gefitinib-resistant cell lines cultured in the tobacco extracts. The mTOR signaling pathway was involved in PD-L1 expression and in regulating the expression of cytokines IL-6 and IL-23. In addition, the tobacco extracts could promote macrophage migration via mTOR/IL-6.

CONCLUSIONS

PD-L1 can transmit inhibitory signals and reduce the proliferation of CD8 + T cells in lymph nodes. Tobacco extracts upregulate PD-L1 expression via mTOR/IL-6. These results imply that lung cancer patients should not smoke and stay away from a smoke environment.

E-cigarettes: Effects in phagocytosis and cytokines response against Mycobacterium tuberculosis

Cigarette smoking and tuberculosis are a significant cause of death worldwide. Several epidemiological studies have demonstrated cigarette smoking is a risk factor for tuberculosis. Electronic cigarettes have recently appeared as a healthier alternative to conventional smoking, although their impact in tuberculosis is not well understood. The aim of this study was to explore the effect of electronic cigarettes in phagocytosis of Mycobacterium tuberculosis and cytokines production. In vitro infection was carried out by exposing THP-1 macrophages to four electronic vapor extracts and the intracellular burden of M. tuberculosis was determined. The percentage of infection was evaluated by confocal microscopy and the cytokine production by Luminex. A reduction of intracellular M. tuberculosis burden in THP-1 macrophages was found after its exposure to electronic vapor extract; the same trend was observed by confocal microscopy when Mycobacterium bovis BCG-GFP strain was used. Electronic cigarettes stimulate a pro-inflammatory cytokine response. We conclude that electronic cigarettes impair the phagocytic function and the cytokine response to M. tuberculosis.

A review of the effects of tobacco smoking on cancer treatment: smoking cessation intervention should be integrated into the cancer care continuum

Background:

The adverse health effects associated with smoking tobacco have been well investigated, and its detrimental effects on cancer treatment outcomes, efficacy and quality of life (QOL) for cancer patients have also been well documented. Tobacco smoke contains many thousands of chemicals, including a plethora of carcinogens, and the exposure of human cells to these carcinogens, and their metabolic activation, is the main mechanism by which smoking-related cancer is initiated.

Materials and Methods:

This paper reports on a narrative review of recent studies in the field of effects of tobacco smoking on cancer treatment, including the effects of carcinogens in smoke on carcinogenesis, cell mutations and the immune system. The health effects of smokeless tobacco, effects of tobacco smoking on cancer treatment, and its impact on surgery, radiation therapy and chemotherapy are reported. The potential risks of second primary cancers or recurrence from tobacco use, the effects of second-hand smoking and cancer treatment, the impact of smoking on the QOL after cancer treatment and the need to integrate smoking cessation programs into the cancer care continuum are also reported.

Conclusions:

Tobacco use has a direct impact on cellular function by inhibiting apoptosis, stimulating proliferation and decreasing the efficacy of cancer treatment; therefore, quitting its use has the potential to improve treatment response rates and survival, as well as reduces the risk of developing second cancers and potentially improves the QOL after treatment. Smoking cessation is one of the most important interventions to prevent cancer and is also essential after the diagnosis of cancer to improve clinical outcomes. Due to the numerous benefits of smoking cessation, it should become a critical component of the cancer care continuum in all oncology programs – from prevention of cancer through diagnosis, treatment, survivorship and palliative care. Evidence-based smoking cessation intervention should be sustainably integrated into any comprehensive cancer program, and the information should be targeted to the specific benefits of cessation in cancer patients.

Cigarette Smoking Modulation of Saliva Microbial Composition and Cytokine Levels

Tobacco use has been implicated as an immunomodulator in the oral cavity and contributes to the development of oral cancer. In the present study, we investigated the effects of cigarette smoking on bacterial diversity and host responses compared to healthy nonsmoking controls. Saliva samples were collected from eighteen smokers and sixteen nonsmoking individuals by passive drool. The 16S rRNA gene was used to characterize the salivary microbiome by using the Illumina MiSeq platform. Cytokine and chemokine expression analyses were performed to evaluate the host response. Significant differences in cytokine and chemokine expression levels of MDC, IL-10, IL-5, IL-2, IL-4, IL-7, adrenocorticotropic hormone (ACTH), insulin, and leptin were observed between smokers and nonsmokers. Taxonomic analyses revealed differences between the two groups, and some bacterial genera associated with the smokers group had correlations with hormones and cytokines identified as statistically different between smokers and nonsmokers. These factors have been associated with inflammation and carcinogenesis in the oral cavity. The data obtained may aid in the identification of the interactions between the salivary microbiome, host inflammatory responses, and metabolism in smokers.

Tobacco Smoke Induces and Alters Immune Responses in the Lung Triggering Inflammation, Allergy, Asthma and Other Lung Diseases: A Mechanistic Review

Many studies have been undertaken to reveal how tobacco smoke skews immune responses contributing to the development of chronic obstructive pulmonary disease (COPD) and other lung diseases. Recently, environmental tobacco smoke (ETS) has been linked with asthma and allergic diseases in children. This review presents the most actual knowledge on exact molecular mechanisms responsible for the skewed inflammatory profile that aggravates inflammation, promotes infections, induces tissue damage, and may promote the development of allergy in individuals exposed to ETS. We demonstrate how the imbalance between oxidants and antioxidants resulting from exposure to tobacco smoke leads to oxidative stress, increased mucosal inflammation, and increased expression of inflammatory cytokines (such as interleukin (IL)-8, IL-6 and tumor necrosis factor α ([TNF]-α). Direct cellular effects of ETS on epithelial cells results in increased permeability, mucus overproduction, impaired mucociliary clearance, increased release of proinflammatory cytokines and chemokines, enhanced recruitment of macrophages and neutrophils and disturbed lymphocyte balance towards Th2. The plethora of presented phenomena fully justifies a restrictive policy aiming at limiting the domestic and public exposure to ETS.