Vaping renders immune cells unable to move to meet threats

Inhaling vapour from an e-cigarette may be stopping frontline immune cells from working typically, as a new study shows that even moderate smoke exposure suppresses cell activity.

The findings are published in the Journal of Allergy and Clinical Immunology and suggest that inhaling e-cigarette smoke could be damaging neutrophils, the first line of defence the human immune system has. The findings are important as previous research has shown that damage caused to neutrophil by cigarette smoking can lead to long-term lung damage.

Researchers from the University of Birmingham and the NIHR Birmingham Biomedical Research Centre (BRC) took blood samples from healthy donors who had never smoked or vaped. The team then exposed neutrophils taken from the blood to 40 puffs of unflavoured vape, which previous studies have shown is a low daily exposure; with half of the samples were exposed to nicotine-containing vapour while the rest to nicotine-free alternatives.

“E-cigarettes are a proven, lower-harm, tool to help smokers quit smoking but our data adds to current evidence that e-cigarettes are not harmless and highlights the need to fund longer-term studies in vapers.”

– Dr Aaron Scott

Results of the tests showed that in both the nicotine and non-nicotine groups, the neutrophils remained alive but were stuck in place, rendering them incapable of effectively tackling threats to the body.

Dr Aaron Scott, Associate Professor in Respiratory Science at the University of Birmingham, researcher at the NIHR Birmingham BRC, and lead author of the study said: “We found that after short, low-level exposure to e-cigarette vapour, the cells remain alive but can no longer move as effectively and are unable to carry out their normal protective functions. Interestingly, vapour from e-liquids which did not contain nicotine also had the same negative effects as vapour from e-liquids which did contain nicotine.

“E-cigarettes are a proven, lower harm, tool to help smokers quit smoking but our data adds to current evidence that e-cigarettes are not harmless and highlights the need for to fund longer-term studies in vapers.”

Further experiments with neutrophils exposed to e-cigarette vapour suggest a build-up of a microfilament within the cells which are unable to re-arrange themselves properly is driving the suppression of the cells normal function.

Actin is usually found as small filaments within cells and rearrange themselves into a network to help a cell change its shape. This function is used by neutrophils so that they can move towards and surround threats to destroy them.

The team observed that there were high concentrations of the filament F-actin within the neutrophils that had been exposed to e-cigarette vapour, whether containing nicotine or not. The accumulation of the F-actin resulted in the immune cells being less able to move and function typically.

Many colourful e cigarettes on a flat surface

David Thickett, Professor in Respiratory Medicine at the University of Birmingham, Clinical Lead for the University Hospitals Birmingham (UHB) NHS Foundation Trust, and a co-author of the paper smoking cessation service and co-author of the paper said: “In health neutrophils normally protect the lungs by moving from the blood to the site of possible harm before using a number of protective functions to protect the lung. The observed impact that e-cigarette vapour had on their mobility is therefore of significant concern, and if this were to happen in the body would make those who regularly use e-cigarettes at greater risk of respiratory diseases.”

Professor Liz Sapey, Director of the Institute of Inflammation and Ageing at the University of Birmingham, co-lead of the NIHR Birmingham BRC Infection and Acute Care research theme, Honorary Acute Medicine and Respiratory Consultant Physician at UHB, and a co-author of the paper said: “Smoking has a well-documented impact on neutrophils, and this study further shows the impact that e-cigarettes still have on the immune system. Neutrophils are heavily implicated in ageing and chronic obstructive disease and their relationship with tissue damage, and the impact of vaping in suppressing neutrophil activity regardless of nicotine could have long term implications for health.”

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You can read the full paper in the Journal of Allergy and Clinical Immunology.

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Birmingham Health Partners (BHP)

The University of Birmingham is a founding member of Birmingham Health Partners (BHP), a strategic alliance which transcends organisational boundaries to rapidly translate healthcare research findings into new diagnostics, drugs and devices for patients. Birmingham Health Partners is a strategic alliance between seven organisations who collaborate to bring healthcare innovations through to clinical application:

    • University of Birmingham
    • University Hospitals Birmingham NHS Foundation Trust
    • Birmingham Women’s and Children’s Hospitals NHS Foundation Trust
    • Aston University
    • The Royal Orthopaedic Hospital NHS Foundation Trust
    • Sandwell and West Birmingham Hospitals NHS Trust
    • West Midlands Academic Health Science Network
    • Birmingham and Solihull Mental Health NHS Foundation Trust

About The National Institute for Health and Care Research

The mission of the National Institute for Health and Care Research (NIHR) is to improve the health and wealth of the nation through research. We do this by:

  • Funding high-quality, timely research that benefits the NHS, public health and social care;
  • Investing in world-class expertise, facilities and a skilled delivery workforce to translate discoveries into improved treatments and services;
  • Partnering with patients, service users, carers and communities, improving the relevance, quality and impact of our research;
  • Attracting, training and supporting the best researchers to tackle complex health and social care challenges;
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  • Funding applied global health research and training to meet the needs of the poorest people in low and middle-income countries.

NIHR is funded by the Department of Health and Social Care. Its work in low and middle-income countries is principally funded through UK Aid from the UK government.

The NIHR Birmingham Biomedical Research Centre is part of the NIHR and hosted by University Hospitals Birmingham NHS Foundation Trust in partnership with the University of Birmingham.

Dr Aaron Scott
Dr Aaron Scott