Home Medizin Studie zeigt die langfristigen Auswirkungen des Rauchens auf die Immunität

Studie zeigt die langfristigen Auswirkungen des Rauchens auf die Immunität

von NFI Redaktion

Smoking, like other factors such as age, gender, and genetics, has a significant impact on the immune response. This recent discovery was made by a team of scientists at the Pasteur Institute using the „Inner Milieu“ cohort of 1,000 healthy volunteers, which was established to understand the variability of immune responses. In addition to its short-term effects on immunity, smoking also has long-term consequences. Many years after quitting smoking, smokers retain the effects on some of their body’s defense mechanisms that they acquired from smoking. These findings, revealing a long-term memory of the effects of smoking on immunity, are published in the journal „Nature“ on February 14, 2024.

The individual immune system varies significantly in terms of its effectiveness in responding to microbial attacks. But how can this variability be explained? What factors cause these differences? „To answer this key question, we established the ‚Inner Milieu‘ cohort of 1,000 healthy individuals aged 20 to 70 in 2011,“ commented Darragh Duffy, head of the translational immunology department at the Pasteur Institute and last author of the study. While certain factors such as age, gender, and genetics are known to be important, the aim of this new study was to determine which other factors had the greatest impact on the immune system.

The scientists exposed blood samples from individuals in the „Inner Milieu“ cohort to a variety of microbes (viruses, bacteria, etc.) and observed their immune response by measuring the amount of secreted cytokines. Based on the large amount of data collected for individuals in the cohort, the team determined which of the 136 variables investigated (body mass index, smoking, number of hours of sleep, physical activity, childhood illnesses, vaccinations, living environment, etc.) had the greatest impact on the immune responses studied. Three variables stood out: smoking, latent cytomegalovirus infection, and body mass index. „The influence of these three factors on certain immune responses could be equivalent to that of age, gender, or genetics,“ emphasizes Darragh Duffy.

With regard to smoking, an analysis of the data showed that the inflammatory response triggered immediately by an infection with a pathogen was enhanced in smokers, and furthermore, the activity of certain cells involved in immune memory was impaired. In other words, this study shows that smoking not only disrupts innate, but also some adaptive immune mechanisms. „A comparison of the immune responses in smokers and ex-smokers found that the inflammatory response returned to a normal level quickly after smoking cessation, while the effects on adaptive immunity persisted for 10 to 15 years,“ observes Darragh Duffy. „This study provides the first evidence of the long-term impact of smoking on immune response.“

Fundamentally, the immune system seems to have a long-term memory for the effects of smoking. But how?

„When we found that the profiles of smokers and ex-smokers were similar, we immediately suspected that epigenetic processes were at play.“

Violaine Saint-André, bioinformatician in the translational immunology department of the Pasteur Institute and lead author of the study.

„We have shown that the long-term effects of smoking on the immune response are associated with differences in DNA methylation between smokers, ex-smokers, and non-smokers – with the potential to alter the expression of genes involved in the metabolism of immune cells.“ Therefore, it seems that smoking can induce persistent changes in the immune system through epigenetic mechanisms.

„This is an important discovery that highlights the effects of smoking on the immunity of healthy individuals and, in comparison, on the immunity of people with various diseases,“ concludes Violaine Saint-André.


Journal reference:

Saint-André, V., et al. (2024). Smoking alters adaptive immunity with lasting effects. Nature. doi.org/10.1038/s41586-023-06968-8.

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