The Effects of Combustible Cigarettes and Electronic Nicotine Delivery Systems on Immune Cell-Driven Inflammation and Mucosal Healing in Ulcerative Colitis

Introduction:
This text discusses a study that investigates the effects of combustible cigarettes (CCs) and electronic nicotine delivery systems (ENDS) on immune cell-driven colon inflammation and mucosal healing in patients with ulcerative colitis (UC). The study compares the phenotype and function of immune cells in UC patients who use CCs or ENDS and analyzes changes in the phenotype of immune cells that infiltrate the colons of CC-exposed and ENDS-exposed mice suffering from DSS-induced colitis.

Key Points:

* The study found that continuous use of CCs and ENDS did not negatively affect progression of colon inflammation and mucosal healing in UC patients.
* Flow cytometry analysis revealed differences in the total number of leukocytes present in the blood of UC patients from experimental and control groups.
* The study found that an increased number of immunosuppressive T cells was observed in the blood of UCENDS patients, while a reduced presence of inflammatory Th1, Th2, and Th17 lymphocytes was noticed in the blood of UCCC patients.
* Exposure to either CC-derived smoke or ENDS-sourced aerosols was associated with enhanced mucosal healing, ameliorated spontaneous recovery, and improved survival of DSS-treated mice.
* An exposure to ENDS-sourced aerosols was linked to increased presence of immunosuppressive T lymphocytes, while exposure to CC-derived smoke was associated with reduced presence of inflammatory T cells in injured colons of DSS-treated mice.
* The study found that nicotine, contained within ENDS-sourced aerosol smoke, promoted generation of immunosuppressive immune cells, while CCs generated tar, CO, and harmful chemicals that impair survival and inhibit the proliferation of inflammatory immune cells in the injured colons.
* The study notes limitations, such as the relatively small size of the study cohorts and the challenge of determining cause-and-effect relationships, particularly in the human arm of the research.

Main Message:
The study suggests that despite different mechanisms of action, both ENDS and CCs attenuate ongoing colon inflammation, enhance healing, and ameliorate recovery of injured intestines of DSS-treated mice and UC patients. However, the study notes that ENDS and CC-dependent immunosuppression could have detrimental effects on immune surveillance of altered cells in the inflamed intestines, and the long-term effects of ENDS and CCs on the effectiveness of anti-tumor immunity against colon cancer cells should be analyzed in detail in subsequent experimental and clinical studies.

Nikolina Kastratovic, Vladimir Markovic, Aleksandar Arsenijevic, Ana Volarevic, Natasa Zdravkovic, Marija Zdravkovic, Marija Brankovic, Tijana Gmizic, Carl Randall Harrell, Vladimir Jakovljevic, Valentin Djonov, Vladislav Volarevic, The Effects of Combustible Cigarettes and Electronic Nicotine Delivery Systems on Immune Cell-Driven Inflammation and Mucosal Healing in Ulcerative Colitis, Nicotine & Tobacco Research, Volume 27, Issue 3, March 2025, Pages 542–552, https://doi.org/10.1093/ntr/ntae193