Immune cells show difference between e-cigarette and cigarette exposure

New research demonstrates how an analytical technique known as morphometric phenotyping can distinguish between the effects of different nicotine products on immune cells. This study lays the groundwork for more thorough safety testing of inhaled substances.

A new study carried out by ImmuONE’s Chief Scientific Officer Dr Victoria Hutter and ImmuONE’s Principal Lead Scientist Dr Ewelina Hoffman shows that morphometric phenotyping, a technique used to analyse the physical characteristics of cells, can discriminate between the effects of cigarette smoke and e-liquids on the immune cells of the lungs.

Many aerosolised products on the market are known to be deposited in the deep lung. However, in the past, these products either haven’t required thorough safety testing to reach the market or have not been able to be tested in animal studies. To improve product safety, it’s important for us to develop and refine methods that don’t use animals.

In vitro approaches, i.e. tests that are performed outside of living organisms, have previously been used to look at the effects of inhaled substances on epithelial cells, but less is known about immunological effects.

A study published in the journal Toxicology in Vitro demonstrates how an in vitro approach can be used to distinguish the effects of cigarette smoke and e-liquids on immune cells. Since e-cigarettes only date back to the mid-2000s, little is known about their long-term effects on lung health, especially in regard to possible harmful interactions with the immune system.

Cigarette smoke and e-liquids were extracted into ImmuPHAGE™ cell growth medium and applied to human alveolar-like macrophages, cell models designed to mirror the behaviour and function of immune cells in the deep lung. The study used two types of cell models, both provided by ImmuONE. The first model, ImmuPHAGE™ , contains macrophages, while ImmuLUNG™ contains a mixture of macrophages and epithelial cells.

The effects of e-liquids and cigarette smoke on the macrophages were contrasted through morphometric phenotyping. Compared to cigarette smoke, e-liquids had only minor effects on the physical characteristics of the immune cells. Additionally, while cigarette smoke increased cell membrane permeability, reduced mitochondrial activity, and reduced the number of cells, e-liquids had no significant effect on any of these factors. These findings suggest that the immune cells of the lung respond differently to cigarette smoke and e-liquids.

This study presents a rapid method of determining detailed immunological responses in the airways. These responses could be used to identify mechanisms of toxicity in inhaled substances, potentially leading to more thorough safety testing of aerosolised products.