Tag: immune suppression

Categories : Exercise Immune SystemTags :

Firefighter Study Reveals how Extreme Exercise can Suppress the Immune System

On By ModernMedia
Source: CC0

A study of firefighters on a punishing training course has revealed clues as to why extreme exercise temporarily weakens the immune system – a phenomenon seen in elite athletes. The findings, published in Military Medical Research, may lead to better ways to support the health of people who undergo extreme exertion, such as firefighters tackling wildfires.

Thirteen firefighters volunteered for the study, average age 25 and male. They went through a rigorous training exercise, carrying 9 to 20kg of gear over hilly terrain during a 45-minute training exercise in the California sun. Gloves, helmets, flashlights, goggles, and more weighted them down as they sprinted through the countryside wearing fire-resistant clothing to show they were ready to serve as wildland firefighters.

After the training, they immediately gave samples of their blood, saliva, and urine for analysis. Two were excluded, one being unable to finish the course and the other arriving to late to provide a sample. The 11 participants who completed the course lost an average of 2.2% of their initial weight.

Then, the scientists from the Department of Energy’s Pacific Northwest National Laboratory (PNNL) analysed more than 4700 molecules, consisting of proteins, lipids, and metabolites, from each of the firefighters, looking to understand what happens when the body undergoes intense physical exercise. Measuring and interpreting the data from thousands of such measurements is a specialty of PNNL scientists who explore issues related to climate science and human health by analysing millions of sensitive measurements using mass spectrometry each year.

The researchers’ aim was to increase safety for first responders and others.

“Heat stress can be life threatening,” said Kristin Burnum-Johnson, a corresponding author of the study. “We wanted to take an in-depth look at what’s happening in the body and see if we’re able to detect danger from exhaustion in its earliest stages. Perhaps we can reduce the risk of strenuous exercise for first responders, athletes, and members of the military.”

As expected, the team detected hundreds of molecular changes in the firefighters. The differences before and after exercise underscored the body’s efforts at tissue damage and repair, maintenance of fluid balance, efforts to keep up with increased energy and oxygen demand, and the body’s attempts to repair and regenerate its proteins and other important substances.

But in the saliva, the team found some unexpected results. There was a change in the microbial mix of the mouth – the oral microbiome – showing that the body was increasingly on the lookout for bacterial invaders. Scientists also saw a decrease in signaling molecules important for inflammation and for fighting off viral infections.

A decrease in inflammation makes sense for people exercising vigorously; less inflammation allows people to breathe in air more quickly, meeting the body’s eager demand for more oxygen. Having fewer inflammatory signals in the respiratory system helps the body improve respiration and blood flow.

Less inflammation, more inhalation

But less inflammation leaves the body more vulnerable to viral respiratory infection, which other studies observed in elite athletes and others who exercise vigorously. Some studies have shown that a person is up to twice as likely to come down with a viral respiratory infection in the days after an especially energetic workout.

“People who are very fit might be more prone to viral respiratory infection immediately after vigorous exercise. Having less inflammatory activity to fight off an infection could be one cause,” said Ernesto Nakayasu, a corresponding author of the paper. He notes that the work provides a molecular basis for what clinicians have noticed in their patients who do strenuous workouts.

The team hopes that the findings will help explain why come people are more vulnerable to respiratory infection after a workout.

Source: DOE/Pacific Northwest National Laboratory

Categories : Immune SystemTags :

Airway Immune Risks of Fourth Generation e-Cigarettes

On By ModernMedia
Photo by Nery Zarat on Unsplash

Fourth-generation e-cigarettes, such as Juul devices, are associated with unique changes in markers of immune responses inside our airways, according to a new peer-reviewed paper in the American Journal of Respiratory and Critical Care Medicine.

Third-generation e-cigarettes include vape pens and box mods. Fourth generation include nicotine-salt-containing e-cigarettes, such as Juul products, and disposable e-cigarettes, which have become increasingly popular, especially after the recent FDA ban on the sale of Juul products.

Researchers in the lab of Professor Ilona Jaspers at the UNC School of Medicine found that users of fourth-generation nicotine-salt-containing devices display a unique mix of cellular biomarkers indicative of immune suppression.

“Our work demonstrates the importance of considering device type in future clinical, epidemiological, and mechanistic studies on the health effects of e-cigarettes,” said Prof Jasper, who led the study. “We also think this research can help regulators determine which products cause the most severe types of biological changes in airway cells important for maintaining proper health.”

E-cigarettes have become popular in the last decade. Some started used them to quit smoking, believing vaping was a safer alternative, both in the short-term and long-term. Also, because electronic cigarettes don’t contain tar, consumers assumed vaping decreased their risk of cancer down the road.

“It’s impossible to know if vaping decreases cancer risk or many other long-term conditions,” Prof Jaspers said. “It took 60 years of research to show that smoking causes cancer.” In contrast, e-cigarettes have only been around for about 15 years. “Still, the research from our lab and many others has shown many of the same acute biological effects in the airways that we have documented in smokers,” she said. “And we’ve seen some changes to cells and immune defences in people who vape that, frankly, we’ve never seen before, which is very concerning.”

A major concern for researchers, doctors, and public health officials is the fact that teenagers who would not have otherwise tried cigarettes began using e-cigarettes, which contain nicotine – with its attendant health implications – and thousands of chemicals, many of which are FDA-approved for eating but not inhaling.

Several studies have documented that inhaling chemical-laden nicotine aerosols suppresses the immune responses in the respiratory tracts of smokers and e-cigarette users. Some studies, including some at UNC, have detailed how different chemicals in various e-cigarettes, including chemicals that make up thousands of different flavours, have adverse effects on airway cells. The Jaspers lab, which has been at the forefront of such research, set out to study the effects of different varieties of e-cigarette devices. For this study, her team collected central airway (sputum) samples from non-smokers, smokers, and users of both third-generation and fourth-generation e-cigarette devices.

They found that users of fourth-generation e-cigarettes had significantly more bronchial epithelial cells in their sputum, suggestive of airway injury because normally, bronchial epithelial cells make up an intact barrier in the airways and are not found in sputum samples. Levels of two proteins, sICAM1 and sVCAM1, were significantly lower in fourth-generation e-cigarette users compared to all other groups. These proteins are important in fighting infections and other disease.

In addition, proteins are important for overall immune defence were significantly lower in fourth versus third generation e-cigarette users. Lower of these proteins – CRP, IFN-g, MCP-1, uteroglobin, MMP-2, and VEGF – indications immune system depression. “Another key finding of the study was that, when examining the mixture of immune markers overall rather than one by one, fourth generation e-cigarette users had the most distinguishable changes out of all of the groups, indicating a shift away from immune homeostasis,” said the study’s lead author, Elise Hickman, PhD.

The study did not demonstrate that e-cigarettes cause cancer, emphysema, COPD, or other long-term diseases associated with long-term cigarette smoking. But researchers think that altering immune responses in the respiratory tract over the course of many years, especially for teens, could play a major role in the development of long-term health conditions and in susceptibility to inhaled pathogens.

Source: University of North Carolina