Heightened Immunity To Colds Makes Asthma Flare-Ups Worse, U-M Research Shows

Tempering the immune response — rather than enhancing it — in asthma patients might be a better strategy when combating cold symptoms

People often talk about “boosting” their immunity to prevent and fight colds. Nutritional supplements, cold remedies and fortified foods claim to stave off colds by augmenting the immune system.

A new University of Michigan study shows this strategy might actually be flawed. The results may hold important implications for individuals with asthma, who often experience life-threatening flare-ups due to infections with cold viruses.

The study, using a novel mouse model, shows that, in the airways, the immune response to the common cold is actually maladaptive. Mice that were engineered to have a reduced innate immune response to the common cold actually showed less – not more – airway inflammation and bronchoconstriction (airway spasm) following infection.

The results of this study appeared online ahead of print in the journal PLoS Pathogens, currently available online. Marc B. Hershenson, M.D., professor of pediatrics and communicable diseases and director of the division of pediatric pulmonology, is the study’s senior author.

“You often hear that people want to boost their immunity to prevent and fight colds,” says Hershenson. “However, boosting the immune response could increase inflammation. Up to now there have been no convincing data supporting the theory that the immune response might be deleterious. In our study, we offer the first direct evidence that limiting the immune response reduces the manifestations of rhinovirus infection.”

“In our model, cold-induced asthma flare-ups were caused by the body’s immune response to the virus, not the virus itself. Chemicals produced by the immune system inflame cells and tissues, causing asthma symptoms such as cough and wheeze,” Hershenson explained.

Hershenson and his group hypothesized that limiting the immune response to viral infection would actually reduce their symptoms. Using a rhinovirus 1B, a cold virus strain that replicates in mouse lungs, they infected mice deficient in MDA5 and TLR3 – two receptors that trigger the protective defenses of the immune system against viruses and other pathogens.

MDA5-deficient mice showed a delayed defensive response to the infection, leading to a small increase in the level of virus in the lungs. Nevertheless, these mice showed less airway inflammation and bronchoconstriction following infection compared to wild-type mice. TLR3-deficient mice also showed diminished airway responses.

In addition, MDA5- and TLR3-null mice that were made asthmatic by exposure to allergen showed decreased airway inflammatory and contractile responses in response to rhinovirus infection compared to normal mice. These results suggest that, in the context of rhinovirus infection, reducing the mouse’s innate immune system led to reduced inflammatory signaling pathways and reduced airways inflammation and hyper-responsiveness.

“This study shows that, once you have a cold, elements of the immune response actually make the symptoms worse,” Hershenson adds. “A better strategy might be to modulate the immune response in asthma patients with colds.”

Contacts and sources:

Written by Margarita Wagerson

University of Michigan Health System

Authors: Qiong Wang, Ph.D., David J. Miller, M.D., Ph.D., Emily R. Bowman, Deepti R. Nagarkar, Ph.D., Dina Schneider, Ph.D., Ying Zhao, Marisa J. Linn, Adam M. Goldsmith, Ph.D., J. Kelley Bentley, Ph.D., Umadevi S. Sajjan, Ph.D, Marc B. Hershenson, M.D., all of the University of Michigan

Funding: National Institutes of Health

Disclosures: None

Citation: Wang Q, Miller DJ, Bowman ER, Nagarkar DR, Schneider D, et al. (2011) MDA5 and TLR3 Initiate Pro-Inflammatory Signaling Pathways Leading to Rhinovirus-Induced Airways Inflammation and Hyperresponsiveness. PLoS Pathog 7(5): e1002070. doi:10.1371/journal.ppat.1002070

The University of Michigan C.S. Mott Children’s Hospital is consistently ranked as one of the best hospitals in the country. It was nationally ranked in all ten pediatric specialties in the U.S. News Media Group’s 2011 edition of “America’s Best Children’s Hospitals” including third in the country for heart and heart surgery. In November, the hospital moves to a new 1.1 million square feet, $ 754 million state-of-the-art facility that will be home to cutting-edge specialty services for newborns, children and women.

What is the best natural treatment for colds ?

Natural cold remedies can reduce the effects of the cold and help your body fight it off in a completely natural way. The common cold is the most common ailment in the world.

Children in school are more prone to the common cold because of their proximity to each other and families that have children in school are more apt to have the condition make its way through every member of the family.

Low Immune System

When your immune system is low you are even more likely to catch one of the many cold viruses.
Health nutrition , eating a well balanced and healthy , is a great way to make sure that your immune system is able to fight off the viruses that are the causes of a cold.

Herbal Treatments

There are a number of natural cold remedies and herbs that can be used to treat the symptoms of a cold that are very beneficial and can help you to feel better in a short period of time. Home cold remedies and herbal treatments are a wonderful alternative for many people because there is generally a lack of side effects with these treatments. Many commercial common cold remedies will leave you feeling drowsy when you take them to fight the symptoms of a cold. Natural herbal remedies used in the treatment for colds are not as likely to cause these effects.

These natural common cold remedies and teas can be very effective at eliminating the body aches that accompany colds and will work to restore your immune system so that it is better able to fight off the virus that is causing all of your symptoms.

There are also Preventive Steps you can Take to Avoid Colds:

Hand Washing is a simple habit, something most people do without thinking. However, hand washing, when done properly, is one of the best ways to avoid getting sick. If you don’t wash your hands frequently enough, you can affect yourself with these germs by touching your eyes, nose and mouth or by touching surfaces that they also touch, such as door knobs.

Properly washing your hand with soap and water for 15 – 20 seconds has a great impact on keeping the infection away. When soap and water are not available, then the next best alternative is an alcohol-based hand sanitizer. Hand washing does not take much time and becomes more of a habit over time, but it offers great reward in terms of preventing illness.

Using Water and herbal teas. Drink lots of liquids, at least 8 – 12 cups per day.You can’t flush a cold out of your system, but drinking plenty of liquids can help. Water, juice, clear broth or warm lemon water with honey helps loosen congestion and prevent dehydration. Keeping the body well hydrated helps the immune system work better and flushes our systems of bacteria and viruses.

Cold Remedy – using Saltwater gargle. Add a 1/2 teaspoonful of salt to a 8-ounce glass of warm water stir until salt dissolves. This will temporarily comfort a sore or scratchy throat.

Cold Remedy – using Garlic is one of the more favorite home cures for colds. Many cultures have a home remedy for the cold using garlic, whether it’s chicken soup with lots of garlic, a drink made with raw crushed garlic, or if it just involves eating raw garlic. Garlic has lots of immune boosting capabilities.

Garlic remedy

Squirt a dab of honey onto a teaspoon
Press one garlic clove on top of the honey
Cover with another dab of honey.
This may be hard on your stomach at first. The garlic adds a bit of bitterness, but the honey does a great job lessening the bitterness.

Avoid Sugary drinks and caffeinated sodas should be avoided. A high sugar intake decreases the ability of the white blood cells to kill bacteria.

Contaminated toothbrush When you are recovering from illness, it is a good time to change your toothbrush. Your toothbrush can hide the germs you have just been fighting off.