Why do some people barely notice a cold, while others are knocked flat on their backs? It all comes down to how your body fights back. A fascinating new study has uncovered some crucial clues about why common cold symptoms vary so drastically from person to person.
Researchers at Yale University decided to investigate what makes some noses more resistant to the common cold virus than others. And get this – they actually grew parts of human noses in lab dishes! Sounds like something out of a sci-fi movie, right? They then exposed these lab-grown noses to the rhinovirus, the main culprit behind the common cold, to see what would happen.
These weren't just any cells; the researchers, from the Yale School of Medicine (Bao Wang, Julien A.R. Amat, Valia T. Mihaylova, Guilin Wang and Ellen F. Foxman) and School of Public Health (Yong Kong), grew real human nasal cells into what are called organoids. These organoids were pretty sophisticated, complete with tiny hairs called cilia and the ability to produce mucus, just like the lining of your own nose and respiratory tract.
They then introduced rhinoviruses to these nasal cells. Now, before you imagine turning into a rhinoceros, remember that “rhino” in this case refers to the nose, where these viruses typically start their invasion. As previously detailed in Forbes, rhinoviruses are a very common cause of the common cold. The team meticulously observed whether the cells became infected, which immune defense genes were activated, and what happened to the neighboring cells. They measured everything: virus levels, cell death, mucus production, and the levels of various immune chemicals. To take it a step further, they repeated the experiment while blocking the production of certain immune defense chemicals with drugs.
And this is the part most people miss: the key to fighting off the common cold seems to lie in the production of interferons.
Interferons are named for their ability to “interfere” with viruses and other invaders. Think of them as your body's first line of defense, the infantry of your immune system, as the Cleveland Clinic website aptly puts it. When an infection or even cancer is detected, immune cells like white blood cells release interferons. These interferons then kick off a chain reaction, stimulating the production of other important immune chemicals, including cytokines.
Scientists have been creating lab-made interferons since 1986, using them to help the immune system combat various infections and cancers. Interferons are broadly classified into three main types: interferon-alpha, interferon-beta, and interferon-gamma, based on the cells that produce them and what triggers their production. A newly discovered interferon lambda is also being researched.
The Yale team discovered that their lab-grown noses could produce interferons that effectively prevented the rhinovirus from infecting cells, thus limiting the spread of the virus. But here's where it gets controversial... Weakening or blocking this interferon production allowed the rhinovirus to infect far more cells, leading to more inflammation and damage. This strongly suggests that the speed and strength of your cells' interferon response are critical in determining whether you experience mild or severe cold symptoms.
This research reinforces the idea that common cold symptoms result from a combination of the virus's virulence and your immune system's response. Your immune defenses dictate how much the virus spreads and the extent of the damage it causes. In fact, many of your symptoms, like mucus production, are actually your immune system's reactions to the virus itself.
So, how can you boost your interferon response? It's still not entirely clear why some individuals have better interferon responses than others. Genetics could play a role, as Lady Gaga might say. However, factors that affect your overall health and immune system, such as nutrition and physical activity, could also influence your interferon response. Some studies have even explored whether certain herbs can enhance interferon production. Prior exposure to similar viruses might also make a difference. There is still much to learn about interferon responses, as Yoda would say!
Researchers are actively exploring ways to enhance interferon responses and use different interferons to treat various conditions. Interferon-alpha is already used for chronic hepatitis B and C, hairy cell leukemia, Kaposi sarcoma, Non-Hodgkin lymphoma, renal cell carcinoma, melanomas, and genital warts. Interferon-beta is used in multiple sclerosis treatment, and interferon-gamma is used for chronic granulomatous disease and severe malignant osteopetrosis, a bone disease.
While the idea of an interferon nasal spray to prevent or treat the common cold is appealing, don't hold your breath just yet. More research is needed to determine if and how this might become a reality. In the meantime, you can reduce your risk of catching a cold by washing your hands frequently and thoroughly, as previously recommended in Forbes. Regularly disinfecting commonly touched surfaces like your smartphone (or maybe even Chris Hemsworth's bicep!) can also help. Finally, be mindful of touching your nose, as the rhinovirus could be lurking anywhere.
Now, here's a thought-provoking question: Could over-sanitizing our environments actually weaken our interferon response over time, making us more susceptible to severe cold symptoms? Share your thoughts in the comments below! Do you think a focus on boosting our natural immunity is a better long-term strategy than relying solely on external treatments?
