消灭感冒病毒或应对其他威胁, 身体在权衡

龙血树

Fighting the cold virus and other threats, body makes trade-off, says study
Date:
September 11, 2018
Source:
Yale University
Summary:
A research team has revealed how cells in different parts of the human airway vary in their response to the common cold virus. Their finding could help solve the mystery of why some people exposed to the cold virus get ill while others don't, said the researchers.
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New research could help solve the mystery of why some people exposed to the cold virus get ill while others don't.
Credit: © Nichizhenova Elena / Fotolia
A Yale research team has revealed how cells in different parts of the human airway vary in their response to the common cold virus. Their finding, published in Cell Reports, could help solve the mystery of why some people exposed to the cold virus get ill while others don't, said the researchers.

Rhinovirus is a leading cause of the common cold, asthma attacks, and other respiratory illnesses. When the cold virus enters the nose, cells that line the airways, known as epithelial cells, respond and often clear the virus before it can replicate and trigger symptoms. But in other cases, individuals exposed to the virus get either mildly or seriously ill. A team of researchers, led by Ellen Foxman, set out to determine why.

The research team used epithelial cells from healthy human donors. The cells were derived from either the nasal passages or the lungs. They exposed both cell types, maintained under the same conditions in cell culture, to rhinovirus. To their surprise, the researchers observed a more robust antiviral response in nasal cells.

To investigate further, the researchers triggered the virus surveillance pathway -- known as the RIG-I pathway -- in both nasal and lung cells. They found that both cell types generated an antiviral response and a defense response against oxidative stress, a form of cell damage induced by viruses and other inhaled irritants such as cigarette smoke or tree pollen. In nasal cells, the antiviral response was stronger, but in bronchial cells, defense against oxidative stress was more pronounced.

In additional experiments, the research team found evidence for a tradeoff: The defense response against oxidative stress shut off antiviral defenses. To probe this further, the team exposed nasal cells to oxidative stress in the form of cigarette smoke, and then to the cold virus, and found that the nasal cells were more susceptible to the virus. "They survive the cigarette smoke but can't fight the virus as well," Foxman said. "And the virus grows better."

This finding points to a delicate balance between the body's different defense mechanisms, Foxman said. "Your airway lining protects against viruses but also other harmful substances that enter airways. The airway does pretty well if it encounters one stressor at a time. But when there are two different stressors, there's a tradeoff," Foxman explained. "What we found is that when your airway is trying to deal with another stress type, it can adapt but the cost is susceptibility to rhinovirus infection."

The study, she said, shows a mechanistic link between environmental exposures and susceptibility to the common cold, and also may explain why smokers tend to be more susceptible to rhinovirus infection. The researchers hope the finding will lead to the discovery of new strategies to combat respiratory viruses, which cause an estimated 500 million colds and 2 million hospitalizations in the United States per year.

Other Yale authors are Valia T. Mihaylova, Yong Kong, Olga Fedorova, Lokesh Sharma, Charles S. Dela Cruz, Anna Marie Pyle, and Akiko Iwasaki.

This work was supported in part by the National Institutes of Health and the Howard Hughes Medical Institute. A.M.P. has a patent pending for RIG-I stimulation agent SLR-14.

Story Source:

Materials provided by Yale University. Original written by Ziba Kashef. Note: Content may be edited for style and length.

Journal Reference:

Valia T. Mihaylova, Yong Kong, Olga Fedorova, Lokesh Sharma, Charles S. Dela Cruz, Anna Marie Pyle, Akiko Iwasaki, Ellen F. Foxman. Regional Differences in Airway Epithelial Cells Reveal Tradeoff between Defense against Oxidative Stress and Defense against Rhinovirus. Cell Reports, September 11, 2018 DOI: 10.1016/j.celrep.2018.08.033

龙血树

文章大意：抗感冒病毒还是抗其他威胁？人体需要权衡。（西医研究越来越有中医风格了，机械性在减少）

这个研究是看机体对于鼻病毒的反应，鼻病毒是引起感冒、哮喘等呼吸道疾病的主要病毒。人体有时候直接清除鼻病毒，有时候不管它，直到发展成症状。

研究者发现，机体的反应是因为还需要应对氧化损伤等其他威胁，需要权衡先去清除哪一些威胁。当抽烟引起氧化损伤，常常先去清除抽烟引起的危害，而顾不上清除鼻病毒，所以抽烟的人往往更容易感冒。

lorry

Good to know.