|
For most people with asthma , a couple of puffs from an inhaler filled with steroids makesbreathing easy. But if their lungs become resistant to the calmingeffect of that medicine, they live in fear of severe asthma attacksthat could send them to the hospital - or worse. Now, new research from the University of Michigan Health System mayhelp explain what's going on in the lungs of thesesteroid-resistant individuals. The findings could aid thedevelopment of new treatment options, and of better ways toidentify people at risk of becoming steroid-resistant. The U-M scientists have discovered a new type of cell in mice thatappears to be crucial to causing asthma symptoms - even in thepresence of steroid. The research, published in Nature Medicine , also showed that people with asthma have a very similar cell typein their blood at higher levels than people without the condition. The researchers call the new cell type T2M, for type 2 myeloid -reflecting its origin in the bone marrow and its involvement in the"type 2" immune response that causes asthma symptoms. In the lungs,T2M cells were shown to receive specific distress signals sent outby cells in the lung lining - and to produce molecules that lead tomore inflammation. The role of these cells was uncovered after a persistent search bya team led by pathology professor Nicholas Lukacs, Ph.D., and BryanPetersen, a student in U-M Medical School's Medical ScientistTraining Program who recently completed a Ph.D. thesis based onthese findings. They found the cells while examining the role of a signalingmolecule called interleukin 25, or IL-25 -- a type of proteincalled a cytokine that other asthma-probing scientists andpharmaceutical companies are also looking closely at. The U-M team searched for cells that had a receptor on theirsurface capable of receiving IL-25's inflammation-promoting signal,and isolated a type of granulocyte that hadn't been observedbefore. They found that when these cells received IL-25 signals,they pumped out more inflammation-promoting cytokines called IL-4and IL-13 that drive hallmarks of asthma such as mucus formation. What's more, the cells could still do this in the presence of asteroid medication. And, the researchers showed they couldessentially give steroid-resistant asthma to an animal that didn'thave it or IL-25 receptors, by transferring the cells to theirlungs. They then partnered with U-M asthma and allergy specialist AlanBaptist, M.D., an assistant professor of internal medicine, to seeif T2M-like cells could be found in humans. They recruited volunteers both with and without asthma, and drewsmall amounts of blood from their arms. Sure enough, cells of avery similar type as that found in mice, with very similar proteinson their cell surface, showed up in higher amounts in the blood ofthe asthma sufferers. Despite these results, Lukacs cautioned, "It's still too early tosay that we could target these cells in humans. But because of theindustry interest in IL-25 and its receptors, these results givethat line of inquiry more fuel." Lukacs is also assistant dean forresearch at the U-M Medical School. Petersen, who is also earning a medical degree as well as thedoctorate he recently defended, notes that more research volunteerswill be needed to explore the cells' role in humans. He, Lukacs andBaptist hope to open a new clinical trial soon that would allowboth people with asthma - and those without - to aid the research. "While we've verified that this cell can be seen in people withasthma, we need to find out in a large group if it is moreprominent in people with more severe, treatment-resistant forms ofthe disease - and even whether it could help define thecharacteristics of someone who will eventually develop that form ofasthma," he says. Meanwhile, the researchers will continue exploring IL-25's role,and the way different irritants cause the cells in the lung liningto release it. For instance, viruses that infect the lungs cancause the release of IL-25 - and such infections are also a knowncause of asthma attacks. Additional References Citations. I am an expert from uninterrupted-power-supply.com, while we provides the quality product, such as China Outdoor UPS , Low Frequency Online UPS, Low Frequency Online UPS,and more.
Related Articles -
China Outdoor UPS, Low Frequency Online UPS,
|
