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Innate differences in immunity can be detected at birth, accordingto new research at Washington University School of Medicine in St.Louis. And babies with a better innate response to viruses havefewer respiratory illnesses in the first year of life. "Viral respiratory infections are common during childhood," saysfirst author Kaharu Sumino, MD, assistant professor of medicine."Usually they are mild, but there's a wide range of responses -from regular cold symptoms to severe lung infections and even, inrare instances, death. We wanted to look at whether the innateimmune response - the response to viruses that you're born with -has any effect on the risk of getting respiratory infections duringthe baby's first year." Reporting in the May issue of the Journal of Allergy and Clinical Immunology , Sumino and her colleagues found that newborns with a diminishedimmune response to viruses experienced more respiratory infectionsin their first year of life than newborns whose immune response wasmore robust. Using umbilical cord blood samples taken in the delivery room, theresearchers measured a specific immune system response to viralinfection known as interferon-gamma (IFN-gamma). IFN-gamma isreleased by some cells of the immune system when they encounter avirus. An important weapon in the immune system's arsenal,IFN-gamma helps fight viruses by stopping them from replicating. The researchers studied cord blood samples from 82 babies in St.Louis enrolled in the Urban Environment and Childhood Asthma(URECA) trial. Eighty-five percent of the infants wereAfrican-American, and all lived in an area where at least 20percent of the residents were below the poverty level. All had atleast one parent with allergies, asthma or eczema , putting them at higher risk for these conditions themselves. As reported by their caregivers, the babies averaged four colds intheir first year with 88 percent of them suffering at least onecold. But the range varied widely with some caregivers reporting nocolds and a few reporting as many as nine or 10. To measure the innate immune response, the blood samples were takenat birth, before any exposure to the environment could influencethe child's immunity. The researchers isolated monocytes, aspecific type of white blood cell, from the babies' cord blood, andinfected these cells with a common respiratory virus. They thenmeasured the amount of IFN-gamma produced by the monocytes inresponse to the virus. In general, babies whose monocytes responded to the virus byproducing higher levels of IFN-gamma had fewer reported colds.Likewise, babies whose monocytes produced lower IFN-gamma levelshad more reported colds. The scientists also found that newborns whose monocytes producedless IFN-gamma also experienced more ear infections, sinusinfections, pneumonia , and hospitalizations due to respiratory illness during theirfirst year. But low IFN-gamma levels were not associated with croup or "stomach flu ," indicating that this system may be closely associated withrespiratory viruses and not other types of infections. In an effort to identify other indicators of viral response, theresearchers measured amounts of two other immune molecules:chemokine CCL5 and STAT1. Unlike IFN-gamma, neither showed anycorrelation with the number of illnesses the babies experienced. This study in infants, as well as research in mice and human cells,supports the idea that dialing up the body's IFN-gamma signalingsystem may help protect against viral infection. The report'ssenior author Michael J. Holtzman, MD, the Selma and Herman SeldinProfessor of Medicine, is working on drug discovery in this area.Unlike a vaccine, which protects against a specific virus, a drugthat improves the body's innate immunity could help fight a broadrange of viruses, including the constantly evolving seasonal flu. "Ideally, if these results are confirmed, we would like to be ableto intervene based on knowledge of the innate IFN-gamma response,"Sumino says. "We're not there yet - measuring IFN-gamma levels iscomplex. But in the future, if we can develop a relatively easy wayto find out if someone has a deficiency in this system, we wouldlike to be able to give a drug that can boost the innate immuneresponse." Additional References Citations. The e-commerce company in China offers quality products such as Oakley Womens Sunglasses Manufacturer , Levis Eyeglass Frames Manufacturer, and more. For more , please visit Branded Optical Frames today!
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