用telomere 長度 預測感冒 ! (非老化)

CD8CD28-细胞端粒较短的人群更易感染上呼吸道病毒 发布时间：2013-3-5 来源：药品资讯网信息中心较短的白细胞端粒长度与老化相关性疾病及涉及免疫系统情况的死亡有关，其中包括传染病、癌症及心血管疾病。然而，人们不知道白细胞端粒长度是否与年轻健康人群中的急性病有关。在线发表于2013年2月20日的《美国医学会杂志》上的一篇文章显示，在接种某种感冒病毒的健康成年人群中，那些在某些细胞中有着较短端粒长度（这是染色体末端的一个结构）的人比那些有着较长端粒长度的人更可能出现试验诱发的上呼吸道感染。 来自匹茨堡市卡内基-梅隆大学的Sheldon Cohen博士及其同事开展了一项研究，旨在确定白细胞，尤其是CD8CD28-T细胞中较短的端粒是否与年轻及中年人中的上呼吸道感染抵抗力下降及临床疾病有关。在2008年至2011年期间，宾西法尼亚州匹茨堡市有152名18-52岁的健康居民接受了外周血液中单核细胞（PBMCs）和亚组T细胞（CD4，CD8CD28+ ，CD8CD28-）的端粒长度评估。这些实验的参与者随后被隔离在单个的房间中，他们被给予了含有普通感冒病毒（鼻病毒39）的滴鼻剂，并接受了为期5天的是否会被感染并出现临床病症的监测。试验主要终点为感染（病毒脱落或病毒特异性抗体滴度增加4倍）和临床疾病（证实为感染且出现疾病体征）。 结果显示，69%的参与者（n=105）出现了呼吸道感染；整个样本中有22%（n=33）的人出现了临床病症（普通感冒），端粒较短与感染风险增加相关，且这种关联独立于病毒特异性抗体、人口统计学因素、避孕药物使用、季节、以及体重指数。分析表明，只有CD8CD28-亚组的端粒长度与临床病症的风险有关，而较短的端粒长度与该风险的增加有关。在有着最短端粒的参与者中，26%的人出现了临床病症。在那些有着最长端粒的组群中，临床病症的发生率为13%。此外，在CD8CD28-端粒长度与感染之间的相关性会随着年龄的增加而增加。 文章的作者从这项初步研究中得出结论，对于18到55岁的健康人群，较短的CD8CD28-细胞端粒长度与实验性接触鼻病毒后出现上呼吸道感染及临床病症有关。由于这些数据是初步的，因此它们的临床涵义还是未知的。

Susceptibility to flu may be found in your chromosomes SCI/TECH | Brooke Kuei How often do you get a cold? Have you noticed that you get sick more or less often than your friends? Carnegie Mellon Robert E. Doherty Professor of Psychology Sheldon Cohen recently identified a biological marker — an indicator of a biological state — that corresponds with one's susceptibility to the common cold. Telomeres are cap-like protein complexes found at the ends of chromosomes whose function is to protect those chromosomes during replication. It has long been known that as you age and undergo more cell replication, your telomeres shorten, leading to the possibility of aging-related diseases. What is remarkable about Cohen's work is the discovery that telomere length not only predicts susceptibility of disease in the elderly, but also does so for younger people. Cohen cites two reasons that led him to conduct a study on the correlation between telomere length in young adults and their ability to fight off disease: "First, even though telomere length decreases as we age, the evidence suggested that there was variation in telomere length even in young adults. Second, telomere length is often measured in white blood cells. Our interest is in how the immune system responds to infectious agents like cold viruses," he said. "The most prevalent diseases in the age group we study, 18-to-55-year-olds, are upper respiratory infections, and it seemed to us that those with shorter telomeres in key white blood cells would be less able to prevent cold viruses from replicating." Indeed, the results of Cohen's experiments aligned with his prediction. Cohen and his team measured the telomere length of white blood cells in 152 volunteers between the ages of 18 and 55. These volunteers were then quarantined for five days after being exposed to the virus that causes the common cold. "We have studied the role of psychological and behavioral factors in the common cold for over 30 years. Unlike most diseases, we can actually experimentally expose people to the disease-causing agent. Hence, colds have provided an excellent model for us," Cohen said. The results of the experiment showed that individuals with shorter telomere length were more likely to contract the common cold than those with longer telomeres. Another result of their experiment was the discovery that telomere length only started predicting an individual's susceptibility to the common cold for those who were about 22 or older. Telomere length was increasingly indicative of an individual's ability to fight off disease as the age of the individual increased. "The increased importance of telomere length with age is likely because the younger participants had fewer very short telomeres, or that their young immune systems were able to compensate for the loss of effective cells," Cohen said in a university press release. Sheldon and his team also found that a particular type of white blood cell — a CD8CD28- T-cytolytic cell — was the best indicator of the likelihood of contracting the cold because the telomeres found in CD8CD28- cells shorten at a more rapid speed than those found in other cell types. Now that it's known that telomere length corresponds with an individual's ability to fight off disease, the obvious question one might ask is, what factors — besides natural aging — affect telomere length? "Shorter telomere length is associated with traumaatic childhood experiences, with exposure to chronic enduring stressors, with poor health behaviors such as smoking and excessive consumption of alcohol, with lower levels of education, and with stable psychological dispositions like hostility," Cohen said. These factors may decrease telomere length through their effects on telomerase — an enzyme that rebuilds telomeres. Further studies with other viruses and natural infections will increase the understanding of how telomere length corresponds to susceptibility to disease. Perhaps, in the future, telomeres will be the key to improving human health. How often do you get a cold? Have you noticed that you get sick more or less often than your friends? Carnegie Mellon Robert E. Doherty Professor of Psychology Sheldon Cohen recently identified a biological marker — an indicator of a biological state — that corresponds with one's susceptibility to the common cold. Telomeres are cap-like protein complexes found at the ends of chromosomes whose function is to protect those chromosomes during replication. It has long been known that as you age and undergo more cell replication, your telomeres shorten, leading to the possibility of aging-related diseases. What is remarkable about Cohen's work is the discovery that telomere length not only predicts susceptibility of disease in the elderly, but also does so for younger people. Cohen cites two reasons that led him to conduct a study on the correlation between telomere length in young adults and their ability to fight off disease: "First, even though telomere length decreases as we age, the evidence suggested that there was variation in telomere length even in young adults. Second, telomere length is often measured in white blood cells. Our interest is in how the immune system responds to infectious agents like cold viruses," he said. "The most prevalent diseases in the age group we study, 18-to-55-year-olds, are upper respiratory infections, and it seemed to us that those with shorter telomeres in key white blood cells would be less able to prevent cold viruses from replicating." Indeed, the results of Cohen's experiments aligned with his prediction. Cohen and his team measured the telomere length of white blood cells in 152 volunteers between the ages of 18 and 55. These volunteers were then quarantined for five days after being exposed to the virus that causes the common cold. "We have studied the role of psychological and behavioral factors in the common cold for over 30 years. Unlike most diseases, we can actually experimentally expose people to the disease-causing agent. Hence, colds have provided an excellent model for us," Cohen said. The results of the experiment showed that individuals with shorter telomere length were more likely to contract the common cold than those with longer telomeres. Another result of their experiment was the discovery that telomere length only started predicting an individual's susceptibility to the common cold for those who were about 22 or older. Telomere length was increasingly indicative of an individual's ability to fight off disease as the age of the individual increased. "The increased importance of telomere length with age is likely because the younger participants had fewer very short telomeres, or that their young immune systems were able to compensate for the loss of effective cells," Cohen said in a university press release. Sheldon and his team also found that a particular type of white blood cell — a CD8CD28- T-cytolytic cell — was the best indicator of the likelihood of contracting the cold because the telomeres found in CD8CD28- cells shorten at a more rapid speed than those found in other cell types. Now that it's known that telomere length corresponds with an individual's ability to fight off disease, the obvious question one might ask is, what factors — besides natural aging — affect telomere length? "Shorter telomere length is associated with traumaatic childhood experiences, with exposure to chronic enduring stressors, with poor health behaviors such as smoking and excessive consumption of alcohol, with lower levels of education, and with stable psychological dispositions like hostility," Cohen said. These factors may decrease telomere length through their effects on telomerase — an enzyme that rebuilds telomeres. Further studies with other viruses and natural infections will increase the understanding of how telomere length corresponds to susceptibility to disease. Perhaps, in the future, telomeres will be the key to improving human health.