Herpesviruses might have benefits Viral infections give mice an immunity boost
疱疹病毒带来的益处：病毒感增强小鼠免疫
The herpesviruses bring untold suffering, but may not be all bad. Chronic latent infection with specific viral strains protects mice against some bacterial infections, a Nature study reveals this week1.
疱疹病毒带来的痛苦自不必说，但是也不是一无是处。本周的《自然》上说，某些病毒株的持续潜在感染能保护小鼠免受一些细菌的感染。
Almost all humans become infected with herpesviruses during childhood. After the acute initial infection ends, most of these viruses enter a dormant state and remain in the host for the rest of its life. In the vast majority of the population this will only result in a one-time, non-lethal infection such as chickenpox, herpes or mononucleosis. But in some people they can be devastating, leading to cancers such as lymphoma, blindness in AIDS patients, and congenital deafness in infants.
几乎每个人在儿童时期都受到过疱疹病毒的感染。在感染初期结束后，大多数病毒进入了静止期，一直潜伏在宿主体内。大多数人只有一过性非致死的感染，如水痘、疱疹或单核细胞增多症。但是在有些人则是灾难性的，可引起癌症，如淋巴瘤，在艾滋病患者能致盲，还能引起胎儿的先天性耳聋。
Unsurprisingly, the viruses are generally thought of as having no redeeming qualities. But Herbert Virgin and his colleagues at Washington University School of Medicine in St Louis, Missouri, have discovered that this is not necessarily true.
毫不奇怪，通常是不会有人认为这种病毒有任何益处的。但是位于密苏里圣路易斯的华盛顿大学医学院的Herbert Virgin和他的同事们的发现推翻这种观点。
Unplagued mice
未被传染的小鼠
Virgin and his team were curious about the effect of latent herpesvirus infection on the function of the immune system. They infected some mice with one of two types of mouse herpesvirus and exposed them to bacterial pathogens that cause encephalitis, meningitis and plague. Mice that had been infected with herpesvirus showed significantly more resistance to these bacteria than mice that had not been infected.
Virgin和他的小组对潜伏的疱疹病毒感染对免疫系统的功能的影响很好奇。他们用两种鼠疱疹病毒感染了一些小鼠，然后把它们暴露于能引起脑炎、脑膜炎和鼠疫的致病菌。感染过疱疹病毒的小鼠和未感染过的小鼠相比具有更强抵抗这些细菌的能力。
Not all herpesviruses have this effect, the team adds. The type that causes herpes itself does not seem to have a protective effect. And they suspect, but don't yet know, that the type that causes chickenpox doesn't either.
不是所有的疱疹病毒都有这样的作用，他们补充道。能引起疱疹的病毒类型本身是乎没有保护作用。他们怀疑，但是尚未知晓，能引起水痘的也没有作用。
The team wondered whether the latent version of some herpesviruses might have an effect on the immune system. To test this, they used a mutant strain of a mouse herpesvirus that could only initiate an acute infection and then faded away. Mice infected with this virus showed no resistance to bacterial pathogens.
他们怀疑一些潜伏型的疱疹病毒可能对免疫系统有作用。为了证明这点，他们使用了变异的鼠疱疹病毒，该病毒只能引发急性感染，然后就隐匿了。感染这种病毒的小鼠对致病菌没有抵抗力。
"I think our data are going to change the way we look at herpesvirus infection, but more importantly they are going to change the way we view our own immune systems," says Virgin. If these infections are playing a part in preparing us for subsequent bacterial infection then their relationship shifts from pathogenic to symbiotic, somewhat similar to the relationship we have with our gut bacteria, he says.
“我认为我们的资料将改变我们对疱疹病毒感染的看法，但是更重要的是这将改变我们对自己免疫系统的看法，”Virgin说。如果这些感染能让我们对以后的细菌感染做好准备，那么他们之间的关系将从病原性转化到共生性，跟我们和肠道细菌的关系相似，他说。
Odd couple
This raises questions about how long a love-hate relationship has existed between herpesviruses and humans, and even about whether viral DNA should be considered a part of the infected person. "Perhaps we can consider these viruses, at least for some of us, as part of our 'normal' immune system," says Virgin.
这就产生了一些问题，人类和疱疹病毒之间这种”爱恨”关系已经存在了多久，还有能否认为病毒DNA就是感染者的一部分呢？“也许我们可以认为这些病毒是我们“正常”免疫系统的一部分，至少有些人是这样的，”Virgin说。
Herpesviruses descended from a strain that once infected a common ancestor of mammals, birds and reptiles. So animals and passenger herpesviruses have had more than 100 million years to co-evolve. It is possible that these viruses have had an important role in the evolution of human defences against disease.
疱疹病毒源于一度感染哺乳动物、鸟类和昆虫的始祖的病毒株。所以动物和寄居疱疹病毒已经拥有了1亿多年的共进化史。这些病毒对人类疾病防御的进化具有重要作用是可能的。
But Virgin's results should not lead people to consider going and getting themselves infected. "I would not recommend that anyone be infected with a virus to enable them to develop an immune response to thwart infection," says Bernard Roizman, professor of virology at the University of Chicago, Illinois. "This research is very exciting, but in my mind the only good virus is a dead one or one that has been silenced for life."
但是Virgin的结果不是要让人们去感染这种病毒。“我不会建议任何人感染这种病毒，让其产生免疫应答来阻止感染，”位于伊利诺斯的芝加哥大学的病毒学教授Bernard Roizman说。“这项研究很激动人心，但是在我看来有益的病毒只能是灭活的或终生沉默的。”
Virgin agrees. "The degree to which our results apply to human disease and treatment remains to be determined," he says.
Virgin表示同意。“我们的结果对人类疾病和治疗的应用程度有待明确，”他说。
编译：
疱疹病毒带来的益处：病毒感增强小鼠免疫
疱疹病毒带来的痛苦自不必说，但是也不是一无是处。本周的《自然》上说，某些病毒株的持续潜在感染能保护小鼠免受一些细菌的感染。
几乎每个人在儿童时期都受到过疱疹病毒的感染。在感染初期结束后，大多数病毒进入了静止期，一直潜伏在宿主体内。大多数人只有一过性非致死的感染，如水痘、疱疹或单核细胞增多症。但是在有些人则是灾难性的，可引起癌症，如淋巴瘤，在艾滋病患者能致盲，还能引起胎儿的先天性耳聋。
毫不奇怪，通常是不会有人认为这种病毒有任何益处的。但是位于密苏里圣路易斯的华盛顿大学医学院的Herbert Virgin和他的同事们的发现推翻这种观点。
未被传染的小鼠
Virgin和他的小组对潜伏的疱疹病毒感染对免疫系统的功能的影响很好奇。他们用两种鼠疱疹病毒感染了一些小鼠，然后把它们暴露于能引起脑炎、脑膜炎和鼠疫的致病菌。感染过疱疹病毒的小鼠和未感染过的小鼠相比具有更强抵抗这些细菌的能力。
不是所有的疱疹病毒都有这样的作用，他们补充道。能引起疱疹的病毒类型本身是乎没有保护作用。他们怀疑，但是尚未知晓，能引起水痘的也没有作用。
他们怀疑一些潜伏型的疱疹病毒可能对免疫系统有作用。为了证明这点，他们使用了变异的鼠疱疹病毒，该病毒只能引发急性感染，然后就隐匿了。感染这种病毒的小鼠对致病菌没有抵抗力。
“我认为我们的资料将改变我们对疱疹病毒感染的看法，但是更重要的是这将改变我们对自己免疫系统的看法，”Virgin说。如果这些感染能让我们对以后的细菌感染做好准备，那么他们之间的关系将从病原性转化到共生性，跟我们和肠道细菌的关系相似，他说。
不是冤家不聚头
这就产生了一些问题，人类和疱疹病毒之间这种”爱恨”关系已经存在了多久，还有能否认为病毒DNA就是感染者的一部分呢？“也许我们可以认为这些病毒是我们“正常”免疫系统的一部分，至少有些人是这样的，”Virgin说。
疱疹病毒源于一度感染哺乳动物、鸟类和昆虫的始祖的病毒株。所以动物和寄居疱疹病毒已经拥有了1亿多年的共进化史。这些病毒对人类疾病防御的进化具有重要作用是可能的。
但是Virgin的结果不是要让人们去感染这种病毒。“我不会建议任何人感染这种病毒，让其产生免疫应答来阻止感染，”位于伊利诺斯的芝加哥大学的病毒学教授Bernard Roizman说。“这项研究很激动人心，但是在我看来有益的病毒只能是灭活的或终生沉默的。”
Virgin表示同意。“我们的结果对人类疾病和治疗的应用程度有待明确，”他说。
