Imagine that you’re an insect, and that you’ve fallen ill because some bacteria or parasites have invaded your body. If you want to make it to a ripe old bug age, your body will need to fight off these invaders.
想象一下，假如你是一只小昆虫，因为某些细菌或寄生虫侵入你的身体导致你生病了。假如你想要寿终正寝的话，那么，你的身体就需要对抗这些外来的入侵者了。
Invaders
入侵者
The problem is that if you’re a bug, your life span may be only a few days long. This means that unlike humans, you simply don’t have the time to lounge around in bed, watching TV and waiting for your body to figure out how to fight off each disease it encounters.
问题在于，假如你是一只小虫，你的存活寿命可能仅几天长。这就意味着你不能像人类一样，还有足够的时间在床上躺着，看看电视，然后看看你的身体是否能抵御并击败这些遇到的疾病。
Still, there’s no reason for your insect self to panic. Evolution has provided you with what scientists call innate immunity, which you inherit from your parents. Innate immunity means that your bug body has the capability to instantly recognize and destroy many dangerous intruders.
但是，作为一只小虫，你也没必要为此恐慌或担忧。大自然的进化过程已使你获得科学家们所谓的“先天免疫”能力-这是你从父母那里遗传而来的。先天免疫可以使得你作为昆虫的身体有足够的能力在最短时间内发现并且摧毁这些危险的入侵者们。
Here’s How Innate Immunity Works
接下来是先天免疫系统如何发挥作用
In your bug body there is a fluid called hemolymph, which is equivalent to human blood. If you’re injured, components in the hemolymph interact with specialized cells in your immune system to clot and form a scab that seals off your wound and prevents infection. The hemolymph also contains proteins that are ready to kill invaders like bacteria or fungi. However, some invaders, like tiny parasitic insects, may be too large for the proteins to handle.
在昆虫身体里有一种液体被称为血淋巴，它和人类的血液发挥着相同的作用。当你受伤时，血淋巴里面的某种成分开始与你的免疫系统中某些特殊细胞进行相互作用，从而使得伤口处开始凝结并结痂，并使伤口与外界环境相隔离以避免感染。而且，在血淋巴中还包含某些蛋白质可以有效杀灭这些入侵者，比如细菌或真菌。当然，也有某些入侵者比如小寄生昆虫由于体积较大，蛋白质对它们的杀灭能力还远远不够。
In this case, your body encapsulates the invader and walls it off from the rest of the body. The encapsulated invader then stays inside you for the rest of your natural bug life, or until you fly into a windshield, whichever comes first.
在这个案例中，你的身体中封装了入侵者，并与身体其他部分隔开。这个被封装的小小入侵者会与你一起度过余生，又或者可能与你撞上挡风玻璃一起身亡，就看哪一种情况先发生了。 |