時差N小時:昆蟲是如何對抗細菌和寄生蟲的?

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.

想象一下你是一只昆蟲，由于細菌或者寄生蟲的入侵，你生病了。如果你想保持跟過去一樣的體質(zhì)，那么你就要跟這些入侵者做斗爭了。

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.

問題在于，假如你是一只小蟲，你的生命周期可能僅有幾天。這意味著你不能像人類一樣有足夠的時間在床上躺著，看看電視，然后等著觀察身體是如何抵御這些入侵的疾病。

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.

但是作為一只小蟲，你也沒必要為此恐慌或擔(dān)憂。大自然的進化過程已使你獲得科學(xué)家們所謂的“先天免疫”能力，你從父母那里遺傳而來的能力。先天免疫能幫助昆蟲的身體在最短時間內(nèi)發(fā)現(xiàn)并且摧毀這些危險的入侵者們。

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.

在昆蟲身體里有一種被稱為“血淋巴”的液體，它與人類的血液發(fā)揮著相同的作用。當你受傷時，血淋巴里的某種成分便與免疫系統(tǒng)中某些特殊細胞進行相互作用，從而使傷口凝結(jié)并結(jié)痂，保護傷口不受外界環(huán)境干擾以避免感染。而且，在血淋巴中還包含某些蛋白質(zhì)，它能有效地殺滅這些入侵者，比如細菌或真菌。當然，像小寄生昆蟲這樣的入侵者，由于它們的體積較大，血淋巴里的蛋白質(zhì)的殺滅能力對此還是望塵莫及。

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.

在這種情況下，你的身體中封裝了入侵者，且與身體其他部分隔離開來。在你短暫的昆蟲生涯中，這個被封裝的小小入侵者會一直保留在你體內(nèi)，或者某天你不小心撞上擋風(fēng)玻璃，這個封裝的過程才會提前宣告結(jié)束。