Key regions of the genetic code determine how the immune system identifies foreign cells.

遗传基因中有关键区域决定免疫系统如何识别外来细胞。

Antibodies latch onto the antigens, signaling other immune cells to attack and destroy the foreign cells.

抗体附着于抗原上，标志着其他的免疫细胞开始攻击并摧毁外来细胞。

Plants manufacture numerous chemicals to defend themselves from insects and microbes, by poisoning or ripping apart foreign cells.

植物产生许多化学物质来保护自己免受昆虫和微生物的侵害，毒杀或撕裂外来细胞。

As these circulate, they destroy any foreign cells they encounter, simply by consuming them.

当它们循环时，它们会简单地通过消耗它们来破坏它们遇到的任何外来细胞。

This alerts the immune system to crank out more antibodies to destroy the invading virus, bacteria or other foreign cell.

这会提醒免疫系统产生更多抗体来摧毁入侵的病毒、细菌或其他外来细胞。

Ultimately though, TB can avoid the mucus traps and make its way to the deep airways in alveoli where we have macrophages which eat up foreign cells, digest and destroy them.

然而最终，结核分枝杆菌可以避开被粘膜所困，然后到达深部呼吸道里的肺泡；在肺泡内有巨噬细胞可以吞噬掉异物并在细胞内部消化并且破坏异物。

The damage they cause can be devastating in our own bodies, but they’re almost impossible to pass between people because the foreign cells would trigger an immune system response.

它们造成的损害对我们自己的身体可能是毁灭性的，但它们几乎不可能在人与人之间传播， 因为外来细胞会触发免疫系统反应。