These are things that must be taken in from the environment because your body cannot manufacture them and they promote specific chemical reactions in the body.

这些都是必须从外界摄取的物质,因为无法通过自身合成,它们能促进体内特定的化学反应

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

Don't worry about how they work in the immune system, but what if you could manufacture antibodies then you could make a chemical, an antibody, that is capable of binding to a specific other chemical and you could use that for things.

别管它们在免疫系统内是怎么工作的,只要考虑能不能制造抗体,那么假设你能制造这种化学物质 抗体,抗体又能够同其他特别的化学物质结合,你就可以让抗体为我所用

耶鲁公开课 - 生物医学工程探索课程节选