They're ready to rapidly differentiate into antibody producing cells and they're waiting for that second signal to come.

并可以迅速分化为,抗体分泌细胞,记忆细胞在等待第二次信号的到来

耶鲁公开课 - 生物医学工程探索课程节选

They often involve the generation of what are called 'second messenger' molecules which carry the signal further into the cell.

过程中通常会生成一种叫做,第二信使的分子,将信号更深入地传递至细胞内部

耶鲁公开课 - 生物医学工程探索课程节选

That signal is carried here, for example, by the concentration of second messengers - the concentration of something else.

这里这个信号由,第二信使的浓度,即另一种物质的浓度来传递

耶鲁公开课 - 生物医学工程探索课程节选