Mechanisms of Generation, Maintenance, and Activation of Humoral Memory

一旦病原体侵入我们的身体，免疫系统就会运作并记住这种病原体，即使在病原体从体内消除后也是如此。然后，当同样的病原体再次入侵时，我们的免疫系统能够迅速做出反应，从而非常有效地清除病原体。在这里，我们一直在讨论这种快速反应背后的机制。首先，我们已经证明了记忆B细胞残留在这些B细胞容易接触入侵病原体的地方。第二，记忆B细胞通过下调转录因子Bach2获得快速分化活性。这种下调发生在初次感染期间。最后，记忆B细胞迅速激活记忆T细胞，这反过来又促进记忆B细胞的分化。上述三个机制正在以合作的方式运作。

Once the pathogen invades into our body, the immune system operates and remembers this pathogen even after the pathogen is eliminated from the body. Then, when the same pathogen is invaded again, our immune system is able to respond to it quickly, thereby eliminating the pathogen very efficiently. Here, we have been addressing the mechanism underlying such quick responses. First, we have shown that memory B cells residue in the place, where these B cells easily access to the invaded pathogen. Second, memory B cells acquire the rapid differentiation activity through down-regulation of the transcription factor Bach2. This down-regulation took place during primary infection. Finally, memory B cells activate memory T cells quickly, which, in turn, facilitate differentiation of memory B cells. The above three mechanisms are operating in a cooperative manner.