Immune memory — comprising T cells, B cells and plasma cells and their secreted antibodies — is crucial for human survival. It enables the rapid and effective clearance of a pathogen after re-exposure, to minimize damage to the host. When antigen-experienced, memory T cells become activated, they proliferate and produce effector molecules at faster rates and in greater magnitudes than antigen-inexperienced, naive cells. Similarly, memory B cells become activated and differentiate into antibody-secreting cells more rapidly than naive B cells, and they undergo processes that increase their affinity for antigen. The ability of T cells and B cells to form memory cells after antigen exposure is the rationale behind vaccination. Understanding immune memory not only is crucial for the design of more-efficacious vaccines but also has important implications for immunotherapies in infectious disease and cancer. This ‘guide to’ article provides an overview of the current understanding of the phenotype, function, location, and pathways for the generation, maintenance and protective capacity of memory T cells and memory B cells.

免疫记忆——包括 T 细胞、B 细胞和浆细胞及其分泌的抗体——对人类生存至关重要。它能够在再次暴露后快速有效地清除病原体，从而最大限度地减少对宿主的损害。当经历过抗原的记忆 T 细胞被激活时，它们会比未经历过抗原的初始细胞以更快的速度和更大的程度增殖并产生效应分子。同样，记忆 B 细胞比初始 B 细胞更快地被激活并分化为抗体分泌细胞，并且它们经历了增加对抗原的亲和力的过程。 T 细胞和 B 细胞在抗原暴露后形成记忆细胞的能力是疫苗接种背后的基本原理。了解免疫记忆不仅对于设计更有效的疫苗至关重要，而且对传染病和癌症的免疫疗法也具有重要意义。这篇“指南”文章概述了当前对记忆 T 细胞和记忆 B 细胞的表型、功能、位置以及生成、维持和保护能力的途径的理解。