Takahashi Yoshimasa, Kelsoe Garnett
Department of Immunology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan.
Department of Immunology and Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.
Curr Opin Immunol. 2017 Apr;45:119-125. doi: 10.1016/j.coi.2017.03.002. Epub 2017 Mar 27.
Virus-specific memory B cells (B) play a crucial role in protecting against variant viruses. The ability to recognize these variant viruses, defined as antibody breadth, is achieved in B populations by two very different pathways, germline-encoded cross-reactivity and affinity-driven, somatic evolution in germinal centers (GCs) for conserved viral epitopes. The latter class of broadly-reactive B cells are not cross-reactive per se, but bind epitopes crucial for viral fitness. Although these conserved epitopes are often weakly immunogenic, the GC reaction is surprisingly permissive for the continued survival/proliferation of B cells that bind with low affinity or react to cryptic epitopes, increasing their chance of memory recruitment. In this review, we discuss the adaptive strategies of B-cell memory to viral antigenic variations.
病毒特异性记忆B细胞（B细胞）在抵御变异病毒方面发挥着关键作用。识别这些变异病毒的能力，即抗体广度，在B细胞群体中通过两种截然不同的途径实现：种系编码的交叉反应性以及生发中心（GC）中针对保守病毒表位的亲和力驱动的体细胞进化。后一类广泛反应性B细胞本身并非交叉反应性的，而是结合对病毒适应性至关重要的表位。尽管这些保守表位通常免疫原性较弱，但GC反应对于低亲和力结合或对隐蔽表位起反应的B细胞的持续存活/增殖出人意料地宽容，增加了它们被招募为记忆细胞的机会。在本综述中，我们讨论了B细胞记忆针对病毒抗原变异的适应性策略。
