Center for Comparative Medicine, University of California, Davis, CA 95616, USA.
Adv Exp Med Biol. 2013;785:57-66. doi: 10.1007/978-1-4614-6217-0_7.
Antibodies are an integral part of the immune system. They are produced in response to an infection or insult but are also present prior to any encounter with antigen as so-called natural antibodies. This review focuses on the tissues and cellular origins of natural antibodies. It summarizes recent data showing that B-1 cells, an innate-like B cell population distinct in development, repertoire, and tissue location from the majority conventional or B-2 cells, are the main contributors of natural antibodies in mice in steady state. Furthermore, they show that natural IgM production appears largely confined to B-1 cell populations in the spleen and bone marrow. In contrast, B-1 cells in the body cavities, sites of predominance of this population, harbor B-1 cells that do not constitutively produce antibodies. Instead, these cells act as rapid immune responders that relocate to secondary lymphoid tissues and differentiate to cytokine and antibody-secreting cells shortly after an infection. Thus, the process of B-1 cell response participation is distinct from that of B-2 cell activation as the accumulation of effector B-1 cells does not rely on extensive clonal expansion, but instead on their rapid migration and redistribution, a process that appears under the control of infection-induced innate signals.
抗体是免疫系统的重要组成部分。它们是针对感染或损伤产生的,但也存在于与抗原接触之前,即所谓的天然抗体。这篇综述重点介绍了天然抗体的组织和细胞起源。它总结了最近的数据,表明 B-1 细胞,一种在发育、 repertoire 和组织位置上与大多数常规或 B-2 细胞不同的先天样 B 细胞群体,是小鼠在稳态下天然抗体的主要贡献者。此外,它们表明天然 IgM 的产生似乎主要局限于脾脏和骨髓中的 B-1 细胞群体。相比之下,体腔中该群体占优势的部位的 B-1 细胞并不持续产生抗体。相反,这些细胞作为快速免疫应答者,在感染后迅速迁移到次级淋巴组织,并分化为细胞因子和抗体分泌细胞。因此,B-1 细胞反应参与的过程与 B-2 细胞激活的过程不同,因为效应 B-1 细胞的积累不依赖于广泛的克隆扩增,而是依赖于它们的快速迁移和再分布,这一过程似乎受到感染诱导的先天信号的控制。