Laboratory of Molecular Immunology, The Rockefeller University, New York City, NY 10021, USA.
Cell Mol Life Sci. 2012 May;69(9):1435-45. doi: 10.1007/s00018-011-0872-6. Epub 2011 Nov 2.
B cells express immunoglobulins on their surface where they serve as antigen receptors. When secreted as antibodies, the same molecules are key elements of the humoral immune response against pathogens such as viruses. Although most antibodies are restricted to binding a specific antigen, some are polyreactive and have the ability to bind to several different ligands, usually with low affinity. Highly polyreactive antibodies are removed from the repertoire during B-cell development by physiologic tolerance mechanisms including deletion and receptor editing. However, a low level of antibody polyreactivity is tolerated and can confer additional binding properties to pathogen-specific antibodies. For example, high-affinity human antibodies to HIV are frequently polyreactive. Here we review the evidence suggesting that in the case of some pathogens like HIV, polyreactivity may confer a selective advantage to pathogen-specific antibodies.
B 细胞在其表面表达免疫球蛋白，作为抗原受体。当作为抗体分泌时，相同的分子是针对病毒等病原体的体液免疫反应的关键要素。尽管大多数抗体仅限于结合特定抗原，但有些是多反应性的，能够与几种不同的配体结合，通常亲和力较低。在 B 细胞发育过程中，生理耐受机制（包括删除和受体编辑）会从库中清除高度多反应性的抗体。然而，低水平的抗体多反应性是被容忍的，并且可以赋予针对病原体特异性抗体的额外结合特性。例如，针对 HIV 的高亲和力人抗体通常是多反应性的。在这里，我们回顾了一些证据，表明在某些病原体（如 HIV）的情况下，多反应性可能会赋予针对病原体的特异性抗体选择性优势。
