期刊
IMMUNOLOGICAL REVIEWS
卷 284, 期 1, 页码 106-119出版社
WILEY
DOI: 10.1111/imr.12669
关键词
antigen-binding site; B cells; CDR-H3; DH; repertoire
类别
资金
- [AI117703]
Although at first glance the diversity of the immunoglobulin repertoire appears random, there are a number of mechanisms that act to constrain diversity. For example, key mechanisms controlling the diversity of the third complementarity determining region of the immunoglobulin heavy chain (CDR-H3) include natural selection of germline diversity (D-H) gene segment sequence and somatic selection upon passage through successive B-cell developmental checkpoints. To test the role of D-H gene segment sequence, we generated a panel of mice limited to the use of a single germline or frameshifted D-H gene segment. Specific individual amino acids within core D-H gene segment sequence heavily influenced the absolute numbers of developing and mature B-cell subsets, antibody production, epitope recognition, protection against pathogen challenge, and susceptibility to the production of autoreactive antibodies. At the tip of the antigen-binding loop (PDB position 101) in CDR-H3, both natural (germline) and somatic selection favored tyrosine while disfavoring the presence of hydrophobic amino acids. Enrichment for arginine in CDR-H3 appeared to broaden recognition of epitopes of varying hydrophobicity, but led to diminished binding intensity and an increased likelihood of generating potentially pathogenic dsDNA-binding autoreactive antibodies. The phenotype of altering the sequence of the D-H was recessive for T-independent antibody production, but dominant for T-cell-dependent responses. Our work suggests that the antibody repertoire is structured, with the sequence of individual D-H selected by evolution to preferentially generate an apparently preferred category of antigen-binding sites. The result of this structured approach appears to be a repertoire that has been adapted, or optimized, to produce protective antibodies for a wide range of pathogen epitopes while reducing the likelihood of generating autoreactive specificities.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据