Affinity maturation and autoimmunity to DNA.
Affinity maturation and autoimmunity to DNA.
复制标题
DNA 的亲和力成熟和自身免疫。
DOI：
10.1159/000066859
复制
发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Desai,DharmeshD
中科院分区：
文献类型：
--
作者：
Marion,TonyN;Krishnan,MeeraR;Steeves,MeredithA;Desai,DharmeshD
Affinity or specificity maturation is the term used to describe the improvement in antibody quality that occurs subsequent to each new encounter with the same immunogen [1]. The change in antibody quality can best be defined as an increase in specificity or relative affinity for a respective immunogen and may be concomitant with or subsequent to heavy chain isotype switching, for example from IgM to IgG. Primary antibody responses are generally IgM with relatively low affinity for the relevant antigen. Secondary immune antibodies are generally IgG, IgA or IgE and, because of affinity maturation, are more specific or have higher relative affinity for the relevant antigen. Specificity maturation is dependent upon two major functions that operate during B cell clonal expansion stimulated by specific antigen and activated helper T cells. One of the functions is controlled by antibody receptor-dependent selection by specific antigen [2–6]. At the initiation of B cell activation in response to a given antigen, the antigen concentration will be relatively high. B cells with relatively low affinity receptors for the respective antigen may be activated. As activated B cells clonally expand and begin to secrete antibody, the relative antigen concentration will be decreased as it is bound by secreted antibody. With the relative decrease in antigen concentration, only B cells with relatively high affinity receptors will be stimulated. Eventually the only available antigen to sustain B cell activation may be in the form of immune complexes on follicular dendritic cells (FDC)[7, 8]. At low antigen concentrations, B cells with relatively low affinity receptors cannot bind antigen and may be lost to apoptosis. In normal immune responses to foreign antigens, the antigenic epitopes that initiate an immune response and that control specificity maturation can usually be easily
