Bullock W W, Rittenberg M B
J Exp Med. 1970 Nov;132(5):926-40. doi: 10.1084/jem.132.5.926.
Decreasing antigen in vivo may preferentially stimulate cells with the potential for synthesis of high-affinity antibody through activation of surface receptors with similarly high affinity. This selection should result in cells with increased sensitivity to lower antigen concentrations, cells with greater avidity for antigen. We have followed the in vivo changes in anti-TNP memory-cell sensitivity by initiating the secondary anti-hapten response in vitro. This response was determined by anti-TNP plaque assay. The results indicate that cell populations with increased sensitivity for antigen continue to emerge with time after priming and that this sensitivity may increase 1000-fold in a 4 month period. Increased sensitivity to stimulation by antigen is concomitant with suppression by higher, previously stimulatory doses as in high zone immune tolerance. The data support the hypothesis that memory cells of high avidity result from the selective pressure of diminishing in vivo antigen concentration.
体内抗原减少可能会通过激活具有相似高亲和力的表面受体，优先刺激具有合成高亲和力抗体潜力的细胞。这种选择应会产生对较低抗原浓度更敏感的细胞，即对抗原有更高亲和力的细胞。我们通过在体外引发二次抗半抗原反应，跟踪了抗TNP记忆细胞敏感性的体内变化。这种反应通过抗TNP空斑试验来确定。结果表明，致敏后随着时间推移，对抗原敏感性增加的细胞群体持续出现，并且这种敏感性在4个月内可能增加1000倍。对抗原刺激的敏感性增加与高剂量（先前具有刺激作用）的抑制作用同时出现，就像在高区免疫耐受中一样。这些数据支持这样的假设，即高亲和力记忆细胞是由体内抗原浓度降低的选择压力产生的。
