Luzzati A L, Tosi R M, Carbonara A O
J Exp Med. 1970 Aug 1;132(2):199-210. doi: 10.1084/jem.132.2.199.
10(6) splenocytes from primed donors were injected, together with sheep erythrocytes (SRBC), into X-irradiated syngeneic mice. 8 days later the spleens were excised and cut into small fragments, keeping track of their location in the organ. Each fragment was cultured individually for 24 hr in the presence of (14)C amino acids and the culture fluids were assayed for antibody activity. The antibody-producing fragments were found to be clustered in few restricted areas (foci) surrounded by negative tissue. The anti-SRBC antibody from single foci was purified by absorption on stroma followed by acid elution. Thereafter, it was subjected to electrophoresis and immunoelectrophoresis. The radioautography of the runs showed a considerable degree of homogeneity. Distinct and sharp spikes were localized in the beta and gamma region. The pattern of each focus is unique from the point of view of the number of spikes and their mobility. Eluates obtained from many pooled fragments gave a broad radioactive smear in beta-gamma region. Many foci synthesized antibody migrating as a single band. This homogeneous protein is probably the product of a clone of cells homogeneously differentiated. However, some foci producing two and probably more antibody bands were also encountered. Two interpretations of the finding can be given. Either more than one precursor may participate in the formation of a focus or a differentiation switch may occur during the clonal expansion.
将来自致敏供体的10(6)个脾细胞与绵羊红细胞(SRBC)一起注射到经X射线照射的同基因小鼠体内。8天后，切除脾脏并切成小碎片，记录它们在器官中的位置。每个碎片在含有(14)C氨基酸的情况下单独培养24小时，然后检测培养液中的抗体活性。发现产生抗体的碎片聚集在少数几个由阴性组织包围的受限区域(病灶)中。来自单个病灶的抗SRBC抗体通过在基质上吸附然后酸洗脱进行纯化。此后，对其进行电泳和免疫电泳。电泳的放射自显影片显示出相当程度的同质性。在β和γ区域定位有明显且尖锐的峰。从峰的数量及其迁移率来看，每个病灶的模式都是独特的。从许多合并碎片中获得的洗脱液在β-γ区域产生宽的放射性涂片。许多病灶合成的抗体迁移为单一带。这种同质蛋白质可能是均匀分化的细胞克隆的产物。然而，也遇到了一些产生两条且可能更多抗体带的病灶。对这一发现可以有两种解释。要么不止一种前体可能参与病灶的形成，要么在克隆扩增过程中可能发生分化转换。
