Philp J R, Huffman A L, Johnson J E
Infect Immun. 1976 Oct;14(4):872-5. doi: 10.1128/iai.14.4.872-875.1976.
Upon exposure to specific antigen in tissue culture, sensitive lymphocytes released macrophage migration inhibition factor and other lymphokines into the supernatant culture medium. Migration of peritoneal macrophages from nonsensitive animals was inhibited in the presence of such supernatants. However, with previous techniques it was found that an inhibitory effect was present at only low low titers (less than 10(2)). It is therfore of great interest that by increasing cellular density, the total number of cells being kept constant, inhibitory activity can be amplified by a factor as great as 10(10). This amplification was observed only when lymphocytes and macrophages were loosely packed, as by spontaneous sedimentation in a conical test tube. The effect was abolished by dispersing the cell suspension in a flat-bottomed flask or, alternatively, by shaking the test tube so that intimate prolonged intercellular contact was prevented.
在组织培养中接触特定抗原后，敏感淋巴细胞会将巨噬细胞移动抑制因子和其他淋巴因子释放到上清培养基中。在这种上清液存在的情况下，来自非敏感动物的腹腔巨噬细胞的移动受到抑制。然而，使用以前的技术发现，只有在低滴度（小于10²）时才存在抑制作用。因此，非常有趣的是，通过增加细胞密度（细胞总数保持不变），抑制活性可以放大高达10¹⁰倍。只有当淋巴细胞和巨噬细胞松散堆积时，如在锥形试管中自然沉降那样，才观察到这种放大作用。通过将细胞悬液分散在平底烧瓶中，或者通过摇晃试管以防止细胞间长时间紧密接触，这种作用就会消失。
