Söder O, Ernström U
Thymus. 1983 Apr;5(3-4):141-52.
A growth factor prepared from calf thymus has been described previously (Thymus 3, 289, 1981). The factor was shown to stimulate the DNA synthesis in thymic cells but not in peripheral lymphocytes in guinea pigs. We now present a further analysis of the target cell. Thymus cells were fractionated into subpopulations based on their different adherence to plastic, buoyant density and agglutinability by peanut agglutinin (PNA) and the influence of the growth factor on DNA synthesis was studied. The results showed that the responding cell was enriched in the population of non-adherent PNA-positive (PNA +) cells of low buoyant density. This cell population showed high spontaneous DNA synthesis in vitro, but did not contain the phytohemagglutinin-responsive thymocyte, which resided in the PNA-negative (PNA -) population of low density. The results strongly indicated that the target cell of the thymic growth factor is the immunologically immature proliferating thymocyte of the thymic cortex.
先前已描述了一种从小牛胸腺制备的生长因子（《胸腺》第3卷，第289页，1981年）。该因子被证明能刺激豚鼠胸腺细胞中的DNA合成，但不能刺激外周淋巴细胞中的DNA合成。我们现在对靶细胞进行进一步分析。根据胸腺细胞对塑料的不同黏附性、浮力密度以及花生凝集素（PNA）的凝集性，将胸腺细胞分离成亚群，并研究生长因子对DNA合成的影响。结果表明，反应细胞富集于低浮力密度的非黏附性PNA阳性（PNA +）细胞群体中。该细胞群体在体外表现出较高的自发DNA合成，但不包含存在于低密度PNA阴性（PNA -）群体中的对植物血凝素反应性的胸腺细胞。结果有力地表明，胸腺生长因子的靶细胞是胸腺皮质中免疫不成熟的增殖性胸腺细胞。
