Dy M, Schneider E, Mavier P, Kamoun P, Lebel B, Hamburger J
J Immunol. 1983 Apr;130(4):1937-42.
The production of urea and ornithine is increased greatly in spleen cell cultures of an allograft recipient in the presence of donor cells (secondary MLC) in comparison to that of primary MLC (without previous allograft). This phenomenon appears after 24 hr of culture and reaches its maximum at 48 hr. The greatest increase in urea production is observed when the recipient spleen cells are collected at the time of allograft rejection. To obtain this extra production of urea, the stimulating cells in MLC should specifically be of the donor type or at least bear one homology with donor cells at the K or D locus. The increased production of urea and ornithine during MLC results from the action of a lymphokine released by recipient cells in the presence of donor cells. This factor acts upon cells present in bone marrow, spleen, and elicited peritoneal cells but is absent or is present in smaller quantities in thymus and lymph node cells. Target cells of this factor possess numerous macrophage features and could be immature cells of the macrophage line. The lymphokine responsible for this phenomenon is heat-stable, destroyed by trypsin, chymotrypsin, and neuraminidase, and has a m.w. around 32,000. It acts upon its target cells by increasing arginase activity, which results in the production of a large amount of ornithine, an important precursor of polyamine biosynthesis.
与初次混合淋巴细胞培养（无先前同种异体移植）相比，在存在供体细胞的同种异体移植受体的脾细胞培养物（二次混合淋巴细胞培养）中，尿素和鸟氨酸的产生显著增加。这种现象在培养24小时后出现，并在48小时达到最大值。当在同种异体移植排斥时收集受体脾细胞时，观察到尿素产生的最大增加。为了获得这种额外的尿素产生，混合淋巴细胞培养中的刺激细胞应特别为供体类型，或者至少在K或D位点与供体细胞有一个同源性。混合淋巴细胞培养期间尿素和鸟氨酸产生的增加是由于受体细胞在存在供体细胞时释放的一种淋巴因子的作用。该因子作用于骨髓、脾脏和诱导腹膜细胞中的细胞，但在胸腺和淋巴结细胞中不存在或含量较少。该因子的靶细胞具有许多巨噬细胞特征并且可能是巨噬细胞系的未成熟细胞。负责这种现象的淋巴因子是热稳定的，被胰蛋白酶、糜蛋白酶和神经氨酸酶破坏，并且分子量约为32,000。它通过增加精氨酸酶活性作用于其靶细胞，这导致产生大量鸟氨酸，鸟氨酸是多胺生物合成的重要前体。
