de Vries J E, Caviles A P, Bont W S, Mendelsohn J
J Immunol. 1979 Mar;122(3):1099-107.
Studies were performed to determine the role of monocytes in human lymphocyte activation by mitogens. Velocity sedimentation at 1 x G in a new apparatus was utilized to obtain highly purified lymphocyte fractions (LF) nearly free of monocytes (0.02 to 0.4%) and a fraction (MF) enriched for monocytes (64 to 92%). The average peak responses of the lymphocyte fractions to phytohemagglutinin, concanavalin A, and pokeweed mitogen were 19, 10, and 9% of the responses achieved with unfractionated lymphocyte cultures containing approximately 20% monocytes. These changes were not attributable to altered dose requirements. When mitomycin-C-treated MF cells were used to reconstitute LF cultures, it was found that 4% monocytes fully restored the response to phytohemagglutinin whereas 8 to 16% monocytes were required for a normal response to the other mitogens. Higher numbers of MF cells produced supranormal responses, with 35 to 50% monocytes resulting in the optimal stimulation. Allogeneic monocytes were able to fully reconstitute the response of LF, and 2-mercaptoethanol (50 microM) was only slightly effective. In exploring possible mechanisms by which monocytes potentiate the mitogenic activity of lymphocytes, it was found that the supernatants of MF cultures could partially, but not completely, reconstitute LF responses, suggesting that contact with MF may be required for optimal effectiveness. Addition of graded numbers of monocytes to LF altered both the kinetics of the response and the peak level of proliferation. Monocyte depletion also resulted in markedly decreased survival of cultured unstimulated LF. These observations suggest a variety of possible effects of monocytes in potentiating mitogenic responses, including contact-mediated interactions with lymphocytes (possibly to present the mitogen optimally); enhancement of proliferation kinetics and the size of the responding subpopulation, and maintenance of a requisite growth factor(s) in the culture. Small differences in the monocyte content of cultured lymphocyte preparations may thus account for many of the often observed variations in mitogen responsiveness.
开展了多项研究以确定单核细胞在有丝分裂原激活人淋巴细胞过程中的作用。利用一种新装置在1×G条件下进行速度沉降，以获得几乎不含单核细胞（0.02%至0.4%）的高度纯化淋巴细胞组分（LF）和富含单核细胞（64%至92%）的组分（MF）。淋巴细胞组分对植物血凝素、刀豆球蛋白A和商陆有丝分裂原的平均峰值反应分别为含约20%单核细胞的未分级淋巴细胞培养物所获反应的19%、10%和9%。这些变化并非归因于剂量需求的改变。当用丝裂霉素-C处理的MF细胞来重建LF培养物时，发现4%的单核细胞可完全恢复对植物血凝素的反应，而对其他有丝分裂原的正常反应则需要8%至16%的单核细胞。更多数量的MF细胞产生超正常反应，35%至50%的单核细胞可导致最佳刺激。同种异体单核细胞能够完全重建LF的反应，而2-巯基乙醇（50微摩尔）的效果则很轻微。在探索单核细胞增强淋巴细胞有丝分裂活性的可能机制时，发现MF培养物的上清液可部分但不能完全重建LF反应，这表明可能需要与MF接触才能达到最佳效果。向LF中添加不同数量的单核细胞会改变反应动力学和增殖峰值水平。单核细胞耗竭还导致未刺激的培养LF的存活率显著降低。这些观察结果表明单核细胞在增强有丝分裂反应方面有多种可能的作用，包括与淋巴细胞的接触介导相互作用（可能是为了最佳地呈现有丝分裂原）；增强增殖动力学和反应亚群的大小，以及在培养物中维持必需的生长因子。因此，培养的淋巴细胞制剂中单核细胞含量的微小差异可能解释了许多经常观察到的有丝分裂原反应性变化。
