Lohrmann H P, Novikovs L, Graw R G
J Exp Med. 1974 Jun 1;139(6):1553-67. doi: 10.1084/jem.139.6.1553.
In vitro studies were performed to determine the proliferative responsiveness of human peripheral blood thymus-dependent (T) and thymus-independent (B) lymphocytes to phytomitogens and allogeneic lymphocytes. Recombination of T and B cells, with selective inhibition of proliferation of one of the two populations, was used to identify cellular interactions which may contribute to cell proliferation. The distinctive feature of human T lymphocytes to form rosettes with unsensitized sheep erythrocytes was utilized to separate human peripheral blood lymphocytes into highly purified resetting (T) and non-rosetting (B) cells. The proliferative response of these separated lymphocyte subpopulations to various stimulants was assessed from the uptake of tritiated thymidine into DNA. Phytohemagglutinin, concanavalin A, pokeweed mitogen, and allogeneic lymphocytes stimulated separated T cells, whereas no proliferation was observed with the T-cell-depleted B-cell population. This suggests that it is the human T cell which is activated directly by these stimulants. In the presence of T cells (proliferating or nonproliferating), B cells were capable of proliferation following stimulation with phytomitogens, but not in response to histocompatibility antigens. Thus, T-cell-mediated B-cell proliferation contributes to the overall lymphocyte response in phytomitogen-stimulated T + B cell mixtures, but not in human mixed leukocyte cultures. T-cell activation by allogeneic cells required the presence of monocytes; in contrast, the three tested phytomitogens stimulated T cells in the absence of monocytes. This indicates that direct interaction of mitogens with lymphocyte membrane receptors is sufficient to trigger T cells into proliferative response. However, monocytes considerably enhanced the proliferative response of T cells in a dose-dependent fashion; this monocyte-dependent mechanism of T-cell activation was predominant at lower concentrations of phytomitogens, and contributed relatively less at higher mitogen doses. Both, the direct, monocyte-independent, and the indirect, monocyte-dependent T-lymphocyte activation contribute to the total in vitro response of lymphocyte preparations to phytomitogens.
进行了体外研究，以确定人外周血中胸腺依赖性（T）淋巴细胞和非胸腺依赖性（B）淋巴细胞对植物凝集素和同种异体淋巴细胞的增殖反应性。通过T细胞和B细胞的重组以及对两个群体之一增殖的选择性抑制，来确定可能有助于细胞增殖的细胞间相互作用。利用人T淋巴细胞与未致敏绵羊红细胞形成玫瑰花结的独特特性，将人外周血淋巴细胞分离为高度纯化的形成玫瑰花结的（T）细胞和不形成玫瑰花结的（B）细胞。通过将氚标记的胸腺嘧啶核苷摄取到DNA中，评估这些分离的淋巴细胞亚群对各种刺激物的增殖反应。植物血凝素、刀豆球蛋白A、商陆有丝分裂原和同种异体淋巴细胞刺激分离的T细胞，而去除T细胞的B细胞群体未观察到增殖。这表明这些刺激物直接激活的是人T细胞。在有T细胞（增殖或不增殖）存在的情况下，B细胞在用植物凝集素刺激后能够增殖，但对组织相容性抗原无反应。因此，在植物凝集素刺激的T + B细胞混合物中，T细胞介导的B细胞增殖有助于总体淋巴细胞反应，但在人混合白细胞培养物中则不然。同种异体细胞对T细胞的激活需要单核细胞的存在；相反，三种测试的植物凝集素在没有单核细胞的情况下刺激T细胞。这表明有丝分裂原与淋巴细胞膜受体的直接相互作用足以触发T细胞进入增殖反应。然而，单核细胞以剂量依赖的方式显著增强了T细胞的增殖反应；这种单核细胞依赖性的T细胞激活机制在较低浓度的植物凝集素时占主导地位，在较高的有丝分裂原剂量时贡献相对较小。直接的、不依赖单核细胞的以及间接的、依赖单核细胞的T淋巴细胞激活都有助于淋巴细胞制剂对植物凝集素的总体体外反应。
