Characterization and induction of antitumor lymphokine derived from human lymph node cell

本研究旨在探讨淋巴结细胞是否能通过细胞因子介导对肿瘤细胞发挥抗增殖作用。采用人肿瘤克隆实验（HTCA）研究了宫颈癌患者局部淋巴结细胞的可溶性抗肿瘤活性。淋巴细胞（LNCs）对宫颈癌细胞系HeLa细胞具有显著的抗增殖活性，这是通过植物血凝素（PHA）或豆豆蛋白A（ConA）刺激而不是白介素-2（IL-2）来证明的。此外，从宫颈癌和子宫内膜癌患者中获得的LNCs在受到PHA刺激时，对子宫内膜癌细胞株RL95-2也显示出显著的抗增殖活性。这种抗增殖活性主要在非贴壁细胞中发现，可能是t细胞。LNCs同时产生干扰素γ (IFNgamma)和肿瘤坏死因子（TNF），结果表明HeLa细胞对重组人IFNgamma敏感，RL95-2细胞对重组人TNF敏感。这些发现表明，抗肿瘤活性分别归因于IFNgamma和TNF。此外，对于HeLa细胞，通过中和实验证实IFNgamma对其活性负责。这些结果表明，在适当的刺激下，人类LNCs能够通过细胞因子介导发挥抗增殖活性。在这两项研究中，LNCs不能通过IL-2刺激表现出抗增殖活性，但在某些情况下，外周血淋巴细胞通过IL-2刺激HTCA发挥了抗增殖活性（已提交论文）。此外，当LNCs被IL-2刺激较长时间时，它们会产生细胞因子，如TNFalpha、TNFbeta和IFNgamma（正在进行的研究）。IL-2刺激LNCs可能是一种很有前途的方法，因此目前正在深入研究中。

This study was designed to investigate whether lymph node cells could exert an antiproliferative activity on tumor cells that are mediated through cytokines. The soluble antitumor activity of regional lymph node cells obtained from patients with cervical cancer was investigated by using a human tumor clonogenic assay (HTCA). A significant antiproliferative activity of the lymph node cells (LNCs) against a cervical cancer cell line, HeLa cells, was demonstrated by stimulation with either phytohemagglutinin (PHA) or concanavalin A(ConA), but not with interleukin-2(IL-2). In addition, a significant antiproliferative activity of the LNCs obtained from cervical cancer and endometrial cancer patients against a endometrial cancer cell line, RL95-2, was also demonstrated when they were stimulated by PHA. This antiproliferative activity was found mainly in nonadherent cells, possibly T-cells. LNCs produced both interferon gamma(IFNgamma) and tumor necrosis factor (TNF), and it was demonstrated that HeLa cells were sensitive to recombinant human IFNgamma and RL95-2 cells were sensitive to recombinant human TNF. These findings suggested the antitumor activities were attributed to IFNgamma and TNF, respectively. Moreover, about HeLa cells, it was confirmed that IFNgamma was responsible for the activity by using neutralizing experiments. These results indicate that human LNCs were able to exert an antiproliferative activity mediated through the cytokines by appropriate stimulation. In the two studies, LNCs could not demonstrate an antiproliferative activity by stimulation with IL-2, but peripheral blood lymphocytes, in some cases, exerted antiproliferative activity by stimulation with IL-2 on HTCA (submitted paper). In addition, LNCs produced cytokines, such as TNFalpha, TNFbeta, and IFNgamma when they were stimulated by IL-2 for longer duration (ongoing study). IL-2 stimulation on LNCs might be a promising procedure, so it is presently under intensive research investigation.