Yang S S, Malek T R, Hargrove M E, Ting C C
J Immunol. 1985 Jun;134(6):3912-9.
Lymphokines induce the generation of cytotoxic cells (LICC) in the absence of antigenic or mitogenic stimulation. In the present study, we have demonstrated that at least two lymphokines are involved. They are interleukin 2-conditioned medium (CM-IL 2), which was produced by W/Fu rat spleen cells cultured with concanavalin A-conjugated Sepharose beads, and cytotoxic cell differentiation factor-conditioned medium (CM-CCDF), which was produced primarily by the unstimulated mouse peritoneal macrophages. It was first established that CCDF synergized with IL 2 to induce the generation of LICC in normal spleen cells, and that this process was specifically blocked by the rat anti-IL 2 receptor monoclonal antibody. The maximal synergistic effect was obtained by using 10% CM-CCDF (v/v) and 0.1 to 0.3 U/ml of CM-IL 2. Higher doses of IL 2 (3 to 10 U/ml) reduced the cytotoxic response. The effectors of LICC were Thy-1+, Lyt-2- and AGM1-; therefore, they were neither classic CTL nor NK cells. The precursors were AGM1+, Lyt-2- cells that were consistent of being NK-like cells. When examining the temporal relationship between CCDF and IL 2, we found that 4 hr preincubation of the responders with IL 2 was sufficient to activate the cytotoxic precursor cells. CCDF was needed later for the differentiation of the activated precursors into cytotoxic effectors. In contrast, preincubation of the responders with CCDF, followed by additional incubation with IL 2, failed to induce any cytotoxic response. These results established that lymphokine-induced cytotoxicity can be separated into two phases. In the activation phase, IL 2 provides the first signal to activate the cytotoxic precursors, with the process being completed in 4 hr. In the differentiation phase, CCDF provides the second signal to induce the differentiation of the IL 2-activated precursors into cytotoxic effectors, with this process requiring 48 hr to complete. The sequential presence of these lymphokines at an appropriate time during the activation and differentiation phases is critical for the generation of LICC response.
淋巴因子在无抗原或丝裂原刺激的情况下可诱导细胞毒性细胞（LICC）的产生。在本研究中，我们已证明至少有两种淋巴因子参与其中。它们是白细胞介素2条件培养基（CM-IL 2），由用伴刀豆球蛋白A偶联的琼脂糖珠培养的W/Fu大鼠脾细胞产生；以及细胞毒性细胞分化因子条件培养基（CM-CCDF），主要由未刺激的小鼠腹腔巨噬细胞产生。首先确定CCDF与IL 2协同作用以诱导正常脾细胞中LICC的产生，并且该过程被大鼠抗IL 2受体单克隆抗体特异性阻断。使用10%（体积/体积）的CM-CCDF和0.1至0.3 U/ml的CM-IL 2可获得最大协同效应。更高剂量的IL 2（3至10 U/ml）会降低细胞毒性反应。LICC的效应细胞为Thy-1+、Lyt-2-和AGM1-；因此，它们既不是经典的细胞毒性T淋巴细胞（CTL）也不是自然杀伤（NK）细胞。前体细胞为AGM1+、Lyt-2-细胞，符合NK样细胞的特征。在研究CCDF与IL 2之间的时间关系时，我们发现用IL 2对反应细胞进行4小时预孵育足以激活细胞毒性前体细胞。随后需要CCDF将活化的前体细胞分化为细胞毒性效应细胞。相反，先用CCDF对反应细胞进行预孵育，然后再用IL 2进行孵育，未能诱导任何细胞毒性反应。这些结果表明，淋巴因子诱导的细胞毒性可分为两个阶段。在激活阶段，IL 2提供第一个信号来激活细胞毒性前体细胞，该过程在4小时内完成。在分化阶段，CCDF提供第二个信号以诱导IL 2活化的前体细胞分化为细胞毒性效应细胞，该过程需要48小时完成。在激活和分化阶段的适当时间依次存在这些淋巴因子对于LICC反应的产生至关重要。
