Human T cell activation with phytohemagglutinin. The function of IL-6 as an accessory signal.
Human T cell activation with phytohemagglutinin. The function of IL-6 as an accessory signal.
复制标题
用植物血凝素激活人类 T 细胞。
作者：
Jan L. Ceuppens;M. Baroja;K. Lorré;J. V. Damme;A. Billiau
凝集素 PHA 诱导的 T 细胞增殖需要单核细胞的存在。在这里，我们报告说，IL-6 代表了 PHA 刺激人类 T 细胞的单核细胞衍生辅助活性的一部分。从外周血或扁桃体分离并完全耗尽辅助细胞（单核细胞和 NK 细胞）的静息 T 细胞不会单独响应 PHA 而增殖。将无细胞单核细胞培养物上清液（不含 IL-2）添加到 PHA 刺激的培养物中会导致 T 细胞增殖。我们确定 IL-6 是这些单核细胞上清液中的重要辅助因子，因为 IL-6 抗血清（但不是抗 IL-1-β）完全中和了单核细胞上清液的辅助作用。此外，向 T 细胞培养物中添加纯化的人 IL-6（但不是 IL-1-β）会导致 PHA 刺激的 T 细胞增殖。虽然IL-1本身不能恢复PHA诱导的分离T细胞的增殖反应，但它强烈增强了IL-6的辅助作用。与完整的单核细胞相比，IL-6 在 PHA 刺激的 T 细胞培养物中不会诱导可检测到的 IL-2 产生。此外，抗 IL-2R mAb（抗 Tac）不会阻断 PHA 和 IL-6 诱导的增殖反应，表明涉及不依赖 IL-2 的 T 细胞增殖途径。总之，我们的结果表明，先前被鉴定为 B 细胞杂交瘤生长和 B 细胞分化因子的人 IL-6，代表了 PHA 诱导的人 T 细胞活化和增殖的单核细胞辅助功能的一部分。
T cell proliferation induced by the lectin PHA requires the presence of monocytes. Here, we report that IL-6 represents part of the monocyte-derived helper activity for human T cell stimulation with PHA. Resting T cells isolated from peripheral blood or tonsils and completely depleted of accessory cells (monocytes and NK cells) did not proliferate in response to PHA alone. Addition of a cell-free monocyte culture supernatant (not containing IL-2) to the PHA-stimulated cultures resulted in T cell proliferation. We identified IL-6 as an essential helper factor in these monocyte supernatants, because antisera to IL-6 (but not anti-IL-1-beta) completely neutralized the helper effect of the monocyte supernatant. Moreover, addition of purified human IL-6 (but not IL-1-beta) to T cell cultures resulted in proliferation of PHA-stimulated T cells. Although IL-1 could not restore the PHA-induced proliferative response of isolated T cells by itself, it strongly enhanced the helper effect of IL-6. In contrast to intact monocytes, IL-6 did not induce detectable IL-2 production in cultures of PHA-stimulated T cells. Furthermore, an anti-IL-2R mAb (anti-Tac) did not block the proliferative response induced by PHA and IL-6, suggesting that an IL-2-independent pathway of T cell proliferation was involved. In conclusion our results show that human IL-6, previously identified as a B cell hybridoma growth and a B cell differentiation factor, represents part of the monocyte helper function for PHA-induced human T cell activation and proliferation.