The use of chimeric antigen receptor-modified T cells (CAR T cells) is an effective therapy for advanced cancer, especially hematological malignancies, and this method has attracted widespread attention in the last several years. The type, number and vitality of the effector cells clearly play important roles in this approach. In this study, to expand the possibility of curing cancer through adoptive cell therapy (ACT), we developed a novel method for effectively obtaining abundant T cells in vitro. The fusion proteins of three cytokines, SA-hIL-2, SA-hIL-7 and SA-hIL-21, were anchored onto biotin magnetic beads to increase the number of cytokines on the surface of the magnetic beads, which increased the local concentration of cytokines and thus promoted the binding of cytokines to T cells. Next, we examined the effects of these modified magnetic beads on the proliferation rate of T cells and CD19 CAR T cells. In this study, we report the expression and purification of the active bifunctional fusion proteins SA-hIL-2, SA-hIL-7 and SA-hIL-21, which were bound to biotin magnetic beads to develop a platform that was employed to increase the local concentration of cytokines. When the cells had been cultured for 14 days, the proliferation rate of the CD3⁺ T cells in the group that received cytokine-coupled biotin magnetic beads (Beads-SA-CK) was higher than that of the cells in the groups that received soluble cytokines (Soluble-SA-CK) and that of the cells in the standard group (Standard-CK). We speculate that this difference may be the result of the increased expression of Bcl-2 and the increased phosphorylation of Stat5. Moreover, our results preliminarily indicate that compared with the other two treatments, Soluble-SA-CK and Standard-CK, adding cytokine-coupled biotin magnetic beads more effectively increases the proliferation rate of CD19 CAR-T cells. As expected, the CD19 CAR-T cells stimulated by Beads-SA-CK had a stronger anticancer effect than the cells stimulated by the other two treatments. An effective method of preparing abundant T cells in vitro was developed, and it may provide a novel strategy for ACT.

嵌合抗原受体修饰的T细胞（CAR T细胞）的使用是治疗晚期癌症（尤其是血液系统恶性肿瘤）的有效方法，并且这种方法在最近几年引起了广泛的关注。效应细胞的类型，数量和活力显然在这种方法中起着重要的作用。在这项研究中，为了扩大通过过继细胞疗法（ACT）治愈癌症的可能性，我们开发了一种有效地体外获得大量T细胞的新方法。将三种细胞因子SA-hIL-2，SA-hIL-7和SA-hIL-21的融合蛋白固定在生物素磁珠上，以增加磁珠表面的细胞因子数量，从而增加了局部浓度细胞因子的结合，从而促进细胞因子与T细胞的结合。接下来，我们检查了这些修饰的磁珠对T细胞和CD19 CAR T细胞增殖速率的影响。在这项研究中，我们报告了活性双功能融合蛋白SA-hIL-2，SA-hIL-7和SA-hIL-21的表达和纯化，它们与生物素磁珠结合，从而开发了一个平台，用于增加细胞因子的局部浓度。将细胞培养14天后，CD3 ⁺的增殖速率接受细胞因子偶联生物素磁珠（Beads-SA-CK）的组中的T细胞高于接受可溶性细胞因子（Soluble-SA-CK）的组和标准组中的T细胞（标准-CK）。我们推测这种差异可能是Bcl-2表达增加和Stat5磷酸化增加的结果。此外，我们的结果初步表明，与其他两种治疗方法（Solble-SA-CK和Standard-CK）相比，添加细胞因子偶联的生物素磁珠可以更有效地提高CD19 CAR-T细胞的增殖率。不出所料，Beads-SA-CK刺激的CD19 CAR-T细胞比其他两种治疗方法刺激的细胞具有更强的抗癌作用。一种体外制备大量T细胞的有效方法 被开发出来，它可能为ACT提供一种新颖的策略。