Immunotherapy of pancreatic ductal adenocarcinoma with human gammadelta T lymphocytes

循环中的和肿瘤浸润性的人类γδT细胞以一种MHC非限制性方式杀死各种肿瘤细胞。人类Vγ9Vδ2γδT细胞的优势亚群识别甲氧戊酸途径的中间产物异戊烯焦磷酸，它在肿瘤细胞中增加。治疗用含氮双膦酸盐(n-BPS)可以进一步增加转化细胞中IPP的产量。将人Vγ9Vδ2γδT细胞和n-BPS/IL-2过继转移到SCID小鼠体内，在体内外均显示了γδT细胞和n-BPS/IL-2过继转移对胰腺癌的抑制作用。其他人发表的几项先导性研究报告称，肾癌或前列腺癌患者在接受n-BPS和低剂量IL-2治疗后，γδT细胞被选择性激活，肿瘤生长部分减少。为了促进以γδT细胞为基础的免疫治疗，将解决以下问题：(I)肿瘤反应性γδT细胞体外扩增和细胞毒效应活性的优化；(Ii)对γδ细胞系的细胞毒性的表征，包括n-Bps的直接作用、相互作用分子的调节和肿瘤逃逸机制；(Iii)在SCID-Beige小鼠中使用过继转移模型进一步研究γδ反应性PdAC T细胞的临床前特征和n-Bps的抗肿瘤作用；(4)以γδT细胞为重点的免疫监测，对接受n-BPS加低剂量IL-2治疗的晚期PDAC患者进行原则验证研究；和(5)建立γδT细胞最终过继转移到患者体内的GMP方案。

Circulating as well as tumor-infiltrating human γδ T cells kill various tumor cells in a MHC-non-restricted fashion. The dominant subset of human Vγ9Vδ2 γδ T cells recognizes isopentenyl pyrophosphate (IPP), an intermediate of the mevalonate pathway, which is increased in tumor cells. The augmented production of IPP in transformed cells can be further increased by therapeutically administered nitrogen-containing-bisphosphonates (n-BPs). We have shown the efficacy of human Vγ9Vδ2 γδ T cells against pancreatic ductal adenocarcinoma (PDAC) in vitro as well as in vivo after adoptive transfer of γδ T cells and n-BPs/IL-2 into SCID mice. Several pilot studies published by others reported a selective activation of γδ T cells and a partial reduction of tumor growth in renal or prostate cancer patients after treatment with n-BPs and low dose IL-2. To promote γδ T cell-based immunotherapy, the following issues will be addressed: (i) optimization of in vitro expansion and cytotoxic effector activity of tumor-reactive γδ T cells; (ii) characterization of cytotoxicity against PDAC cell lines including direct effects of n-BPs, regulation of interacting molecules and tumor escape mechanisms in the interplay of γδ T cells and PDAC cells; (iii) use of an adoptive transfer model in SCID-Beige mice for further preclinical characterization of PDAC-reactive γδ T cells and anti-tumor effects of n-BPs; (iv) γδ T cell focused immune-monitoring in proof-of-principle studies in patients with advanced PDAC treated with n-BPs plus low dose IL-2; and (v) establishment of GMP protocols for ultimate adoptive transfer of γδ T cells into patients.