Imura Kenichiro, Ueda Yuji, Hayashi Takashi, Itoh Tsuyoshi, Shimizu Keiji, Tamai Hidemasa, Yano Yutaro, Naito Kei, Kohara Junji, Nakane Kazuki, Matsuura Yuko, Takeda Atsuko, Takeda Takahisa, Kawai Keiichi, Yamagishi Hisakazu
Department of Surgery, Division of Digestive Surgery, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kyoto 602-8566, Japan.
Int J Oncol. 2006 Sep;29(3):531-9.
Recently, dendritic cells (DCs) and DC-tumor cell hybrids (DC-tumor hybrids) have been used for cancer vaccine therapy in a clinical trial. DC-tumor hybrids combine the potent antigen-presenting capacity of DCs with the ability to present all tumor antigens expressed on tumor cells to T cells. We used DC-tumor hybrids as stimulator cells to induce tumor-specific cytotoxic T lymphocytes (CTLs) in vitro. DC-tumor hybrids were generated from human monocyte-derived DCs and human cancer-cell lines (GT3TKB, lung cancer; GCIY, gastric cancer) by our newly developed electrofusion technique, established and refined with the use of mouse cells. To evaluate the capacity of DC-tumor hybrids generated by our method to induce tumor antigen-specific CTLs, we performed a cytotoxic assay and an interferon-gamma release assay using CD8-dominant effector lymphocytes induced by them. DC-tumor hybrids more effectively induced tumor-specific primary T-cell response than did stimulation with DCs co-cultured with irradiated tumor cells overnight, irradiated tumor cells alone, or a mixture of DCs and irradiated tumor cells. DC-tumor hybrids were generated at a high fusion rate by our electrofusion technique. When CTLs were induced by DC-tumor hybrids in vitro, the high fusion rate did not contribute to the induction of CTLs with increased tumor-specific cytotoxicity. The addition of interleukin-12 to the culture medium did not augment the cytotoxicity of CTLs. Overall, our results suggest that DC-tumor hybrids effectively induce human tumor-specific CTLs and may thus be applicable for clinical trials of adoptive immunotherapy.
最近，树突状细胞（DCs）和DC-肿瘤细胞杂交体（DC-肿瘤杂交体）已被用于一项癌症疫苗治疗的临床试验。DC-肿瘤杂交体将DC强大的抗原呈递能力与向T细胞呈递肿瘤细胞上表达的所有肿瘤抗原的能力结合在一起。我们使用DC-肿瘤杂交体作为刺激细胞在体外诱导肿瘤特异性细胞毒性T淋巴细胞（CTLs）。DC-肿瘤杂交体是通过我们新开发的电融合技术，由人单核细胞衍生的DCs和人癌细胞系（GT3TKB，肺癌；GCIY，胃癌）产生的，该技术利用小鼠细胞得以建立和完善。为了评估我们方法产生的DC-肿瘤杂交体诱导肿瘤抗原特异性CTLs的能力，我们使用由它们诱导的CD8主导的效应淋巴细胞进行了细胞毒性测定和干扰素-γ释放测定。与用过夜共培养的DCs与照射过的肿瘤细胞、单独的照射过的肿瘤细胞或DCs与照射过的肿瘤细胞的混合物进行刺激相比，DC-肿瘤杂交体更有效地诱导了肿瘤特异性的原发性T细胞反应。通过我们的电融合技术，DC-肿瘤杂交体以高融合率产生。当在体外由DC-肿瘤杂交体诱导CTLs时，高融合率对诱导具有增强的肿瘤特异性细胞毒性的CTLs没有作用。向培养基中添加白细胞介素-12并没有增强CTLs的细胞毒性。总体而言，我们的结果表明，DC-肿瘤杂交体有效地诱导了人肿瘤特异性CTLs，因此可能适用于过继性免疫治疗的临床试验。
