Shinagawa Naofumi, Yamazaki Koichi, Tamura Yasuaki, Imai Akihito, Kikuchi Eiki, Yokouchi Hiroshi, Hommura Fumihiro, Oizumi Satoshi, Nishimura Masaharu
First Department of Medicine, Hokkaido University School of Medicine, North 15, West 7, Kita-ku, Sapporo 060-8638, Japan.
Cancer Immunol Immunother. 2008 Feb;57(2):165-74. doi: 10.1007/s00262-007-0359-3. Epub 2007 Jul 13.
Immunization with heat shock proteins, gp96, elicits specific protective immunity against parent tumors. However, it is marginally effective as a therapeutic tool against established tumors. In the present study, we evaluated the efficacy and mechanism of immunotherapy with bone marrow-derived dendritic cells (DCs) pulsed with tumor-derived gp96 against murine lung cancer.
Mice were transplanted subcutaneously with ovalbumin (OVA)-transfected Lewis Lung Cancer (LLC-OVA) cells and immunized with gp96 derived from LLC-OVA, DCs, or DCs pulsed with gp96 derived from LLC-OVA.
The antitumor effect was significantly enhanced in the mice immunized with DCs pulsed with gp96 derived from LLC-OVA, compared to mice immunized with gp96 or DCs (P<0.05). The antitumor effect was significantly dependent on natural killer (NK) cells and CD8(+) cells and partially dependent on CD4(+) cells. Analysis by laser confocal microscopy demonstrated that gp96 was shown on the cell surface at 15 min, and after 30 min internalized in the endosomes and not in the endoplasmic reticulum or lysosomes. OVA-specific(+) CD8(+) cells were more readily recruited into the draining lymph nodes and higher CD8(+) cytotoxic T cell activity against LLC-OVA was observed in splenocytes from mice immunized with DCs pulsed with gp96 derived from LLC-OVA. Re-challenge of the surviving mice with LLC-OVA tumors after the initial tumor inoculation showed dramatic retardation in tumor growth.
In conclusion, immunotherapy of DCs pulsed with tumor-derived gp96 against murine lung cancer is effective through immune response of CD8(+) cytotoxic T lymphocytes and NK cells.
用热休克蛋白gp96进行免疫接种可引发针对原发肿瘤的特异性保护性免疫。然而，作为针对已形成肿瘤的治疗工具，其效果甚微。在本研究中，我们评估了用肿瘤来源的gp96脉冲处理的骨髓源性树突状细胞（DCs）对小鼠肺癌进行免疫治疗的疗效及机制。
将卵清蛋白（OVA）转染的刘易斯肺癌（LLC-OVA）细胞皮下移植到小鼠体内，并用源自LLC-OVA的gp96、DCs或用源自LLC-OVA的gp96脉冲处理的DCs进行免疫接种。
与用gp96或DCs免疫的小鼠相比，用源自LLC-OVA的gp96脉冲处理的DCs免疫的小鼠的抗肿瘤效果显著增强（P<0.05）。抗肿瘤效果显著依赖于自然杀伤（NK）细胞和CD8(+)细胞，部分依赖于CD4(+)细胞。激光共聚焦显微镜分析表明，gp96在15分钟时出现在细胞表面，30分钟后被内化到内体中，而不是在内质网或溶酶体中。OVA特异性(+) CD8(+)细胞更容易被募集到引流淋巴结中，在用源自LLC-OVA的gp96脉冲处理的DCs免疫的小鼠的脾细胞中观察到针对LLC-OVA的更高的CD8(+)细胞毒性T细胞活性。在初始肿瘤接种后，用LLC-OVA肿瘤对存活小鼠进行再次攻击，结果显示肿瘤生长显著延迟。
总之，用肿瘤来源的gp96脉冲处理的DCs对小鼠肺癌进行免疫治疗通过CD8(+)细胞毒性T淋巴细胞和NK细胞的免疫反应是有效的。
