Cytokine gene therapy for brain tumors using neural progenitor cells

细胞因子基因治疗中枢神经系统肿瘤已被证明具有巨大的潜力，但在抗原提呈过程和/或免疫活性细胞招募不足方面需要改进，以实现对已建立的脑肿瘤的成功根除。我们研究了在周围组织中诱导系统免疫并结合脑瘤周围各种细胞因子的产生来治疗已建立的脑瘤的治疗潜力。序列磁共振成像(MRI)监测显示，综合治疗包括脑内(I.C.)产生IL-2的同种或异种细胞和皮下移植(S.C.)用照射后的9L或9L/IL-2细胞接种可治愈9L荷瘤大鼠，而皮下注射9L或9L/IL-2细胞均可治愈。注射IL-2产生物或S.C.单独接种疫苗的抗肿瘤效果分别很小或微乎其微。其他细胞因子如IL-4、IL-12或GM-CSF不能诱导SIGN…对已建立的脑肿瘤有更显著的治疗效果。在皮下接种的大鼠体内，同样能诱导出胶质瘤特异性CTL活性。照射9L、照射产生IL-2的9L细胞或照射后的9L和C1300/IL-2混合细胞，照射后的9L细胞与C1300/IL-4或C1300/GM-CSF混合免疫的大鼠，其IL-2活性相对较低。在免疫的大鼠中，S.C.照射后的9L细胞，I.C.9L肿瘤与C1300/IL-2或C1300/IL-4联合移植均被完全排斥。预先形成的脑瘤也可以被S.C.消除。照射后的9L细胞和I.C.IL-2产生者的移植。免疫组织化学分析显示，联合治疗后的脑瘤组织中有大量的CD_4~+和CD_8~+T细胞浸润。细胞浸润程度与S.C.相似。9L/IL-2肿瘤，随后被排斥。这些结果提示S.C.能有效地诱导胶质瘤特异性CTL。不产生人工细胞因子的照射野生型肿瘤细胞的免疫。组合策略，I.C.将产生IL-2的细胞与S.C.因此，照射的全肿瘤细胞疫苗免疫可以有效地将激活的T细胞重新招募到脑瘤部位，并可能成为治疗脑瘤的一种潜在方法。较少

Cytokine gene therapy for the central nervous system tumors has proven to have significant potential, but it needs improvement in the process of antigen presentation and/or in insufficient recruitment of immunocompetent cells to achieve successful eradication of established brain tumors. We investigated the therapeutic potential of induced systemic immunity in peripheral tissues combined with the production of various cytokines in the vicinity of brain tumors to treat established brain tumors. Sequential magneti resonance image (MRI) monitoring showed that the combinatory therapy consisting of intracerebral (i.c.) transplantation of IL-2-producing syngeneic or xenogeneic cells and subcutaneous (s.c.) vaccination using irradiated 9L or 9L/IL-2 cells could cured 9L-bearing rats, whereas either the i.c. injection of IL-2-producers or the s.c. vaccination alone produced little or marginal anti-tumor effects, respectively. Other cytokines such as IL-4, IL-12, or GM-CSF could not induce sign … More ificant therapeutic effects against the established brain tumors. Glioma-specific CTL activity was equivalently induced in the rats vaccinated s.c. with irradiated 9L, irradiated IL-2-producing 9L cells or the mixed population of irradiated 9L and C1300/IL-2 cells, while the activity was relatively lower in the rats vaccinated with irradiated 9L cells mixed with either C1300/IL-4 or C1300/GM-CSF cells. In the rats immunized s.c. with irradiated 9L cells, i.c. 9L tumors implanted together with either C1300/IL-2 or C1300/IL-4 were completely rejected. Pre-established brain tumor also could be eliminated by the s.c. immunization of irradiated 9L cells and i.c. transplantation of IL-2-producers. Immunohistochemical analysis revealed that a number of CD4^+ and CD8^+ T cells infiltrated into the brain tumors which were treated with the combinatory therapy. The level of cell infiltration was similar to that found in s.c. 9L/IL-2 tumors which were subsequently rejected. These results suggest that glioma-specific CTLs could be effectively induced by s.c. immunization of irradiated wild-type tumor cells without artificial cytokine production. The combinatory strategy, i.c. grafting of IL-2-producing cells and s.c. immunization of irradiated whole tumor cell vaccine, is thus effective for recruiting activated T cells into the brain tumor site and could be a potential therapy for brain tumors. Less