PARACRINE CYTOKINE DELIVERY FOR BRAIN TUMOR IMMUNOTHERAPY

对T细胞免疫生物学的了解的进展产生了 快速增长的抗肿瘤免疫分子工程研究兴趣 回应。尤其是编码基因的鉴定和克隆 细胞因子为激活免疫提供了一套有效的试剂 体内的效应器反应。细胞因子生物学中的主要概念之一 当它们被表达在一个 旁分泌方式，即局部到抗原部位。我们有 发展了两种主要的细胞因子旁分泌表达策略 在活体内。一种方法是用基因转导肿瘤细胞。 编码细胞因子。观察到两种截然不同的现象 分泌细胞因子的肿瘤在体内注射。阿司匹林局部缓释 某些细胞因子如IL-2、IL-4和肿瘤坏死因子-α可导致炎症 调节转导的肿瘤被破坏的反应。另外， 某些产生肿瘤的细胞因子导致激活有效的 全身性T细胞依赖性抗肿瘤反应。产生GM-CSF的肿瘤 似乎产生了最有效的疫苗。最近，我们开发了一种 另一种持续局部释放细胞因子的方法 可生物降解的聚合物微球。辐照非换能器混合物 含有GM-CSF的生物聚合物微球可产生肿瘤细胞 GM-CSF基因转导的肿瘤细胞的等量免疫。这 对于临床应用，该方法更简单，劳动强度更低 而不是直接的基因转移，因为它消除了 人肿瘤外植体的培养和转导。总的目标是 这个项目，是为了探索这些细胞因子增强的策略 治疗脑部肿瘤的免疫疗法。评估……的可行性 这种方法我们开发了一个颅内肿瘤模型，使用的是 B16F10黑色素瘤，一种典型的自发性黑色素瘤变种 最初来源于C57BL/6小鼠。因为它的免疫原性很差，所以它 不会激发有效的局部或系统免疫反应，因此 为研究细胞因子如何增强免疫力提供了一个理想的模型 对肿瘤的反应。我们将使用两种互补的策略：B16F10细胞， 转导GM-CSF基因作为全身肿瘤疫苗的研究 预防中枢神经系统肿瘤的挑战；并在当地交付 受辐射的肿瘤细胞通过基因编程产生特异性的 细胞因子IL-2、IL-4和肿瘤坏死因子-α直接作用于脑瘤部位。 此外，我们将开发聚合物介导的细胞因子传递作为一种 将这些方法转化为人类脑癌的前奏 心理治疗。

Advances in understanding of T cell immunobiology have engendered a rapidly expanding interest in molecular engineering of antitumor immune responses. In particular, the identification and cloning of genes encoding cytokines provides a potent set of reagents for activating immunologic effector responses in vivo. One of the major concepts in cytokine biology is that their activity is most potent when they are expressed in a paracrine fashion, that is, local to the site of antigen. We have developed two major strategies for the paracrine expression of cytokines in vivo. One approach involves the transduction of tumor cells with genes encoding cytokines. Two distinct phenomena are observed when these cytokine secreting tumors are injected in vivo. Local sustained release of some cytokines such as IL-2, IL-4 and TNF-alpha result in inflammatory responses that mediate destruction of the transduced tumors. Additionally, certain cytokine producing tumors result in the activation of potent systemic T cell dependent antitumor responses. GM-CSF producing tumors appear to generate the most potent vaccines. Recently, we have developed an alternate approach to sustained local cytokine release using biodegradable polymer microspheres. Mixture of irradiated nontransduced tumor cells with biopolymer microspheres containing GM-CSF produce equivalent immunization to GM-CSF gene transduced tumor cells. This approach is simpler and less labor intensive for clinical applications than direct gene transfer because it eliminated the necessity for culturing and transducing human tumor explants. The overall objective of this project, is to explore these strategies of cytokine-enhanced immunotherapy to treat tumors in the brain. To assess the feasibility of this approach we have developed an intracranial tumor model using the B16F10 melanoma, a well characterized variant of a spontaneous melanoma originally derived from C57BL/6 mice. Because it is poorly immunogenic, it does not incite an effective local or systemic immune response, and hence provides an ideal model to examine how cytokines enhance the immune response to tumor. We will use two complementary strategies: B16F10 cells, transduced with the gene for GM-CSF, as a systemic tumor vaccine to protect against challenge with tumor in the CNS; and local delivery of irradiated tumor cells genetically programmed to produce specific cytokines IL-2, IL-4, and TNF-alpha directly to the site of a brain tumor. Additionally, we will develop polymer mediated delivery of cytokines as a prelude to the translation of these approaches to human brain cancer therapy.