PARACRINE CYTOKINE DELIVERY FOR BRAIN TUMOR IMMUNOTHERAPY

对T细胞免疫生物学的理解的进展产生了一个 抗肿瘤免疫分子工程的兴趣迅速扩大 应答特别是，鉴定和克隆编码 细胞因子提供了一组有效的试剂，用于激活免疫系统， 体内效应子应答。细胞因子生物学的主要概念之一 当它们以一种 旁分泌方式，即，局部抗原位点。我们有 开发了两种主要的细胞因子旁分泌表达策略 in vivo.一种方法是用基因转导肿瘤细胞 编码细胞因子。两种不同的现象被观察到，当这些 体内注射分泌细胞因子的肿瘤。当地持续释放 一些细胞因子如IL-2、IL-4和TNF-α导致炎性 介导转导肿瘤破坏的反应。此外，本发明还 某些产生细胞因子的肿瘤导致有效的 系统性T细胞依赖性抗肿瘤应答。产生GM-CSF的肿瘤 似乎可以产生最有效的疫苗。最近，我们开发了 另一种持续局部细胞因子释放的方法， 生物可降解聚合物微球。辐照的未转导的 肿瘤细胞与含有GM-CSF的生物聚合物微球产生 等效免疫GM-CSF基因转导的肿瘤细胞。这 该方法对于临床应用来说更简单，劳动强度更低 比直接基因转移更重要，因为它消除了 培养和转导人肿瘤外植体。的总体目标 这个项目，是为了探索这些策略， 免疫疗法来治疗脑肿瘤的可行性进行评估 这种方法，我们已经开发了一个颅内肿瘤模型，使用 B16 F10黑色素瘤，一种特征明确的自发性黑色素瘤变体 最初来源于C57 BL/6小鼠。由于其免疫原性差， 不会引起有效的局部或全身免疫反应，因此 提供了一个理想的模型来研究细胞因子如何增强免疫 对肿瘤的反应我们将使用两种互补的策略：B16 F10细胞， 转导GM-CSF基因，作为全身性肿瘤疫苗， 保护免受CNS中肿瘤的攻击;和局部递送 辐射过的肿瘤细胞， 细胞因子IL-2、IL-4和TNF-α直接作用于脑肿瘤部位。 此外，我们将开发聚合物介导的细胞因子递送， 人类脑癌的这些方法的翻译的前奏 疗法

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.