MELANOMA ANTIGENS INDENTIFIED FROM GMCSF VACCINATION

操纵编码潜在免疫调节剂的基因的能力 随着细胞因子和肿瘤抗原的研究开启了一个新时代 尝试。免疫原性差的小鼠肿瘤模型系统显示 用受辐射的肿瘤细胞进行免疫是为了分泌 粒细胞-巨噬细胞集落刺激因子(GM-CSF)产生强大的、 特定的、持久的免疫力。为了在患者身上测试这一策略 对于晚期黑色素瘤，申请者的实验室进行了 自体致死照射疫苗接种的临床试验 表达人GM-CSF的黑色素瘤细胞。接种疫苗引起了惊人的反响 原已存在的转移性病变的浸润性 淋巴细胞、浆细胞、巨噬细胞和嗜酸性粒细胞，导致 肿瘤破坏、纤维化和水肿。持续不断的产生体液 细胞免疫反应的例证是肿瘤特异性 肿瘤浸润性的细胞毒作用和细胞因子的产生 淋巴细胞和疫苗接种后的血清中含有 识别细胞内和细胞表面黑色素瘤的决定因素。这些 结果为进行分子分析提供了坚实的基础 刺激特异性T和B细胞反应的黑色素瘤抗原 接种疫苗的病人。一些候选抗原已经被 用一株自体血清进行初步筛选鉴定 从患者的肿瘤细胞系构建的表达文库。这个 首次发现了一种与MUC-1结构相似的新产品， 免疫原性细胞表面分子家族的成员，表达于 各种癌症。这种基于抗体的策略很可能是 对于鉴定一些黑色素瘤抗原是有效的。这个 申请者设计了几种方法来表征免疫 对每个候选抗原的反应。幽默的回应将是 免疫印迹法检测CRIP包装细胞株裂解产物 以MFG为基础的逆转录病毒载体表达每个候选者。 转MFG基因的自体EBV转化的淋巴母细胞 逆转录病毒将被用来确定T细胞的细胞毒性， 增殖和细胞因子的产生，以响应每个候选人 抗原。表达模式将由Northern分析确定 以及各种肿瘤及其正常组织的RT-PCR 对口单位。众多调查人员试图利用之前 疫苗策略中已识别的抗原证明了一种能力 针对这些抗原产生显著的免疫反应。这个 对申请者的分析应有助于理解 共同靶点与独特靶点在抗肿瘤中的相对重要性 豁免权。黑色素瘤免疫原性抗原的进一步鉴定 为未来的治疗提供了希望。

The ability to manipulate genes encoding potential immunomodulators such as cytokines and tumor antigens has opened a new era of research attempts. Poorly immunogenic murine tumor model systems demonstrate that vaccination with irradiated tumor cells engineered to secrete granulocyte-macrophage colony stimulating (GM-CSF) generates potent, specific, and long-lasting immunity. To test this strategy in patients with advanced melanoma, the laboratory of the applicants performed a clinical trial of vaccination with lethally irradiated, autologous melanoma cells expressing human GM-CSF. Vaccination elicits a striking infiltrate of pre-existing metastatic lesions with large numbers of lymphocytes, plasma cells, macrophages, and eosinophils, resulting in tumor destruction, fibrosis, and edema. Consistent production of humoral and cellular immune responses is exemplified by tumor specific cytotoxicity and cytokine production characterizing tumor-infiltrating lymphocytes, and post-vaccination sera containing IgG antibodies that recognize intracellular and cell surface melanoma determinants. These results provide a solid foundation for undertaking a molecular analysis of the melanoma antigens stimulating specific T and B cell responses in vaccinated patients. A number of candidate antigens have been identified from initial screening with autologous sera of a cDNA expression library constructed from a patient's tumor cell line. The first revealed a novel product with structural similarities to MUC-1, a member of a family of immunogenic cell surface molecules expressed in a variety of cancers. This antibody-based strategy will likely be productive for identifying a number of melanoma antigens. The applicants have designed several approaches to characterize immune responses against each candidate antigen. Humoral responses will be evaluated by immunoblotting lysates of CRIP packaging cell lines transfected with MFG based retroviral vectors expressing each candidate. Autologous EBV transformed lymphoblasts transfected with MFG retroviruses will be used to determine T cell cytotoxicity, proliferation, and cytokine production in response to each candidate antigen. Expression patterns will be determined by Northern analyses and RT-PCR from a variety of tumors and their normal tissue counterparts. Attempts by numerous investigators to utilize previously identified antigens in vaccine strategies demonstrate an ability to develop significant immune responses against these antigens. The analysis of the applicants should contribute to the understanding of the relative importance of common versus unique targets in anti-tumor immunity. Further identification of immunogenic antigens in melanoma offers promise for future therapies.