CLONING OF TUMOR ANTIGENS RECOGNIZED BY CYTOTOXIC T CELL

免疫疗法已显示出作为一种重要的新方法的前景 恶性肿瘤的治疗。几种免疫效应细胞和分子 促进肿瘤细胞的破坏。这个项目的目标是 识别细胞毒性T细胞识别的肿瘤抗原。我们会 实现这一目标的方法是分离出自一株 肿瘤细胞库，编码这些抗原。克隆的cdna将 利用克隆的细胞毒性T淋巴细胞的特异性进行鉴定 (CTL)从荷瘤动物中分离出来。两只弱免疫原性小鼠 肿瘤、CT26(结肠腺癌)和MCA 106(纤维肉瘤)将 被研究。因为肿瘤的免疫原性很弱，所以前驱 肿瘤反应性T细胞的频率将会很低。他们将会增加 通过导入同种异体的I类主要组织相容性 复合体(MHC)基因体内直接导入肿瘤细胞的技术 在这个实验室里研发的。联合用药治疗H-2b或H-2d肿瘤 H-2ks基因而不是对照基因对 Lyt2+介导转化细胞表达同种异体MHC蛋白 CTL.更重要的是，H-2ks基因诱导免疫反应 以前未被识别的抗原存在于未修饰的细胞上。这 免疫反应抑制肿瘤生长，在某些情况下会导致 已建立的肿瘤完全消退。基因诱导的T细胞 H-2ks直接转移到免疫原性低的肿瘤将被克隆 并被选择用于对亲本肿瘤细胞的反应。克隆的细胞 将用于筛选在同源基因中表达的肿瘤cDNA文库， 转化的B细胞系。候选的cDNA克隆将被识别， 克隆并测序。然后，他们将被分析他们的能力 诱导免疫反应，并确定它们的过度表达 可以增强免疫识别能力。这些肿瘤的临床分析 抗原将增强对人类免疫缺陷病毒分子变化的理解 激发免疫力的肿瘤细胞。此外，识别 这些肿瘤抗原可能在发展特定的 恶性肿瘤的免疫治疗，包括肿瘤疫苗。

Immunotherapy has shown promise as an important new approach to the treatment of malignancy. Several immune effector cells and molecules facilitate tumor cell destruction. The goal of this project is to identify tumor antigens recognized by cytotoxic T cells. We will accomplish this goal through the isolation of cDNA clones derived from a tumor cell libraries, which encode these antigens. The cDNA clones will be identified using the specificity of cloned cytotoxic T lymphocytes (CTL) isolated from tumor-bearing animals. Two weakly immunogenic murine tumors, CT26, (a colon adenocarcinoma), and MCA 106 (a fibrosarcoma) will be studied. Because the tumors are weakly immunogenic, the precursor frequency of tumor reactive T cells will be low. They will be increased through transfection of an allogeneic class I major histocompatibility complex (MHC) gene directly into tumor cells in vivo; a technique developed in this laboratory. Treatment of H-2b or H-2d tumors with the H-2Ks gene but not a control gene generates a cytolytic response to the allogeneic MHC protein expressed on transformed cells, mediated by Lyt2+ CTL. More importantly, the H-2Ks gene induces an immune response to previously unrecognized antigens present on unmodified cells. This immune response attenuates tumor growth and in some cases results in complete regression of established tumors. T cells induced by gene transfer of H-2Ks directly into poorly immunogenic tumors will be cloned and selected for reactivity to parental tumor cells. The cloned cells will be used to screen a tumor cDNA library expressed in syngeneic, transformed B cell lines. Candidate cDNA clones will be identified, cloned and sequenced. They will then be analyzed for their ability to induce immune reactivity and to determine whether their overexpression can lead to enhanced immune recognition. Analyses of these tumor antigens will enhance the understanding of molecular changes in neoplastic cells that provoke immunity. In addition, identification of these tumor antigens may be useful in the development of specific immunotherapy of malignancies, including tumor vaccines.