CLONING AND MODIFICATION OF ANTI-TUMOR ANTIGEN IMMUNOGLOBULIN GENES

正在进行的研究涉及设计和使用重组 免疫球蛋白(Ig)形式用于癌症治疗和诊断。小鼠 单抗(Mab)CC49选择性地与肿瘤发生反应 抗原，肿瘤相关糖蛋白(TAG)-72。临床前研究 临床试验已经证明了诊断和潜在的 这种单抗的治疗作用。以优化治疗效果和 将毒性和宿主免疫反应降至最低，现在的重点是 致力于新型重组蛋白的设计和翻译研究 CC49的IG表格。编码这些抗体的基因已经被克隆 这些单抗的鼠-人嵌合体和人源化版本 已生成。以人源化单抗CC49(HuCC49)为原型 开发转基因单抗。人源化CH2结构域缺失的CC49 已经被建造并展示了明显更快的等离子体 清除性和更好的肿瘤靶向性比完整的CC49。至 促进重组蛋白的体外转染和体内表达 CC49用于治疗，我们开发了一种单基因结构 编码单链免疫球蛋白-IL-2融合蛋白。活体内 成功地在Balb/c小鼠中表达了融合蛋白 同时使用经皮基因枪和肌肉注射进行演示 注射。在另一项研究中，为了将独特型反应降至最低 对HuCC49、小鼠CDR不是抗原结合关键的患者 识别并替换为人类CDR。目前正在努力 识别基本的小鼠CDR的可有可无的区域 用人类CDR的同源区域替换它们。协作性 最近已经启动了一些研究，以生成特定的重定向 抗肿瘤人T细胞群。为此，MHC-不受限制 含有单链抗肿瘤免疫球蛋白基因的抗原受体和 T细胞CD3复合体的Zeta链已被引入 通过逆转录病毒基因转移获得T淋巴细胞。又一项倡议 最近进行的人类癌症的免疫治疗是基于 关于将肿瘤抗原抗原肽基因偶联到 抗人FcgR1抗体。这些分子将被用来靶向 将抗原肽传递给专业抗原提呈细胞 多肽在MHC中的内化和递呈 类别1.编码抗人FcgR1的Fab‘片段的构建体 抗体和一种来自癌胚胎的免疫原肽 抗原已经制造出来了。

Ongoing studies involve the design and use of recombinant immunoglobulin (Ig) forms for cancer therapy and diagnosis. Murine monoclonal antibody (MAb) CC49 selectively reacts with the pancarcinoma antigen, tumor associated glycoprotein (TAG)-72. Preclinical studies and clinical trials have demonstrated the diagnostic and potential therapeutic utility of this MAb. To optimize therapeutic efficacy and minimize toxicity and host immune responses, emphasis is now being placed on the design and translational research of novel recombinant Ig forms of CC49. The genes encoding these antibodies have been cloned and mouse-human chimeric and humanized versions of these MAbs have been generated. The humanized MAb CC49 (HuCC49) was used as a prototype to develop genetically altered MAbs. A humanized CH2 domain-deleted CC49 has been constructed and demonstrates significantly faster plasma clearance and better tumor-targeting than the intact CC49. To facilitate ex vivo transfection and in vivo expression of recombinant CC49 for therapeutic use, we developed a single-gene construct encoding a single-chain immunoglobulin-IL-2 fusion protein. In vivo expression of the fusion protein in Balb/c mice was successfully demonstrated using both a transcutaneous gene gun and intramuscular injection. In a separate study, to minimize idiotypic responses of patients to HuCC49, murine CDRs not critical for antigen binding were identified and replaced with human CDRs. Efforts are underway to identify dispensable regions of the essential murine CDRs and to replace them with the homologous regions of human CDRs. Collaborative studies have recently been initiated to generate specific redirected antitumor human T-cell populations. To that end, MHC-unrestricted antigen receptors, containing single-chain antitumor Ig genes and the zeta chain of the CD3 complex of the T cell have been introduced into T lymphocytes by retroviral gene transfer. Yet another initiative recently undertaken for the immunotherapy of human carcinomas is based on genetically conjugating an antigenic peptide of a tumor antigen to the anti-human FcgR1 antibody. These molecules will be used to target antigenic peptides to professional antigen presenting cells for internalization and presentation of the peptide in the context of MHC class 1. Constructs encoding a Fab' fragment of an anti-human FcgR1 antibody and an immunogenic peptide derived from carcinoembryonic antigen have already been made.