CLONING AND MODIFICATION OF ANTI-TUMOR ANTIGEN IMMUNOGLOBULIN GENES

这项研究工作的主要目标是设计、建造和 产生新的重组免疫学试剂用于诊断和 人类癌症的治疗。已经培育了几个杂交瘤细胞系 在这个实验室中，有选择性地产生单抗 与肿瘤相关抗原反应。其中包括单抗 癌胚抗原(CEA)、肿瘤相关糖蛋白(TAG)-72、a 高分子量粘蛋白存在于多种癌症上，单抗 D612与细胞表面表达的48kD抗原发生反应 正常胃肠道上皮和恶性胃肠上皮。正在进行的临床中 试验，抗TAG-72单抗、B72.3和CC49、D612和抗CEA单抗， COL-1，已经显示出不同程度的发展潜力 诊断和治疗试剂。然而，小鼠的有用性 体内诊断和治疗的单抗是有限的，因为它们 免疫原性。为了减少这个潜在的问题，我们开发了鼠标- 使用重组DNA的人嵌合(C)单抗，包括cB72.3(Gamma1) 技巧。为了优化血浆的药代动力学 并最大限度地提高本地化效率，以及 我们开发的新型嵌合免疫球蛋白可以穿透到肿瘤中 变异体；包括糖基化cB72.3(Gamma1)单抗和常量 CB72.3(Gamma1)的区域结构域缺失变体。与之前的 CB72.3单抗，CH2结构域缺失的CMAB表现出更快的清除速度 速度和更快的肿瘤靶向。用于第二代抗TAG-72 单抗CC49和CC83的重链和轻链基因已被克隆 克隆、测序并插入逆转录病毒载体。最近， CCC49(Gamma1)已得到表达和纯化。我们还开发了一种 单基因编码具有效应功能的Ig分子。我们 我还开发了一种cD612单抗，它已经由 一种人类T细胞系。分泌的免疫球蛋白保留其抗原- 结合特性及其介导ADCC抗人肿瘤能力的研究 细胞。据我们所知，这是该产品的第一次演示 人类T细胞产生的一种免疫球蛋白，并开启了一种治疗的可能性 T细胞分泌人源化抗肿瘤单抗的途径 在肿瘤部位介导ADCC。

The major goal of this research effort is to design, construct and generate novel recombinant immunological reagents for the diagnosis and therapy of human cancers. Several hybridoma cell lines have been developed in this laboratory that produce monoclonal antibodies (MAbs) selectively reactive with carcinoma associated antigens. These include MAbs against carcinoembryonic antigen (CEA), tumor associated glycoprotein (TAG)-72, a high-molecular weight mucin present on a variety of carcinomas, and MAb D612, which is reactive with a 48 kD antigen expressed on the surface of normal and malignant gastrointestinal epithelium. In ongoing clinical trials, the anti-TAG-72 MAbs, B72.3 and CC49, D612 and an anti-CEA MAb, COL-1, have shown various degrees of potential for being developed into diagnostic and therapeutic reagents. However, the usefulness of murine MAbs for in vivo diagnosis and therapy is limited because of their immunogenicity. To reduce this potential problem we have developed mouse- human chimeric (c) MAbs, including cB72.3 (gamma1), using recombinant DNA techniques. In an effort to optimize the pharmacokinetics of plasma clearance and to maximize the efficiency of localization of, and penetration into, tumors we have developed novel chimeric immunoglobulin variants; these include aglycosylated cB72.3 (gamma1) MAb and constant region domain-deleted variants of cB72.3 (gamma1). In comparison with the cB72.3 MAb, the CH2 domain-deleted cMAb demonstrated a faster clearance rate and a more rapid tumor targeting. For second generation anti-TAG-72 MAbs, the heavy and light chain genes of MAb CC49 and CC83 have been cloned, sequenced and inserted into retroviral vectors. Recently, the cCC49 (gamma1) has been expressed and purified. We have also developed a single gene enoded Ig molecule which has retained effector functions. We have also developed a cD612 MAb which has been expressed and secreted by a human T cell line. The secreted immunoglobulin retained its antigen- binding properties and its ability to mediate ADCC against human tumor cells. To our knowledge, this is the first demonstration of the production of an IgG by human T cells and opens the possibility of a therapeutic approach in which T-cells secrete humanized anti-tumor MAb capable of mediating ADCC at the tumor site.