Anti-cancer therapy for gastrointestinal canser using cytotoxic T cells and bispecific antibody

细胞毒性T淋巴细胞在体外抗cd3抗体存在的情况下可以裂解携带Fc受体的靶细胞。这种“重定向”裂解不受主要组织相容性抗原的限制，也不需要CTL的名义抗原识别。通过比较转染了小鼠Fc受体基因的黑素瘤细胞系与未转染的黑素瘤细胞系在接种同源小鼠CTL和抗cd3抗体时的存活率，来评估体内重定向裂解的效果。在注射Fc受体阳性黑色素瘤、CTL和抗cd3单克隆抗体的动物中，存活率显著提高。重定向裂解并不排除肿瘤免疫的建立，因为由于重定向裂解而排斥肿瘤的动物表现出对肿瘤细胞再接种的抵抗力增加。过去几年的研究表明，针对TCR或CD3的抗体可以在没有Ag和MHC基因产物的情况下激活细胞。利用CTL的细胞毒性潜能的另一种方法是使用双特异性抗体来指导和激活不同特异性的CTL来裂解表达病毒或肿瘤Ag的细胞。对TCR/CD3复合物和靶细胞表面Ag具有特异性的双特异性抗体可以重定向CTL裂解靶细胞。我们已经产生了一种杂交瘤，HHA6，它分泌双特异性抗体，能够重定向CTL来裂解流感病毒感染的靶细胞。当与CTL一起加入病毒感染的细胞时，这些抗体非常有效地增强了CTL的细胞毒性能力。由于杂交瘤随机重组H链和L链，我们尝试用高效液相色谱法纯化双特异性抗体。纯化后HHA6的效价增加。这种增加和去除抑制抗体的种类。根据这些实验结果，我们已经尝试制造能够分泌双特异性抗体的人杂交瘤，这种抗体能够重定向人CTL来裂解人肿瘤细胞。由于人杂交瘤的不稳定性，我们还没有成功地制造人双特异性抗体，重定向人CTL来破坏人靶细胞。少

Cytotoxic T lymphocytes can lyse Fc receptor-bearing target cells in vitro in the presence of anti-CD3 antibodies. This "redirected" lysis is not restricted by major histocompatibility antigen nor does it require nominal antigen recognition by the CTL.The efficacy of redirected lysis in vivo was assessed by comparing the survival of mice inoculated with a melanoma cell line transfected with the gene for mouse Fc receptor versus the untransfected melanoma when inoculated with syngenic mouse CTL and anti-CD3 antibody. Survival was significantly higher in the animals given injections of Fc receptor positive melanoma, CTL,and anti-CD3 monoclonal antibody. Redirected lysis does not preclude the establishment of tumor immunity, since animals that rejected the tumor as a result of redirected lysis exhibited an increased resistance to reinoculation with tumor cells.Studies over the last several years have demonstrated that antibodies to the TCR or CD3 can activate cells in the absence of Ag an … More d MHC gene products. An alter native approach to harnessing the cytotoxic potential of CTL can be to use bispecific antibodies to direct and activate CTL of various specificities to lyse cells expressing virus or tumor Ag. Bispecific antibodies with specificity for the TCR/CD3 complex as well as to a target cell-surface Ag can redirect CTL to lyse the target cell. We have produced a hybridhybridoma, HHA6, which secretes bispecific antibodies capable of redirecting CTL to lyse influenza virus-infected target cells. When added along with CTL to virus-infected cells, these antibodies very efficientlyenhace cytotoxic abilities of CTL.Because hybridhybridomas reassort H and L chains randomly we attempted to purify bispecific antibody by using HPLC.The purification increased the potency of HHA6. This increase and removal of inhibiting antibody species. From these experimental results, we have attempted to produce human hybridhybridoma which secretes bispecific antibodies capable of redircting human CTL to lyse human tumor cells.Because of unstableness of human hybridhybridoma, we have not succeeded in producing human bispecific antibodies redirected human CTL to destroy human target cells. Less