New strategy for pancreatic cancer. immunotargeting therapy by chimeric monoclonal antibody

嵌合体ND2(c-ND2)是一种抗胰腺癌粘蛋白的单抗，其识别抗原表位被认为是包括肿瘤相关碳水化合物在内的MUC5AC的核心多肽。已知嵌合体ND2对正常组织几乎没有反应，但通过免疫染色研究发现对胰腺癌有特异性反应。在本研究中，我们研究了它是否可以诱导抗体依赖的细胞介导的细胞毒(ADCC)和补体依赖的细胞毒(CDC)，这两种细胞毒是抗体用于免疫治疗的重要功能效应。体外研究表明，c-ND2在与靶向细胞、胰腺癌细胞(SW1990)和健康志愿者外周血中的效应细胞共培养时具有诱导ADCC的能力。C-ND2诱导ADCC的效应细胞不仅包括单核细胞(单核细胞和NK细胞)，还包括中性粒细胞。The…中性粒细胞经G-CSF预处理后，ADCC活性明显增强。此外，在靶细胞与补体孵育的过程中，可以发现c-ND2诱导CDC。因此，我们研究了c-ND2对胰腺癌裸鼠移植瘤的体内抗肿瘤作用。C-Nd2对裸鼠移植瘤有明显的抑制作用。延长裸鼠原位移植瘤的存活时间。还能抑制小鼠脾内注射癌细胞诱导的肝转移。将G-CSF应用于裸鼠移植瘤中，可通过激活中性粒细胞来增强其抗肿瘤作用。根据目前的研究结果，c-ND2具有较高的特异性和诱导ADCC或CDC的能力，有望作为胰腺癌的靶向免疫治疗。在目前的研究中，我们正在准备生产人源化抗体用于临床应用，以更坚定地降低实际临床试验中的免疫原性和副作用。较少

Chimeric Nd2 (c-Nd2) is a monoclonal antibody produced against pancreatic cancer mucin and its recognizing antigen epitope is supposed to be a core peptide of MUC5AC including cancer-associated carbohydrates. Chimeric Nd2 has been known to demonstrate almost no reaction to normal tissues, but specific reaction to pancreatic cancer by immunostaining study. In the present study, we investigated whether it can induce an antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) which are known to be an important for functioning effect in the use for immunotherapy of antibody. By in vitro investigation, c-Nd2 demonstrated the ability inducing ADCC during co-culture with targeting cells, pancreatic cancer cells (SW1990) and effector cells which were obtained from peripheral blood of healthy volunteers. The effector cells inducing ADCC by c-Nd2 were clarified not only mononuclear cells (monocytes and NK cells) but also polymorphonuclear neutrophils. The … More ADCC activity was enhanced by pretreatment of neutrophils with G-CSF. Furthermore, CDC could be found to be induced by c-Nd2 during target cells incubation with complement. Consequently, we investigated whether the in vivo anti-tumor effect can be induced by treatment of pancreatic cancer transplanted nude mice with c-Nd2. C-Nd2 demonstrated the growth inhibition of xenografted tumor by intra-peritoneal injection (i.p.) and enlonged the survival of nude mice which had orthotopic transplanted tumor. It could also inhibit liver metastasis induced by injecting cancer cells into spleen. When G-CSF were administered to xenografted nude mice, anti-tumor effect was enhanced by activating neutrophils corresponding to the in vitro results. According to the present results, c-Nd2 is suggested to have high clinical possibility as targeting immunotherapy for pancreatic cancer by its high specificity and ADCC or CDC inducing ability. In the current study, we are preparing to produce humanized antibody for the clinical application to more firmly reduce the immunogenicity and side effect in the actual clinical trial. Less