Development of the specific immunotherapy targeting to HM1.24 antigen against lung cancer

HM 1.24抗原(CD317)最初被鉴定为一种细胞表面蛋白，在多发性骨髓瘤细胞上优先过度表达。我们检测了HM1.24抗原在肺癌细胞中的表达，以及抗HM1.24抗体诱导抗体依赖性细胞毒(ADCC)免疫治疗的可能性。用抗HM1.24抗体用流式细胞仪检测HM1.24抗原的表达。ADCC的评价采用6-h^&lt；51&gt；Cr释放试验。检测不同细胞因子对HM1.24和ADCC表达的影响。体内抗HM1.24抗体在SCID小鼠体内的抗肿瘤活性。33株肺癌细胞株中有15株(45%)检测到HM1.24抗原。抗HM1.24抗体可有效诱导抗HM1.24阳性肺癌细胞的ADCC。干扰素-β和-γ可增加肺癌细胞对阿霉素的敏感性和HM1.24抗原水平。抗HM1.24抗体对肺癌细胞…生长的抑制作用在SOD小鼠中表达HM1.24抗原的细胞更多。干扰素-β联合抗HM1.24单抗在延缓治疗方案下仍表现出增强的抗肿瘤作用。接下来，我们评价了鼠-人嵌合和人源化的抗HM1.24单抗的体外抗肿瘤活性。以人外周血淋巴细胞和从单个核细胞(PBMC)分离的单核细胞作为效应细胞。嵌合和人源化抗1-1M1.24单抗能有效地诱导ADCC，淋巴细胞比单核细胞更能有效地介导ADCC。细胞毒活性与HM1.24在肺癌细胞上的表达水平相关。自然杀伤细胞是ADCC的主要效应细胞。IL-2、IL-12、IL-15处理淋巴细胞后，ADCC活性显著升高。肺癌患者PBMC诱导的ADCC水平与健康人PBMC相当，HM1.24抗原是抗HM1.24抗体治疗肺癌的新的免疫学靶点。较少

HM 1.24 antigen (CD317) was originally identified as a cell surface protein that is preferentially overexpressed on multiple myeloma cells. We examined the expression of HM1.24 antigen in lung cancer cells and the possibility of immunotherapy with anti-HM1.24 antibody which can induce antibody-dependent cellular cytotoxicity (ADCC). The expression of HM1.24 antigen was examined by flow cytometry using anti-HM1.24 antibody. ADCC was evaluated using a 6-h ^<51>Cr release assay. Effects of various cytokines on the expression of HM1.24 and the ADCC were examined. The antitumor activity of anti-HM1.24 antibody in vivo was examined in SCID mice. HM1.24 antigen was detected in 15 of 33 lung cancer cell lines (45%). Anti-HM1.24 antibody effectively induced ADCC against HM1.24-positive lung cancer cells. Interferon-β and -y increased the levels of HM1.24 antigen and the susceptibility of lung cancer cells to ADCC. Treatment with anti-HM1.24 antibody inhibited the growth of SBC-5 lung cancer cel … More ls expressing HM1.24 antigen in SOD mice. The combined therapy with IFN-β and anti-HM1.24 antibody showed the enhanced antitumor effects even in the delayed treatment schedule.Next, we evaluated the and-tumor activity of mouse-human chimeric and humanized anti-HM1.24 monoclonal antibodies (mAbs) in vitro. Human peripheral blood lymphocytes and monocytes separated from mononuclear cells (PBMCs) were used as effector cells. Chimeric and humanized anti-1-1M1.24 mAbs effectively induced ADCC which is mediated more efficiently by lymphocytes than monocytes. The cytotoxic activity correlated with the level of HM1.24 expression on lung cancer cells. Natural Killer cells were identified as the major effector cells in ADCC. The treatment of lymphocytes with IL-2, IL-12 or IL-15 significantly increased the ADCC activity. PBMCs from patients with lung cancer induced a level of ADCC comparable to that induced by PBMCs from healthy donors.Collectively, HM1.24 antigen is a novel immunological target for the treatment of lung cancer with anti-HM1.24 antibody. Less