Evaluation of antitumor immunity and paraneoplastic neurological syndrome evoked by murine dendritic cells pulsed with HuD antigen.

在小细胞肺癌（SCLC）患者中，抗副肿瘤脑脊髓炎抗原HuD （HuD抗原）抗体的存在与肿瘤扩散限制之间存在临床意义显著的相关性。用肿瘤特异性抗原（如HuD抗原）脉冲的树突状细胞将增强对肿瘤的细胞免疫。用Western blotting检测表达腺病毒载体HuD抗原感染小鼠脾树突状细胞后HuD抗原的表达情况。然而，即使在感染50moi（感染多重度）时，用western blotting方法也无法检测到表达HuD抗原的细胞。接下来，我们评估了颗粒蛋白酶（一种由细胞毒性T细胞（CTL）和自然杀伤细胞（NK）分泌的杀瘤分子）在表达HuD抗原的小细胞肺癌小鼠模型细胞（结肠26/HuD）感染表达颗粒蛋白酶腺病毒载体后的作用。与对照组相比，腺病毒载体介导的9kDa颗粒蛋白转染使结肠26/HuD细胞DNA片段化增加2.5倍，第3天结肠26/HuD细胞增殖抑制21% （p<0.05）。与此同时，腺病毒载体介导的9kDa颗粒蛋白的转移不会增加DNA片段化，也不会抑制结肠26亲本细胞的增殖。表达hud的肿瘤细胞对颗粒蛋白的敏感性可能部分解释了SCLC对细胞介导免疫的敏感性。这些结果支持HuD抗原仍然是SCLC抗肿瘤免疫的良好候选分子，并建议评价重组HuD抗原脉冲树突状细胞的抗肿瘤作用。

There is a clinically significant correlation between the presence of an antibody against the paraneoplastic encephalomyelitis antigen HuD (HuD antigen) and limitation of tumor spread in patients with small cell lung cancer (SCLC). The dendritic cells pulsed with tumor specific antigen such as HuD antigen will potentate the cellular immunity against the tumors. The expression of HuD antigen was evaluated by Western blotting in the murine splenic dendritic cells infected with HuD antigen expressing adenovirus vector. However, the expression of HuD antigen was not detectable by western blotting in the cells infected with our HuD-expressing adenovirus vector even at 50 moi (multiplicity of infection). Next we evaluated the effects of granulysin, a tumorcidal molecule secreted by cytotoxic T cells (CTL) and natural killer (NK) cells in HuD antigen-expressing small cell lung cancer murine model cells (Colon 26/HuD) infected with granulysin expressing adenovirus vector. Adenovirus vector-mediated transfer of 9kDa granulysin increased DNA fragmentation in Colon 26/HuD cells 2.5-fold and suppressed 21% of the Colon 26/HuD proliferation on day 3 (p<0.05 for each value) after the transfer of granulysin, compared with the control adenovirus vector transfer. In contract, adenovirus vector-mediated transfer of 9kDa granulysin did not increase DNA fragmentation nor suppress the proliferation of Colon 26 parent cells. The sensitivity of HuD-expressing tumor cells to granulysin is likely to partially explain the susceptibility of SCLC to cell-mediated immunity. These results support that HuD antigen is still good candidate molecule for antitumor immunity against SCLC and propose to evaluate the anti-tumor effect of dendritic cells pulsed with recombinant HuD antigen.