Immunotherapy of hematological melignancies based on activation of innate immunity and costimulation through OX40/OX40L

在本研究中，我们试图基于先天免疫的激活和OX40/OX40L的共刺激，开发针对血液恶性肿瘤的新型免疫治疗模式。将一种脂多糖衍生化合物ONO-4007包裹在脂质体中，注射到预先接种了小鼠T细胞淋巴瘤细胞系EL4的C57/B6小鼠体内。24h后肿瘤出现中性粒细胞浸润，72h后肿瘤出现坏死改变。脂质体封闭与非脂质体封闭的ONO-4007间差异无统计学意义。用SCF、Flt3-L、GM-CSF和TNF-α培养5例AML患者的新鲜白血病细胞，分化为树突状细胞（DC）样细胞。同时，用OX40L或模拟对照逆转录病毒转导部分培养的白血病细胞。我们发现ox40l转导的白血病- dc具有诱导同种异体CD-4+ T细胞增殖和IFN-g产生的最高能力。C57BL/6小鼠分别接种亲本EL4、转染ox40l的EL4 （EL4- ox40l）或转染模拟对照载体EL4 （EL4-mock）的1×10^5细胞。虽然亲本EL4和EL4-mock生长迅速，但EL4- ox40l被排斥或生长慢于亲本EL4或EL4-mock。体外CTL试验表明，小鼠脾细胞对EL4- ox40l有明显的细胞毒活性。综上所述，激活先天免疫可有效根除肿瘤，将OX40L基因转移到淋巴瘤细胞中是诱导抗淋巴瘤免疫的一种合适且有效的方式。

In the present study, we attempted to develop novel immune therapeutic modalities against hematological melignancies based on activation of innate immunity and costimulation through OX40/OX40L..A LPS-derived compound, ONO-4007, was enclosed in liposomes and injected to C57/B6 mice that had been preinoculated with EL4, a mouse T cell lymphoma cell line. The tumor was infiltrated with neutrophils after 24 h and showed necrotic change after 72 h. However, we could not detect significant difference between liposome-enclosed and non-enclosed ONO-4007.Fresh leukemic cells from 5 AML patients were cultured with SCF, Flt3-L, GM-CSF, and TNF-α to differentiate into dendritic cell (DC)-like cells. At the same time, a part of cultured leukemic cells were retrovirally transduced with OX40L or mock control. We showed that OX40L-transduced leukemia-DC had the highest capacity to induce proliferation and IFN-g production of allogeneic CD-4+ T cells.C57BL/6 mice were inoculated with 1×10^5 cells of parental EL4, OX40L-transfected EL4 (EL4-OX40L), or mock control vector-transfected EL4 (EL4-mock). While both parental EL4 and EL4-mock grew rapidly, EL4-OX40L was rejected or grew slower than parental EL4 or EL4-mock. In vitro CTL assay demonstrated that spleen cells of mice that had rejected EL4-OX40L had significant cytotoxic activity against parental EL4.In conclusion, activation of innate immunity was demonstrated to be efficacious to eradicate tumors, and the gene transfer of OX40L into lymphoma cells is an eligible and efficient modality to induce anti-lymphoma immunity.