Induction of anti-glioma natural killer cell response following multiple low-dose intracerebral CpG therapy.
Induction of anti-glioma natural killer cell response following multiple low-dose intracerebral CpG therapy.
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DOI：
10.1158/1078-0432.ccr-09-3087
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发表时间：
2010-07-01
期刊：
影响因子：
--
通讯作者：
Badie B
中科院分区：
文献类型：
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作者：
Alizadeh D;Zhang L;Brown CE;Farrukh O;Jensen MC;Badie B
在胶质瘤模型中，CpG寡脱氧核苷酸（CpG- odn）刺激toll样受体-9 （TLR9）可以抵消免疫抑制微环境并抑制肿瘤生长。然而，这些研究使用了高剂量的CpG-ODN，这在临床环境中会引起毒性。本研究的目的是评估多种低剂量肿瘤内CpG- ODN在胶质瘤模型中的抗肿瘤效果。4龄GL261脑胶质瘤小鼠每4天接受一次或多次（2次或4次）瘤内注射CpG-ODN （3 μg）。通过生物发光成像、脑组织组织学和动物存活率来测量肿瘤生长。流式细胞术和细胞毒性试验用于评估抗胶质瘤免疫反应。在70%的小鼠中，两次和四次颅内注射低剂量CpG-ODN，而不是一次注射，根除了胶质瘤。此外，存活的动物表现出持久的无肿瘤缓解（bbb3个月），并且受到GL21胶质瘤颅内再攻击的保护，显示出长期抗肿瘤免疫的能力。尽管大多数炎症细胞似乎增加，但在cpg - odn处理动物的大脑中，活化的NK细胞（即NK+CD107a+）比CD8+CD107a+更频繁，并且对GL261靶细胞表现出更强的体外细胞毒性。白细胞消耗研究证实NK细胞在初始CpG-ODN抗肿瘤反应中起重要作用，但CD8和NK细胞在长期免疫胶质瘤中同样重要。这些发现表明，多次低剂量肿瘤内注射CpG-ODN可能通过NK介导的效应功能机制来根除颅内胶质瘤。
Stimulation of toll-like receptor-9 (TLR9) by CpG oligodeoxynucleotides (CpG-ODN) has been shown to counteract the immunosuppressive microenvironment and to inhibit tumor growth in glioma models. These studies, however, have used high doses of CpG-ODN which can induce toxicity in a clinical setting. The goal of this study was to evaluate the anti-tumor efficacy of multiple low-dose intratumoral CpG- ODN in a glioma model. Mice bearing four-day old intracranial GL261 gliomas received a single or multiple (two or four) intratumoral injections of CpG-ODN (3 μg) every 4 days. Tumor growth was measured by bioluminescent imaging, brain histology, and animal survival. Flow cytometry and cytotoxicity assays were used to assess anti-glioma immune response. Two and four intracranial injections of low-dose CpG-ODN, but not a single injection, eradicated gliomas in 70% of mice. Moreover, surviving animals exhibited durable tumor free remission (> 3 months), and were protected from intracranial rechallenge with GL21 gliomas, demonstrating the capacity for long-term anti-tumor immunity. Although most inflammatory cells appeared to increase, activated NK cells (i.e. NK+CD107a+) were more frequent than CD8+CD107a+ in the brains of rechallenged CpG-ODN-treated animals and demonstrated a stronger in vitro cytotoxicity against GL261 target cells. Leukocyte depletion studies confirmed that NK cells played an important role in the initial CpG-ODN anti-tumor response, but both CD8 and NK cells were equally important in long-term immunity against gliomas. These findings suggest that multiple low-dose intratumoral injections of CpG-ODN can eradicate intracranial gliomas possibly through mechanisms involving NK mediated effector function.