Gene Therapeutics Research Institute, Cedars-Sinai Medical Center and Department of Medicine and Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA.
PLoS One. 2010 Jun 11;5(6):e11074. doi: 10.1371/journal.pone.0011074.
Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults and carries a dismal prognosis. We have developed a conditional cytotoxic/immunotherapeutic approach using adenoviral vectors (Ads) encoding the immunostimulatory cytokine, human soluble fms-like tyrosine kinase 3 ligand (hsFlt3L) and the conditional cytotoxic molecule, i.e., Herpes Simplex Type 1- thymide kinase (TK). This therapy triggers an anti-tumor immune response that leads to tumor regression and anti-tumor immunological memory in intracranial rodent cancer models. We aim to test the efficacy of this immunotherapy in dogs bearing spontaneous GBM. In view of the controversy regarding the effect of human cytokines on dog immune cells, and considering that the efficacy of this treatment depends on hsFlt3L-stimulated dendritic cells (DCs), in the present work we tested the ability of Ad-encoded hsFlt3L to generate DCs from dog peripheral blood and compared its effects with canine IL-4 and GM-CSF.
METHODOLOGY/PRINCIPAL FINDINGS: Our results demonstrate that hsFlT3L expressed form an Ad vector, generated DCs from peripheral blood cultures with very similar morphological and phenotypic characteristics to canine IL-4 and GM-CSF-cultured DCs. These include phagocytic activity and expression of CD11c, MHCII, CD80 and CD14. Maturation of DCs cultured under both conditions resulted in increased secretion of IL-6, TNF-alpha and IFN-gamma. Importantly, hsFlt3L-derived antigen presenting cells showed allostimulatory potential highlighting their ability to present antigen to T cells and elicit their proliferation.
CONCLUSIONS/SIGNIFICANCE: These results demonstrate that hsFlt3L induces the proliferation of canine DCs and support its use in upcoming clinical trials for canine GBM. Our data further support the translation of hsFlt3L to be used for dendritic cells' vaccination and gene therapeutic approaches from rodent models to canine patients and its future implementation in human clinical trials.
多形性胶质母细胞瘤（GBM）是成人中最常见的原发性脑肿瘤，预后不良。我们使用编码免疫刺激细胞因子人可溶性 fms 样酪氨酸激酶 3 配体（hsFlt3L）和条件性细胞毒性分子即单纯疱疹病毒 1 胸苷激酶（HSV1-TK）的腺病毒载体（Ads）开发了一种条件性细胞毒性/免疫治疗方法。这种治疗方法引发抗肿瘤免疫反应，导致颅内啮齿动物癌症模型中的肿瘤消退和抗肿瘤免疫记忆。我们旨在测试这种免疫疗法在患有自发性 GBM 的狗中的疗效。鉴于人类细胞因子对狗免疫细胞的影响存在争议，并且考虑到这种治疗的疗效取决于 hsFlt3L 刺激的树突状细胞（DC），在目前的工作中，我们测试了 Ad 编码的 hsFlt3L 从狗外周血中生成 DC 的能力，并将其与犬 IL-4 和 GM-CSF 进行了比较。
方法/主要发现：我们的结果表明，hsFlT3L 表达形式为 Ad 载体，从外周血培养物中生成具有与犬 IL-4 和 GM-CSF 培养的 DC 非常相似的形态和表型特征的 DC。这些包括吞噬活性和 CD11c、MHCII、CD80 和 CD14 的表达。在这两种条件下培养的 DC 成熟后，IL-6、TNF-α和 IFN-γ的分泌增加。重要的是，hsFlt3L 衍生的抗原呈递细胞显示出同种刺激潜能，突出了它们向 T 细胞呈递抗原并引发其增殖的能力。
结论/意义：这些结果表明，hsFlt3L 诱导犬 DC 的增殖，并支持其在即将进行的犬 GBM 临床试验中的应用。我们的数据进一步支持 hsFlt3L 从啮齿动物模型翻译为用于树突状细胞疫苗接种和基因治疗方法，并将其未来应用于人类临床试验。
