■免疫检查点阻断(ICB)正在迅速成为治疗许多癌症类型的标准护理。然而,对这类治疗有反应的患者子集是有限的.另一种促进抗肿瘤免疫的方法是使用免疫刺激分子,例如细胞因子或T细胞共刺激物。免疫疗法的全身给药导致显著的免疫相关不良事件(irAEs),因此,需要局部的抗肿瘤作用.实现这一目标的一种方法是肿瘤内非病毒基因免疫治疗,允许基因的长期和局部表达,和多种药物管理。在这项研究中,我们结合了之前描述的非病毒基因递送系统,PEG-PEI-TAT共聚物,PPT,与鼠OX40L编码质粒DNA。
■所得的OX40L/PPT纳米颗粒通过凝胶迁移率测定进行表征,动态光散射分析和体外转染效率评价。使用皮下(s.c.)植入的CT26(结肠癌)评估肿瘤内(i.t.)施用的纳米颗粒的抗肿瘤功效。B16F0(黑素瘤)和4T1(乳腺癌)肿瘤模子。使用流式细胞术分析基质免疫细胞群的动力学。使用体重减轻和恶病质作为irAE指标。在s.c.CT26肿瘤模型中估计i.t.OX40L/PPT与腹膜内PD-1ICB的组合的效果。
获得的OX40L/PPT纳米颗粒具有适用于细胞转染的性质,并在所有三个研究的癌症模型中提供体外OX40L蛋白表达。我们观察到OX40L/PPT治疗成功地抑制了B16F0和CT26肿瘤模型中的肿瘤生长,并显示出抑制4T1肿瘤生长的趋势。在B16F0肿瘤模型中,OX40L/PPT治疗导致抗肿瘤效应NK和T杀伤细胞的增加,并导致肿瘤基质内促肿瘤骨髓细胞群的减少。在所有3种肿瘤模型中均未观察到irAE征象,这表明小鼠具有良好的治疗耐受性。在CT26皮下结肠癌模型中,将OX40L/PPT与PD-1ICB联合使用可显著提高治疗效果,提供针对CT26结肠癌细胞的保护性免疫。
■总的来说,用OX40L非病毒基因疗法观察到的抗肿瘤疗效,无论是单独给药还是与ICB联合给药,突出了它彻底改变癌症基因疗法的潜力,从而为癌症治疗领域前所未有的进步铺平了道路。
UNASSIGNED: Immune checkpoint blockade (ICB) is rapidly becoming a standard of care in the treatment of many cancer types. However, the subset of patients who respond to this type of therapy is limited. Another way to promote antitumoral immunity is the use of immunostimulatory molecules, such as cytokines or T cell co-stimulators. The systemic administration of immunotherapeutics leads to significant immune-related adverse events (irAEs), therefore, the localized antitumoral action is needed. One way to achieve this is intratumoral non-viral gene-immune therapy, which allows for prolonged and localized gene expression, and multiple drug administration. In this study, we combined the previously described non-viral gene delivery system, PEG-PEI-TAT copolymer, PPT, with murine OX40L-encoding plasmid DNA.
UNASSIGNED: The resulting OX40L/PPT nanoparticles were characterized via gel mobility assay, dynamic light scattering analysis and in vitro transfection efficiency evaluation. The antitumoral efficacy of intratumorally (i.t.) administered nanoparticles was estimated using subcutaneously (s.c.) implanted CT26 (colon cancer), B16F0 (melanoma) and 4T1 (breast cancer) tumor models. The dynamics of stromal immune cell populations was analyzed using flow cytometry. Weight loss and cachexia were used as irAE indicators. The effect of combination of i.t. OX40L/PPT with intraperitoneal PD-1 ICB was estimated in s.c. CT26 tumor model.
UNASSIGNED: The obtained OX40L/PPT nanoparticles had properties applicable for cell transfection and provided OX40L protein expression in vitro in all three investigated cancer models. We observed that OX40L/PPT treatment successfully inhibited tumor growth in B16F0 and CT26 tumor models and showed a tendency to inhibit 4T1 tumor growth. In B16F0 tumor model, OX40L/PPT treatment led to the increase in antitumoral effector NK and T killer cells and to the decrease in pro-tumoral myeloid cells populations within tumor stroma. No irAE signs were observed in all 3 tumor models, which indicates good treatment tolerability in mice. Combining OX40L/PPT with PD-1 ICB significantly improved treatment efficacy in the CT26 subcutaneous colon cancer model, providing protective immunity against CT26 colon cancer cells.
UNASSIGNED: Overall, the anti-tumor efficacy observed with OX40L non-viral gene therapy, whether administered alone or in combination with ICB, highlights its potential to revolutionize cancer gene therapy, thus paving the way for unprecedented advancements in the cancer therapy field.