PDF(Pubmed)
Abstract：
The human CC chemokine receptor 8 (CCR8) is specifically expressed on tumor-infiltrating regulatory T cells (TITRs) and is a promising drug target for cancer immunotherapy. However, the role of CCR8 signaling in TITR biology and the effectiveness of CCR8 small molecule antagonists as TITR-targeting immunotherapy remain subjects of ongoing debate. In this work, we generated a novel cellular model of TITRs by culturing peripheral blood mononuclear cell-derived regulatory T cells in medium containing tumor cell-conditioned medium, CD3/CD28 activator, interleukin-2 and 1α,25-dihydroxyvitamin D3. This cellular model (named TITR mimics) highly and stably expressed a series of TITR signature molecules, including CCR8, FOXP3, CD30, CD39, CD134, CD137, TIGIT and Tim-3. Moreover, TITR mimics displayed robust in vitro immunosuppressive activity. To unravel the functional role of CCR8 in TITR mimics, a chemotaxis assay was performed showing strong and CCR8-specific migration toward CCL1, the natural chemokine agonist of CCR8. However, either stimulation (with CCL1) or blocking (with the small molecule antagonist NS-15) of CCR8 signaling did not affect the immunosuppressive activity, proliferation and survival of TITR mimics. Collectively, our work provides a method for the generation of TITR mimics in vitro, which can be used to study TITR biology and to evaluate drug candidates targeting TITRs. Furthermore, our findings suggest that CCR8 signaling primarily regulates migration of these cells.
摘要：
人类CC趋化因子受体8(CCR8)在肿瘤浸润性调节性T细胞(TITRs)上特异性表达,并且是用于癌症免疫疗法的有前景的药物靶标。然而,CCR8信号传导在TITR生物学中的作用以及CCR8小分子拮抗剂作为TITR靶向免疫治疗的有效性仍是争论的主题.在这项工作中,我们通过在含有肿瘤细胞条件培养基的培养基中培养外周血单核细胞衍生的调节性T细胞来建立TITR的新细胞模型。CD3/CD28激活剂，白细胞介素-2和1α，25-二羟基维生素D3。该细胞模型（命名为TITR模拟）高度稳定地表达了一系列TITR特征分子，包括CCR8、FOXP3、CD30、CD39、CD134、CD137、TIGIT和Tim-3。此外，TITR模拟物显示出强大的体外免疫抑制活性。为了揭示CCR8在TITR模拟中的功能作用，进行了趋化性测定,显示向CCL1(CCR8的天然趋化因子激动剂)的强和CCR8特异性迁移.然而,CCR8信号的刺激（用CCL1）或阻断（用小分子拮抗剂NS-15）均不影响免疫抑制活性，TITR模拟物的增殖和存活。总的来说，我们的工作提供了一种在体外产生TITR模拟物的方法，可用于研究TITR生物学和评估靶向TITR的候选药物。此外，我们的研究结果表明,CCR8信号传导主要调节这些细胞的迁移.
