Laboratory of Molecular and Cellular Therapy, Department of Immunology-Physiology, Vrije Universiteit Brussel, Brussels, Belgium.
1] Division of Infection and Immunity, Rayne Institute, University College London, London, UK [2] Navarrabiomed-FMS, Complejo Hospitalario de Navarra, Pamplona, Spain.
Gene Ther. 2014 Mar;21(3):262-71. doi: 10.1038/gt.2013.80. Epub 2014 Jan 9.
The release of cytokines by T cells strongly defines their functional activity in vivo. The ability to produce multiple cytokines has been associated with beneficial immune responses in cancer and infectious diseases, while their progressive loss is associated with T-cell exhaustion, senescence and anergy. Consequently, strategies that enhance the multifunctional status of T cells are a key for immunotherapy. Dendritic cells (DCs) are professional antigen presenting cells that regulate T-cell functions by providing positive and negative co-stimulatory signals. A key negative regulator of T-cell activity is provided by binding of programmed death-1 (PD-1) receptor on activated T cells, to its ligand PD-L1, expressed on DCs. We investigated the impact of interfering with PD-L1/PD-1 co-stimulation on the multifunctionality of T cells, by expression of the soluble extracellular part of PD-1 (sPD-1) or PD-L1 (sPD-L1) in human monocyte-derived DCs during antigen presentation. Expression, secretion and binding of these soluble molecules after mRNA electroporation were demonstrated. Modification of DCs with sPD-1 or sPD-L1 mRNA resulted in increased levels of the co-stimulatory molecule CD80 and a distinct cytokine profile, characterized by the secretion of IL-10 and TNF-α, respectively. Co-expression in DCs of sPD-1 and sPD-L1 with influenza virus nuclear protein 1 (Flu NP1) stimulated Flu NP1 memory T cells, with a significantly higher number of multifunctional T cells and increased cytokine secretion, while it did not induce regulatory T cells. These data provide a rationale for the inclusion of interfering sPD-1 or sPD-L1 in DC-based immunotherapeutic strategies.
T 细胞释放细胞因子强烈地定义了它们在体内的功能活性。能够产生多种细胞因子与癌症和传染病中的有益免疫反应相关，而其逐渐丧失与 T 细胞衰竭、衰老和失能相关。因此，增强 T 细胞多功能状态的策略是免疫治疗的关键。树突状细胞（DC）是专业的抗原呈递细胞，通过提供正性和负性共刺激信号来调节 T 细胞功能。T 细胞活性的一个关键负性调节因子是激活的 T 细胞上程序性死亡受体 1（PD-1）与其在 DC 上表达的配体 PD-L1 的结合。我们通过在抗原呈递过程中在人单核细胞来源的 DC 中表达 PD-1（sPD-1）或 PD-L1（sPD-L1）的可溶性细胞外部分，研究了干扰 PD-L1/PD-1 共刺激对 T 细胞多功能性的影响。证明了这些可溶性分子在 mRNA 电穿孔后的表达、分泌和结合。用 sPD-1 或 sPD-L1 mRNA 修饰 DC 导致共刺激分子 CD80 的水平增加，并具有独特的细胞因子谱，分别表现为 IL-10 和 TNF-α的分泌。在 DC 中共表达 sPD-1 和 sPD-L1 与流感病毒核蛋白 1（Flu NP1）刺激 Flu NP1 记忆 T 细胞，具有显著更多的多功能 T 细胞和增加的细胞因子分泌，而不诱导调节性 T 细胞。这些数据为在基于 DC 的免疫治疗策略中包含干扰 sPD-1 或 sPD-L1 提供了依据。
