Huang Xueting, Pawge Girija, Snicer Christina E, Hsiao Chia-Hung Christine, Wiemer Andrew J
Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT, United States.
Institute for Systems Genomics, University of Connecticut, Storrs, CT, United States.
J Immunol. 2025 Jan 1;214(1):55-71. doi: 10.1093/jimmun/vkae002.
Poliovirus receptor (PVR) ligands have gained attention as immunotherapy targets, yet their regulation remains unclear. Here, we examine the impact of PVR exposure on primary human CD8+ T cells. We used flow cytometry and Western blot analysis to quantify expression of PVR and its ligands in naïve and effector T cells and used adhesion assays and enzyme-linked immunosorbent assay (ELISA) to assess the impact of PVR on T cell adhesion and cytokine production. Stimulation with phytohemagglutinin P strongly increased DNAM-1 expression and caused a less robust and more variable increase in TIGIT expression. Exposure to PVR-Fc enhanced the CD8+ T cell adhesion to ICAM-1-coated plates in a dose-dependent manner, while exposure to PVR-expressing K32 cells mildly decreased CD8+ T cell interferon γ release. However, PVR exposure strongly decreased the expression of DNAM-1, TIGIT, and CD96. The reduction of DNAM-1, TIGIT, and CD96 induced by PVR was dominant to the increase caused by T cell receptor signaling. The impact of PVR on their expression was completely abolished by the Q63R and F128R point mutations of PVR, while DNAM-1 was partially rescued by inhibitors of Src and protein kinase C. Additionally, PVR exposure along with T cell receptor signaling promoted the transfer of surface proteins including PVR from K32 cells to CD8+ T cells. This PVR transfer was mediated by the IgV domain of PVR and CD96 on CD8+ T cells and required cellular contact. Our findings collectively demonstrate that PVR engagement has a mild antagonistic effect on interferon γ production but strongly impacts CD8+ T cell adhesion and protein expression.
脊髓灰质炎病毒受体（PVR）配体作为免疫治疗靶点已受到关注，但其调控机制仍不清楚。在此，我们研究了PVR暴露对原代人CD8 + T细胞的影响。我们使用流式细胞术和蛋白质印迹分析来定量幼稚和效应T细胞中PVR及其配体的表达，并使用黏附试验和酶联免疫吸附测定（ELISA）来评估PVR对T细胞黏附和细胞因子产生的影响。用植物血凝素P刺激可强烈增加DNAX辅助分子-1（DNAM-1）的表达，并导致T细胞免疫球蛋白和ITIM结构域（TIGIT）表达的增加幅度较小且变化更大。暴露于PVR-Fc以剂量依赖的方式增强了CD8 + T细胞与细胞间黏附分子-1（ICAM-1）包被平板的黏附，而暴露于表达PVR的K32细胞则轻度降低了CD8 + T细胞干扰素γ的释放。然而，PVR暴露强烈降低了DNAM-1、TIGIT和CD96的表达。PVR诱导的DNAM-1、TIGIT和CD96的减少对由T细胞受体信号传导引起的增加具有主导作用。PVR的Q63R和F128R点突变完全消除了PVR对其表达的影响，而Src和蛋白激酶C的抑制剂部分挽救了DNAM-1的表达。此外，PVR暴露与T细胞受体信号传导一起促进了包括PVR在内的表面蛋白从K32细胞向CD8 + T细胞的转移。这种PVR转移由PVR的免疫球蛋白可变区（IgV）结构域和CD8 + T细胞上的CD96介导，并且需要细胞接触。我们的研究结果共同表明，PVR参与对干扰素γ的产生具有轻微的拮抗作用，但对CD8 + T细胞黏附和蛋白表达有强烈影响。
