The research on the immunoregulatory effect of programmed death-1 (PD-1) in infectious diseases mainly focuses on chronic viral infection, but there are few studies on acute viral infection. In chronic viral infection, PD-1 is highly expressed on the surface of CD8+ T cells, which is a sign of CD8+ T cell depletion. Recent studies have shown that in chronic viral infection, PD-1 is also highly expressed on the surface of regulatory T cells and binds to programmed death-ligand 1 (PD-L1) on the surface of exhausted CD8+ T cells, resulting in a stronger inhibitory effect on CD8+ T cell immunity. Blocking the PD-1/PD-L1 signaling pathway between exhausted CD8+ T cells and regulatory T cells can significantly reverse the depletion of CD8+ T cells and greatly improve the antiviral effect of CD8+ T cells. However, the role of the PD-1/PD-L1 signaling pathway in acute viral infection remains unknown. This article summarizes the latest research on PD-1 in infectious diseases and discusses its role in acute and chronic viral infection.
目前对于程序性死亡因子1（PD1）在感染性疾病中对免疫调节的作用主要集中在慢性病毒感染相关的研究，而在急性病毒感染中研究较少。在慢性病毒感染中，PD1高表达于CD8+T细胞表面，这是CD8+T细胞耗竭的标志之一。最近研究显示，在慢性病毒感染中，也存在高表达于调节性T细胞表面的PD1，与耗竭CD8+T细胞表面PD1配体1（PD-L1）结合导致对CD8+T细胞免疫产生更强的抑制效应。阻断耗竭CD8+T细胞与调节性T细胞之间的PD1/PD-L1信号通路可以明显逆转耗竭CD8+T细胞功能，并极大改善耗竭CD8+T细胞抗病毒效应。然而，在急性病毒感染中，PD1/PD-L1信号通路的作用并不明确。本文主要概括了关于PD1在感染性疾病中最新的研究，并论述其在急性、慢性病毒感染中的作用。