研究人员在《自然—免疫学》期刊上指出，他们发现了免疫系统被耗尽的途径，以及让它们恢复活力的方法。
病毒感染会引起普通感冒或流感，因此会触发免疫系统。一种名为“CD8+T”特定的杀手T细胞能进攻感染细胞的病毒，摧毁病毒的防御系统，患者通常在几天内就痊愈了。然而，像肺炎病毒和人体免疫缺损病毒等，会引发相当顽固的感染，导致免疫系统精疲力竭而丧失功能，最终疾病无法治愈。
John Wherry和同事认真研究了这种免疫无反应机制。他们发现，通过让免疫细胞表达多种抑制受体，小鼠体内的慢性感染会让免疫细胞无能为力。这些受体的表达不是随机的，而是以一种特定的秩序进行，越严重的感染会触发更多种类的抑制受体的表达。通过阻断多种抑制受体，研究小组恢复了CD8+T细胞的杀敌能力。
他们计划通过进一步的研究，确定阻断抑制受体是否真能恢复慢性感染患者体内被耗尽的T细胞的功能。（生物谷Bioon.com）
生物谷推荐原始出处：
Nature Immunology，doi:10.1038/ni.1679，Shawn D Blackburn，E John Wherry
Coregulation of CD8+ T cell exhaustion by multiple inhibitory receptors during chronic viral infection
Shawn D Blackburn1, Haina Shin1, W Nicholas Haining2,3, Tao Zou1, Creg J Workman6, Antonio Polley1, Michael R Betts5, Gordon J Freeman4, Dario A A Vignali6 & E John Wherry1
Abstract
T cell exhaustion often occurs during chronic infection and prevents optimal viral control. The molecular pathways involved in T cell exhaustion remain poorly understood. Here we show that exhausted CD8+ T cells are subject to complex layers of negative regulation resulting from the coexpression of multiple inhibitory receptors. Exhausted CD8+ T cells expressed up to seven inhibitory receptors. Coexpression of multiple distinct inhibitory receptors was associated with greater T cell exhaustion and more severe infection. Regulation of T cell exhaustion by various inhibitory pathways was nonredundant, as blockade of the T cell inhibitory receptors PD-1 and LAG-3 simultaneously and synergistically improved T cell responses and diminished viral load in vivo. Thus, CD8+ T cell responses during chronic viral infections are regulated by complex patterns of coexpressed inhibitory receptors.
1 Immunology Program and Wistar Vaccine Center, The Wistar Institute, Philadelphia, Pennsylvania 19104, USA.
2 Department of Hematology/Oncology, Children's Hospital, Boston, Massachusetts, USA.
3 Pediatric Oncology, Dana Farber Cancer Institute, Boston, Massachusetts 02115, USA.
4 Medical Oncology, Dana Farber Cancer Institute, Boston, Massachusetts 02115, USA.
5 Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
6 Department of Immunology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA.
