慢性乙型肝炎病毒感染中 T 细胞耗竭的 Tim-3/galectin-9 通路的上调。
Upregulation of the Tim-3/galectin-9 pathway of T cell exhaustion in chronic hepatitis B virus infection.
机构信息
Division of Infection and Immunity, University College London, London, United Kingdom.
出版信息
PLoS One. 2012;7(10):e47648. doi: 10.1371/journal.pone.0047648. Epub 2012 Oct 24.
The S-type lectin galectin-9 binds to the negative regulatory molecule Tim-3 on T cells and induces their apoptotic deletion or functional inactivation. We investigated whether galectin-9/Tim-3 interactions contribute to the deletion and exhaustion of the antiviral T cell response in chronic hepatitis B virus infection (CHB). We found Tim-3 to be expressed on a higher percentage of CD4 and CD8 T cells from patients with CHB than healthy controls (p<0.0001) and to be enriched on activated T cells and those infiltrating the HBV-infected liver. Direct ex vivo examination of virus-specific CD8 T cells binding HLA-A2/peptide multimers revealed that Tim-3 was more highly upregulated on HBV-specific CD8 T cells than CMV-specific CD8 T cells or the global CD8 T cell population in patients with CHB (p<0.001) or than on HBV-specific CD8 after resolution of infection. T cells expressing Tim-3 had an impaired ability to produce IFN-γ and TNF-α upon recognition of HBV-peptides and were susceptible to galectin-9-triggered cell death in vitro. Galectin-9 was detectable at increased concentrations in the sera of patients with active CHB-related liver inflammation (p = 0.02) and was strongly expressed by Kupffer cells within the liver sinusoidal network. Tim-3 blockade resulted in enhanced expansion of HBV-specific CD8 T cells able to produce cytokines and mediate cytotoxicity in vitro. Blocking PD-1 in combination with Tim-3 enhanced the number of patients from whom functional antiviral responses could be recovered and/or the strength of responses, indicating that these co-inhibitory molecules play a non-redundant role in driving T cell exhaustion in CHB. Patients taking antivirals able to potently suppress HBV viraemia continued to express Tim-3 on their T cells and respond to Tim-3 blockade. In summary, both Tim-3 and galectin-9 are increased in CHB and may contribute to the inhibition and deletion of T cells as they infiltrate the HBV-infected liver.
S 型凝集素半乳糖凝集素-9 与 T 细胞上的负调控分子 Tim-3 结合,诱导 T 细胞凋亡或功能失活。我们研究了 galectin-9/Tim-3 相互作用是否有助于慢性乙型肝炎病毒感染 (CHB) 中抗病毒 T 细胞反应的缺失和衰竭。我们发现 Tim-3 在 CHB 患者的 CD4 和 CD8 T 细胞中的表达百分比高于健康对照组 (p<0.0001),并且在活化的 T 细胞和浸润 HBV 感染肝脏的 T 细胞中富集。直接对病毒特异性 CD8 T 细胞结合 HLA-A2/肽多聚体的体外研究表明,与 CMV 特异性 CD8 T 细胞或 CHB 患者的全球 CD8 T 细胞群体相比,Tim-3 在 HBV 特异性 CD8 T 细胞上的上调更为显著 (p<0.001),或者在感染后恢复的 HBV 特异性 CD8 T 细胞上的上调更为显著。表达 Tim-3 的 T 细胞在识别 HBV 肽时产生 IFN-γ 和 TNF-α 的能力受损,并且容易在体外受到半乳糖凝集素-9 触发的细胞死亡。在活动性 CHB 相关肝炎症患者的血清中可检测到半乳糖凝集素-9 的浓度增加 (p = 0.02),并且在肝窦状网络内的枯否细胞中强烈表达。Tim-3 阻断导致 HBV 特异性 CD8 T 细胞的扩增增强,这些细胞能够在体外产生细胞因子并介导细胞毒性。PD-1 阻断与 Tim-3 阻断联合使用可增加能够恢复功能抗病毒反应的患者数量和/或反应强度,表明这些共抑制分子在驱动 CHB 中的 T 细胞衰竭中发挥非冗余作用。正在服用能够有效抑制 HBV 病毒血症的抗病毒药物的患者继续在其 T 细胞上表达 Tim-3,并对 Tim-3 阻断有反应。总之,Tim-3 和半乳糖凝集素-9 在 CHB 中均增加,并且可能在它们浸润 HBV 感染的肝脏时有助于 T 细胞的抑制和缺失。