最近发现的Ⅲ型IFN家族由IFN-λ1、IFN-λ2、IFN-λ3（也称作IL-29、IL-28A、IL-28B）和IFN-λ4组成。IFN-λ通过结合IFN-λR1和IL-10R2组成的异二聚体受体复合物，激活Janus激酶-信号转导及转录活化因子信号通路，诱导IFN刺激基因的表达并发挥生物学作用。近年来，对IFN-λ抗病毒作用的研究十分广泛，IFN-λ与HCV感染引起的免疫应答密切相关。IL-28B的单核苷酸多态性和新发现的IFN-λ4与HCV的自发清除也有关，预示IFN-λ在HCV感染治疗中具有潜在作用。此文介绍了IFN-λ的抗病毒作用机制及其在HCV感染临床治疗中的研究进展。

Type-Ⅲ IFN family, composed of IFN-λ1, IFN-λ2, IFN-λ3 (also named as IL29, IL28A, IL28B) and IFN-λ4, is recently identified. IFN-λ binds a heterodimeric receptor complex of IFN-λR1 and IL10R2 to activate Janus kinase-signal transducer and activator of transcription pathway to induce the expression of IFN-stimulated genes, ultimately leading to biological functions. Recently, the antiviral activity of IFN-λs has been studied extensively and evidence suggests that IFN-λs are intimately associated with the immune response to HCV infection. Additionally, IL-28B polymorphisms and the newly described IFN-λ4 are linked to spontaneous clearance of HCV, suggesting potential roles of IFN-λ in HCV infection therapy. This review summarizes research progress of antiviral mechanism of IFN-λ and its clinical application in the therapy of HCV infection.