Andreakos Evangelos, Salagianni Maria, Galani Ioanna E, Koltsida Ourania
Laboratory of Immunobiology, Center for Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece.
Front Immunol. 2017 Sep 29;8:1232. doi: 10.3389/fimmu.2017.01232. eCollection 2017.
Type III interferons (IFNs), also termed lambda IFNs (IFNλs) or interleukins-28/29, constitute a new addition to the IFN family. They are induced upon infection and are particularly abundant at barrier surfaces, such as the respiratory and gastrointestinal tracts. Although they signal through a unique heterodimeric receptor complex comprising IFNLR1 and IL10RB, they activate a downstream signaling pathway remarkably similar to that of type I IFNs and share many functions with them. Yet, they also have important differences which are only now starting to unfold. Here, we review the current literature implicating type III IFNs in the regulation of immunity and homeostasis in the respiratory tract. We survey the common and unique characteristics of type III IFNs in terms of expression patterns, cellular targets, and biological activities and discuss their emerging role in first line defenses against respiratory viral infections. We further explore their immune modulatory functions and their involvement in the regulation of inflammatory responses during chronic respiratory diseases, such as asthma and chronic obstructive pulmonary disease. Type III IFNs are, therefore, arising as front-line guardians of immune defenses in the respiratory tract, fine tuning inflammation, and as potential novel therapeutics for the treatment of diverse respiratory diseases, including influenza virus infection and asthma.
III型干扰素（IFNs），也被称为λ干扰素（IFNλs）或白细胞介素-28/29，是干扰素家族的新成员。它们在感染后被诱导产生，在诸如呼吸道和胃肠道等屏障表面特别丰富。尽管它们通过由IFNLR1和IL10RB组成的独特异二聚体受体复合物发出信号，但它们激活的下游信号通路与I型干扰素的非常相似，并与它们共享许多功能。然而，它们也存在重要差异，而这些差异直到现在才开始显现。在这里，我们综述了当前有关III型干扰素参与呼吸道免疫调节和稳态维持的文献。我们从表达模式、细胞靶点和生物学活性方面审视了III型干扰素的共同和独特特征，并讨论了它们在抵抗呼吸道病毒感染的一线防御中的新作用。我们进一步探讨了它们的免疫调节功能以及它们在慢性呼吸道疾病（如哮喘和慢性阻塞性肺疾病）炎症反应调节中的作用。因此，III型干扰素正成为呼吸道免疫防御的一线守护者，精确调节炎症，并且作为治疗包括流感病毒感染和哮喘在内的多种呼吸道疾病的潜在新型疗法。
