The unexpected discovery of a novel family of antiviral mediators, type III IFNs or IFN-λs, challenged the widely accepted primacy of type I IFNs in antiviral immunity, and it is now well recognized that the IFN-λ-based antiviral system plays a major role in antiviral protection of epithelial barriers. The recent characterization of previously unknown IFN-λ-mediated activities has prompted further reassessment of the role of type I IFNs in innate and adaptive immune and inflammatory responses. Since type I and type III IFNs are co-produced in response to a variety of stimuli, it is likely that many physiological processes are simultaneously and coordinately regulated by these cytokines in pathological conditions, and likely at steady state, as baseline expression of both IFN types is maintained by microbiota. In this review, we discuss emerging differences in the production and signaling of type I and type III IFNs, and summarize results of recent studies describing the involvement of type III IFNs in anti-bacterial and anti-fungal, as well as antiviral, defenses.

意外发现的新型抗病毒介体家族，即III型IFN或IFN-λs挑战了在抗病毒免疫中广为接受的I型IFN的首要地位，现在人们已经认识到基于IFN-λ的抗病毒系统起着重要作用。在抗病毒保护上皮屏障中的作用。先前未知的IFN-λ介导的活性的最新特征促使人们进一步重新评估了I型IFN在先天性和适应性免疫与炎症反应中的作用。由于I型和III型IFN是响应各种刺激而共同产生的，因此很可能在这些病理条件下并且可能在稳态下，许多细胞因子同时协调地调节了许多生理过程，作为两种IFN的基线表达类型由微生物群维持。在这篇评论中