Role of ROS and NF-κB in Drosophila gut immunity

다국어 초록 (Multilingual Abstract)

A fundamental question that can be applied to all life forms is how barrier epithelia of an organism can efficiently manage continuous contact with microorganisms. Here, we show that redox balancing is a key host defense system and is needed during host-microbe interaction in Drosophila. Strikingly, flies with reduced intestinal ROS production and/or elimination capacity are burdened with high mortality rates, even after trivial infection such as simple ingestion of microbe-contaminated foods. Intestinal NF-κB pathway activation and subsequent antimicrobial peptide(AMP) production is normally dispensable in this type of gut infection. However, intestinal NF-κB/AMP-dependent immunity becomes crucial to host survival in cases in which the host encounters pathogenic microbes which somehow counteract host intestinal ROS. These results imply that the epithelia of Drosophila developed two evolutionally distinct innate immune effectors, AMPs and ROS. Such multiple layers immunity endows the Drosophila gastrointestinal epithelia a versatility which makes it difficult for pathogens to completely resist or circumvent.