The innate immune response of insects provides a robust line of defense against pathogenic microbes and eukaryotic parasites. It consists of two types of overlapping immune responses, named humoral and cellular, which share protective molecules and regulatory mechanisms that closely coordinate to prevent the spread and replication of pathogens within the compromised insect hemocoel. The major feature of the humoral part of the insect immune system involves the production and secretion of antimicrobial peptides from the fat body, which is considered analogous to adipose tissue and liver in vertebrates. Previous research has identified and characterized the nature of antimicrobial peptides that are directed against various targets during the different stages of infection. Here we review this information focusing mostly on the diversity and mode of action of these host defense components, and their critical contribution to maintaining host homeostasis. Extending this knowledge is paramount for understanding the evolution of innate immune function and the physiological balance required to provide sufficient protection to the host against external enemies while avoiding overactivation signaling events that would severely undermine physiological stability.

昆虫的先天免疫反应为抵御病原微生物和真核寄生虫提供了强大的防线。它由两种类型的重叠免疫反应组成，称为体液和细胞，它们共享保护分子和调节机制，密切协调以防止病原体在受损昆虫血腔内的传播和复制。昆虫免疫系统体液部分的主要特征涉及从脂肪体产生和分泌抗菌肽，脂肪体被认为类似于脊椎动物的脂肪组织和肝脏。先前的研究已经确定并表征了在感染的不同阶段针对各种目标的抗菌肽的性质。在这里，我们回顾了这些信息，主要集中在这些宿主防御组件的多样性和作用方式上，以及它们对维持宿主稳态的关键贡献。扩展这些知识对于理解先天免疫功能的进化以及为宿主提供足够保护以抵御外部敌人同时避免会严重破坏生理稳定性的过度激活信号事件所需的生理平衡至关重要。