Amphibian innate immunity and impact of environmental stress

全球超过7000种两栖动物中有三分之一受到威胁。病因是复杂的，与新兴的病原体的近端原因。真菌和病毒感染导致的两栖动物大规模死亡表明，环境破坏了青蛙免疫系统抵御感染的能力。在先天免疫的最前沿，抵抗病原体的第一道防线是皮肤上皮屏障和表面分泌的宿主防御肽（HDPs）。它们共同充当有机体外部和内部环境之间的界面。在两栖动物中发现了多种多样的HDPs，研究证明了它们对广谱病原体的抗菌活性。最近在哺乳动物中的发现表明HDP是多方面的，并且通过分子和细胞网络的协调在免疫调节中发挥重要作用。尽管如此，由于缺乏可行的方法，对两栖类HDP的研究受到了很大的阻碍。

One third of >7000 amphibian species are threatened globally. The etiology is complex, with emerging pathogens the proximal cause. Mass amphibian die-offs resulting from fungal and viral infections suggest an environment that undermines frog immune system competency to defend against infection. At the forefront of innate immunity, the first line of defense against pathogens, is the skin epithelial barrier and the surface secreted host defense peptides (HDPs). Together they act as the interface between an organism’s external and internal environments. Great diversity of HDPs is found amongst amphibians and studies have documented their antimicrobial activity against a broad-spectrum of pathogens. Recent discoveries in mammals suggest HDPs are multifaceted and play an important role in immune modulation through coordination of molecular and cellular networks. Despite this, studies on amphibian HDPs have been greatly hampered due to a lack of feasible