The amphibian immune system

Amphibians are at the forefront of bridging the evolutionary gap between mammals and more ancient, jawed vertebrates. Currently, several diseases have targeted amphibians and understanding their immune system has importance beyond their use as a research model. The immune system of the African clawed frog, Xenopus laevis, and that of mammals is well conserved. We know that several features of the adaptive and innate immune system are very similar for both, including the existence of B cells, T cells and innate-like T cells. In particular, the study of the immune system at early stages of development is benefitted by studying X. laevis tadpoles. The tadpoles mainly rely on innate immune mechanisms including pre-set or innate-like T cells until after metamorphosis. In this review we lay out what is known about the innate and adaptive immune system of X. laevis including the lymphoid organs as well as how other amphibian immune systems are similar or different. Furthermore, we will describe how the amphibian immune system responds to some viral, bacterial and fungal insults.This article is part of the theme issue 'Amphibian immunity: stress, disease and ecoimmunology'.

Automated summary

Amphibians play a crucial role in bridging the evolutionary gap between mammals and ancient vertebrates. Understanding their immune system, which is similar to that of mammals, is important for disease research. The African clawed frog, Xenopus laevis, is a good model for studying the immune system, particularly during early development stages. This review summarizes the knowledge about the innate and adaptive immune system of X. laevis and compares it with other amphibians. It also discusses the response of amphibians to viral, bacterial, and fungal infections.