Evolutionary plasticity of vertebrate immune systems

Objetivo

"In vertebrates, innate and adaptive immunity together protect against infections and ensure tissue homeostasis. However, the impact of the astounding phenotypic diversity of the about 60,000 known vertebrate species on immune system function is largely unknown. To explore the evolutionary plasticity of vertebrate immune systems, we propose to study the unique immune systems of deep-sea anglerfishes (Ceratioidei). They exhibit distinctive reproductive habits, which involve either temporary or permanent physical pair formation that, in some species, results in the connection of the male and female circulatory systems, a form of naturally occurring anatomical joining (parabiosis), which otherwise is known only from rare instances of genetically identical conjoined twins. It is associated with drastic immunogenetic changes, culminating in the pseudogenization of recombination activating genes in some species, providing a unique opportunity to reconstruct the conversion of a canonical vertebrate immune system to a ""post-adaptive"" state lacking somatic diversification of antigen receptor genes. Comparative genomic, transcriptomic, histological, and mechanistic studies will illuminate the features of unusual vertebrate immune systems that enable tissue fusion between genetically distinct individuals without eliciting a destructive immune response, and that at the same time provide durable and efficient immune defence. We envision that our studies will contribute to the understanding of vertebrate immune plasticity, the balance between adaptive and innate functions, and the immunological adaptations associated with other forms tissue chimaerism, i. e., the maternal and foetal tissue apposition in pregnancy. Moreover, we expect to provide an evolutionarily informed context to interpret the acute changes associated with inborn and acquired immunodeficiency, and those caused by therapeutic immune interventions aimed at the modulation of mal-adapted immune responses."