New immune systems: Disease-specific immune responses in invertebrates, and their potential applications in aquaculture

摘要

Immunology that studies how animals defend themselves from infection is in the middle of a paradigm shift. New evidence suggests that invertebrates, including important aquaculture species such as oysters, mussels, abalone and shrimp, have sophisticated immune systems that allow them to accurately discriminate between different types of infection. In the future, it may be possible to tailor these immune systems to combat infection and prevent disease outbreaks that cause huge losses in aquaculture worldwide. This article describes the discovery of entirely new families of proteins that may underpin novel forms of disease-specific immunity. These new proteins are characterized by extremely high levels of variability, meaning that every individual can have hundreds, if not thousands, of subtly different forms of the protein. So far these types of "hyper-variable" systems have been found in sea urchins, molluscs, insects and ascid-ians. Here, we focus on very recent research, which shows that at least some invertebrates can differentiate between infectious disease agents with great accuracy, possibly using molecular hyper-variablity. If the results of this research can be used to produce economical, efficacious disease management systems for cultured animals, possibly including immunization against specific diseases, the benefits to global aquaculture will be enormous.