Adaptive immunity in marsupials

Marsupials diverged from eutherian mammals 125–160 million years ago. Although evolutionarily distinct, both groups of mammals can produce complex adaptive immune responses to antigens with several key differences. This review analyses the current understanding of the adaptive immune system in marsupials and highlights key differences, including the absence of IgD in marsupial genomes and the presence of an additional T cell receptor. We summarize what is known about T cells and antibodies of marsupials, and their role in marsupial diseases including tuberculosis and sarcoptic mange. We also discuss how the innate immune system interacts with the adaptive immune system. As vaccinology becomes increasingly incorporated into marsupial disease management and conservation, we review key vaccine research within this mammalian clade. Further research is needed to expand and improve our understanding of disease responses in marsupials and help prevent further disease-driven extinctions.