Regulatory T Cells in Avian Species

摘要

The immune system protects the host from foreign pathogens while avoiding damage towards self–antigens. T regulatory cells (Tregs), a subset of T cells, specialize in immune suppression. A host immune response is a result of interplay between different components of the immune system. Interplay between Tregs and other components of the immune system will determine whether the outcome will be a persistent infection or successful pathogen clearance. Avian Tregs are characterized by the presence of both CD4 and CD25. Avian CD4+ and CD25+ cells produce high amounts of IL–10 and lack IL–2 mRNA; and suppress T cell proliferation in vitro through both contact–dependent and independent pathways. Avian Treg properties and numbers are influenced by infections and inflammatory status of the bird. Compared to mammals, avian Treg research is still in early stages of reseearch and, thus, extensive characterization of avian Tregs is required. In mammals, Treg–targeted therapy is applied for numerous situations, e.g. infections, tumors, autoimmune diseases, sepsis, shock, and vaccine. Similar to mammals, avian diseases will benefit from Treg–targeted therapy.