IL-2 is a 15.5-kDa cytokine secreted predominately by Agsimulated CD4+ T cells, but it can also be produced by CD8+ cells, NK cells, and activated dendritic cells. IL-2 can stimulate cells that express either a trimeric high-affinity IL-2 receptor containing the a-, b-, and g-chains or a low-affinity dimeric receptor consisting of only the b- and g-chains. In CD8 cells, IL-2 can simulate cell growth, as well as differentiation into memory and more terminally differentiated lymphocytes. IL-2 is the predominant factor responsible for the maintenance of CD41 regulatory T cells and plays a role in the differentiation of CD4 T cells into a variety of subsets with different T cell functions. The ability of IL-2 to expand T cells with maintenance of functional activity has been translated into the first reproducible effective human cancer immunotherapies.
As part of the haematopoietin family, GM-CSF is a four-helix packing cytokine. The GM-CSF gene is located in the 5q31 region. GM-CSF effects on the inflammatory response influence the outcome of multiple tissue insults in several systems and organs. Virus-based immune agents such as GM-CSF armed vectors are among the early efforts to reach a potent immunostimulation therapy. GM-CSF has a wide range of lymphoid regulatory actions, linking innate and adaptive immunity, acting as a bridge between haematopoietic and lymphoid factors and should be considered first-line treatment for all kind of illnesses requiring a fully competent immune response.
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