T-Lymphocytes regulate the growth and differentiation of certain lymphopoietic and haemopoietic cells through the release of various secreted protein factors [ PUBMED:3918306 ]. These factors, which include interleukin-2 (IL2), are secreted by lectin- or antigen-stimulated T-cells, and have various physiological effects. … expand

T-Lymphocytes regulate the growth and differentiation of certain lymphopoietic and haemopoietic cells through the release of various secreted protein factors [ PUBMED:3918306 ]. These factors, which include interleukin-2 (IL2), are secreted by lectin- or antigen-stimulated T-cells, and have various physiological effects. IL2 is a lymphokine that induces the proliferation of responsive T-cells. In addition, it acts on some B-cells, via receptor-specific binding [ PUBMED:3517854 ], as a growth factor and antibody production stimulant [ PUBMED:1510960 ]. The protein is secreted as a single glycosylated polypeptide, and cleavage of a signal sequence is required for its activity [ PUBMED:3517854 ]. Solution NMR suggests that the structure of IL2 comprises a bundle of 4 helices (termed A-D), flanked by 2 shorter helices and several poorly-defined loops. Residues in helix A, and in the loop region between helices A and B, are important for receptor binding. Secondary structure analysis has suggested similarity to IL4 and granulocyte-macrophage colony stimulating factor (GMCSF) [ PUBMED:1510960 ].