Recombinant Human IL7

IL-7 is secreted constitutively into the conditioned medium of adherent bone marrow stromal cells and thymic cells. Mouse and human keratinocytes have been shown also to express and secrete IL7. Human IL-7 (152 amino acids; 17.4 kDa) and murine IL-7 (129 amino acids) show 60% sequence homology at the protein level. The human IL-7 receptor is an integral strongly glycosylated membrane proteins of 76 kDa expressed on activated T cells. This receptor has been designated as CD127. IL-7 receptors are expressed on pre-B cells and their progenitors. They are not expressed on mature B cells. IL-7 receptors are expressed also on bone marrow macrophages. Functional IL-7 receptors are found on the cell surface of multiphenotypic, biphenotypic, and immature lymphoid progenitors of B cells with the gene arrangement of the heavy immunoglobulin chain such as those observed in the germ line.