Interleukin-7 human

General description

The interleukin-7 human (IL-7) gene is mapped to human chromosome 8q21.13. It is a non-hematopoietic cell-derived cytokine. IL-7 is majorly produced by the fibroblastic stromal cells, dendritic cells, thymus epithelial cells and skin keratinocytes. Structurally, IL-7 takes up an up-up-down-down 4-helix bundle topology and has two crossover loops.

Biochem/physiol Actions

IL-7 helix A is crucial for its interaction with the interleukin-7 human receptor (IL-7Rα). It is reported to enhance immunity during viral infections and may be useful in cancer immunotherapy. Mutation in the IL-7 gene is implicated in CD4⁺ T-cell lymphopenia.

Interleukin-7 is a lymphoid cell growth factor which affects pre-B, pro-B and early T cells. It was first isolated by Namen in 1988. IL-7 has a number of known activities. It supports the growth of early B cells from long-term lymphoid bone marrow cultures. It is mitogenic for thymocytes and co-mitogenic with PHA and Con A. IL-7 also stimulates the proliferation of CD4/CD8 cells. The proliferative response of thymocytes to IL-7 is not affected by antibodies to the T cell growth factors such as IL-2, IL-4, and IL-6. Mature T cells respond to IL-7 and Con A, but not to IL-7 alone. Antibodies against IL-2 affect its activity, suggesting that it functions through IL-2 production. Human natural IL-7 is 25 kDa glycoprotein that has 6 cysteine residues which are important for biological activity. Human and mouse IL-7 have 60% amino acid sequence homology.

Lymphoid cell growth factor which affects pre-B, pro-B and early T cells; supports the growth of early B cells and is mitogenic for thymocytes and co-mitogenic with PHA and Con A; stimulates the proliferation of CD4/CD8 cells.

Physical form

Lyophilized from a 0.2 μm filtered solution in 10 mM acetic acid containing 250 μg bovine serum albumin.