Interleukin 14 (IL-14)

A glycoprotein with MW 55 kDA which previously was termed a high molecular B-cell growth factor. It is secreted mainly by follicular dendritic cells, T-cells of the germinal centres and certain neoplastic cells. Its main function is to increase B-cell proliferation and to induce and maintain the production of memory B-cells. The receptor for IL-14 can be found only on activated B-lymphocytes, not on resting ones. The IL-14 molecule has a similar amino-acid sequence as the Bb factor, present in the alternative pathway of complement activation.