COMPOSITIONS AND METHODS FOR STIMULATING MEGAKARYOCYTE GROWTH AND DIFFERENTIATION

摘要

Disclosed are novel proteins, referred to as megakaryocyte growth and develo pment factors (MGDFs; also generally referred to as Mpl ligands), that have a biological activity of stimulating the growth of m egakaryocytes and augmenting the differentiation or matu ration of megakaryocytes, ultimately to result in the production of platelets. MGD F derivatives comprising MGDF molecules attached to wate r- soluble polymers, such as polyethylene glycol, are also disclosed, along wit h methods for their preparation. Also disclosed are pro cesses for obtaining the MGDFs in homogeneous form from natural sources and produci ng them by recombinant genetic engineering techniques from mammals, including humans.