CD34 BINDING FACTOR AND ITS PRODUCTION

摘要

PURPOSE:To obtain a new CD34 binding factor originated from stroma cell, specifically binding to a CD34 antigen expressed in human hematopoietic stem cell, exhibiting the function to promote and maintain the proliferation of hematopoietic stem cell and useful for the diagnosis, treatment, etc., of leukemia, cytopenia, etc. CONSTITUTION:This new protein CD34 binding factor has a molecular weight of 14 kD by SDS-polyacrylamide gel electrophoresis, is capable of specifically binding to CD34 antigen expressed in human hematopoietic stem cell, has a function of a regulator to regulate the proliferation and differentiation of hematopoietic stem cell, is producible from a cultured product obtained by culturing a normal fibroblast cell originated from the lung of human fetus (HFL-III) and useful as a diagnostic agent and therapeutic agent for cytopenia and anaplastic anemia accompanying to the radiation therapy and chemotherapy of a patient of hematopoietic organ tumor such as leukemia, heterogenous and autogenous bone marrow transfusion and cancer. This protein can be produced by culturing stroma cell, treating the obtained culture product with a CD34 antigen protein column and separating and collecting the protein bonded to the column and having a molecular weight of 14 kD.