Methods for Manipulating Phagocytosis Mediated by CD47

Abstract

Methods are provided to manipulate phagocytosis of cells, including hematopoietic cells, e.g. circulating hematopoietic cells, bone marrow cells, acute leukemia cells, etc.; and solid tumor cells. In some embodiments of the invention the circulating cells are hematopoietic stem cells, or hematopoietic progenitor cells, particularly in a transplantation context, where protection from phagocytosis is desirable. In other embodiments the circulating cells are leukemia cells, particularly acute myeloid leukemia (AML), where increased phagocytosis is desirable.

What is claimed is: 
     
         1 . A method of treating a human subject for myelodysplastic syndrome (MDS), the method comprising:
 administering to a human subject in need thereof an antibody that disrupts the binding of CD47 with SIRPα, at a dose that achieves a depletion in MDS tumor cells by increasing phagocytosis of MDS tumor cells.   
     
     
         2 . The method of  claim 1 , wherein the antibody that disrupts the binding of CD47 with SIRPα specifically binds to CD47. 
     
     
         3 . The method of  claim 1 , wherein the antibody is a humanized or chimeric monoclonal antibody. 
     
     
         4 . The method of  claim 1 , wherein the MDS is a preleukemia.