Vaccine composition comprising Flt3-ligand

Abstract

Flt3-ligand can be used to generate large numbers of dendritic cells from hematopoietic progenitor and stem cells. Flt3-ligand can be used to augment immune responses in vivo, and expand dendritic cells ex vivo. Such dendritic cells can then be used to present tumor, viral or other antigens to naive T cells, can be useful as vaccine adjuvants. When flt3-L is used and/or administered in combination with other reactive agents, e.g. CD40 binding proteins, 4-1BBL or antibodies reactive with 4-1BB, CD30 ligand antagonists, RANKL, and/or interferon alpha the combination further enhances immune responses and the effectiveness of vaccine adjuvants.

1 . A vaccine composition comprising: 
 (a) as an adjuvant, Flt-3 ligand in an amount sufficient increase the number of dendritic cells in a patients in vivo; and    (b) an antigen,    wherein said Flt3-ligand comprises an amino acid sequence that is at least 90% identical to amino acids 28-Xaa of SEQ ID NO:2, wherein Xaa is an amino acid from 160-235 of SEQ ID NO:2, and wherein said Flt3-ligand binds Flt-3.    
     
     
         2 . The vaccine composition of  claim 1 , wherein said Flt3-ligand comprises amino acids 28-Xaa of SEQ ID NO:2, wherein Xaa is an amino acid from 160-235 of SEQ ID NO:2.  
     
     
         3 . The vaccine composition of  claim 1 , wherein said Flt3-ligand comprises amino acids 28-235 of SEQ ID NO:2.  
     
     
         4 . The vaccine composition of  claim 1 , wherein said Flt3-ligand comprises amino acids 28-182 of SEQ ID NO:2.  
     
     
         5 . The vaccine composition of  claim 1 , wherein said antigen is selected from the group consisting of a tumor antigen, a bacterial antigen and a viral antigen.  
     
     
         6 . A method of immunizing a patient, comprising administering the vaccine composition of any of claim  1 - 5  to a patient in need thereof.  
     
     
         7 . The method of  claim 6 , wherein said administering is parenteral, topical or inhalation.