Flt3-ligand as a vaccine adjuvant

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.

What is claimed is:  
     
         1 . A vaccine adjuvant, comprising Flt3-ligand.  
     
     
         2 . A method of immunizing a patient in need thereof, comprising: 
 (a) administering Flt3-ligand to the patient; and    (b) administering an antigen to the patient.    
     
     
         3 . The method according to  claim 2 , wherein the Flt3-ligand is administered prior to, concurrently with and/or subsequent to administration of the antigen.  
     
     
         4 . The method according to  claim 2 , wherein the antigen is a tumor antigen.  
     
     
         5 . The method according to  claim 2 , wherein the antigen is a bacterial antigen.  
     
     
         6 . The method according to  claim 2 , wherein the antigen is a viral antigen.  
     
     
         7 . The method according to  claim 2 , wherein the Flt3-ligand is administered parenterally, topically and/or by inhalation.  
     
     
         8 . The method according to  claim 2 , wherein the antigen is administered parenterally, topically and/or by inhalation.