Use of flt3-ligand in the treatment of infection

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 method for treating infection in a patient having an infection, comprising administering a composition comprising Flt3-ligand, wherein the Flt3-ligand comprises an amino acid sequence that is at least 90% identical to amino acids 28 to Xaa of SEQ ID NO:2, wherein Xaa is an amino acid from 160 to 235, and wherein the Flt3-ligand binds Flt3.  
     
     
         2 . The method of  claim 1 , wherein the infection is bacterial.  
     
     
         3 . The method of  claim 1 , wherein the infection is viral.  
     
     
         4 . The method of  claim 1 , wherein the Flt3-ligand comprises amino acids 28 to Xaa of SEQ ID NO:2, wherein Xaa is an amino acid from 160 to 235.  
     
     
         5 . The method of  claim 1 , wherein the Flt3-ligand comprises amino acid residues 28-160 of SEQ ID NO:2.  
     
     
         6 . The method of  claim 1 , wherein the Flt3-ligand comprises amino acid residues 28-182 of SEQ ID NO:2.  
     
     
         7 . The method of  claim 1 , wherein the Flt3-ligand stimulates the proliferation of hematopoietic stem and/or progenitor cells.  
     
     
         8 . The method of  claim 1 , wherein the Flt3-ligand stimulates the proliferation of cells selected from the group consisting of myeloid precursor cells, monocytic cells, macrophages, B-cells, T-cells and dendritic cells.  
     
     
         9 . A method of increasing the number of dendritic cells in a patient having an infection, comprising administering a composition comprising Flt3-ligand, wherein the Flt3-ligand comprises an amino acid sequence that is at least 90% identical to amino acids 28 to Xaa of SEQ ID NO:2, wherein Xaa is an amino acid from 160 to 235, and wherein the Flt3-ligand binds Flt3.  
     
     
         10 . The method of  claim 9 , wherein the infection is bacterial.  
     
     
         11 . The method of  claim 9 , wherein the infection is viral.  
     
     
         12 . The method of  claim 9 , wherein the Flt3-ligand comprises amino acids 28 to Xaa of SEQ ID NO:2, wherein Xaa is an amino acid from 160 to 235.  
     
     
         13 . The method of  claim 9 , wherein the Flt3-ligand comprises amino acid residues 28-160 of SEQ ID NO:2.  
     
     
         14 . The method of  claim 9 , wherein the Flt3-ligand comprises amino acid residues 28-182 of SEQ ID NO:2.  
     
     
         15 . A method of augmenting immune responses in a patient having an infection, comprising administering a composition comprising Flt3-ligand, wherein the Flt3-ligand comprises an amino acid sequence that is at least 90% identical to amino acids 28 to Xaa of SEQ ID NO:2, wherein Xaa is an amino acid from 160 to 235, and wherein the Flt3-ligand binds Flt3.  
     
     
         16 . The method of  claim 15 , wherein the infection is bacterial.  
     
     
         17 . The method of  claim 15 , wherein the infection is viral.  
     
     
         18 . The method of  claim 15 , wherein the Flt3-ligand comprises amino acids 28 to Xaa of SEQ ID NO:2, wherein Xaa is an amino acid from 160 to 235.  
     
     
         19 . The method of  claim 15 , wherein the Flt3-ligand comprises amino acid residues 28-160 of SEQ ID NO:2.  
     
     
         20 . The method of  claim 15 , wherein the Flt3-ligand comprises amino acid residues 28-182 of SEQ ID NO:2.  
     
     
         21 . The method of claims  1 ,  9  or  15 , wherein the Flt3-ligand further comprises a pharmaceutically suitable carrier, diluent and/or preservative.  
     
     
         22 . The method of claims  1 ,  9  or  15 , wherein the Flt3-ligand is complexed with polyethylene glycol.  
     
     
         23 . The method of claims  1 ,  9  or  15 , wherein the Flt3-ligand is administered topically, parenterally or by inhalation.