Dendritic cell potentiation

Abstract

A molecule capable of potentiating immune responses is described, as well as methods for using the molecule to enhance immune responses and enhance dendritic cell function. Also described are compositions containing the molecule and methods for using the compositions to treat or immunize individuals.

1 . A method of enhancing dendritic cell function in a mammal, said method comprising administering to said mammal in need thereof a composition comprising a purified IgM antibody that binds to B7-DC polypeptides on a cell, wherein said binding results in cross-linking of a plurality of said B7-DC polypeptides, and wherein said IgM antibody can potentiate an immune response upon administration to a mammal. 
     
     
         2 . The method of  claim 1 , wherein said enhancing dendritic cell function involves prolonging the longevity of said dendritic cells. 
     
     
         3 . The method of  claim 1 , wherein said IgM antibody is rHIgM12, and wherein the antibody is obtainable from the hybridoma deposited by Applicants as ATCC Designation number PTA-8932. 
     
     
         4 . The method of  claim 1 , wherein said mammal is a human. 
     
     
         5 . A method of potentiating an immune response in a mammal in need thereof, said method comprising administering to said mammal a composition comprising a purified IgM antibody that binds to B7-DC polypeptides on a cell, wherein said binding results in cross-linking of a plurality of said B7-DC polypeptides, and wherein said IgM antibody can potentiate an immune response upon administration to a mammal. 
     
     
         6 . The method of  claim 5 , wherein said IgM antibody is sHIgM12. 
     
     
         7 . The method of  claim 5 , wherein said mammal is a human. 
     
     
         8 . A method of treating a tumor in a mammal, said method comprising administering to said mammal a composition comprising a purified IgM antibody and an antigen, wherein said purified IgM antibody binds to B7-DC polypeptides on a cell, wherein said binding results in cross-linking of a plurality of said B7-DC polypeptides, wherein said IgM antibody can potentiate an immune response upon administration to a mammal, and wherein said antigen is capable of eliciting an immune response when said composition is administered to a mammal. 
     
     
         9 . The method of  claim 8 , wherein said antigen is a tumor antigen. 
     
     
         10 . The method of  claim 8 , wherein said mammal is a human. 
     
     
         11 . A method of inducing immunity to a pathogen in a mammal, said method comprising administering to said mammal a composition comprising a purified IgM antibody and an antigen, wherein said purified IgM antibody binds to B7-DC polypeptides on a cell, wherein said binding results in cross-linking of a plurality of said B7-DC polypeptides, wherein said IgM antibody can potentiate an immune response upon administration to a mammal, wherein said antigen is capable of eliciting an immune response when said composition is administered to a mammal, and wherein said antigen is from a pathogen. 
     
     
         12 . The method of  claim 11 , wherein said antigen is a component of a killed virus or a component of a killed bacterium. 
     
     
         13 . The method of  claim 11 , wherein said antigen is a killed virus or a killed bacterium. 
     
     
         14 . The method of  claim 11 , wherein said mammal is a human. 
     
     
         15 . A method of potentiating an immune response in a mammal in need thereof, said method comprising:
 (a) contacting dendritic cells of said mammal in vitro with a composition comprising a purified IgM antibody and an antigen, wherein said purified IgM antibody binds to B7-DC polypeptides on a cell, wherein said binding results in cross-linking of a plurality of said B7-DC polypeptides, wherein said IgM antibody can potentiate an immune response upon administration to a mammal, and wherein said antigen is capable of eliciting an immune response when said composition is administered to a mammal; and   (b) transferring said contacted dendritic cells into said mammal.   
     
     
         16 . The method of  claim 15 , wherein said mammal is a human.