Methods and compositions to induce antitumor response

Abstract

The present invention provides compositions which are engineered to induce killing of tumor cells and concomitantly mobilize differentiate, activate and attract dendritic cells through the expression of cytokines and dendritic cell chemoattractants. The present invention invention is induces multiple stages of dendritic cell differentiation, activation and migration in vivo using gene therapy delivery systems. Moreover, this invention describes the rational design of utilizing viral vectors (preferred vector is rAd) for multiple administrations of targeted delivery to dendritic cells which can promote differentiation and activation of the transduced dendritic cells (thus augmenting in vivo stimulation of T cells, NK cells and B cells. The present invention provides a method to induce an antitumor immune response through the use of such compositions.

I claim:  
     
         1 . A recombinant expression vector capable of expressing a cytotoxic transgene and a dendritic cell chemoattractant.  
     
     
         2 . The vector of  claim 1  wherein said vector is a viral vector.  
     
     
         3 . The vector of  claim 2  wherein said vector is an adenoviral vector.  
     
     
         4 . The vector of  claim 3  wherein said dendritic cell chemoattractant is MIP-3-α.  
     
     
         5 . The vector of  claim 4  wherein the cytotoxic transgene is p53.  
     
     
         6 . The vector of  claim 5  wherein the p53 and MIP-3-α genes are linked by an IRES element.  
     
     
         7 . The vector of  claim 6  wherein the p53 and MIP-3-α genes are operably linked to the CMV promoter.  
     
     
         8 . A recombinant viral vector capable of selective replication in tumor cells wherein said vector expresses a dendritic cell chemoattractant.  
     
     
         9 . The vector of  claim 8  wherein said vector is an adenoviral vector.  
     
     
         10 . The vector of  claim 9  wherein said adenoviral vector contains deletions in the E1a region so as to reduce binding of the E1g gene products to p300 and pRb protein family members.  
     
     
         11 . The vector of  claim 10  wherein said deletions comprise deletions of amino acids 4-25 and amino acids 111-123 of the E1a 243R and 289R proteins.  
     
     
         12 . The vector of  claim 11  wherein said adenoviral vector further comprises a p53 or TGF-β pathway responsive promoter driving expression of an inhibitor of viral replication.  
     
     
         13 . The vector of  claim 12  wherein said inhibitor of viral replication is E2F-Rb.  
     
     
         14 . The vector of  claim 13  wherein the E1a gene is operably linked to an E2F pathway responsive promoter.  
     
     
         15 . A pharmaceutical formulation comprising a vector capable of expressing a cytotoxic transgene and a dendritic cell chemoattractant and a pharmaceutically acceptable carrier.  
     
     
         16 . The formulation of  claim 15  wherein said vector is an adenoviral vector containing an expression cassette comprising the CMV promoter driving expression of p53 and MIP-3-α wherein the p53 and MIP-3-α coding sequences are linked by an IRES element.  
     
     
         17 . A method of inducing the migration of dendritic cells to the site of a tumor in a mammal by the administration vector capable of expressing a cytotoxic transgene and a dendritic cell chemoattractant.  
     
     
         18 . The method of  claim 17  wherein said cytotoxic transgene is p53 and said dendritic cell chemoattractant is MIP-3-α.  
     
     
         19 . The method of  claim 18  wherein said vector is an adenoviral vector.  
     
     
         20 . The method of  claim 19  wherein said vector further comprises deletions of amino acids 4-25 and amino acids 111-123 of the E1a 243R and 289R proteins.