Vivo Delivery of Double Stranded RNA to an Interleukin-12 Producing Organ or Tissue

Abstract

The invention encompasses methods of delivering nucleic acids, including dsRNA, to mammalian target cells in vivo via intercellular transfer, wherein the dsRNA is delivered to or expressed in a first cell different from the target cell, wherein the first cell facilitates delivery of the dsRNA to the target cell.

What is claimed: 
     
         1 . A method of delivering at least one RNA to an interleukin-12 (IL-12) producing organ or tissue in an animal comprising:
 transfecting at least one muscle or skin cell of said animal with a double-stranded RNA (dsRNA) or with a nucleic acid encoding said RNA, wherein said transfection results in said RNA being delivered to at least one cell in the IL-12-producing organ or tissue, wherein one strand of said dsRNA is substantially complementary to a region of a target gene in the cell in the IL-12-producing organ or tissue, wherein delivery of the dsRNA to the target gene inhibits or reduces expression of the target gene, and wherein the target gene regulates the expression of IL-12.   
     
     
         2 . The method of  claim 1  wherein the muscle or skin cell is selected from the group consisting of fibroblast cells, cells in a dermal layer in the skin, cells in a subcutaneous layer of the skin, myocytes and myoblasts. 
     
     
         3 . The method of  claim 1  wherein the nucleic acid encoding said RNA is a DNA. 
     
     
         4 . The method of  claim 1  wherein the transfecting of the muscle cell is comprised of administering intramuscularly the dsRNA or nucleic acid encoding the RNA. 
     
     
         5 . The method of  claim 1  wherein the transfecting of the skin cell is comprised of administering subcutaneously or intradermally the dsRNA or nucleic acid encoding the RNA. 
     
     
         6 . The method  claim 1  wherein one strand of said dsRNA is substantially complementary to a region of a messenger RNA transcribed by the target gene. 
     
     
         7 . The method of  claim 1  wherein the at least one cell in the target organ or tissue distal from the site of the transfected cell is an immune cell. 
     
     
         8 . The method of  claim 7  wherein the immune cell is selected from the group consisting of macrophages, monocytes, dendritic cells, and B cells. 
     
     
         9 . The method of  claim 1  wherein said transfection is facilitated by one or more agents selected from the group consisting of polymer or peptide complexes, cationic amphiphiles, cationic lipids, cationic liposome formulations, a local anaesthetic, bupivacaine, particulates, gold particles, gene gun delivery, polycationic agents, cationic agents, spermine, spermine derivatives, spermidine, spermidine derivatives, cholesteryl spermine compounds, cholesteryl spermine carbamates, an electroporation-facilitating agent, poly-L-glutamate, electroporation, needle injection, needleless injection, and transdermal patch. 
     
     
         10 . The method of  claim 1  wherein said transfected cells further express a transmembrane or surface ligand specific for a receptor on the target organ or tissue. 
     
     
         11 . The method of  claim 10  wherein a nucleic acid expressing said transmembrane or surface ligand is co-transfected with said nucleic acid encoding said dsRNA. 
     
     
         12 . The method of  claim 11  wherein said nucleic acid expressing said transmembrane or surface ligand and said nucleic acid encoding said dsRNA are encoded on a single vector or plasmid. 
     
     
         13 . The method of  claim 1  wherein said dsRNA is an shRNA or an siRNA having between 15 to about 50 base pairs. 
     
     
         14 . The method of  claim 1  wherein said transfection of said dsRNA to said muscle or skin cell does not trigger a detectable PKR response.