Abstract: The invention relates to methods of reducing an immune response to a transgene product in a mammal by co-administration of a small-interfering ribonucleic acid (siRNA) molecule that temporarily inhibits or reduces transgene expression, wherein the siRNA is administered in an amount, and for a period of time, sufficient to reduce an immune response to the transgene product when it is expressed at therapeutic levels. The present invention further relates to methods of administering siRNAs to a mammal to reduce an immune response to an immunogenic protein, such as an enzyme used in enzyme replacement therapy.

Abstract: The effective introduction of foreign genes and other biologically active molecules into targeted mammalian cells is a challenge still facing those skilled in the art. Gene therapy, for example, requires successful transfection of target cells in a patient. The present invention relates to novel micellar complexes of cationic amphiphilic compounds that facilitate delivery of biologically active molecules to the targeted cells of a mammal. The novel micellar complexes are comprised of a cationic amphiphile, a biologically active molecule, a derivative of polyethylene glycol (PEG), and optionally, a co-lipid. A further aspect of the invention is the use of targeting agents in any of the methods that effectuate the delivery of biologically active molecules into the cells of mammals. A targeting agent is usually any molecule, peptide sequence, or large protein that preferentially targets or binds to specific mammalian celis.

Abstract: The well-differentiated airway epithelium is the principal target tissue for gene therapy for the treatment of CF. However, recent studies have shown that gene delivery vehicles, such as cationic lipid:DNA complexes, can be inefficient at binding to and internalizing into polarized epithelial cells. The present invention provides a method to improve gene therapy by using a compound capable of disrupting tight junctions. In the practice of the invention, the transfection of a biologically active molecule by a cationic amphiphile:biologically active molecule complex or other lipid or viral or nonviral vectors is improved by treating the cells with a class of compounds known in the art as absorption enhancers or tight junction disrupting compounds.