Targeting intracellular target-binding determinants with intracellular antibodies

1. A method for inhibiting an intracellular target in a cell with a bispecific antibody comprising contacting the cell with a bispecific antibody having a first Fv fragment with a cell-penetrating determinant and a second Fv fragment with an intracellular target-binding determinant under suitable conditions so that the first Fv fragment causes the bispecific antibody to enter the cell and the second Fv fragment binds the intracellular target in the cell, and wherein the second Fv fragment is directed to the Mdm2 oncoprotein, thereby inhibiting the intracellular target.

2. The method of claim 1 , wherein the second Fv fragment comprises an anti-Mdm2 oncoprotein mAb 3G5 idiotype or an idiotype that competes with a monoclonal antibody directed to the Mdm2 oncoprotein mAb 3G5.

3. A bispecific antibody comprising a first Fv fragment with a cell-penetrating determinant from an anti-DNA monoclonal antibody 3E10 or an antibody which competes with monoclonal antibody 3E10 and a second Fv fragment with an intracellular target-binding determinant that inhibits the biological activity, biochemical activity, regulatory activity or cellular signal associated with the determinant or a macromolecule to which the determinant is attached, wherein the second Fv fragment is directed to the Mdm2 oncoprotein.

4. The bispecific antibody of claim 3 , wherein the second Fv fragment comprises an anti-Mdm2 oncoprotein mAb 3G5 idiotype or an idiotype that competes with a monoclonal antibody directed to the Mdm2 oncoprotein mAb 3G5.