Patent ID: 7977091

Claim:
A method of inhibiting binding of a first ligand to a receptor, comprising introducing into a eukaryotic cell a eukaryotic layered vector initiation system which comprises a eukaryotic promoter 5′ of alphaviral cDNA, wherein the eukaryotic promoter initiates within the eukaryotic cell 5′ to 3′ synthesis of alphaviral RNA from the alphaviral cDNA; wherein the alphaviral RNA comprises a vector that autonomously amplifies in the eukaryotic cell; wherein the vector comprises: (1) a 5′ sequence capable of initiating transcription of alphaviral RNA, (2) an RNA that encodes alphaviral nonstructural proteins, (3) an alphaviral RNA polymerase recognition sequence, and (4) a heterologous RNA which encodes a second ligand, whereby the second ligand binds to the receptor, thereby blocking binding of the first ligand.