Patent ID: 7078218

Claim:
A method for preparing alphaviral replicon particles (ARPS), said method comprising the steps of: (a) introducing an alphavirus replicon nucleic acid into a host cell, said replicon nucleic acid comprising at least a virus packaging signal and at least one heterologous coding sequence expressible in said alphaviral replicon nucleic acid, wherein said host cell comprises at least one helper function, to produce a modified host cell; (b) culturing said modified host cell under conditions allowing expression of the at least one helper function, allowing replication of said alphaviral replicon nucleic acid and packaging of said alphaviral replicon nucleic acid to form ARPS, wherein said ARPs are heparin-binding ARPS; (c) contacting the modified host cells after step (b) with an aqueous solution having an ionic strength of from 0.2 M to 5 M to release the ARPS into the aqueous solution to produce a ARP-containing solution and; (d) collecting ARPS from the ARP-containing solution of step (c).