alphaviral particles and methods of preparation

A method for preparing alphavirus replicon particles (ARP) carrying mutations conferring the ability glycosaminoglycan binding in mammalian cells, said method comprising the steps of: (a) introducing a nucleic acid alphavirus replicon in a permissive host cell alphavirus, said replicon nucleic acid at least one signal viral packaging and at least one sequence expressible heterologous coding in said nucleic acid alphavirus replicon comprising, wherein said host cell comprises at least one collaborative role, producing a modified host cell ; (B) culturing said modified host cell under conditions allowing expression of the at least one collaborator function, allowing replication of said alphavirus replicon nucleic acid and packaging of said alphavirus replicon nucleic acid, forming ARP; (C) contacting the modified host cells after step (b) with an aqueous solution of saline lavage having an ionic strength of 0.5 to 5 M to release the ARP binding capacity glycosaminoglycan in aqueous solution producing a solution containing ARP; (D) collecting the ARP ARP-containing solution of step (c), followed by affinity chromatography with heparin.