Methods for providing purified viral particles of Semliki Forest Virus (SFV), preparations obtainable thereby, and uses thereof

A method for providing purified viral replicon particles of Semliki Forest Virus (SFV), comprising the steps of

• i) providing a preparation comprising crude SFV replicon particles;
• ii) subjecting said preparation to an endonuclease treatment under conditions allowing for degradation of exogenous/host cell DNA and RNA;
• iii) bringing said endonuclease-treated preparation with a zwitterionic buffer solution to a conductivity of up to about 5.5 mS/cm, preferably to a conductivity in the range of 4.5-5.0 mS/cm;
• iv) contacting the preparation obtained in step (iii) with a strong anion exchange resin under conditions and for a time sufficient to bind to said resin, followed by washing the resin with a zwitterionic buffer solution to remove the portion of the preparation which does not bind to said anion exchange resin from said anion exchange resin;
• v) eluting the bound SFV replicon particles from said anion exchange resin;
• vi) bringing the eluted SFV replicon particles to a conductivity in the range of 7.0 to 9.0 mS/cm, preferably in the range of 7.5-8.2 mS/cm;
• vii) contacting the preparation obtained in step (vi) with a strong cation exchange resin under conditions and for a time sufficient to bind to said resin, followed by washing the resin to remove the portion of the preparation which does not bind to said cation exchange resin from said cation exchange resin;
• viii) eluting the bound SFV replicon particles from said cation exchange resin with a zwitterionic buffer solution and collecting at least one fraction containing purified SFV replicon particles
• ix) stabilizing the at least one purified fraction by adding human serum albumin (HSA) to a final concentration in the range of 0.5-2 w/v %, preferably about 1 w/v %.