Methods for the Release of Virus-Like Particles

Abstract

The present invention relates to methods for the release of baculovirus-expressed Virus-like Particles (VLP's) of non-enveloped viruses from insect cells.

1 - 10 . (canceled) 
     
     
         11 . A method for the release of baculovirus-expressed Virus-like Particles (VLP's) of non-enveloped viruses from insect cells, comprising the step of mixing the insect cells with a salt in water solution,
 wherein the salt in water solution resulting from the mixing comprises at least 300 mOsmol/l of a salt of which the cation is selected from the group consisting of the alkali metals and the earth alkali metals, and of which the anion is selected from the group consisting of Cl − , Br −  and I − ; and   wherein the method is free of lysis or cell disruption steps.   
     
     
         12 . The method of  claim 11 , wherein the step of mixing the insect cells with a salt is preceded by a concentration step during which the insect cells are concentrated. 
     
     
         11 . The method of  claim 11 , wherein the cation is selected from the group consisting of Na + , Mg 2+ , Ca 2+ , and K + . 
     
     
         14 . The method of claim  13 , wherein the salt is selected from the group consisting of NaCl, KCl, CaCl 2 , and MgCl 2 . 
     
     
         15 . The method of  claim 11 , wherein the salt in the water solution resulting from the mixing essentially consists of a salt selected from the group consisting of NaCl, KCl, CaCl 2 , and MgCl 2  and water. 
     
     
         16 . The method of  claim 11 , wherein the non-enveloped virus is a member of the family Parvoviridae or Circoviridae. 
     
     
         17 . The method of  claim 11 , wherein the salt in water solution is kept at a temperature of between 35-50° C. 
     
     
         18 . The method of  claim 17 , wherein the salt in water solution is kept at a temperature of between 40-45° C. 
     
     
         19 . The method of  claim 11 , wherein the insect cells are SF9 or SF21 cells. 
     
     
         20 . A method for the purification of baculovirus-expressed Virus-like Particles (VLP's) of non-enveloped viruses, comprising the steps of
 a) infecting insect cells with a recombinant baculovirus encoding VLP-proteins;   b) culturing the insect cells;   c)sing the VLP's from the insect cells by the method of  claim 11 ;   d) isolating the VLP's;
 wherein the method is free of lysis or cell disruption steps.