Method for preparing virus-like particle and recombinant baculovirus used therein

A method for preparing picornavirus virus-like particles, comprising:

• providing a recombinant baculovirus comprising:
• a first nucleotide sequence, for being translated to a capsid protein of a picornavirus;
• a first promoter, located in the upstream region of the first nucleotide sequence and selected from the group consisting of p10 promoter, polyhedrin (polh) promoter, p6.9 promoter and capsid protein promoter;
• a second nucleotide sequence, for being translated to a protease of the picornavirus;
• and
• a second promoter, located in the upstream region of the second nucleotide sequence, wherein the second promoter is weaker than the first promoter in the context of recombinant baculovirus infection to an insect cell and ChiA and v-cath genes of the recombinant baculovirus are functionally disrupted;
• and
• infecting insect cells with the recombinant baculovirus whereby the capsid protein is translated and hydrolyzed by the protease to produce picornavirus virus-like particles;
• and
• collecting the picornavirus virus-like particles at day 5 or day 6 after the insect cells are infected.