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 a truncated segment of the first promoter, 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.