RECOMBINANT VIRUS-LIKE CIRCOVIRUS CAPSID PARTICLE (VLP): COMPOSITIONS, METHODS AND USES Russian patent published in 2024 - IPC C12N7/04 

FIELD: biotechnology; virology; veterinary science.

SUBSTANCE: disclosed is an expression system in mammals for producing recombinant virus-like particles (VLP) of porcine circovirus type 2 (PCV2), wherein said expression system comprises: a mammalian cell; plasmid containing the PCV2 gene coding capsid protein, wherein said capsid protein contains the amino acid sequence SEQ ID NO: 4 and/or said capsid protein is encoded by nucleotide sequence SEQ ID NO: 3; wherein said mammalian cell is transfected with said plasmid; and wherein said expression system produces recombinant VLP PCV2, and wherein said capsid protein is modified by a secretion signal sequence introduced at the NH2-end of said capsid protein. Disclosed is a method of producing porcine circovirus type 2 (PCV2) virus-like particles (VLP), comprising: providing a suspension of cultured mammalian cells; transfection of said mammalian cells with a plasmid containing the PCV2 gene, coding capsid protein, wherein said capsid protein contains the amino acid sequence SEQ ID NO: 4 and/or said capsid protein is encoded by nucleotide sequence SEQ ID NO: 3, and wherein said capsid protein is modified with a secretion signal sequence introduced at the NH2-terminus of said capsid protein; addition of sodium salt of valproic acid (VPA) to transfected mammalian cells, wherein the addition of the sodium salt of VPA inhibits cell proliferation; centrifuging and washing transfected mammalian cells; suspending the centrifuged mammalian cells in phosphate buffered saline (PBS); carrying out several cycles of freezing and thawing of mammalian cells; ultrasound treatment of mammalian cells in several cycles; and performing two successive cycles of centrifugation of mammalian cells to obtain VLP PCV2, wherein most of the produced VLP PCV2 are present in the mammalian cell nucleus. Disclosed is a recombinant virus-like particle of porcine circovirus type 2 (VLP PCV2), wherein the capsid protein included in said PCV2 VLP is modified by the secretion signal sequence introduced at the NH2-end of said capsid protein and wherein said capsid protein comprises the amino acid sequence SEQ ID NO: 4 and/or said capsid protein is encoded by nucleotide sequence SEQ ID NO: 3.

EFFECT: invention widens the range of means of producing recombinant virus-like particles for inducing an immune response.

18 cl, 2 tbl, 25 dwg, 2 ex