The invention discloses a novel Kdo-MPLA
adjuvant, and relates to the technical field of
synthetic biology, the
adjuvant is formed by connecting monophosphate
lipid A (MPLA) and Kdo
sugar through an alpha-glucosidic bond, MPLA is of a structure formed by modifying
salmonella lipid A through 4 '-site monophosphorylation, and the Kdo
sugar is endowed with amphipathy, so that the Kdo
sugar is self-assembled into
liposome nanoparticles in an
aqueous solution; the rfaC and eptA genes are double knocked out through a
gene editing
salmonella attenuated strain, wherein the rfaC knockout blocks the synthesis of LPS core
polysaccharide, and
lipid A-Kdo connection is reserved; knocking out eptA to obtain a monophosphorylated lipid A; after the
engineering bacteria are fermented, high-purity Kdo-MPLA is obtained by adopting a
phenol-
chloroform-
petroleum ether extraction method, the process is simplified, and the product is uniform; the
adjuvant can activate a TLR4
signal channel and induce Th1 type immune response, the levels of
inflammatory factors IL-6 and IL-1beta are remarkably lower than those of natural LPS, and the adjuvant is suitable for a mixed preparation of vaccine antigens such as HPV and
malaria; the method overcomes the defects of
hydrolysis uncontrollability and high
chemical synthesis cost of the traditional MPLA chemical extraction process.