Enterovirus 71 virus-like particle vaccine: improved production conditions for enhanced yield.
To develop the enterovirus 71 (EV71) vaccine, we previously constructed a recombinant baculovirus (Bac-P1-3CD) co-expressing EV71 P1 (under polyhedrin promoter) and 3CD (under p10 promoter) proteins, which caused P1 cleavage by 3CD protease and self-assembly of virus-like particles (VLPs) in Sf-9 cells. Assuming that reducing the 3CD expression can alleviate the competition with P1 expression and elevate the VLPs yield, hereby we constructed Bac-P1-C3CD and Bac-P1-I3CD expressing 3CD under weaker CMV and IE-1 promoters, respectively. Western blot and ELISA analyses revealed that Bac-P1-C3CD and Bac-P1-I3CD led to the VLPs release into the supernatant and enhanced the extracellular VLPs yield in Sf-9 cells, but gave poor VLPs production in High Five™ (Hi-5) cells. By optimizing the process parameters including host cells, cell density, culture mode and dissolved oxygen (DO), the best extracellular VLPs yield was achieved by infecting Sf-9 cells (4 × 10(6)cells/mL) cultured in the bioreactor (DO=30%) with Bac-P1-C3CD, which approached ≈64.3mg/L and represented a ≈43-fold increase over the yield (1.5mg/L) attained using the old process (Bac-P1-3CD infection of Sf-9 cells in the spinner flasks). The resultant VLPs not only resembled the VLPs produced from Bac-P1-3CD infection in density, size and shape, but also induced potent antibody responses in mouse models. The antibodies neutralized EV71 strains of homologous and heterologous genogroups, implicating the potential of the VLPs to confer cross-protection for the prevention of future epidemics. Altogether, Bac-P1-C3CD and the bioprocess render mass production more economical, obviate the need for cell lysis and hold promise for future industrial vaccine production.
Chung
Cheng-Yu
CY
Department of Chemical Engineering, National Tsing Hua University, 101, Sec. 2, Kuang Fu Rd., Hsinchu 300, Taiwan.
Chen
Chi-Yuan
CY
Lin
Shih-Yeh
SY
Chung
Yao-Chi
YC
Chiu
Hsin-Yi
HY
Chi
Wei-Kuang
WK
Lin
Yu-Li
YL
Chiang
Bor-Luen
BL
Chen
Wei-Jheng
WJ
Hu
Yu-Chen
YC
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D016367:Baculoviridae / Q000235:genetics; D019149:Bioreactors; D002452:Cell Count; D018929:Cell Culture Techniques; D002460:Cell Line; D029821:Enterovirus A, Human / Q000302:isolation & purification*; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D018411:Spodoptera / Q000166:cytology; D058425:Vaccines, Virus-Like Particle / Q000096:biosynthesis*; D014765:Viral Vaccines / Q000096:biosynthesis*; D014776:Virus Cultivation / Q000379:methods
D000914:Antibodies, Viral; D058425:Vaccines, Virus-Like Particle; D014765:Viral Vaccines