Modified H5 promoter improves stability of insert genes while maintaining immunogenicity during extended passage of genetically engineered MVA vaccines.
We have engineered recombinant (r) Modified Vaccinia Ankara (MVA) to express multiple antigens under the control of either of two related vaccinia synthetic promoters (pSyn) with early and late transcriptional activity or the modified H5 (mH5) promoter which has predominant early activity. We sequentially passaged these constructs and analyzed their genetic stability by qPCR, and concluded that rMVA expressing multiple antigens using the mH5 promoter exhibit remarkable genetic stability and maintain potent immunogenicity after serial passage. In contrast, rMVA expressing antigens using engineered vaccinia synthetic E/L (pSyn I or II) promoters are genetically unstable. Progressive accumulation of antigen loss variants resulted in a viral preparation with lower immunogenicity after serial passage. Metabolic labeling, followed by cold chase revealed little difference in stability of proteins expressed from mH5 or pSyn promoter constructs. We conclude that maintenance of genetic stability which is achieved using mH5, though not with pSyn promoters, is linked to timing, not the magnitude of expression levels of foreign antigen, which is more closely associated with immunogenicity of the vaccine.
Wang
Zhongde
Z
Division of Translational Vaccine Research, Department of Virology, Beckman Research Institute of the City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA.
Martinez
Joy
J
Zhou
Wendi
W
La Rosa
Corinna
C
Srivastava
Tumul
T
Dasgupta
Anindya
A
Rawal
Ravindra
R
Li
Zhongqui
Z
Britt
William J
WJ
Diamond
Don
D
D000818:Animals; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D005822:Genetic Vectors; D042822:Genomic Instability; D006564:Herpesviridae / Q000235:genetics; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA; D012692:Serial Passage; D014612:Vaccines / Q000235:genetics* / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology; D014616:Vaccinia virus / Q000235:genetics*
D004279:DNA, Viral; D014612:Vaccines; D014614:Vaccines, Synthetic