Expression of a synthetic E. coli heat-labile enterotoxin B sub-unit (LT-B) in maize

Rachel Chikwamba, Jennifer McMurray, Huixia Shou, Bronwyn Frame, Sue Ellen Pegg, Paul Scott, Hugh Mason, Kan Wang

Research output: Contribution to journalArticle

40 Citations (Scopus)

Abstract

We have produced the B subunit of the enterotoxigenic Escherichia coli (ETEC) heat-labile enterotoxin (LT-B) in transgenic maize seed. LT-B is a model antigen that induces a strong immune response upon oral administration and enhances immune responses to conjugated and co-administered antigens. Using a synthetic LT-B gene with optimized codon sequence, we examined the role of promoters and the SEKDEL endoplasmic reticulum retention motif in LT-B accumulation in callus and in kernels. Two promoters, the constitutive CaMV 35S promoter and the maize 27 kDa gamma zein promoter, which directs endosperm-specific gene expression in maize kernels, regulated LT-B expression. Ganglioside-dependent ELISA analysis showed that using the constitutive promoter, maximum LT-B level detected in callus was 0.04% LT-B in total aqueous-extractable protein (TAEP) and 0.01% in R1 kernels of transgenic plants. Using the gamma zein promoter, LT-B accumulation reached 0.07% in R1 kernels. The SEKDEL resulted in increased LT-B levels when combined with the gamma zein promoter. We monitored LT-B levels under greenhouse and field conditions over three generations. Significant variability in gene expression was observed between transgenic events, and between plants within the same event. A maximum of 0.3% LT-B in TAEP was measured in R3 seed of a transgenic line carrying CaMV 35S promoter/LT-B construct. In R3 seed of a transgenic line carrying the gamma zein promoter/LT-B construct, up to 3.7% LT-B in TAEP could be detected. We concluded that maize seed can be used as a production system for functional antigens.

Original languageEnglish (US)
Pages (from-to)253-265
Number of pages13
JournalMolecular Breeding
Volume10
Issue number4
DOIs
StatePublished - 2002
Externally publishedYes

Fingerprint

Zein
enterotoxins
Zea mays
Seed
Seeds
promoter regions
gamma-zein
Escherichia coli
heat
corn
Bony Callus
Antigens
Gene expression
seeds
Gene Expression
Enterotoxigenic Escherichia coli
genetically modified organisms
Endosperm
Proteins
Gangliosides

Keywords

  • Functional antigen
  • Gene expression
  • LT-B
  • Zea mays

ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Horticulture
  • Biotechnology
  • Plant Science
  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry

Cite this

Chikwamba, R., McMurray, J., Shou, H., Frame, B., Pegg, S. E., Scott, P., ... Wang, K. (2002). Expression of a synthetic E. coli heat-labile enterotoxin B sub-unit (LT-B) in maize. Molecular Breeding, 10(4), 253-265. https://doi.org/10.1023/A:1020509915672

Expression of a synthetic E. coli heat-labile enterotoxin B sub-unit (LT-B) in maize. / Chikwamba, Rachel; McMurray, Jennifer; Shou, Huixia; Frame, Bronwyn; Pegg, Sue Ellen; Scott, Paul; Mason, Hugh; Wang, Kan.

In: Molecular Breeding, Vol. 10, No. 4, 2002, p. 253-265.

Research output: Contribution to journalArticle

Chikwamba, R, McMurray, J, Shou, H, Frame, B, Pegg, SE, Scott, P, Mason, H & Wang, K 2002, 'Expression of a synthetic E. coli heat-labile enterotoxin B sub-unit (LT-B) in maize', Molecular Breeding, vol. 10, no. 4, pp. 253-265. https://doi.org/10.1023/A:1020509915672
Chikwamba, Rachel ; McMurray, Jennifer ; Shou, Huixia ; Frame, Bronwyn ; Pegg, Sue Ellen ; Scott, Paul ; Mason, Hugh ; Wang, Kan. / Expression of a synthetic E. coli heat-labile enterotoxin B sub-unit (LT-B) in maize. In: Molecular Breeding. 2002 ; Vol. 10, No. 4. pp. 253-265.
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