Transgenic chloroplasts are efficient sites for high-yield production of the vaccinia virus envelope protein A27L in plant cells

M. Manuela Rigano, Carmela Manna, Anna Giulini, Emanuela Pedrazzini, Maria Capobianchi, Concetta Castilletti, Antonino Di Caro, Giuseppe Ippolito, Paola Beggio, Carlo De Giuli Morghen, Luigi Monti, Alessandro Vitale, Teodoro Cardi

Research output: Contribution to journalArticlepeer-review


Orthopoxviruses (OPVs) have recently received increasing attention because of their potential use in bioterrorism and the occurrence of zoonotic OPV outbreaks, highlighting the need for the development of safe and cost-effective vaccines against smallpox and related viruses. In this respect, the production of subunit protein-based vaccines in transgenic plants is an attractive approach. For this purpose, the A27L immunogenic protein of vaccinia virus was expressed in tobacco using stable transformation of the nuclear or plastid genome. The vaccinia virus protein was expressed in the stroma of transplastomic plants in soluble form and accumulated to about 18% of total soluble protein (equivalent to approximately 1.7 mg/g fresh weight). This level of A27L accumulation was 500-fold higher than that in nuclear transformed plants, and did not decline during leaf development. Transplastomic plants showed a partial reduction in growth and were chlorotic, but reached maturity and set fertile seeds. Analysis by immunofluorescence microscopy indicated altered chlorophyll distribution. Chloroplast-synthesized A27L formed oligomers, suggesting correct folding and quaternary structure, and was recognized by serum from a patient recently infected by a zoonotic OPV. Taken together, these results demonstrate that chloroplasts are an attractive production vehicle for the expression of OPV subunit vaccines.

Original languageEnglish
Pages (from-to)577-591
Number of pages15
JournalPlant Biotechnology Journal
Issue number6
Publication statusPublished - Aug 2009


  • A27L
  • Chloroplast transformation
  • Plant vaccine
  • Smallpox vaccine
  • Tobacco
  • Transgenic plants

ASJC Scopus subject areas

  • Plant Science
  • Biotechnology
  • Agronomy and Crop Science


Dive into the research topics of 'Transgenic chloroplasts are efficient sites for high-yield production of the vaccinia virus envelope protein A27L in plant cells'. Together they form a unique fingerprint.

Cite this