High‑level expression of nucleocapsid protein from Canine Distemper Virus in tobacco transplastomic plants

LAGUIA BECHER, MELINA; GALLO CALDERON, MARINA; CARINA ROMANUTTI; ANDREA TRENTINI; ALVAREZ, ALEJANDRA; JON VERAMENDI ; MARCONI, PATRICIA

Conferencia; International Conference On Plant Science and Molecular Biology; 2018

Meetings International

Canine Distemper Virus (CDV) produces ahighly contagious disease in domestic dogs and other wild animals. Althoughimmunization with attenuated CDV vaccines has been shown to be effective, inrecent years there has been an increase in the incidence of CDV infection,including vaccinated dogs. Therefore, a more effective vaccine formulationcontaining updated immunogens is necessary. The use of plants as biofactoriesfor the expression of antigens is an attractive alternative to producecost-effective subunits vaccines. In particular, chloroplast transplastomictechnology offers stable high-level of recombinant protein expression andtransgene containment. In this study, we evaluated the production of thenucleocapsid protein (NP) from an Argentinian CDV strain in transplastomictobacco plants. Protein expression analysis by Western blot showed the presenceof two specific bands in total protein extracts. The expected band of 62 kDafor NP represented approximately 60% of the signal in mature leaves.Furthermore, full-length NP was expressed mainly as an insoluble protein. Theconcentration of NP in young, mature and old leaves was estimated to be 6.2,4.4 and 6.7 % of total protein, equivalent to 1.2, 0.7 and 0.4 mg/g freshweight, respectively. We also evaluated the functionality of the plant-derivedNP in a murine model. Oral and subcutaneous immunization with transplastomicextracts elicited an increase of NP-specific serum antibodies compared withcontrol mice. Our results show that NP can be efficiently expressed intransplastomic tobacco plants and maintains its immunogenic properties.