Enhanced-Transient Expression of Hepatitis C Virus Core Protein in Nicotiana tabacum, a Protein With Potential Clinical Applications

Mohammadzadeh, Sara; Khabiri, Alireza; Roohvand, Farzin; Memarnejadian, Arash; Salmanian, Ali Hatef; Ajdary, Soheila; Ehsani, Parastoo

Taken together, the present study was the first (to our best of knowledge) to address construction of a transient tobacco expression system for HCVcp. For highest possible expression efficiency, the HCVcp DNA sequence was codon optimized (based on the CAI for nuclear-encoded genes of tobacco), destabilizing of the GGTAAG sequence in the native HCVcp coding sequence was altered and Kozak and KDEL sequences were included at the 5' and 3' ends, respectively. Two types of plant expression vectors (PVX-based and classic pBI121 binary) for HCVcp were constructed and their levels of protein expression in the presence and absence of P19 co-agroinfiltration were compared. The results indicated the significant effect of our approach in enhancement of the expression levels for pHCVcp. To our knowledge, all the above mentioned reports were first of their kinds for HCVcp and provided valuable information for plant-based expression studies on this antigen. The preliminary results (with five HCV positive sera) showed that plant-HCVcp has the capability to capture anti-HCVcp antibodies for potential clinical applications which should be further evaluated and confirmed by statistically acceptable numbers of positive sample sera. The next steps might be standardization of pHCVcp for application in diagnostic ELISA through application of positive sera with determined viral loads as well as precisely predetermined standard positive sera together with high number of optimization studies with different concentrations of antigen/antibody in ELISA with precise statistical analyses and evaluation of the pHCVcp for immunization studies.