utility of p19 gene-silencing suppressor for high level expression of recombinant human therapeutic proteins in plant cells

background: the potential of plants as a safe and eukaryotic systems, are considered for producing recombinant therapeutic human protein today; but the expression level of heterologous proteins is limited by the post-transcriptional gene silencing (ptgs) response in this new technology. the use of viral suppressors of gene silencing can prevent ptgs and improve transient expression level of foreign proteins. materials and methods: in this study we investigated the effect of p19 silencing suppressor on recombinant human nerve growth factor expression in n. benthamiana. therefore, the p19 coding region was inserted in the downstream of the camv 35s promoter, and upstream of the nos terminator in the pcambia using ncoi and bsteii recognition sites. also, the cloned synthesized recombinant human ngf fragment was cloned directly into pvx vector by clai and sali restriction enzymes. the co-agroinfiltration of recombinant human ngf (rhngf) with p19 viral suppressor of gene silencing was evaluated by dot-blot and sds-page. the amount of expressed recombinant human ngf protein was calculated by alphaeasefc software. results: co-agroinfiltration of hngf with p19 suppressor showed about forty-fold increase (8%tsp) when compered to absence of p19 suppressor (0.2%tsp). conclusion: the results presented here confirmed that the use of p19 gene silencing suppressor derived from tomato bushy stunt virus (tbsv), could efficiently increase the transient expression of recombinant proteins in n. benthamiana manifold.