en بیوتکنولوژی Biotechnology پژوهشي Research <p style="text-align: justify;"><strong>Background: </strong>The potential of plants, as a safe and eukaryotic system, is considered in the production of 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. In this study, we investigated the effect of p19 silencing suppressor on recombinant human nerve growth factor expression in <em>Nicotiana benthamiana.</em></p> <p style="text-align: justify;"><strong>Materials and Methods: </strong>The p19 coding region was inserted in the pCAMBIA using NcoI and BstEII recognition sites. Also, the cloned synthesized recombinant human <em>NGF (rhNGF)</em> fragment was cloned directly into PVX vector by ClaI and SalI restriction enzymes. The co-agroinfiltration of rhNGF with p19 viral suppressor of gene silencing was evaluated by dot-blot and SDS-PAGE. The amount of expressed rhNGF protein was calculated by AlphaEaseFC software.</p> <p style="text-align: justify;"><strong>Results: </strong>Co-agroinfiltration of <em>hNGF</em> with <em>P19</em> suppressor showed about forty-fold increase (8% total soluble protein (TSP)) when compared to the absence of P19 suppressor (0.2%TSP).</p> <p style="text-align: justify;"><strong>Conclusion:</strong> 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 <em>Nicotiana benthamiana</em> manifold.</p> Nerve growth Factor, Nicotiana benthamiana, p19 suppressor of gene-silencing, Recombinant therapeutic human protein, Tomato bushy stunt virus. 35 40 http://rmm.mazums.ac.ir/browse.php?a_code=A-10-837-1&slc_lang=en&sid=1 Maryam Zangi zangi.m@irost.ir 10031947532846005369 10031947532846005369 No Department of Biotechnology, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran. Hamideh Ofoghi ofoghi@irost.ir 10031947532846005370 10031947532846005370 Yes Department of Biotechnology, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran. Zahra Amini-Bayat Amini-Bayat@irost.ir 10031947532846005371 10031947532846005371 No Department of Biotechnology, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran. Parastoo Ehsani P_ehsani@pasteur.ac.ir 10031947532846005372 10031947532846005372 No Molecular Biology Unit, Pasteur Institute of Iran, Tehran, Iran.