Effect of plant host and signal peptide on anti-virus Griffithisn protein accumilation

The production of pharmaceutical compounds having role in treating diseases like AIDS is necessary. In this regard, griffithsin (GRFT) (an algae lectin) can inhibit HIV entry to the cell at picomolar concentration. To production of recombinant GRFT protein, alfalfa, soybean and lettuce were used as hosts for transient expression. Effect of KDEL, signal peptide of carrot extensin and SP subunit of ZERA signal peptide that target protein to endoplasmic reticulum, apoplastic space and space around the cell wall, respectively was studied. 72 hours after agroinfiltration, qRT- PCR analysis showed high potential of lettuce to express of GRFT at transcript level while alfalfa had lowest transcription level. ELISA result using polyclonal anti-mouse anti-GRFT antibody confirmed that targeting of GRFT to apoplast space of soybean led to highest amount of GRFT. Lettuce despite of high level of gene expression, showed low level of GRFT accumulation which may be due to posttranscriptional and post translational modifications. Our results suggest using of soybean leaf tissue for fast and reliable production of pharmaceutical using transient expression.