Expression of cholera toxin B–proinsulin fusion protein in lettuce and tobacco chloroplasts – oral administration protects against development of insulitis in non‐obese diabetic mice

Abstract

SummaryLettuce and tobacco chloroplast transgenic lines expressing the cholera toxin B subunithuman proinsulin (CTB-Pins) fusion protein were generated. CTB-Pins accumulated up to ~16% of total soluble protein (TSP) in tobacco and up to ~2.5% of TSP in lettuce. Eight This opens up the possibility for the low-cost production and delivery of human therapeutic proteins, and a strategy for the treatment of various other autoimmune diseases.

Enhanced green fluorescent protein (egfp) gene expression in Tetraselmis subcordiformis chloroplast with endogenous regulators

“…It is generally accepted that the efficiency of regulatory elements (promoters) is higher than foreign promoters for chloroplast transformation (Fukuda et al 2008;Ruhlman et al 2010;Wei et al 2012). Prrn (Svab and Maliga 1993;Sidorov et al 1999), PpsbA (Li et al 2011), TpsbA (Svab and Maliga 1993;Sidorov et al 1999), and TrbcL (Doetsch et al 2001;Cui et al 2014) are commonly used endogenous regulators.…”

“…Prrn (Svab and Maliga 1993;Sidorov et al 1999), PpsbA (Li et al 2011), TpsbA (Svab and Maliga 1993;Sidorov et al 1999), and TrbcL (Doetsch et al 2001;Cui et al 2014) are commonly used endogenous regulators. Prrn, as a promoter, is derived from plastid-encoded 16S RNA, and TpsbA, as a terminator, comes from the psbA gene that encodes endogenous PS II protein D1 (Ruhlman et al 2010). Furthermore, Prrn is a strong rRNA operon promoter that usually drives transgenic expression (Kuroda and Maliga 2001).…”

“…Chloroplast transformation has many advantages, such as high expression concentrations of foreign genes (De Cosa et al 2001), the homologous integration of foreign genes, and coexpression of multigenes (Quesada-Vargas et al 2005;Ruhlman et al 2007). Thus, in T. subcordiformis, it is possible to obtain high chloroplast expression of foreign nutrient-related protein.…”

Transgenic Expression and Identification of Recombinant Human Proinsulin in Peanut

“…From 2004 to 2013, biopharmaceuticals were largely derived from E. Coli (24%), yeast (13%), mammalian cells (56%), transgenic animals and plant expression systems (3%) and insect cells (4%) (Gurramkonda et al 2010;Qian et al 2011;Walsh 2012;Nielsen 2013;Walsh 2013;Baeshen et al 2014). Transgenic plant expression systems have attracted attention due to advantages such as high-capacity production, safety, inexpensive investment, and fast and easy scale-up (Arakawa et al 1998;Ruhlman et al 2007;Xie et al 2008;Boothe et al 2010;Boyhan and Daniell 2011;Soltanmohammadi et al 2014). Transgenic seeds and leaves exhibit long-term stability and can be used to stockpile insulin until it is needed.…”

“…Nykiforuk et al expressed an insulin-oleosin fusion in Arabidopsis thaliana seeds, and the insulin that accumulated in the transgenic seeds could significantly reduce glucose levels to a similar extent as commercially available insulin ). Ruhlman et al expressed a recombinant cholera toxin Bproinsulin fusion protein (CTB-Pins) in lettuce and tobacco chloroplasts, in which CTB-Pins accounted for almost 16% and 2.5% of the total soluble protein, respectively (Ruhlman et al 2007;Boyhan and Daniell 2011). Interestingly, the transformed tobacco leaves were able to lower blood and urine glucose levels when administered orally to non-obese diabetic mice (Ruhlman et al 2007;Boyhan and Daniell 2011).…”