Oral administration of recombinant human granulocyte-macrophage colony stimulating factor expressed in rice endosperm can increase leukocytes in mice

Abstract

Human granulocyte-macrophage colony stimulating factor (hGM-CSF) is used clinically to treat leucopenia typically caused by cancer chemotherapy or radiotherapy. This study used multiple strategies to obtain very high expression levels of OsrhGM-CSF (14 microg/seed) in rice endosperm. Electron micrographs of immunogold-labeled transgenic endosperm showed that rhGM-CSF was not only localized in protein bodies but was also distributed in the apoplast. A biological activity assay indicated that OsrhGM-CSF stimulated the growth of TF-1 cells in vitro. In addition, the transgene was used to effectively treat leucopenia by oral administration of the unprocessed transgenic grains. In cyclophosphamide-induced leucopenic mice, transgenic seeds produced a 27% (t=0.021) gain in leukocytes after 14 days feeding. Even in non-leucopenic mice, leukocyte gain was 37% (t=0.002) more than that of mice fed non-transgenic seeds. This study provides a novel approach to the use of oral unprocessed transgenic OsrhGM-CSF seeds to treat leucopenia.

Large-scale production of functional human serum albumin from transgenic rice seeds

“…To obtain high expression levels of rHSA and to ensure cost-effective production, a strong endosperm-specific promoter, Gt13a and its signal peptide (26) were used to target rHSA into the protein storage vacuoles. Rice-preferred gene codons were used for transcription of the HSA gene (Fig.…”

“…Plasmids used in this study are described in the SI Materials and Methods or have been previously reported (26,46). Transgenic lines expressing rHSA were obtained by Agrobacterium-mediated transformation as described previously (47).…”

An alternatively spliced heat shock transcription factor, OsHSFA2dI, functions in the heat stress‐induced unfolded protein response in rice

“…To create the reporter constructs P OsAPX2 :GUS, P OsIRE1 :GUS, P OsBiP1 : GUS and P OsbZIP60 :GUS, promoter regions of approximately 1.5 kb in length that included the 5 0 upstream regions were amplified from genomic DNA using PCR. The PCR products were digested with HindIII/SmaI, HindIII/NaeI, SphI/NaeI and SphI and these fragments were then cloned into the Gt13a:GUS vector (Ning et al 2008) to replace the Gt13a promoter. The pAHC18 vector (Christensen & Quail 1996), which contains the luciferase gene driven by a ubiquitin promoter, was used as an internal control.…”

Expression of a Functional Recombinant Human Basic Fibroblast Growth Factor from Transgenic Rice Seeds

“…Low yields, complicated processing and insolubility have been encountered when meeting the demand of the markets, especially, with an increasing number of applications for cell therapy and translational medicine. Recently, rice endosperm has been reported to express various recombinant pharmaceutical proteins, including human lactoferrin [12], human lysozyme [13], rhIGF-1 fusion, human granulocyte-macrophage colony stimulating factor [14] and human serum albumin [15]. These results showed that it is cost effective, safe, easy to scale-up and simpler to process than animal and other plant cell expression systems.…”