[转移帖]植物源人血清白蛋白或可为疫苗制造带来福音

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原帖由论坛会员半拉木匠发表于 2012-3-17 11:07 | ：

Large-scale production of functional human serum albumin from transgenic rice seeds
Yang He,a Tingting Ning,a Tingting Xie,a Qingchuan Qiu,a Liping Zhang,a Yunfang Sun,a Daiming Jiang,a Kai Fu,a Fei Yin,b Wenjing Zhang,b Lang Shen,c Hui Wang,c Jianjun Li,d Qishan Lin,e Yunxia Sun,f Hongzhen Li,f Yingguo Zhu,a and Daichang Yanga1
aEngineering Research Center for Plant Biotechnology and Germplasm Utilization, Ministry of Education, State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China;
bHealthgen Biotechnology Ltd. Co., Wuhan 430074, China;
cBasic Medical School, Wuhan University, Wuhan 430072, China;
dInstitutes for Biological Sciences, National Research Council of Canada, Ottawa, ON, Canada K1A 0R6;
eProteomics and Mass Spectrometry Services, Center for Functional Genomics, University at Albany, Rensselaer, NY 12144; and
fJoinn Laboratory, Beijing 100176, China
1To whom correspondence should be addressed. E-mail: dyang@whu.edu.cn.
Edited* by Diter von Wettstein, Washington State University, Pullman, WA, and approved October 4, 2011 (received for review June 16, 2011)
Contributed by
Author contributions: Y.H. and D.Y. designed research; Y.H., T.N., T.X., Q.Q., L.Z., Yunfang Sun, D.J., K.F., F.Y., W.Z., L.S., H.W., J.L., Q.L., Yunxia Sun, H.L., and Y.Z. performed research; Y.H. analyzed data; and Y.H. and D.Y. wrote the paper.
Human serum albumin (HSA) is widely used in clinical and cell culture applications. Conventional production of HSA from human blood is limited by the availability of blood donation and the high risk of viral transmission from donors. Here, we report the production of Oryza sativa recombinant HSA (OsrHSA) from transgenic rice seeds. The level of OsrHSA reached 10.58% of the total soluble protein of the rice grain. Large-scale production of OsrHSA generated protein with a purity >99% and a productivity rate of 2.75 g/kg brown rice. Physical and biochemical characterization of OsrHSA revealed it to be equivalent to plasma-derived HSA (pHSA). The efficiency of OsrHSA in promoting cell growth and treating liver cirrhosis in rats was similar to that of pHSA. Furthermore, OsrHSA displays similar in vitro and in vivo immunogenicity as pHSA. Our results suggest that a rice seed bioreactor produces cost-effective recombinant HSA that is safe and can help to satisfy an increasing worldwide demand for human serum albumin.Keywords: crystal structure, recombinant human serum albumin, recombinant protein expression, rice endosperm, recombinant protein processing
Human serum albumin (HSA) is a soluble, globular, and unglycosylated monomeric protein; it functions primarily as a carrier protein for steroids, fatty acids, and thyroid hormones, and plays an important role in stabilizing extracellular fluid volume (1). HSA is widely used clinically to treat serious burn injuries, hemorrhagic shock, hypoproteinemia, fetal erythroblastosis, and ascites caused by cirrhosis of the liver (2, 3). HSA is also used as an excipient for vaccines or therapeutic protein drugs and as a cell culture medium supplement in the production of vaccines and pharmaceuticals (4). Many other novel uses for HSA in biological applications have recently been explored, such as carrier of oxygen (5), nanodelivery of drugs (6), and fusion of peptides (7).The market demand for HSA is estimated at more than 500 tons per year worldwide. Currently, commercial production of HSA is primarily based on collected human plasma, which is limited in supply but of high clinical demand, not the least in China. It was reported that the shortage of human plasma led to a rapid increase in price of HSA, which in turn resulted in fake albumin appearing on the market (8). Furthermore, there is an increasing public health concern with plasma-derived HSA (pHSA) with its potential risk for transmission of blood-derived infectious pathogens such as hepatitis and HIV (9, 10). In fact, illegal plasma collection has caused HIV to spread rapidly, creating what are known as AIDS villages in Henan Province in China (11). To eliminate the potential risk of viral contamination, regulatory agencies have encouraged pharmaceutical companies to use non–animal-derived sources for pharmaceutical production (12). Thus, the development of a low-cost method for the production of recombinant HSA (rHSA) is essential as a safer and potentially unlimited alternative to pHSA.Over the past decades, various expression systems have been used to produce rHSA, including Escherichia coli (13), Saccharomyces cerevisiae (14), Kluyveromyces lactis (15), Pichia pastoris (16), transgenic animals (17), and transgenic plants (18–21). Attempts to produce rHSA in tobacco leaves and potato tubers achieved expression levels of 0.02% of total soluble protein (TSP) (18), and expression was increased to 0.2% of TSP by targeting the rHSA to the apoplast of potato tubers (19). Recently, an expression level of 11.1% of TSP was obtained by expressing rHSA in tobacco leaf chloroplasts (20). More recently, an rHSA expression level of 11.5% of total proteins was achieved in a rice cell culture by a sugar starvation-induced promoter (21). Although rHSA has been successfully expressed in these systems, none of them has proven to be cost-effective at large scale.Plant seeds, especially cereal crop seeds, are promising vehicles for producing recombinant proteins, because they can achieve high accumulation of recombinant protein, display high levels of protein stability, stored for long periods of time, and are well controlled on a production scale (22, 23). Human lysozyme and lactoferrin produced for oral administration have been successfully expressed in rice seeds (24, 25). Here, we report rice seeds as a bioreactor for large-scale production of Oryza sativa recombinant HSA (OsrHSA). OsrHSA can be highly and stably expressed in rice seeds and can be processed cost-effectively. OsrHSA was found to be equivalent to pHSA in terms of biochemical properties, physical structure, functions, and immunogenicity.

ps：去年的文章，最近看了一下据说年产10公斤。