Sowing the seeds of success: pharmaceutical proteins from plants

Stöger, Eva; K.‐C., Julian; Fischer, Rainer; Christou, Paul

doi:10.1016/j.copbio.2005.01.005

Cited by 311 publications

(239 citation statements)

References 49 publications

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“…The advantages of plants over fermenter-based systems are described in refs. 18, 19, and 36, but, in the context of our study, the most important benefits of using maize seeds include the enhanced stability of recombinant proteins accumulating in the endosperm, which means that a cold chain is not necessary for product distribution (17,37,38), and the economy of large-scale production both in terms of the upstream phase and downstream processing, which will make the product affordable without detracting from its safety or performance (17,21). …”

Section: Discussionmentioning

confidence: 99%

“…Among the alternative systems available for biopharmaceutical manufacture, only plants provide the scalability and economy required to meet the anticipated demand for such products in the HIV-endemic regions of Africa and Asia at a price the market can bear (17)(18)(19)(20). Cereal seeds are likely to be the most suitable platform for deployment in such areas, because the infrastructure for large-scale cultivation and harvesting is already in place, and the dry seeds favor product stability (21).…”

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confidence: 99%

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Cost-effective production of a vaginal protein microbicide to prevent HIV transmission

Ramessar

Rademacher

Sack

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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148

124

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A series of small-molecule microbicides has been developed for vaginal delivery to prevent heterosexual HIV transmission, but results from human clinical trials have been disappointing. Proteinbased microbicides, such as HIV-specific monoclonal antibodies, have been considered as an alternative approach. Despite their promising safety profile and efficacy, the major drawback of such molecules is the economy of large-scale production in mammalian cells, the current system of choice. Here, we show that an alternative biomanufacturing platform is now available for one of the most promising anti-HIV antibodies (2G12). Our data show that the HIV-neutralization capability of the antibody is equal to or superior to that of the same antibody produced in CHO cells. We conclude that this protein production system may provide a means to achieve microbicide ingredient manufacture at costs that would allow product introduction and manufacture in the developing world.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Cost-effective production of a vaginal protein microbicide to prevent HIV transmission

Ramessar

Rademacher

Sack

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

148

124

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“…Management of many resistance genes on different chromosomes by traditional gene transformation would be cumbersome. There are many other desirable genes that could also be placed on the minichromosomes, such as stress tolerance genes, antibodies, vaccines, and other pharmaceutical proteins of medicinal value (27). With the previous demonstration of transformation and site-specific integration of large inserts (23,28,29), it should be possible to target minichromosomes with a complex of foreign genes or even biochemical pathways to generate complicated products (30,31) from the minichromosome platform.…”

Section: Discussionmentioning

confidence: 99%

Construction and behavior of engineered minichromosomes in maize

Han

Gao

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

136

138

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Engineered minichromosomes were constructed in maize by modifying natural A and supernumerary B chromosomes. By using telomere-mediated chromosomal truncation, it was demonstrated that such an approach is feasible for the generation of minichromosomes of normal A chromosomes by selection of spontaneous polyploid events that compensate for the deficiencies produced. B chromosomes are readily fractionated by biolistic transformation of truncating plasmids. Foreign genes were faithfully expressed from integrations into normal B chromosomes and from truncated miniB chromosomes. Site-specific recombination between the terminal transgene on a miniA chromosome and a terminal site on a normal chromosome was demonstrated. It was also found that the miniA chromosome did not pair with its progenitor chromosomes during meiosis, indicating a useful property for such constructs. The miniB chromosomes are faithfully transmitted from one generation to the next but can be changed in dosage in the presence of normal B chromosomes. This approach for construction of engineered chromosomes can be easily extended to other plant species because it does not rely on cloned centromere sequences, which are species-specific. These platforms will provide avenues for studies on plant chromosome structure and function and for future developments in biotechnology and agriculture.artificial chromosomes ͉ FISH ͉ genetic engineering ͉ telomere truncation A rtificial chromosomes involving de novo centromere formation on an independently assembled unit and engineered minichromosomes produced by telomere truncation provide striking advantages over traditional methods of gene transformation in yeast and mammalian cells (1-5). The development of such chromosomes in plants would provide these advantages for many applications in basic studies, biotechnology, and agriculture. These chromosomes could be used as independent platforms for foreign gene expression without random integration into the normal chromosomes. Further additions of unlimited amounts of DNA could be added to these platforms in a sequential manner via different site-specific recombination cassettes. Genes introduced in this way would be present in a defined context and thus could be expressed at a more predictable level than through random integration (6). Hence, additional genes, multigene complexes, or even whole metabolic pathways could potentially be added to a genotype. Moreover, engineered or artificial chromosomes could be easily introduced or removed from a genotype by genetic crosses and would facilitate introgression of transgenes to different genetic backgrounds.To extend engineered chromosome technology to plants, we developed a method of telomere-mediated chromosomal truncation in maize by Agrobacterium-mediated transformation of constructs with multiple copies of the telomere sequence (7). Here, we report the use of this technology to produce minichromosome platforms by truncating both normal A and supernumerary B maize chromosomes and at the same time introducing site-spe...

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“…For some pharmaceutical proteins expressed in plant systems, yields have varied from 0.01% to 1% of TSP (Hood et al, 2002), and have even been as low as 0.0001% of TSP . Thus, one of the key challenges for recombinant protein production in transgenic plants is the employment of effective strategies to enhance expression levels, which is a requirement for economic effi ciency (Hood et al, 2002;Fischer et al, 2004;Stoger et al, 2005). Different organisms use synonymous codons with different preferences, and the codons in the target gene can be altered to adapt codon usage of host and subsequently improve heterologous protein expression.…”

Section: Discussionmentioning

confidence: 99%

High-level expression of modified gene encoding human adiponectin in transgenic rice

2011

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Adiponectin is a polypeptide specifi cally secreted from human adipocytes, and its defi ciency is closely linked to increased obesity and type II diabetes. There is an urgent demand for large-scale production of human adiponectin for pharmaceutical applications. Here, we report that we have successfully obtained a high-level of expression of modifi ed genes encoding human adiponectin in transgenic rice. The 735 bp cDNA of the native human sequence was adopted to rice codon usage, fused to the translation initiation sequence in the N terminus and to the KDEL signal sequence in the C terminus. An amplifi cation promoting sequence acting as an enhancer of transcription was also introduced to enhance gene expression. The presence of the transgene and mRNA transcripts was confi rmed by PCR, Southern blot and RT-PCR. Western blot analysis revealed that a protein of approximately 30 kDa was produced in rice leaves. ELISA analysis was used to determine the amount of recombinant adiponectin in transformants with the modifi ed gene in up to 0.32% of total soluble leaf protein. Our results establish the feasibility of high-level expression of recombinant human adiponectin in transgenic rice.

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Sowing the seeds of success: pharmaceutical proteins from plants

Cited by 311 publications

References 49 publications

Cost-effective production of a vaginal protein microbicide to prevent HIV transmission

Cost-effective production of a vaginal protein microbicide to prevent HIV transmission

Construction and behavior of engineered minichromosomes in maize

High-level expression of modified gene encoding human adiponectin in transgenic rice

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