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Whitelaw CB, Farini E, Webster J. The changing role of cell culture in the generation of transgenic livestock. Cytotechnology 2008; 31:3-8. [PMID: 19003119 DOI: 10.1023/a:1008044517150] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Transgenesis may allow the generation of farm animals with altered phenotype, animal models for research and animal bioreactors. Although such animals have been produced, the time and expense involved in generating transgenic livestock and then evaluating the transgene expression pattern is very restrictive. If questions about the ability and efficiency of expression could be asked solely in vitro rapid progress could be achieved. Unfortunately, experiments addressing transcriptional control in vitro have proved unreliable in their ability to indicate whether a transgene will be transcribed or not. However, initial studies suggest that cell culture may be able to predict in vivo post-transcriptional events. We review these issues and propose that strategies which engineer the transgene integration site could enhance the probability for efficient expression. This approach has now become feasible with the development of techniques allowing animals to be generated from somatic cells by nuclear transfer. The important step in this procedure is the use of cells grown in culture as the source of genetic information, allowing the selection of specific transgene integration events. This technology which has dramatically increased the potential use of transgenic livestock for both agricultural and biotechnological applications, is based on standard cell culture methodology. We are now at the start of a new era in large animal transgenics.
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Peng SY, Lv N, Zhang Y, Bi CM, Cao JW, Li ZY, Zhang SQ, He XN. Immune response induced by spike protein from transmissible gastroenteritis coronavirus expressed in mouse mammary cells. Virus Res 2007; 128:52-7. [PMID: 17532081 PMCID: PMC7114266 DOI: 10.1016/j.virusres.2007.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2006] [Revised: 04/02/2007] [Accepted: 04/03/2007] [Indexed: 11/29/2022]
Abstract
The present study is undertaken to investigate the immune response that was induced by the recombinant spike (S) protein from swine-transmissible gastroenteritis virus (TGEV) expressed in mouse mammary cells. A mammary-specific expression vector pEBS containing the full-length cDNA of S gene was constructed and expressed in the mouse mammary cells (EMT6). The recombinant S protein from culture supernatant of transgenic EMT6 was harvested and immunized BALB/c mice. The results demonstrated recombinant S protein was expressed at high levels in mammary cells by Western blotting and enzyme-linked immunosorbent assay (ELISA) detection. The antibody titer in BALB/c mice following immunization with recombinant S protein was detectable after the first immunization. Maximum titers of antibody (8.86 ± 0.19 ng/ml of serum) were attained after the second immunization. In conclusion, the recombinant S protein expressed in mammary cells was able to elicit substantial immunological response against TGEV. This lays the basis for using mammary gland bioreactor generating edible vaccine.
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Affiliation(s)
- Shu-Ying Peng
- Institute of Biotechnology, Northwest Agriculture and Forestry University, NO. 3 TaiCheng Road, Yangling 712100, PR China
| | - Ning Lv
- Institute of Biotechnology, Northwest Agriculture and Forestry University, NO. 3 TaiCheng Road, Yangling 712100, PR China
| | - Yong Zhang
- Institute of Biotechnology, Northwest Agriculture and Forestry University, NO. 3 TaiCheng Road, Yangling 712100, PR China
- Corresponding author. Tel.: +86 29 87080085; fax: +86 29 87080085.
| | - Cong-Ming Bi
- Institute of Biotechnology, Northwest Agriculture and Forestry University, NO. 3 TaiCheng Road, Yangling 712100, PR China
- Department of Veterinary Science, Jinzhou Medical University, 40/3 SongPo Road, Jinzhou 121001, PR China
| | - Jun-Wei Cao
- Institute of Biotechnology, Northwest Agriculture and Forestry University, NO. 3 TaiCheng Road, Yangling 712100, PR China
- College of Bioengineering, Inner Mongolia Agricultural University, No. 306, Zhao Wu Da Street, Hohhot 010018, Inner Mongolia, PR China
| | - Zhi-Yan Li
- Institute of Biotechnology, Northwest Agriculture and Forestry University, NO. 3 TaiCheng Road, Yangling 712100, PR China
| | - Shi-Qiang Zhang
- Institute of Biotechnology, Northwest Agriculture and Forestry University, NO. 3 TaiCheng Road, Yangling 712100, PR China
| | - Xiao-Ning He
- Institute of Biotechnology, Northwest Agriculture and Forestry University, NO. 3 TaiCheng Road, Yangling 712100, PR China
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Whitelaw CBA, Hiripi L, Farini E, Opsahl ML, Bosze Z. On the use of post-transcriptional processing elements in transgenes. Transgenic Res 2004; 13:75-9. [PMID: 15070078 PMCID: PMC7089212 DOI: 10.1023/b:trag.0000017178.79427.2c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
RNA processing events modulate final productivity of a given transgene. We have evaluated a series of RNA elements for their ability to enhance α1-antitrypsin production in mammary cells. Our results indicate the need for a case-by-case assessment of each construct design and the occurrence of gene silencing events in vivo.
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Affiliation(s)
- C B A Whitelaw
- Department of Gene Expression and Development, Roslin Institute (Edinburgh), Roslin, Midlothian, EH25 9PS, UK.
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Clark AJ. The mammary gland as a bioreactor: expression, processing, and production of recombinant proteins. J Mammary Gland Biol Neoplasia 1998; 3:337-50. [PMID: 10819519 DOI: 10.1023/a:1018723712996] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A variety of transgenic animal species are being used to produce recombinant proteins. The general approach is to target the expression of the desired protein to the mammary gland using regulatory elements derived from a milk protein gene and then collect and purify the product from milk. Promoter sequences from a number of different milk protein genes have been used to target expression to the mammary gland, although significant problems remain with regard to achieving transgene expression levels consistent with commercial exploitation. The mammary gland appears to be capable of carrying out the complex posttranslational modifications. such as glycosylation and gamma-carboxylation required for the biological activity and stability of specific proteins. Effective purification protocols have been established and products produced by this route have now entered clinical trials.
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Affiliation(s)
- A J Clark
- Division of Molecular Biology, Roslin Institute, Midlothian, Scotland.
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