15 January 2002
GE CROPS ARE NOT NEEDED, SAYS EXPERT
Delegates at the Oxford Conference rejected the motion that 30% of agricultural
land should be organic by 2010. Do you agree with them?
To vote, go to http://www.fwi.co.uk
The poll is half-way down the right hand side of the home page. If you think more agricultural land should be organic, you need to vote 'no'.
1. GE CROPS ARE NOT NEEDED, SAYS EXPERT
January 15, 2002
Australia's top agricultural educators met in Hobart yesterday where keynote speaker Associate Professor Roger Packam was cited as calling for more caution over genetic engineering.
Professor Packam, of the University of Western Sydney, was cited as praising Tasmania's two-year moratorium on open-field GE crop trials. He tabled a report on world farming systems for the next decade, and said access to food is the issue - not productivity, adding, "Genetically engineered crops are not needed to feed the world. There is ample evidence that consumers do not want to purchase the products of GE organisms."
He said economics was driving the global push towards GE, as multinational companies eyed new markets in selling patented GE seed and associated chemicals.
2. foolhardy testing of GM crop pharmaceuticals
January 14, 2002
Prof. Joe Cummins
"Genetically modified crops producing pharmaceutical products may produce undesirable side effects as environmental pollutants"
The production of pharmaceutical products using genetically modified (GM) crops is one of the major areas of emphasis of crop genetic engineering. The abstracts of two papers below shows that GM crops producing pharmaceutical products are being field tested even though the products tested may become pollutants capable of producing severe side effects such as the uterine cancer described below. A tobacco strain was developed to produce interleukin 10 a cytokine useful for treating inflammatory bowel disease and autoimmune disease. Undesirable effects of interleukin 10 include promotion of cancer or immunosuppression leading to spread of virus such as cytomegalovirus dengue virus. The GM tobacco for interleukin production was believed to be sufficiently modified for field trials because the crop was male sterile to reduce gene leakage. However, little concern was given to surface and groundwater pollution by interleukin 10 released by root exudation, sap released following leaf wounding or breakage and by browsing predators. Once the cytokine reaches the groundwater it is unlikely to be destroyed by microbes.
In Canada, field testing of GM crops producing pharmaceuticals
has been regulated by the Canadian Food Inspection Agency, a bureaucracy
originally recruited from Agriculture Canada for the most part.
The agency is poorly equipped to cope with its mandate in foods and apparently
devoid of intelligence in evaluating the safety of pharmaceutical production.
Field tests seem to have required little monitoring of cytokine pollution
thus providing a false sense of safety.
Finally, field testing and environmental release of GM pharmaceutical crops does not appear to have required that the public be informed of field tests nor of public input in oversight of such tests. Even if a population had experienced severe injury from ground or surface water pollution by GM crop pharmaceuticals there is currently no way that public health officials or the public could have an inkling about the source of the problem.
Abstracts of research articles
Molecular Breeding 8 (2):177-185, September 2001.
A self-contained system for the field production of plant recombinant interleukin-10
Rima Menassa, Vi Nguyen, Anthony Jevnikar and Jim Brandle
The production of pharmaceutical proteins in plants is creating a broad spectrum of new high-value traits in traditional crop species. As the production of these recombinant proteins moves from bench to field scale, containment and the presence of unwanted secondary metabolites are significant practical issues. We have developed a hybrid male-sterile low-alkaloid tobacco (MSLA) production platform. Recombinant protein is produced in leaves that are harvested prior to flowering. If considered for direct in vivo mammalian use the low-alkaloid background genotype addresses concerns about nicotine, and male sterility further reduces the risk of gene leakage. We have applied this system to the production of human interleukin-10 (phIL-10), a contra-inflammatory cytokine with potential application in the treatment of inflammatory bowel disease and autoimmune diseases. Transgenic low-alkaloid tobacco lines properly assembled a biologically active phIL-10 homodimer. Hybrids made by crossing a single homozygous high-expressing phIL-10 line with a MSLA female were field tested in a high density production system and harvested after 30 days. Recombinant phIL-10 yields were found to be similar in the hybrids and the homozygous control. MSLA tobacco is a practical, self-contained system for the production of plant recombinant proteins.
Int J Cancer 2001 Dec 15;94(6):792-4 Cancer of the uterine cervix may be significantly associated with a gene polymorphism coding for increased IL-10 production.
Stanczuk GA, Sibanda EN, Perrey C, Chirara M, Pravica V, Hutchinson IV, Tswana SA
The purpose of our prospective, case-controlled study was to investigate
the hypothesis that women who are genetically programmed to produce high
or medium levels of IL-10 were more likely to develop cancer of the uterine
cervix than individuals genetically predisposed to low IL-10 production.
The population was recruited from patients attending gynecological clinics
at 2 hospitals in Harare, Zimbabwe. Laboratory tests were performed in
the Departments of Immunology, Chemical Pathology and Medical Microbiology,
Medical School, University of Zimbabwe, and simultaneously at the Department
of Biological Sciences, University of Manchester, United Kingdom. Included
in our study were 77 women with histologically proven cancer of the uterine
cervix and 69 age- and parity-matched healthy women. All of the patients
and healthy controls were from the Shona ethnic group that inhabits northern
Zimbabwe. DNA was purified from cervical cytobrush samples obtained from
women with cervical cancer. Control DNA was extracted from urine or peripheral
blood samples from the healthy women. The Qiagen DNA extraction kit was
used. Detection of allele A and/or G at -1082 in the promoter region of
the IL-10 gene was carried out using the ARMS-PCR technique. Polymorphism
in the amplified products was detected by gel electrophoresis in the presence
of ethidium bromide and were bands visualized under UV light. The data
comprise 77 women who developed invasive cervical cancer and 69 healthy
women matched for age and parity. Patients with cancer were significantly
(p = 0.001) more likely to be predisposed to produce higher (A/G) levels
of IL-10. The genotype encoding for high (G/G) production of IL-10 was
only observed in one cancer patient. The prevalence of low producers of
IL-10 in the cancer group was significantly lower than in the healthy women.
There were no high producers amongst the healthy women. These data suggest
that the genetically acquired ability to produce higher levels of IL-10
may be a significant factor in the development of cervical cancer.
J Virol 2002 Feb 1;76(3):1285-92 Potent immunosuppressive activities of cytomegalovirus- encoded interleukin-10.
Spencer JV, Lockridge KM, Barry PA, Lin G, Tsang M, Penfold ME, Schall
Cytomegalovirus (CMV) has highly evolved mechanisms for avoiding detection by the host immune system. Recently, in the genomes of human and primate CMV, a novel gene comprising segments of noncontiguous open reading frames was identified and found to have limited predicted homology to endogenous cellular interleukin-10 (IL-10). Here we investigate the biological activities of the CMV IL-10-like gene product and show it to possess potent immunosuppressive properties. Both purified bacterium-derived recombinant CMV IL-10 and CMV IL-10 expressed in supernatants of human cells were found to inhibit proliferation of mitogen-stimulated peripheral blood mononuclear cells (PBMCs), with specific activity comparable to that of recombinant human IL-10. In addition, CMV IL-10 expressed from human cells inhibited cytokine synthesis, as treatment of stimulated PBMCs and monocytes with CMV IL-10 led to a marked decrease in production of proinflammatory cytokines. Finally, CMV IL-10 was observed to decrease cell surface expression of both major histocompatibility complex (MHC) class I and class II molecules, while conversely increasing expression of the nonclassical MHC allele HLA-G. These results demonstrate for the first time that CMV has a biologically active IL-10 homolog that may contribute to immune evasion during virus infection.
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