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[SANET-MG] GM protein in ice cream
Below is our brief on the Unilever application for GM ice cream in UK.
Unilever has been selling GM ice cream in US with FDA approval. Good
Humor ice cream is a major producer of ice cream bars and other products
mainly targeted to young children. The applications for approval of GM
ice cream have all ignored the impact of GM ice cream on children.
In the FDA GRAS application the main focus of safety was the
allergenicity of the ice structuring protein from the pouter fish. The
main test was to examine effect of the ice structuring protein (ISP) on
blood from 10 people with cod allergy. There was no indication that the
blood contained IgE antibodies (allergic response) to the ISP. This
experiment seems very strange to me because it test blood that is
allergic to cod but that allergen is a calcium binding protein called
parvalbumin which is unrelated to ice structuring protein. Cod has an
ice structuring protein but that protein is not at all related to the
pouter ISP in the ice cream. What I am saying is that Unilever's main
allergy test seems to be a dummy test that could never produce results
relevant to the GM ice cream, it could only provide results showing no
allergy, in other words it seems rigged to produce favorable results.
Unilever provided a GRAS panel of experts who ignored the fecklessness
of the allergy tests.
The Unilever approach seems very cold blooded and FDA's response seems
mindless when you consider that the ice cream will target young children
GM Protein in Ice Cream
Genetically modified fish antifreeze protein is potentially able to
cause inflammation and should not be approved without comprehensive tests
Prof. Joe Cummins, Dr. Mae-Wan Ho and Prof. Malcolm Hooper
This report has been submitted to the Food Standards Agency to oppose
approval of Unilever’s application on behalf of the Independent Science
Panel www.indsp.org.uk
Unilever is seeking approval of a genetically modified (GM) (FAQ on
genetic engineering) ice-structuring protein derived from a polar fish,
ocean pout, for use in making ice cream smoother and creamier. The GM
protein is produced in transgenic bakers’ yeast. Ice-structuring, or
antifreeze protein protects the ocean pout in freezing waters by
preventing large ice crystals forming; in ice cream and other frozen
food it would have the same effect. Unilever applied to the Food
Standards Agency (FSA) UK for approval, and its proposal is now open for
public comment [1]. Unilever has sent similar petitions to the United
States Food and Drug Administration (FDA) to obtain the Generally
Recognized As Safe (GRAS) status for the food additive [2] and to Food
Standards Australia New Zealand [3]. Both applications have been
approved, which is unfortunate.
The transgenic protein produced in yeast was designated ISP Type III
HPLC 12 glyco–ISP. The preparation tested by Unilever contained peptides
from yeast and sugars along with the recombinant protein. Unilever
conducted a subchronic feeding test of the preparation on rats by oral
gavage (force feeding) for 3 weeks, as well as a battery of genotoxicity
tests that proved to be negative. A series of tests that included those
suggested by the World Health Organisation for allergy were carried out,
along with tests for reactivity with serum obtained from a few people
allergic to fish. The report stressed that the recombinant protein was
identical to protein found in edible fish [1], although that kind of
statement is generally untrue as will be discussed below.
There is voluminous literature on antifreeze glycoproteins, particularly
those from polar fish. There are four main types of glycoproteins each
differing significantly from the others. Type III proteins are around
6500 daltons in size, they form a beta-sandwich structure and are found
only in ocean pout [4]. Although the antifreeze protein itself is not
immunogenic for the ocean pout, there is nevertheless a strong immune
response to the micro ice crystals complex with antifreeze protein
circulating in the fish’s blood, indicating that the complex functions
as conventional antigens for the ocean pout [5].
The GM protein from transgenic yeast is the product of a synthetic
approximation of the pout antifreeze protein gene. The code sequence was
altered to facilitate production in yeast without altering the amino
acid sequence. Multiple copies of the synthetic gene were inserted into
the yeast chromosomes to boost the synthesis of the protein [1].
Production of proteins in yeast destined for human consumption or
therapy is fraught with the problem of secondary modification of the
proteins by glycosylation or other modifications that result in the
human (or animal) immune system recognizing the yeast modified proteins
as antigens. There has been progress in “humanizing” the glycosylation
patterns of proteins produced in yeast [6, 7]. However, there has been
no effort to “humanize” the glycosylation pattern of the antifreeze
protein produced in the yeast strain used to produce the protein.
Are the cursory studies on allergenicity carried out by Unilever on the
GM protein to be used in ice cream adequate to rule out allergy and
other immune reactions in the tens of millions of people that will
consume the ice cream?
It is worth pointing out that the transgenic protein is already used in
ice cream in the USA, Australia and New Zealand, and that ice cream has
not been labeled, so any problems resulting from its use may go
unrecognized.
We should recall that the transgenic expression of a bean gene in peas
turned it into a strong immunogen, resulting in debilitating even fatal
lung inflammation in mice. That response was related to the
glycosylation pattern of the transgenic protein [8, 9] (“Transgenic pea
that made mice ill”, SiS 29). Unilever does not appear to have carried
out the inflammation tests even though there is every indication from
the scientific literature that pouter antifreeze protein is
immunologically active.
There is also the question of latency. Some chronic inflammatory
diseases emerge gradually, building up from an initial response that is
small and clinically variable or insignificant (asymptomatic) [10]. But
there is a potential cascade effect that when triggered, will lead to
autoimmune effects that could affect any organ. Without long term
testing, we could be letting off an immunological time bomb. Tests for
inflammatory effects must be done in both young and older animals with
full analysis of inflammatory cytokines, antibodies and related
molecules. Tests in young animals are particularly important as ice
cream is consumed from the earliest age when there are crucial
development processes occurring.
In conclusion, contrary to the claims of Unilever, there is no evidence
that the transgenic ice- structuring protein is identical to the protein
produced in pouter fish. The transgenic protein appears to have the
glycosylation pattern of yeast, making that protein a unique antigen.
Even though allergenicity was studied in a cursory way, there is clear
precedent for studying inflammation comprehensively in the long term in
both young and older animals before exposing the European public to the
transgenic ice cream.
References
1. Lewis S. Application for the approval of ice structuring protein typ
III HPLC12 preparation for use in edible ices. Safety and Assurance
Centre 2006 http://www.acnfp.gov.uk/assess/fullapplics/isp
2. US Food and Drug Administration Agency Response Letter GRAS Notice
No. GRN000117 2003, http://www.cfsan.fda.gov/~rdb/opa-g117.html
3. Food Standards Australia New Zealand Initial Assessment Report
Application A544 Ice Structuring Protein as a Processing Aid for Ice
Cream and Edible Ices, 2004,
http://www.foodstandards.gov.au/_srcfiles/A527_Dimethyl_ether_IAR_FINAL.pdf
4. Harding MM, Anderberg PI and Haymet AD 'Antifreeze' glycoproteins
from polar fish. Eur J Biochem. 2003, 270(7), 1381-92.
5. Verdier JM, Ewart KV, Griffith M and Hew CL. An immune response to
ice crystals in North Atlantic fishes. Eur J Biochem. 1996, 241(3), 740-3.
6. Wildt S and Gerngross TU. The humanization of N-glycosylation
pathways in yeast. Nat Rev Microbiol. 2005, 3(2), 119-28.
7. Li H, Sethuraman N, Stadheim TA, Zha D, Prinz B, Ballew N, Bobrowicz
P, Choi BK, Cook WJ, Cukan M, Houston-Cummings NR, Davidson R, Gong B,
Hamilton SR, Hoopes JP, Jiang Y, Kim N, Mansfield R, Nett JH, Rios S,
Strawbridge R, Wildt S and Gerngross TU. Optimization of humanized IgGs
in glycoengineered Pichia pastoris. Nat Biotechnol. 2006, 24(2), 210-5.
8. Prescott VE, Campbell PM, Moore A, Mattes J, Rothenberg ME, Foster
PS, Higgins TJ and Hogan SP. Transgenic expression of bean alpha-amylase
inhibitor in peas results in altered structure and immunogenicity. J
Agric Food Chem. 2005, 53(23), 9023-30.
9. Ho MW. Transgenic pea that made mice ill. Science in Society 2006,
29, 28-29, http://www.i-sis.org.uk/isisnews.php
10. Arbuckle MR, McClain MT, Rubertone MV, Scofield RH, Dennis GJ, James
JA, Harley JB. Development of autoantibodies before the clinical onset
of systemic lupus erythematosus. New Eng J Med 2003, 349, 1526-33.
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