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28 Nov 2005 11:58:13 -0000

Transgenic Pea that Made Mice Ill

press-release

 

 

 

The Institute of Science in Society Science Society

Sustainability http://www.i-sis.org.uk

 

General Enquiries sam Website/Mailing List

press-release ISIS Director m.w.ho

 

This article can be found on the I-SIS website at

http://www.i-sis.org.uk/TPTMMI.php

========================================================

 

 

ISIS Press Release 28/11/05

 

Immune Reactions to Transgenic Protein Serious

*************************************

 

Independent Scientists Demand A Ban on GM Food & Feed while

All GM Crops Are Tested

 

The following memo and report were sent to international and

national regulators on behalf of the Independent Science

Panel.

 

Please circulate widely, forward to your regulators and

policy makers, and the press.

 

Dr. Mae-Wan Ho, member of Independent Science Panel

(www.indsp.org), Director, Institute of Science in Society

(www.i-sis.org.uk)

 

(see list at the end)

 

I am writing on behalf of the Independent Science Panel

(ISP)* to draw your attention to new research findings on

the safety of transgenic proteins that need to be urgently

addressed.

 

Specifically, immunological assessments carried out for the

first time on a transgenic protein revealed that post-

translational processing subsequent to gene transfer into an

alien species introduced new antigenicities that turned a

previously harmless protein into a strong immunogen. In

addition, the transgenic protein promoted immune reactions

against multiple other proteins in the diet. The detailed

findings are reviewed in the report below.

 

As practically all the transgenic proteins involve cross-

species gene transfer, they will be subjected to different

post-translational processing, and hence they too, will have

the potential to become immunogenic. And yet, none of the

transgenic proteins that have been commercially approved has

been tested. This omission is a most serious public health

issue.

 

We call on you to impose an immediate ban on all GM food and

feed until proper assessment on the immunogenicity of all

the transgenic proteins has been carried out.

 

*The ISP, launched 10 May 2003 at a public conference in

London, UK, consists of dozens of prominent scientists from

11 countries spanning the disciplines of agroecology,

agronomy, biomathematics, botany, chemical medicine,

ecology, epidemiology, histopathology, microbial ecology,

molecular genetics, nutritional biochemistry, physiology,

toxicology and virology

(http://www.indsp.org/ISPMembers.php)

 

 

 

 

Transgenic Pea that Made Mice Ill

***************************

 

Raises serious safety concerns on transgenic proteins in

general that must be addressed while a ban on all GM food

and feed is imposed. Dr. Mae-Wan Ho

 

Ten-year project down the drain but are the right lessons

learned?

 

A ten-year project at CSIRO (Commonwealth Scientific and

Industrial Research Organization) in Canberra Australia bit

the dust when peas modified to resist insects caused

inflammation in the lungs of mice [1]. The GM peas will be

destroyed, said Gene Technology Regulator Sue Meeks.

 

The gene coding for the protein, a-amylase inhibitor-1 (aA1)

in the common bean (Phaseolus vulgaris L. cv. Tendergreen),

was inserted into pea (Pisum sativum L.) to make the pea-

plants resistant to attack from weevils.

 

Dr. T.J. Higgins, deputy chief of CSIRO Plant Industry and

co-author of the scientific paper reporting the results

remarked it is only the second time in the world that a GM

project has been abandoned after a gene transfer from one

crop to another, and that it demonstrated the effectiveness

of strict regulations on research into GM crops.

 

Greenpeace campaigner Jeremy Tager said: " It just shows the

failure of the science in relation to this gene product. "

of GeneEthics Network Bob Phelps referred to the

project as a " waste of public money " and highlights the

growing concern worldwide about the health impacts of all GM

foods.

 

There are indeed important lessons to be learned from the

scientific findings [2], which raise serious safety concerns

over transgenic proteins in general.

 

Different processing of transgenic protein

 

The researchers found that the transgenic protein was

processed differently and provoked immune reactions not

exhibited by the native protein (see later).

 

Transgenic aA1 protein was compared with the non-transgenic

protein on Western blot, a technique that separates

different forms of the protein arising from post-

translational processing. Previous studies showed that the

native polypeptide in bean is cleaved into two chains, a and

b, both of which are glycosylated (carbohydrate chains

added), and with one or more amino acids removed from the

tail end. This results in major forms of the a- and b-chains

with molecular masses 11 646 Da and 17 319 Da respectively,

together with minor forms containing alternative

carbohydrate chains. The transgene in pea yielded a- and b-

chains with molecular masses in the11 000 – 18 000 Da

region, but with a banding pattern different from the native

protein. More detailed comparisons on mass spectroscopy

showed that the transgenic a-chain was less heavily

glycosylated; and a form with two fewer mannose residues (11

322 Da) was the dominant in transgenic pea, but the least

abundant in bean. The b-chain in the transgenic protein also

showed a number of other bands besides the major and minor

forms present in the native protein.

 

Immune reactions to transgenic protein

 

Mice were given about 25mg of seed meal in suspension,

containing transgenic pea, nontransgenic pea, or bean, twice

a week for 4 weeks. Seven days after the final feeding, the

mice were subcutaneously injected in the footpad with the

purified protein antigens: native or transgenic aA1, and the

swelling induced in the footpad assessed 24 h later.

 

In a second experiment, the mice were fed seed meal

suspensions as before, and seven and nine days after the

final meal, purified transgenic aA1 or buffered saline was

introduced into the trachea, and inflammation response was

measured in the lungs 24 h later.

 

The results showed that mice fed on non-transgenic pea or

bean showed no inflammation response in the footpad or in

the lungs, indicating normal immune tolerance to common

food.

 

Mice fed with transgenic pea, however, showed aA1-specific

IgG antibodies at two weeks, rising to significant levels

after 4 weeks. There was significant swelling of the

footpad, or delayed type hypersensitive (DTH) response, when

purified aA1 was injected. Similarly, introducing the

antigens into the trachea gave an inflammation response in

the lungs.

 

As a control for the general effect of genetic modification,

the footpad challenge experiment was repeated with material

from two other GM plants, lupin expressing sunflower seed

albumin (SSA) and chickpeas expressing aA1. In contrast to

transgenic pea, mice fed transgenic lupin or transgenic

chickpea did not give DTH response. This shows that the

response to transgenic pea was specific.

 

The peribronchial lymph nodes of the mice were tested for

their response to transgenic aA1. Only the lymph nodes of

mice fed transgenic peas responded by producing the

inflammation cytokines (cell signalling factors) when

challenged with transgenic aA1.

 

Transgenic protein promotes reactions to other proteins

 

In order to test if the transgenic protein promotes immune

reactions to other proteins in the diet, mice were fed

purified transgenic or native aA1, or transgenic aA1 with or

without ovalbumin three times a week for 2 weeks. One week

following feeding, purified ovalbumin or buffered saline

were introduced into the trachea of the mice, and

inflammation response in the lungs was assessed as before.

 

Neither ovalbumin alone, nor ovalbumin in combination with

native aA1 caused any inflammation response in the footpad

or lungs when the mice were challenged with ovalbumin.

However, consumption of transgenic aA1 and ovalbumin

together promoted a strong ovalbumin-specific antibody

response and predisposed the mice to inflammation when

challenged with ovalbumin in both the footpad and the

trachea. This suggests that transgenic aA1 did promote

reactions to other proteins. In confirmation of that, levels

of antigen-specific IgG against other proteins such as pea

globulins, lectin, and vicilin-4 were also significantly

higher in the serum of mice fed transgenic pea than mice fed

non-transgenic pea.

 

Wider implications on the safety of transgenic proteins that

must be addressed

 

The transgenic pea involved gene transfer between plant

species, and is generally thought to be much safer compared

with the cross-kingdom gene transfer – bacteria to plant –

involved in the GM food crops that now cover tens of

millions of hectares worldwide.

 

A harmless bean protein expressed in transgenic pea caused

inflammation in mice, and research showed that the most

likely reason is because the protein is processed

differently in peas. Such post-translational processing of

proteins is well known to be species-specific, and as

genetic modification almost invariably involves cross-

species transfer of proteins, one must expect transgenic

proteins to differ structurally from the native proteins as

a matter of course. Are they also likely to provoke immune

reactions as a result?

 

It would not happen in every case, as the researchers have

found that neither transgenic lupin sunflower seed albumin,

nor transgenic chickpea aA1 gave the same results as

transgenic pea aA1. But how frequently could it happen?

 

" Currently, we do not know the frequency at which

alterations in structure and immunogenicity of

transgenically expressed proteins occur or whether this is

unique to transgenically expressed aA1. " The researchers

admitted.

 

Furthermore, when consumed with other proteins, the

transgenic pea protein promoted immunological `cross-

priming' against those proteins, so that the mice developed

specific immunological reactions to them as well. In other

words, the transgenic protein can provoke generalised immune

response to multiple proteins in the diet, whether

transgenic or not.

 

The previous instance of a GM project being abandoned was

the transfer of a Brazil nut allergen into soya [3], and it

involved a known allergen. The present case involves a

protein that has all the appearance of being harmless.

 

As yet, no other GM crop, especially those already out there

in the fields and in our food and feed, has been tested in

this way. This must now be done. Meanwhile, there must be a

ban imposed on all GM food and feed.

 

References

 

1. " GM crops scrapped as mice made ill " , Selina Mitchell and

Leigh Dayton, The Australian, 18 November 2005.

http://www.theaustralian.news.com.au/common/story_page/0,574

4,17283002%255E2702,00.html

 

Prescott VE, Campbell PM, Moore A, Mattes J, Rothenberg ME,

Foster PS, Higgins TJV and Hogan SP. Transgenic expression

of bean a-amylase inhibitor in peas results in altered

structure and immunogenicity. J Agricultural and Food

Chemistry 2005, 53, 9023-30.

 

Nordlee JA, Taylor SL, Townsend JA, Thomas LA & Bush RK.

Identification of a brazil-nut allergen in transgenic

soybeans. The New England Journal of Medicine 1996, March14,

688-728.

 

Sent to:

 

Mr. Hamdallah Zedan, Executive Secretary, Secretariat of the

Convention on Biological Diversity, secretariat

 

Cc: Mr. David Cooper, Senior Programme Officer – Interagency

and Program (UK and Northern Ireland),

david.cooper

 

Mr. Geoffrey Podger, Executive Director, European Food

Safety Authority Geoffrey.podger

 

Cc: Mr. Herman.Koeter, Director of Science, European Food

Safety Authority, Herman.koeter

 

Dr. Harry Kuiper, Chair of the GMO Panel, EFSA,

h.a.kuiper

 

Colin Ross, Food Standards Agency, UK,

colinRoss

 

Cc: Elliot Morley MP, Minister for the Environment,

Emorley

 

Rt. Hon Michael Meacher MP, meacherm

 

Canadian Food Inspection Agency, Plant Products Directorate,

Plant Biosafety Office, pbo

 

Cc:Hon Andrew Mitchell, Minister of Agriculture and Agri-

Food and Minister of State (Federal Economic Development

Initiative for Northern Ontario), Mitchell.A

 

Mr. Mike Johanns, Secretary of Agriculture, USDA, United

States Mike.Johanns Cc:

 

Dr. Ron DeHaven, Animal and Plant Health Inspection Service

Ron.DeHaven

 

Mr. Stephen L. Johnson, Environment Protection Agency,

USA johnson.stephen

 

 

========================================================

This article can be found on the I-SIS website at

http://www.i-sis.org.uk/TPTMMI.php

 

If you like this original article from the Institute of

Science in Society, and would like to continue receiving

articles of this calibre, please consider making a donation

or purchase on our website

 

http://www.i-sis.org.uk/donations.

 

ISIS is an independent, not-for-profit organisation

dedicated to providing critical public information on

cutting edge science, and to promoting social accountability

and ecological sustainability in science.

 

 

========================================================

CONTACT DETAILS

 

The Institute of Science in Society, PO Box 32097, London

NW1 OXR

 

telephone: [44 1994 231623] [44 20 8452 2729] [44 20

7272 5636]

 

General Enquiries sam Website/Mailing List

press-release ISIS Director m.w.ho

 

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