A. Cry9C is a new Bt protein with insect control properties. Cry9C-based corn provides outstanding protection from European corn borer and Southwestern corn borer, two common pests of corn. These insects can severely effect corn yields. The unique features of the Cry9C protein also make it an excellent insect resistance management tool for growers. 

Q. Where do Bt proteins like Cry9C come from?

A. Bt proteins are made by microbes that are present in soils everywhere. The name of the microbe is Bacillus thuringiensis, or Bt for short. Bt proteins have been used safely for insect control for decades, and are the mainstay for insect control by organic gardeners and growers. 

Q. How do Bt proteins work?

A. All Bt proteins use the same method to control insects. The protein is eaten, activated in alkaline conditions found in the insect stomach, and attaches or binds to the stomach lining. The attachment process causes holes to form in the stomach walls, which in turn causes the insect to stop eating and eventually die. Because Bt proteins must bind to the stomach wall to be active, the range of pest control for any particular Bt protein is limited to a fairly narrow group of related insects.
This method of activity also partly explains why Bt proteins are safe for other animals. If the digestive system of an animal is acidic, such as in most animals and  humans, the protein does not dissolve in a way that allows for attachment to the stomach lining. In addition, the attachment site needed for activity is only found in specific insects, and is otherwise not present in any other animal. Since mammals do not have a specific attachment site present for Bt proteins, the Bt protein cannot attach to the stomach lining, thus no activity is found. For all of these reasons, the specific methods by which Bt proteins control targeted insects do not occur in any other animal. 

Q. Cry9C Bt is a new Bt protein. How similar is it to other more widely used Bt proteins?

A. The Cry9C protein has been isolated from a common soil microbe, Bacillus thuringiensis, just as all other Bt proteins. The general method by which Cry9C Bt works is the same as for other Bt proteins. The Cry9C Bt protein rapidly degrades in the soil and the environment, just as other Bt proteins. However, as the Cry9C acts through a different attachment site in the insect, it provides unique opportunities for pest control and insect resistance management that are not otherwise currently available. 

Q. If Bt proteins kill insects, don’t they also affect people and other animals?

A. No. Bt proteins work by attaching or binding to specific sites in an insect’s stomach. Without this attachment, Bt proteins have no activity. Humans, birds, fish and other non-target species do not have these attachment sites, and therefore the Bt proteins have no effects on these animals. This has been verified for Cry9C proteins in experimental animals. 

Q. Has the Cry9C Bt protein been checked for activity in animals other than those insects targeted for control?

A. A wide variety of birds, mammals, and invertebrates (such as non-target beneficial insects, and earthworms) have been tested with no observable effects. Specifically, beneficial insects including bees and ladybugs were fed pollen containing Cry9C, and found to be completely unaffected by the protein; they grew and reproduced as well as untreated insects.

Q. A recent letter in Nature concluded that Bt corn pollen kills Monarch butterflies. Does pollen from Cry9C-containing corn show any effects on Monarchs?

A. No, Cry9C corn pollen contains only a very low level of the Cry9C protein, so low
that no effects could be measured on target pests such as the European corn borer or non-target pests such as Monarch larvae. While laboratory data such as that from the Nature article are interesting, it can be dangerous to make real world conclusions without valid field data. A full series of field research studies were performed this summer with nearly 20 different scientists across North America. Deposition of corn pollen onto milkweed plants, the preferred Monarch food, was extremely low even in the middle of a cornfield. Observations also indicated that corn pollen doesn’t travel far from the edge of a cornfield and thus would have little if any effect on Monarch larvae. These scientists confirmed the risk assessment performed by the EPA, which concluded that Bt corn is not a threat to Monarch butterflies or other non-target butterflies.

Q. Why is the EPA reviewing Cry9C Food safety, rather than the FDA?

A. The Coordinated Framework for Regulation of Biotechnology (1996) is the comprehensive federal regulatory policy for ensuring the safety in biotechnology
research and policy. The Coordinated Framework describes the regulatory roles of the United States Department of Agriculture (USDA), the United States Environmental Protection Agency (EPA) and the Food and Drug Administration Agency (FDA) in the marketing approval products developed using biotechnology. The agencies are instructed to use existing statutes to regulate and to identify jurisdiction, and to operate their programs in an integrated and coordinated fashion. When there is overlap one agency is identified as the lead.

If the plant is expressing a plant protectant, such as is the case for "Bt plants" that
express a protein with insecticidal activity, and the acreage for field tests is above 10 acres, then the EPA has jurisdiction and is considered the lead agency. For commercial use, a plant-expressed protectant must be registered with the EPA and either a tolerance or exemption from the requirement of a tolerance granted for the introduced protecting compound and genetic material. The EPA reviews data on the product chemistry, ecological safety and human/animal safety of the protecting compound to make a decision regarding the safe and legal use of the plant expressed protectant.

The FDA regulates food biotechnology products in the same manner as they regulate other foods. When an enhanced plant expresses a protecting compound, as in the case of a "Bt plant", the FDA reviews the compositional and nutritional aspects of the enhanced plant. The human food and feed safety of the protectant is reviewed by the EPA.

Background – Allergenicity

An allergy is an inappropriate reaction of the body to one or more foreign substances that in the
majority of people cause no symptoms. An allergic response involves the over-production of specific types of antibodies by the body's immune system. Allergic responses may be triggered by inhalation, dermal, or oral routes of exposure. Between 15-25% of people suffer from some sort of allergy. Food allergies are much less frequent. It is estimated that 1-2% of adults and 2-4% of children suffer from food allergies.

Many different substances can cause an allergenic reaction. The most common are from natural
sources, such as pollen, grasses, weeds, dust, certain foods, drugs and insect bites. Allergenic
symptoms may include sneezing, rashes, coughing, stomach irritation and difficulties breathing.
Asthma is also due to an allergenic reaction. Generally, susceptibility to allergy is an inherited trait. The probability of developing an allergy increases if one or both parents also have allergies. Allergies often vary as a function of age or physiological status. Symptoms of allergy can be reduced by desensitization therapies.

Although the term "food allergy" is widely used for any adverse reaction to food, only rarely is the
immune system involved. The most common adverse reactions to food are toxic reactions and food intolerance. Natural foods, not additives or artificial flavors, are the basis for the majority of food allergies. Any food that contains proteins (i.e. the vast majority) has the potential to cause allergenic reactions in some people. Natural proteins in peanuts, cow’s milk, eggs, wheat, soybean, tree nuts, fish and shellfish cause 90% of all food allergens.

The introduction of new proteins into crops has raised concerns that proteins with allergenic
properties might be introduced unknowingly into genetically modified plants. To avoid this possibility, all genetically modified plants are put through strict safety evaluation procedures. Guidelines have been established by the World Health Organization (WHO), the Organization for Economic Coordination and Development (OECD), the Food and Drug Administration (FDA), Health Canada, the Ministry of Health and Welfare in Japan and the European Union (EU).

Before commercialization, the sponsor of a new product must prove that the food does not contain a new or existing allergen. In fact, biotechnology offers an opportunity to remove allergens from food products for the first time. Experimental work in Japan is directed to eliminating allergenic properties from rice.

The U.S. enjoys the safest food supply of any country in the world because of the detailed scrutiny FDA, EPA and USDA apply to the products they regulate in all sectors of agriculture and the food chain. A very important aspect of U.S. food safety reviews by these agencies is their close attention to the potential allergenicity of new food products.

Questions and Answers on Allergenicity:

Q. What is an allergy?

A. An allergy is an over-reaction by your immune system. Normally, the immune system acts as a watchdog or defense against any foreign substance, such as those that cause diseases. In some cases, the immune system reacts to a substance that the body mistakenly perceives as a threat. Allergies are expressed in people that tend to produce an increased amount of antibodies – the immune system’s tool for inactivating foreign substances – to substances to which most of us do not respond. These antibodies, in turn, stimulate other parts of the immune system, causing the release of histamine, which is responsible for allergy symptoms such as itchy eyes, rashes, hives or stomach irritation. 

In plant foods such as soybean and peanuts, the natural allergens seem to be storage proteins, which are found in large amounts (1% to 80% on a weight to weight basis) in these foods.

Q. Do allergies occur frequently?

A. About 15% to 25% of people suffer from some sort of allergy, but most of them are allergic to environmental substances like pollen, dust and molds. Food allergies are not a major source of allergies. Only 1% to 2% of all adults suffer from food allergies. 

Literally millions of different proteins and other substances are ingested by people without any reaction; only about 150 proteins have been identified as allergens.

Q. Are all food reactions due to allergies?

A. No. An allergy is just one of many reactions that can occur from food. The most common adverse reactions to food are toxic reactions and food intolerance. Many different foodstuffs may be contaminated by foreign or naturally occurring toxic substances but usually the level of these substances is too low to cause a severe reaction. Aflotoxin, naturally present in some peanuts, is an example of a toxic substance. Salt may also be toxic to certain individuals under some circumstances. Small molecules may produce some form of intolerance in certain
people. One of the most common causes of food intolerance is lactose (milk sugar)
intolerance. A food intolerance typically results in inability to digest a substance with resulting symptoms of gastric or bowel distress. Antibody over-production, the bodies' reaction to an allergen, is not related to food intolerance. 

Q. Can a person be allergic to corn or soybeans?

A. Allergies to components found in corn are very rare, while allergies to components of soybean are more common. 

Q. Can you prove that a protein will never cause an allergenic reaction?

A. No, scientists cannot absolutely prove that a food or a protein will not cause an allergic reaction in anybody. However, there are a number of characteristics of allergenic proteins that have been identified, and there are some test models that experts in this area use as predictors to identify potential allergens. In fact, genetically modified plants are extensively tested to ensure that none of the already known allergens will be introduced. One test matches the sequence of the new protein against the sequence of known allergens to look for similarities. 
Another test evaluates the source of the new protein to search for known allergies that the source may produce. Products are also tested for allergenic characteristics. This makes genetically modified plants among the most tested foodstuffs on the market. 

Q. Another company stopped development of a product that contained a gene from Brazil nut due to the allergen issue. Will AgrEvo take the same approach?

A. These two cases are quite different. The gene from Brazil nut clearly led to an enhanced allergenic response, which was not surprising given that nuts are a major source of allergenic proteins. Early experimental work confirmed this and the project was discontinued. In contrast, the source of the Cry9C protein, Bacillus thuringiensis, is not considered an allergenic source and the full testing program has led AgrEvo to conclude that the Cry9C protein poses no risk of increased food allergy. 

Allergy-related Web sites:

http://allergy.mcg.edu/glossary/glossary.html 
http://www.gene.com/ae/TSN/SS/BkgndPaper_Current_Seminar.html 
http://www.allerdays.com/ 
http://vm.cfsan.fda.gov/~1rd/bioallrg.html 
http://betterfoods.org 

Background – Cry9C and Allergenicity

The determination of food safety is a complicated assessment requiring input from a number of
research disciplines. An extensive number of studies have been performed to evaluate whether the Cry9C protein’s effect on toxicity, allergenicity, antinutrients, bioavailability, irritancy, biological specificity and mode of action, and feed wholesomeness. A major area of food safety focus has been to study in great detail any potential for the Cry9C protein to be a food allergen. Extensive testing has been performed to make sure that none of the already known food allergens have been increased or introduced into plants. In addition, introduced substances, i.e. the gene product, have been evaluated against a number of criteria to determine their likelihood to induce allergic responses.

The allergenicity assessment of Cry9C protein has been fully undertaken. The total weight of
evidence is considered before authorities render a safety decision. No food safety clearances will be granted before this step is complete. AgrEvo’s conclusion is that Cry9C protein has shown no
evidence of allergenic potential in exposed humans or animals. However we have consulted with
regulatory experts within agencies in the U.S. (especially the EPA) and overseas. Moreover, to add confidence to this conclusion, we also consulted with a number of scientific experts based in
academia around the world on the general topic of food allergenicity and the safety data as it relates to Cry9C. This has ensured that corn hybrids that contain the Cry9C protein are among the most thoroughly tested and evaluated foodstuffs on the market.

Questions and Answers about the potential allergenicity of the Cry9C protein:

Q. Is the Cry9C protein an allergen?

A. Extensive testing by leading independent food safety experts has demonstrated that corn containing Cry9C is as safe in all aspects as non-modified corn. More than five years of testing by leading international experts in the field of clinical allergy and immunology has demonstrated that Cry9C poses no increased potential for food allergy. We welcome the technical review and believe that the panel will confirm this conclusion based on all the latest studies.

Q. What tests are conducted to determine if a protein has allergenic potential?

A. There are several characteristics seen in certain natural dietary allergens that are considered when evaluating the allergenic potential of a protein. Allergy assessment is currently based upon a composite process that considers if the modified crop is known to have major allergenic properties (e.g. peanut); if the novel protein is from an allergenic source; if the abundance of the protein in the crop is high; if the protein structure matches that of any known allergens; if the protein is stable to digestion; and several other biological characteristics. 

However, it does not appear that gastric stability is a reliable predictor of the allergenic potential of a protein as there are examples of stable proteins that are not allergens and there are examples of unstable proteins that are allergens. 

Allergenicity is a complex issue and can only be ascertained based on a preponderance of evidence from many studies in several scientific disciplines – the so-called "weight of evidence" approach. Using this approach, AgrEvo has established a clear weight of evidence that the Cry9C protein is not likely to be allergenic.

Q. How do livestock perform when fed corn that contains the Cry9C protein?

A. There is no evidence to indicate that consumption of Cry9C corn materials is harmful in any way to animals. Feeding studies found that chickens or beef steers fed this corn grew and developed at the same rate as chickens or steers fed non-transgenic, control corn. No unusual findings have been reported in the first two years of the use of these corn hybrids in feedstuff in North America. 

Q. Have people been exposed to Cry9C?

A. Garst Seeds has been actively working with Cry9C-containing corn since 1996. No unusual reactions have been described by personnel either with or without a history of previous allergies. This includes those involved in the field, harvesting or processing of this corn seed. In consequence there is no evidence that respiratory exposure, generally recognized to be a more sensitive route for hypersensitization, has led to any unusual reactions among respondents. Dermal exposure, likewise, has not resulted in allergic responses. 

Q. How soon will a suitable animal model for allergenicity testing be available?

A. In man the production of a clinical allergenic response to food proteins is a unique response dictated by genetics. There are obvious advantages if a suitable animal model can be found that would accurately predict human response. However, the absence of an animal model test system does not mean that other scientific tools cannot be used to predict human responses. 
AgrEvo recognizes the need for more research in predicting the potential for allergenicity and is actively pursuing and supporting this area of research. 

For more information please contact:

S Meister - Manager, Communication - North America
Tel: (306) 721-4551 
Fax: (306) 721-3119 
E-Mail: steve.meister@agrevo.com 

Dr. W Faust - Head of PR 
Tel: + 49 69 305 3950 
Fax: + 49 69 305 3950 
E-Mail: wolfgang.faust@agrevo.com

S MacIntosh - Product Safety Manager
Tel: +1 515 276 6642 
Fax: + 1 515 278 8054 
E-Mail: susan.macintosh@agrevo.com 

Dr A Cockburn - Head of Toxicology 
Tel: +44 (0) 1799 573645 
Fax: +44 (0) 1799 573476 
E-Mail: andrew.cockburn@agrevo.com  

Company news release
N2378