Genetically Modified Soybeans: Equal Allergenicity as their Wild Type Counterparts?

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23 Οκτ 2013 (πριν από 3 χρόνια και 8 μήνες)

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Genetically Modified
Soybeans: Equal
Allergenicity

as their Wild Type
Counterparts?

Katie Van Den
Einde

November 24, 2009

Advisor: Dr. Chastain

Overview


Introduction: GM foods, allergies,
controversy


Paper 1


Paper 2


Paper 3


Paper 4


Current regulations


Conclusions


Importance


GM foods:


Soybeans


Corn


Tomatoes


Rice


Canola


Potatoes


Sugar beets


Sugar cane





Modifications



Herbicide resistance


Insect resistance


Disease resistance


Addition of proteins/vitamins



2003


84% of US soybean acreage was
glyphosate

tolerant (Roundup
®

ready)


Basics of Genetic Modification


Procedures


1. Plasmid insertion


2. Gene “guns”


3. Protoplasts


Allergies


Majority of allergic reactions are
immunoglobulin E (
IgE
) mediated.


IgE

allergies affect about 1
-
2% of adults


2
-
8% of children

Symptoms:


Itchy, watery eyes


Rash


Congestion


Itchiness


Difficulty breathing


Anaphylactic shock (Can be life
threatening)






Basics of allergic reactions


1
-
Allergen


2
-
IgE antibodies


3
-
Mast cells


4
-
Histamine release

Anti
-
Histamines

GM Controversy


Ethics


Gene flow


Resistance


Harm to other organisms


Allergens???

Overview


Introduction: GM foods, allergies,
controversy


Paper 1


Paper 2


Paper 3


Paper 4


Current regulations


Conclusions


Paper 1:



Identification of a Brazil
-
nut allergen in
transgenic soybeans


New England Journal of Medicine 1996

Purpose:


To assess ability of proteins from



1)soybeans (
Glycine

max
)


2)transgenic soybeans


3)Brazil nuts (
Bertholletia

excelsa
)


4)purified 2S albumin



to bind to
IgE

serum

Methods:


Radio
allergosorbent

test (RAST)


4
serums


Sodium
dodecyl

sulfate
-
polyacrylamide
-
gel
electrophoresis (SDS
-
PAGE)


9 serums


Skin Prick Tests

RAST basics

Results: RAST

More inhibition


of
IgE

binding =


more allergic.

Triangles= WT

Squares= GM soybean

Circles= Brazil nut

Results: SDS
-
PAGE

IgE

binding

Total Proteins

IgE

binding

Results: Skin
-
Prick Test

Main Points:


GM soybean protein successfully
competed with Brazil nut protein.



IgE

from 8/9 allergic to Brazil nut bound
to introduced 2S albumin in GM
soybeans.

Overview


Introduction: GM foods, allergies,
controversy


Paper 1


Paper 2


Paper 3


Paper 4


Current regulations


Conclusions


Paper 2



Lack of detectable
allergenicity

of
transgenic maize and soya samples


Journal of Allergy and Clinical Immunology 2005

Purpose:


Monitor 5 GM products whose
transgenes

came from sources with no
allergenic history

Methods:


Food Survey


Previous exposure?


Skin Prick Tests


27 kids with food allergies


50 patients with asthma rhinitis


SDS
-
PAGE

Flour products tested

Food survey results

Western Blot


Testing Lab Supply

SDS PAGE

Western Blot

SDS PAGE

Western Blot

Skin prick and
IgE

results

Main Point:


No detectable difference in
IgE

reactivity
between wild type and GM soybeans or
corn.



Overview


Introduction: GM foods, allergies,
controversy


Paper 1


Paper 2


Paper 3


Paper 4


Current regulations


Conclusions


Paper 3



A comparative study of the allergenic
potency of wild
-
type and
glyphosate
-
tolerant gene
-
modified soybean cultivars


Acta pathologica, microbiologica et immunologica Scandinavica
2003


Purpose:


To compare
allergenicity

of 8 wild type
and 10 GM soybeans varieties (all for CP4
EPSPS)

Methods:


RAST (serum from 10 patients)


SDS
-
PAGE


Histamine Release test


Skin prick tests

RAST results

More inhibition


of labeled
IgE

binding =


more original

serum bound first.

RAST results

Concentration of extract

needed for 50% inhibition

of
IgE

binding (variety #12)

Histamine Release results

Notice lack of any major differences


no where to point an arrow!

Skin Prick Test

Histamine


Release

(0=negative,

6=lots)

Histamine Release for patient I

Pretty similar!

Main Points:


Difference between patients’ response,
but no statistical difference between WT
and TG soybeans.


Addition of CP4 EPSPS gene ≠ higher
allergenicity


Overview


Introduction: GM foods, allergies,
controversy


Paper 1


Paper 2


Paper 3


Paper 4


Current regulations


Conclusions


Paper 4



Genetic modification removes an
immunodominant

allergen from soybean


Plant Physiology 2003

Purpose:


To silence the
Gly

m
Bd

30K (P34) gene
transgenically


P34


A major soybean allergen


More than 65% of soy
-
sensitive patients
react only to the P34 protein


Less than 1% of total protein


Pigs, calves and salmon also allergic

Methods:


Created a P34 silencing vector (plasmid
pKS73)


Grew these into
homozyous

strains


Used SDS
-
PAGE for presence of P34
protein

Results

Soybean Protein “Map”

Protein Analysis

Wild type

P34 Silenced

Missing P34

proteins and


intermediates

Main Points:


TG and WT were indistinguishable in size,
shape, protein and oil content



P34 gene silencing was successful



Overview


Introduction: GM foods, allergies,
controversy


Paper 1


Paper 2


Paper 3


Paper 4


Current regulations


Conclusions


Who’s in charge?


Coordinated Framework for the Regulation of
Biotechnology
-

1986


3 regulatory bodies

of genetically modified foods:

(Animal and Plant Health Inspection Service)

Considerations:


Effect on environment (animals, insects…)


Transferable to wild type


Digestive stability


Toxicity



Weediness



FDA


Food additives


Manufacturers responsible for checking


Voluntary consultation process
-

but all
on U.S. market have undergone


Conclusions


Allergens can be added


Mostly, there is no difference


Can also remove allergens


Continue studies


Continue monitoring


Additional Works Consulted


USDA Website. “Biotechnology FAQs.” Accessed 11/21/2009.
http://www.usda.gov/wps/portal/!ut/p/_s.7_0_A/7_0_1OB?contentidonly=true&navi
d=AGRICULTURE&contentid=BiotechnologyFAQs.xml



Singer, S., Raven, D., Johnson G.,
Losos
, J. 2005. Biology 7
th

Edition. McGraw Hill.
New York, NY.

Picture References


http://agriculture.sc.gov/UserFiles/Image/soybeans7.jpg


statistihttp://tharwacommunity.typepad.com/tharwa_review/images/2008/03/12/gm_foods.jpg


http://www.mun.ca/biology/desmid/brian/BIOL2060/BIOL2060
-
20/2032.jpg


http://repairstemcell.files.wordpress.com/2009/03/genetically
-
modified
-
food
-
fda.jpg


http://animalid.aphis.usda.gov/nais/wp_images/extension/high_res/usda
-
logo.jpg


http://blogs.venturacountystar.com/motorhead/epa.jpg


http://www.marlerblog.com/uploads/image/fda
-
logo.jpg


http://web.chemistry.gatech.edu/~williams/bCourse_Information/4581/techniques/gel_elect/gel.jpg


http://www.life.umd.edu/classroom/bsci423/song


http://media.photobucket.com/image/Ige%20allergy/belldandy_84/Allergies.jpg/F03
-
44.jpg


http://api.ning.com/files/f7sw9nvb2lvWKi0Z
-
603fV67e5PN0


http://www.flourallergy.com/images/allergy
-
test.jpg
Y5iFz4Ef69JQNJKYzZ5lyynC5e9rpsiR7KJHFqW*CGRvzuPN6AianENPQ159UhHB680/pha0155l.jpg


http://www.worldcommunitycookbook.org/season/guide/photos/corn.jpg


http://e
-
internetbusiness.com/wp
-
content/uploads/2009/06/benadryl.png

http://www.ars.usda.gov/is/graphics/photos/sep02/k9975
-
3i.jpg


http://intmedweb.wfubmc.edu/grand_rounds/1999/Image15.jpg




Questions??