Cow milk allergy occurs in children and in adults.
Scientists at Messerli Research Institute at the Vetmeduni Vienna, the Medical University of Vienna, and the University of Vienna investigated what actually makes the milk allergenic. A specific protein in milk known as beta-lactoglobulin is able to initiate an allergy only when being devoid of iron.
Loaded with iron, the protein is harmless. The scientists discovered the same mechanism recently with regard to birch pollen allergy. Their findings help to decipher allergic reactions and were published in the journal PLOS ONE.
Milk allergy is frequently confused with lactose intolerance. However, these are two entirely different mechanisms that occur in the body. People with lactose intolerance do not digest lactose properly because they lack an enzyme known as lactase. In the case of the potentially much more dangerous cow milk allergy, however, the body's immune system attacks milk proteins with its own IgE antibodies.
According to statistics, about two to three percent of children in Europe suffer from a genuine milk allergy. Less adults are diagnosed with the disease. The formation of so-called Th2 lymphocytes is initiated in these patients. Th2 lymphocytes contribute in great measure to the production of IgE antibodies to milk proteins. Hence, people develop an allergic reaction to milk.
Such an allergy may cause swelling of the mouth and mucous membranes, diarrhea, exacerbation of neurodermitis, and in rare cases even an allergic shock. Precise diagnostic investigation helps to differentiate between allergy and intolerance and thus avoid incorrect diets which, under certain circumstances, may cause malnutrition.
Lack of iron load transforms milk protein into allergen
One of the most important milk allergens, the so-called beta-lactoglobulin, belongs to the protein family of lipocalins. Lipocalins possess molecular pockets which are able to accommodate iron complexes. Iron is bound to the protein by so-called siderophores. The first author Franziska Roth-Walter and her colleagues now show that an "empty" milk protein, one without iron and siderophores, helps to activate Th2 lymphocytes. As a consequence, the production of IgE antibodies against the milk protein is stimulated. The patient gets sensitized and may develop an allergic reaction to milk. Roth-Walter, working at the department of Comparative Medicine at the Messerli Research Institute says: "Knowledge of the molecular structure of allergens has contributed very significantly to our conclusion about milk allergy. This is of enormous practical relevance."
Investigating the difference between organic and conventional milk
As the next step the scientists want to find out, what contributes to the iron load of milk proteins. The lead investigator Erika Jensen-Jarolim explains: "One of the most burning questions we want to answer is: Why are these milk proteins loaded to a greater or lesser extent with iron? The manner of keeping and feeding cows may be a factor involved in this phenomenon. Iron loading may depend on whether the milk is produced organically or conventionally. This will be one of our major interests in the future. Lipocalins exist in all mammals. We assume that our conclusions will be applicable to the milk of other mammals as well."
The article „The major cow milk allergen Bos d 5 manipulates T-helper cells depending on its load with siderophore-bound iron”, by Franziska Roth-Walter, Luis. F. Pacios, Cristina Gomez-Casado, Gerlinde Hofstetter, Georg A. Roth, Josef Singer, Araceli Diaz-Perales and Erika Jensen-Jarolim was published on the 12th of August in the journal PLOS ONE. DOI: 10.1371/journal.pone.0104803
About the Messerli Research Institute
The Messerli Research Institute was founded in 2010 with support from the Messerli Foundation (Sörenberg, Switzerland) under the management of the University of Veterinary Medicine, Vienna in cooperation with the Medical University of Vienna and the University of Vienna. Its research is devoted to the interaction between humans and animals, as well as its theoretical principles in animal cognition and behavior, comparative medicine and ethics. http://www.vetmeduni.ac.at/messerli
About the University of Veterinary Medicine, Vienna
The University of Veterinary Medicine, Vienna in Austria is one of the leading academic and research institutions in the field of Veterinary Sciences in Europe. About 1,200 employees and 2,300 students work on the campus in the north of Vienna which also houses five university clinics and various research sites. Outside of Vienna the university operates Teaching and Research Farms. http://www.vetmeduni.ac.at
Prof. Erika Jensen-Jarolim
Messerli Research Institute
University of Veterinary Medicine Vienna
Medical University Vienna
Science Communication / Public Relations
University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 1 25077-1153
Dr. Susanna Kautschitsch | idw - Informationsdienst Wissenschaft
Common bacteria on verge of becoming antibiotic-resistant superbugs
26.03.2015 | Washington University School of Medicine
Chemical tag marks future microRNAs for processing, study shows
25.03.2015 | Rockefeller University
In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...
The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.
As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...
When an earthquake hits, the faster first responders can get to an impacted area, the more likely infrastructure--and lives--can be saved.
The Atlantic overturning is one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe.
Scientists now found evidence for a slowdown of the overturning – multiple lines of observation suggest that in recent decades, the current system has been...
Because they are regularly subjected to heavy vehicle traffic, emissions, moisture and salt, above- and underground parking garages, as well as bridges, frequently experience large areas of corrosion. Most inspection systems to date have only been capable of inspecting smaller surface areas.
From April 13 to April 17 at the Hannover Messe (hall 2, exhibit booth C16), engineers from the Fraunhofer Institute for Nondestructive Testing IZFP will be...
25.03.2015 | Event News
19.03.2015 | Event News
17.03.2015 | Event News
26.03.2015 | Trade Fair News
26.03.2015 | Trade Fair News
26.03.2015 | Life Sciences