And the scientists did certainly find what they were looking for: When they administered the cows milk constituent casein together with an impact enhancer to the animals, the mice went on to establish neurological conditions. “The bodys defenses really assault the casein, but in the procedure they also ruin proteins included in the formation of myelin.”
In mice injected with casein, the structure of myelin loosens. “We compared casein to various particles that are crucial for myelin production,” Chunder says. It looks markedly similar to casein in some aspects– so much so that antibodies to casein were likewise active versus MAG in the lab animals.”
New research study: Cows milk protein sets off autoimmune response in mice that harms nerve cells.
The timely for the research study came from MS clients: “We hear once again and again from victims that they feel even worse when they consume milk, cottage cheese or yogurt,” describes Stefanie Kürten from the Institute of Anatomy at University Hospital Bonn. “We are interested in the cause of this correlation.”
The teacher of neuroanatomy is thought about a popular professional on several sclerosis. She started the research study in 2018 at the University of Erlangen-Nuremberg. A year and a half back, she relocated to Bonn, where she continued the interact with her research study group. “We injected mice with different proteins from cows milk,” she states. “We desired to learn if there was a constituent that they were responding to with symptoms of disease.”
In healthy mice, the insulating myelin (black) fits snugly as a compact layer around the nerve fibers, the axons. Credit: © Group Prof. Kürten/ University of Bonn
And the scientists did indeed find what they were looking for: When they administered the cows milk constituent casein together with an impact enhancer to the animals, the mice went on to develop neurological conditions. Electron microscopy showed damage to the insulating layer around the nerve fibers, the myelin. The fat-like substance prevents brief circuits and in addition significantly accelerates stimulus conduction.
Perforated myelin layer
In several sclerosis, the bodys immune system ruins the myelin sheath. The insulating sheath was also massively perforated in the mice– apparently set off by casein administration. “The bodys defenses really assault the casein, however in the process they likewise ruin proteins included in the formation of myelin.”
In mice injected with casein, the structure of myelin loosens. Credit: © Group Prof. Kürten/ University of Bonn
Such cross-reactivity can occur when two molecules are extremely comparable, a minimum of in parts. The immune system then in a sense mistakes them for each other. “We compared casein to different particles that are essential for myelin production,” Chunder says. “In the process, we came across a protein called MAG. It looks noticeably comparable to casein in some aspects– a lot so that antibodies to casein were likewise active versus MAG in the laboratory animals.”
To address this question, the scientists included casein antibodies from mice to human brain tissue. These did undoubtedly collect in the cells accountable for myelin production in the brain.
Self-test for antibodies versus casein
The research study found that the B cells in the blood of people with MS react particularly strongly to casein. Presumably, the afflicted people established an allergy to casein at some point as a result of consuming milk.
The antibodies against casein (red) bind to MAG (green) in the brain. They thereby hinder the formation of myelin by special cells, the oligodendrocytes. Credit: © Group Prof. Kürten/ University of Bonn
This only impacts MS patients who are allergic to cows milk casein. “We are presently developing a self-test with which affected people can check whether they bring matching antibodies,” says Kürten, who is likewise a member of the Cluster of Excellence ImmunoSensation2. “At least this subgroup should refrain from taking in milk, cottage, or yogurt cheese.”
It is possible that cows milk also increases the danger of establishing MS in healthy individuals. Due to the fact that casein can likewise activate allergic reactions in them– which is probably not even that rare. When such an immune action exists, cross-reactivity with myelin can in theory occur. This does not indicate that hypersensitivity to casein necessarily leads to the advancement of numerous sclerosis, the teacher stresses. This would presumably need other threat aspects. This connection is nonetheless distressing, Kürten states: “Studies suggest that MS rates are elevated in populations where a great deal of cows milk is consumed.”
Reference: “Antibody cross-reactivity between casein and myelin-associated glycoprotein results in main nerve system demyelination” byRittika Chunder, Alicia Weier, Hannah Mäurer, Nicolas Luber, Michael Enders, Gabriele Luber, Thorsten Heider, Alfred Spitzer, Sabine Tacke, Janine Becker-Gotot, Christian Kurts, Radhika Iyer, Peggy P. Ho, William H. Robinson, Tobias V. Lanz and Stefanie Kuerten, 2 March 2022, Proceedings of the National Academy of Sciences.DOI: 10.1073/ pnas.2117034119.
