Multiple sclerosis (MS) is the most prevalent autoimmune disease of the central nervous system, leading to irreversible deficits in young adults. It is a neuroinflammatory demyelinating disease whose pathophysiology is both complex and incompletely understood. There is currently no cure for MS.
Since the 1970s people with MS have anecdotally reported that eating dairy products worsened their symptoms. et, how milk consumption might trigger autoimmune responses to CNS antigens and contribute to disease development remains obscure.
In a recently published study, researchers from the University of Bonn, in Germany, have performed a series of experiments using a mice model to evaluate if people with MS have an autoimmune reaction in response to cow’s milk. The study appears in the journal of the Proceedings of the National Academy of Sciences.
The researchers used the mice model to provide evidence of how an immune response against casein, another common protein component from the bovine milk can aggravate the demyelinating pathology of MS.
The team did a series of experiments in mice to determine whether antibodies created in response to milk exposure caused a loss of myelin in nerve cells. The researchers injected mice with 3 different proteins from cow’s milk to make them produce antibodies against the proteins. They used casein, which is responsible for cow’s milk allergy in humans, α-lactalbumin, or β-lactoglobulin.
They found that mice injected with casein experienced weakness and disorientation, unlike mice injected with the other proteins. Studies performed postmortem showed demyelination of the nerve cells in the lumbar spinal cord.
The tests also confirmed increased levels of immunoglobulin G in response to the casein. They also took 10 serum samples of people with MS and demonstrated an IgG reaction after exposure to cow’s casein, and they then tested the reactivity of the serum to a protein found in myelin.
The researchers propose that the antibodies for casein and the protein in myelin are similar, and in people with MS, antibodies formed in response to casein can also attack the protein myelin, which is an example of molecular mimicry, causing cross-reactivity between the cow’s milk and antigens in the central nervous system that can exacerbate demyelination in patients with Multiple sclerosis.
Rittika Chunder, et al. Antibody cross-reactivity between casein and myelin-associated glycoprotein results in central nervous system demyelination. PNAS. 2022. 119 (10) e2117034119. https://doi.org/10.1073/pnas.2117034119
Hannah Flynn. (2022, Mar 15). MS: Milk protein may worsen symptoms in some, mouse studies suggest. Medical News Today. Retrieved from:
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