The cause of neuronal death in Parkinson\u2019s disease is still unknown, but a new study proposes that neurons may be mistaken for foreign invaders and killed by the person\u2019s own immune system, similar to the way autoimmune diseases like type I diabetes, celiac disease, and multiple sclerosis attack the body\u2019s cells.
\n‘This is a new, and likely controversial, idea in Parkinson\u2019s disease; but if true, it could lead to new ways to prevent neuronal death in Parkinson\u2019s that resemble treatments for autoimmune diseases,’ said the study\u2019s senior author, David Sulzer, PhD, professor of neurobiology in the departments of psychiatry, neurology, and pharmacology at Columbia University College of Physicians & Surgeons.<\/p>\n
The new hypothesis about Parkinson\u2019s emerges from other findings in the study that overturn a deep-seated assumption about neurons and the immune system.<\/p>\n
For decades, neurobiologists have thought that neurons are protected from attacks from the immune system, in part, because they do not display antigens on their cell surfaces. Most cells, if infected by virus or bacteria, will display bits of the microbe (antigens) on their outer surface. When the immune system recognises the foreign antigens, T cells attack and kill the cells. Because scientists thought that neurons did not display antigens, they also thought that the neurons were exempt from T-cell attacks.<\/p>\n
‘That idea made sense because, except in rare circumstances, our brains cannot make new neurons to replenish ones killed by the immune system,’ Dr. Sulzer says. ‘But, unexpectedly, we found that some types of neurons can display antigens.’
\nCells display antigens with special proteins called MHCs. Using postmortem brain tissue donated to the Columbia Brain Bank by healthy donors, Dr. Sulzer and his postdoc Carolina Cebri\u00e1n, PhD, first noticed\u2014to their surprise\u2014that MHC-1 proteins were present in two types of neurons. These two types of neurons\u2014one of which is dopamine neurons in a brain region called the substantia nigra\u2014degenerate during Parkinson\u2019s disease.<\/p>\n
To see if living neurons use MHC-1 to display antigens (and not for some other purpose), Drs. Sulzer and Cebri\u00e1n conducted in vitro experiments with mouse neurons and human neurons created from embryonic stem cells. The studies showed that under certain circumstances\u2014including conditions known to occur in Parkinson\u2019s\u2014the neurons use MHC-1 to display antigens. Among the different types of neurons tested, the two types affected in Parkinson\u2019s were far more responsive than other neurons to signals that triggered antigen display.<\/p>\n
The researchers then confirmed that T cells recognised and attacked neurons displaying specific antigens.<\/p>\n
The results raise the possibility that Parkinson\u2019s is partly an autoimmune disease, Dr. Sulzer says, but more research is needed to confirm the idea.\nColumbia University Medical Center<\/link>\n","protected":false},"excerpt":{"rendered":"
The cause of neuronal death in Parkinson\u2019s disease is still unknown, but a new study proposes that neurons may be mistaken for foreign invaders and killed by the person\u2019s own immune system, similar to the way autoimmune diseases like type I diabetes, celiac disease, and multiple sclerosis attack the body\u2019s cells. ‘This is a new, […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[35],"tags":[],"_links":{"self":[{"href":"https:\/\/clinlabint.com\/wp-json\/wp\/v2\/posts\/1652"}],"collection":[{"href":"https:\/\/clinlabint.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/clinlabint.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/clinlabint.com\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/clinlabint.com\/wp-json\/wp\/v2\/comments?post=1652"}],"version-history":[{"count":0,"href":"https:\/\/clinlabint.com\/wp-json\/wp\/v2\/posts\/1652\/revisions"}],"wp:attachment":[{"href":"https:\/\/clinlabint.com\/wp-json\/wp\/v2\/media?parent=1652"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/clinlabint.com\/wp-json\/wp\/v2\/categories?post=1652"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/clinlabint.com\/wp-json\/wp\/v2\/tags?post=1652"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}