IRP scientists discover new B cell that tempers autoimmunity

Thursday, December 2, 2021

Findings in mice point to potential therapies for blinding eye disease uveitis and multiple sclerosis

Researchers at the National Eye Institute (NEI) have identified, isolated, and characterized a unique population of B cells that tamps down the immune system, reducing chronic inflammation. Infusions of purified IL-27 regulatory B cells (I27-Breg ) reduced symptoms in mouse models of multiple sclerosis (MS) and the eye disease autoimmune uveitis. The research suggests the cells may play a role in future human therapies. NEI is part of the National Institutes of Health.

“We are the first to describe this unique population of regulatory B cells. While similar in function to other Bregs, I27-Breg have a distinct gene expression profile and originate from the innate B-1a cell lineage,” said Charles Egwuagu, Ph.D., M.P.H., who directs the NEI Molecular Immunology Section. He and colleagues published their findings in PNAS.

Uveitis is a group of sight-threatening inflammatory eye diseases that includes Behcet disease, birdshot retinochoroidopathy, and sympathetic ophthalmia. Of infectious or autoimmune origin, it is characterized by repeated cycles of intraocular inflammation. Current therapies include corticosteroids; however, prolonged use of these drugs risks other eye problems such as optic neuropathy andsteroid-induced glaucoma.

Photographs of mouse retina showing the effect of uveitis treatment with i27-Bregs. The left column represents a normal retina. Photos in the middle and right column are retinal images from mice with uveitis, untreated or treated with i27-Bregs. The central spot is the optic nerve head. Note the absence of inflammation (ring surrounding the optic nerve) in the IL-27-treated retina (top right image).