Myelin basic protein specific T-helper cells induce experimental anterior uveitis

Area of Science:

• Immunology
• Ophthalmology
• Neuroscience

Background:

• Experimental autoimmune encephalomyelitis (EAE) is an animal model for multiple sclerosis.
• Anterior uveitis (AU) is a form of intraocular inflammation.
• The relationship between EAE and AU is not fully understood.

Purpose of the Study:

• To investigate the immunopathological changes in the eyes during EAE induced by myelin basic proteins (MBP).
• To identify the role of MBP-specific T cells in the development of AU.
• To explore the characteristics of T cells involved in ocular inflammation during EAE.

Main Methods:

• Induction of EAE in Lewis rats using active and passive immunization with MBP.
• Histopathological examination of ocular tissues at various stages of EAE.
• Flow cytometry analysis of T cells from the anterior segment of inflamed eyes.

Main Results:

• Anterior uveitis (AU) onset coincided with hind limb paralysis in EAE rats, but uveitis persisted after EAE symptoms resolved.
• Histopathology revealed inflammatory cell accumulation in the iris, ciliary body, and anterior chamber.
• CD4+ T cells expressing V beta 8.2 and OX-40 markers were identified in the inflamed eyes, suggesting their role in MBP-induced EAE and AU.

Conclusions:

• Myelin basic proteins (MBP) are both encephalitogenic and uveitogenic in Lewis rats.
• MBP-specific T cells, particularly V beta 8.2-positive T cells, play a critical role in the pathogenesis of EAE and AU.
• These findings highlight the involvement of specific T cell populations in the ocular manifestations of EAE.