title: The HMGB1-CXCL12 Complex Promotes Inflammatory Cell Infiltration in Uveitogenic T Cell-Induced Chronic Experimental Autoimmune Uveitis.
abstract: It is largely unknown how invading autoreactive T cells initiate the pathogenic process inside the diseased organ in organ-specific autoimmune diseases. In experimental autoimmune uveitis (EAU) induced by uveitogenic, interphotoreceptor retinoid-binding protein (IRBP)-specific T cells (tEAU) in mice, we have previously reported that high mobility group box 1 (HMGB1) released as a consequence of the direct interaction between IRBP-specific T cells and retinal parenchymal cells is an early and critical mediator in induction of intraocular inflammation. Our present study explored the roles of HMGB1 in intraocular inflammation, focusing on its role in recruiting inflammatory cells into the eye. Our results showed that supernatants from retinal explants either stimulated with HMGB1 or cocultured with IRBP-specific T cells attracted leukocytes. Notably, HMGB1 antagonists blocked supernatant-induced chemoattraction when present from the start of coculture, but not when added to the culture supernatants after coculture, indicating that molecules released by HMGB1-treated retinal cells are chemoattractive. Moreover, CXCL12 levels in the coculture supernatants were dependent on HMGB1, since they were increased in the cocultures and reduced when HMGB1 antagonists were added at the beginning of the coculture. When either anti-CXCL12 Ab was added to the supernatants after coculture or the responding lymphocytes were pretreated with Ab against CXCL12 specific receptor, CXCR4, chemoattraction by the coculture supernatants was decreased. Finally, induction of tEAU was significantly inhibited by a CXCR4 antagonist, AMD3100, at the time of autoreactive T cell transfer. Our study demonstrates that, at a very early stage of intraocular inflammation initiated by uveitogenic autoreactive T cells, synergism between HMGB1 and CXCL12 is crucial for the infiltration of inflammatory cells.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Kentucky Lions Eye Center, University of Louisville , Louisville, KY , USA.
authors.forename: Juan
authors.initials: J
authors.lastname: Yun
authors.affiliation: Department of Ophthalmology and Visual Sciences, Kentucky Lions Eye Center, University of Louisville , Louisville, KY , USA.
authors.forename: Guomin
authors.initials: G
authors.lastname: Jiang
authors.affiliation: Department of Ophthalmology and Visual Sciences, Kentucky Lions Eye Center, University of Louisville, Louisville, KY, USA; Department of Ophthalmology, Tangshan Gongren Hospital, Tangshan, China.
authors.forename: Yunsong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Ophthalmology and Visual Sciences, Kentucky Lions Eye Center, University of Louisville , Louisville, KY , USA.
authors.forename: Tong
authors.initials: T
authors.lastname: Xiao
authors.affiliation: Department of Pharmaceutical Sciences, Sullivan University College of Pharmacy , Louisville, KY , USA.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Ophthalmology, Doheny Eye Institute, David Geffen School of Medicine, UCLA , Los Angeles, CA , USA.
authors.forename: Deming
authors.initials: D
authors.lastname: Sun
authors.affiliation: Department of Ophthalmology and Visual Sciences, Kentucky Lions Eye Center, University of Louisville , Louisville, KY , USA.
authors.forename: Henry J
authors.initials: HJ
authors.lastname: Kaplan
authors.affiliation: Department of Ophthalmology and Visual Sciences, Kentucky Lions Eye Center, University of Louisville , Louisville, KY , USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Shao
keywords: CXCL12; CXCR4; HMGB1; autoimmune disease; autoreactive T cells; damage-associated molecular patterns; immune regulation; uveitis