Extracellular high-mobility group box 1 acts as an innate immune mediator to enhance autoimmune progression and diabetes onset in NOD mice.
Authors
Han, JunyanZhong, Jinxin
Wei, Wenzhong
Wang, Ying
Huang, Yafei
Yang, Ping
Purohit, Sharad
Dong, Zheng
Wang, Mong-Heng
She, Jin-Xiong
Gong, Feili
Stern, David M.
Wang, Cong-Yi
Issue Date
2008-07-29
Metadata
Show full item recordAbstract
OBJECTIVE: The implication of innate immunity in type 1 diabetes development has long been proposed. High-mobility group box 1 (HMGB1), an evolutionarily conserved chromosomal protein, was recently recognized to be a potent innate inflammatory mediator when released extracellularly. We sought to test the hypothesis that HMGB1 acts as an innate immune mediator implicated in type 1 diabetes pathogenesis. RESEARCH DESIGN AND METHODS: Eight- and 12-week-old NOD mice were treated with an HMGB1 neutralizing antibody once a week until 25 weeks of age and monitored for insulitis progression and diabetes onset. The underlying mechanisms of HMGB1 regulation of autoimmune response were further explored. RESULTS: During autoimmunity, HMGB1 can be passively released from damaged pancreatic beta-cells and actively secreted by islet infiltrated immune cells. Extracellular HMGB1 is potent in inducing NOD dendritic cell maturation and stimulating macrophage activation. Blockade of HMGB1 significantly inhibited insulitis progression and diabetes development in both 8- and 12-week-old NOD mice. HMGB1 antibody treatment decreased the number and maturation of pancreatic lymph node (PLN) CD11c(++)CD11b(+) dendritic cells, a subset of dendritic cells probably associated with autoantigen presentation to na??ve T-cells, but increased the number for PLN CD4(+)Foxp3(+) regulatory T-cells. Blockade of HMGB1 also decreased splenic dendritic cell allo-stimulatory capability associated with increased tolergenic CD11c(+)CD8a(+) dendritic cells. Interestingly, the number of CD8(+)interferon-gamma(+) (Tc1) T-cells was increased in the PLNs and spleen after blockade of HMGB1, which could be associated with retarded migration of activated autoreactive T-cells into the pancreatic islets. CONCLUSIONS: Extracellular HMGB1 functions as a potent innate immune mediator contributing to insulitis progression and diabetes onset.Citation
Diabetes. 2008 Aug; 57(8):2118-2127ae974a485f413a2113503eed53cd6c53
10.2337/db07-1499