Effect of high mobility group box-1 protein on immune cells and its regulatory mechanism.

High mobility group box-1 protein (HMGB1), which is a nuclear protein, participates in chromatin architecture and transcriptional regulation. When released from cells, HMGB1 also plays a well-established role as a pro-inflammatory mediator during innate immune responses to injury. In the initial stage of injury, there is a release of large quantities of early pro-inflammatory mediators to initiate or perpetuate immune responses against pathogens, but this pro-inflammatory period is transient, and it is followed by a prolonged period of immune suppression. At present, several lines of evidences have suggested that HMGB1 is a late cytokine provoking delayed endotoxin morbidity, which may enhance the production of early proinflammatory mediators, and it can contribute potently to the activation of different immune cells and play a role in the development of host cell-mediated immunity. The biology of HMGB1 has been extensively studied as a pro-inflammatory cytokine of systemic inflammation, however, this review will attempt to provide a summary of the effects of HMGB1 on different immune cells and its regulatory mechanism in acute insults.