The long-term goals of Dr. Wang’s research are to improve our understanding of the intricate mechanisms underlying the regulation of innate immunity, and search for proteins that altered their subcellular localization and/or expression levels in clinical and experimental sepsis. Specifically, Dr. Wang has been systematically assessing the roles of various endogenous immune regulators in sepsis using genetic and pharmacological approaches, and developing novel therapeutic strategies for the clinical management of human inflammatory diseases.
Identification of HMGB1 as a late mediator of lethal systemic inflammation
Because early cytokines are difficult to target in clinical settings, Dr. Wang’s laboratory searched and found a nuclear protein HMG-1 (also known as HMGB1) that could be released extracellularly to function as a late mediator of lethal endotoxemia. Subsequently, they collaborated with many eminent scientists and demonstrated that HMGB1 binds and facilitates the cellular uptake of bacterial CpG-DNA and endotoxins, thereby promoting their innate recognition by their cytoplasmic TLR9 or caspase-11 receptors. Even by itself, HMGB1 can signal through TLR4 and MD2 to activate innate immune cells and endothelial cells to orchestrate a dysregulated inflammation and coagulopathy.
His laboratory collaborated with others to elucidate the mechanisms underlying the regulation of HMGB1 release and extracellular function. They were able to demonstrate that exogenous bacterial endotoxins and CpG-DNA, as well as endogenous cytokines such as IFN-γ, SAA or IFN-α/β uniformly induce HMGB1 release. They also discovered that macrophage cell surface hemichannels such as connexin 43 and pannexin 1, and cytoplasmic enzymes such as PKR and PKM2, are all involved in the regulation of HMGB1 release. Recently, Dr. Wang’s lab discovered that extracellular HMGB1 also acts with a partner-in-crime—a circulation protein called tetranectin (TN)—to cause immunosuppression by killing macrophages, and went on to develop a panel of TN-specific monoclonal antibodies (mAbs) capable of preventing harmful HMGB1/TN interaction and rescuing mice from potentially lethal sepsis. Their findings have suggested an exciting possibility to develop therapeutic antibodies against harmless proteins colluding with sepsis mediators.
Identification of other endogenous regulators of innate immunity
Dr. Wang’s interest in the innate immunity has nourished a close collaboration with eminent scientists (such as Dr. D. Tang), and contributed to the seminal discovery of a series of modulators of the innate immunity that include the PTEN-induced putative kinase 1 (PINK1) and parkin RBR E3 ubiquitin protein ligase (PARK2), the anaplastic lymphoma kinase (ALK), glutathione peroxidase 4 (GPX4), stimulator of interferon genes protein (STING, also known as transmembrane protein 173, TMEM173), circadian clock gene (Bmal1), as well as cAMP immunometabolism.
Search for potential therapeutic agents for inflammatory diseases
By strategic screening of many popular anti-inflammatory medicinal herbs, the lab demonstrated that the extract of Angelica sinensis—as well as herbal ingredients such as nicotine, stearoyl lysophosphatidylcholine, EGCG, tanshinone IIA, and glycyrrhizin/carbenoxolone—could all inhibit HMGB1 release and improve animal survival in models of lethal infections and injury. With financial support from the NIH/NCCIH (R01AT005076), they are developing more efficient high-throughput assays to screen natural product chemical libraries for specific inhibitors of various novel inflammatory mediators to gain an improved understanding of the intricate mechanisms of novel herbal therapies for sepsis.