Professor Feng Shao

Research priorities: Innate immunity, inflammation, pyroptosis, immunogenic cell death, bacterial infection
Feng Shao has discovered a series of cytosolic innate immune receptors for major bacterial products (like LPS) as well as the downstream pyroptosis executioner gasdermin-D (GSDMD). These original contributions lay out the foundation for understanding how our body recognizes and defends against various pathogenic bacterial infections in the cytosol space. His further identification of the Gasdermin family of pore-forming proteins re-defines the concept of pyroptosis, thereby opening a new area in cell death, inflammation and immunity.
Central to the immune system is the sensing of pathogen infection. Toll-like receptors (TLRs) recognize extracellular bacteria and stimulate cytokine production, but little was known about how bacteria are detected in the cytosol. Feng Shao has identified several pattern recognition receptors (PRRs) for invading bacterial pathogens/toxins. These include the NAIP family for bacterial flagellin and type III secretion apparatus, and Pyrin (encoded by the familial Mediterranean fever gene) that senses various bacterial toxins. He has also showed that caspase-4/5 in humans and caspase-11 in mice are intracellular receptors for bacterial LPS. In addition, he has uncovered that ADP-heptose, a precursor of LPS biosynthesis, is recognized by a host kinase ALPK1 and stimulates NF-κB-mediated proinflammatory responses, therefore revealing another way through which LPS is sensed by host immune system. This series of landmark discoveries establish a framework about cytosolic antibacterial immunity.
Cytosolic immune receptors often activate pyroptosis, but the mechanism was unknown for 20 years. Shao has solved the mystery by identifying the GSDMD protein, whose cleavage and activation by caspase-1 and caspase-4/5/11 determines pyroptosis. He further found that GSDMD has a membrane pore-forming activity that directly executes pyroptosis and also mediates the release of caspase-1-processed IL-1β. Shao’s findings raise a novel concept that systemic pyroptosis activated by the intracellular LPS-sensing pathway determines sepsis.
Shao has further discovered that the large gasdermin family are all pyroptosis-inducing factors, redefining pyroptosis as gasdermin-mediated programmed necrosis. His work shows that GSDME is cleaved and activated by caspase-3 and therefore switches apoptosis to pyroptosis. The finding has overturned the dogma that caspase-3 activation is a marker for apoptosis, and changed our understanding about the role of caspases in programmed cell death.