On November 16, 2015, Zhijian James Chen, the Member of National Academy of Sciences (USA), the HHMI Investigator and Prof. of University of Texas Southwestern Medical Center, visited Institute of Biophysics (IBP), CAS and gave a lecture entitled Enemy Within – Immune and Autoimmune Responses to Cytosolic DNA. The lecture, which is a part of the special lecture series of Shizhang Bei Lecture of IBP, was hosted by Prof. LIU Pingsheng.

Prof. Zhijian James Chen focuses on the research of cell signaling transduction mechanism of innate immune. His team mainly involves in the ubiquitin signaling in the NF-κB pathway and innate immune sensing and signaling of cytosolic nucleic acids. These studies reveal how a cell detects harmful or foreign insults and mounts an appropriate response to restore homeostasis. Prof. Zhijian James Chen has published nearly 100 papers in international well-known magazines, cited for more than 34, 000 times with the H factor up to 80.

In the lecture, Prof. Zhijian James Chen introduced the physiological meaning and the relationship between cytosol DNA detection and human diseases. The detection of exogenous DNA facilitates the procedure of the cell to expire the infections such as viruses, bacteria and parasites. And the detection of endogenous cytosol DNA helps the host immune system to eliminate malignant cells. However, the over activation of these pathways can also lead to autoimmune diseases such as lupus. The group of Prof. Zhijian James Chen’s lab recently discovered a new small molecule cGAMP (cyclic GMP-AMP). As the vital DNA sensor of cytosolic DNA, cGAMP is synthesized by cGAS (cyclic GMP-AMP synthase) after the protein binding to DNA. cGAMP functions as a second messenger to bind and activate the protein STING to induce Type I interferons and other inflammatory cytokines. The phenotype of Trex1 mutant mice was almost totally recovered after the cGAS knockout. This discovery will strongly promote the treatment of Aicardi Goutieres Syndrome (AGS).

Prof. Zhijian James Chen gave the lecture with vivid words, rigorous logic and great passion, which could be a lively lesson for the audience. After the lecture, Prof. Zhijian James Chen and the audience shared their views on the issues of common interest.