Jianming Xie received his B.S. degree in Chemistry from Fudan University, Shanghai, China, in 1997, and M.S. degree in Organic Chemistry from Shanghai Institute of Organic Chemistry (SIOC), China, in 2000. In his M.S. research in the laboratory of Prof. Yongzheng Hui and Prof. Biao Yu, he completed the synthesis of a complex natural glycoside using a one-pot four-glycosylation method. He later switched his interest to Chemical Biology, and moved to the United States in 2001 to pursue a Ph.D. degree under the guidance of Prof. Peter Schultz at the Scripps Research Institute, La Jolla, California. There, he helped pioneer a novel biosynthetic method to site-specifically incorporate unnatural amino acids into recombinant proteins in E. coli. His work has enabled the design and synthesis of novel protein structures and functions that do not exist in nature. After receiving his Ph.D. degree in 2006, he became interested in Immunology and joined the laboratory of Prof. Mark Davis as a Cancer Research Institute (CRI) Irvington postdoctoral fellow at Stanford University, Stanford, California. His postdoctoral research integrated the method of site-specific protein modification with fluorescence microscopy and flow cytometry for the study of antigen recognition by T cells. This work revealed ligand-dependent transport of T cell receptors to the immunological synapse, and also led to the development of a protein photochemistry approach to isolate rare, antigen-specific T cells from patient blood samples. In December 2014, he started his lab in the Department of Pharmacology and Pharmaceutical Sciences at the University of Southern California (USC) School of Pharmacy. His lab combines synthetic peptide chemistry, protein design, cellular engineering, and fluorescence microscopy in order to interrogate, engineer, and enhance the specificity and efficiency of T cell antigen recognition. The long-term goal is to use the obtained knowledge to guide the design of enhanced immunotherapy and vaccines against cancer, infection, and autoimmune diseases.
Areas of Expertise (8)
Natural Killer Cells
Chimeric Antigen Receptors
The Scripps Research Institute: Ph.D., Chemical Biology 2006
Shanghai Institute of Organic Chemistry: M.S., Organic Chemistry 2000
Fudan University: B.S. 1997
Orthogonal translation components for the in vivo incorporation of unnatural amino acids
Inventor: Lital Alfonta, Peter Schultz, Huaqiang Zeng, Jianming Xie, Ning Wu, Jiangyun Wang, Meng-Lin Tsao, Daniel Summerer, Dan Groff, Alexander Deiters, Jonathan R. Chittuluru, Mohammad R. Seyedsayamdost, James Turner
Adding photoregulated amino acids to the genetic code
Inventor: Alexander Deiters, Ning Wu, Peter G. Schultz, David King, T. Ashton Cropp, Mohua Bose, Dan Groff, Jianming Xie, Eric Brustad
Site specific incorporation of heavy atom-containing unnatural amino acids into proteins for structure determination
Inventor: Jianming Xie, Lei Wang, Ning Wu, Peter G. Schultz
Translation systems and other compositions including orthogonal aminoacyl tRNA-synthetases that preferentially charge an orthogonal tRNA with an iodinated or brominated amino acid are provided. Nucleic acids encoding such synthetases are also described, as are methods and kits for producing proteins including heavy atom-containing amino acids, e.g., brominated or iodinated amino acids. Methods of determining the structure of a protein, e.g., a protein into which a heavy atom has been site-specifically incorporated through use of an orthogonal tRNA/aminoacyl tRNA-synthetase pair, are also described.
Selected Articles (6)
A hallmark of CD4(+) T cell activation and immunological synapse (IS) formation is the migration of the microtubule organization center and associated organelles toward the APCs. In this study, we found that when murine CD4(+) T cells were treated with a microtubule-destabilizing agent (vinblastine) after the formation of IS, the microtubule organization center dispersed and all of the major cellular organelles moved away from the IS.
Using an elaborately evolved language of cytokines and chemokines as well as cell-cell interactions, the different components of the immune system communicate with each other and orchestrate a response (or wind one down). Immunological synapses are a key feature of the system in the ways in which they can facilitate and direct these responses.
The binding of T cell antigen receptors (TCRs) to specific complexes of peptide and major histocompatibility complex (pMHC) is typically of very low affinity, which necessitates the use of multimeric pMHC complexes to label T lymphocytes stably. We report here the development of pMHC complexes able to be crosslinked by ultraviolet irradiation; even as monomers, these efficiently and specifically stained cognate T cells.
Thymic positive selection is based on the interactions of T cell antigen receptors (TCRs) with self peptide-major histocompatibility complex (MHC) ligands, but the identity of selecting peptides for MHC class II-restricted TCRs and the functional consequences of this peptide specificity are not clear.
Recently, a method to encode unnatural amino acids with diverse physicochemical and biological properties genetically in bacteria, yeast and mammalian cells was developed. Over 30 unnatural amino acids have been co-translationally incorporated into proteins with high fidelity and efficiency using a unique codon and corresponding transfer-RNA:aminoacyl-tRNA-synthetase pair.
A recently developed method makes it possible to genetically encode unnatural amino acids with diverse physical, chemical or biological properties in Escherichia coli and yeast. We now show that this technology can be used to efficiently and site-specifically incorporate p-iodo-L-phenylalanine (iodoPhe) into proteins in response to an amber TAG codon.