OU Xijun

Dr. Xijun Ou completed his BSc degree at Huazhong Agricultural University before undertaking a PhD with Professor Guoping Zhao in the Department of Microbiology and Microbial Engineering at Fudan University. His PhD work was to study the functions of signaling molecules in Streptomyces coelicolor differentiation. After that, he did his postdoctoral research on B cell immune responses with Professor Lam Kong-Peng at the Bioprocessing Technology Institute in Singapore. In the past five years, Dr. Ou has published several papers in peer-reviewed journals including Nature Communications, PNAS, etc.

Research Interests:
Successful vaccination relies on immune memory. The formation of an isotype-switched, high-affinity memory B cell population is usually associated with T cell-dependent antibody responses. T cell-dependent antibody responses are characterized by the rapid development of histological structures called germinal centers (GCs) in secondary lymphoid tissues. Here antigen-activated B cells expand and undergo antibody class-switching, somatic hypermutation and affinity maturation, and finally differentiate into long-lived plasma cells and memory B cells that are essential for the clearance of infectious pathogens such as HBV and Mycobacterium tuberculosis. Although GCs were described more than 100 years ago, the mechanism for the bifurcation of GC B cells into either plasma cells or memory B cells remains poorly understood. Moreover, the molecular basis for survival and maintenance of long-lived plasma cells and memory B cells is still largely unknown.

My research interests are mainly focused on:
1. How long-lived plasma cells and memory B cells are generated and maintained.
2. How B cell immune response is tightly regulated to keep avoiding autoimmune diseases such as lupus.
3. What goes wrong in B cell differentiation to allow the development of cancerous cells such as multiple myeloma.

Professional Experience:
2016-present, Assistant Professor, Department of Biology, SUSTech
2015-2016, Associate Staff Scientist, Bioprocessing Technology Institute, Singapore
2009-2015, Research Scientist, Bioprocessing Technology Institute, Singapore

Educational Background:
2002-2009, Ph.D. (Microbiology), Fudan University, China
1997-2001, B.S. (Microbiology), Huazhong Agricultural University, China

Selected Publication
1. Ou X*, Huo J, Huang Y, Li YF, Xu S*, Lam KP*. Transcription factor YY1 is essential for iNKT cell development. Cellular & Molecular Immunology. 2018 Mar 2. doi: 10.1038/s41423-018-0002-6. (*co-corresponding author)
2. Li YF, Xu S, Huang Y, Ou X, Lam KP. Tyrosine kinase c-Abl regulates the survival of plasma cells. Scientific Reports. 2017 Jan 6;7:40133.
3. Li YF#, Ou X#, Xu S, Jin ZB, Iwai N, Lam KP. Loss of miR-182 affects B-cell extrafollicular antibody response. Immunology 2016, 148(2):140-9. (#co-first author)
4. Xu S#, Ou X#, Huo J, Lim K, Huang Y, Chee S, Lam KP. Mir-17-92 regulates bone marrow homing of plasma cells and production of immunoglobulin G2c. Nature Communications 2015, 6:6764. (#co-first author)
5. Li YF, Lee KG, Ou X, Lam KP. Bruton’s tyrosine kinase and protein kinase C µ are required for TLR7/9-induced IKKα and IRF-1 activation and interferon-β production in conventional dendritic cells. PLoS One 2014, 9(8):e105420.
6. Ou X, Xu S, Li YF, Lam KP. Adaptor protein DOK3 promotes plasma cell differentiation by regulating the expression of programmed cell death 1 ligands. PNAS 2014, 111(31):11431-6.
7. Li YF, Xu S, Ou X, Lam KP. Shp1 signalling is required to establish the long-lived bone marrow plasma cell pool. Nature Communications 2014, 5:4273.
8. Ou X, Xu S, Lam KP. Deficiency in TNFRSF13B (TACI) expands T-follicular helper and germinal center B cells via increased ICOS-ligand expression but impairs plasma cell survival. PNAS 2012, 109(38):15401-6.
9. Zhang X, Bao Y, Shi X, Ou X, Zhou P, Ding X. Efficient transposition of IS204-derived plasmids in Streptomyces coelicolor. Journal of Microbiological Methods 2012, 88(1):67-72.
10. Zhang L, Wang L, Wang J, Ou X, Zhao G, Ding X. DNA cleavage is independent of synapsis during Streptomyces phage phiBT1 integrase-mediated site-specific recombination. Journal of Molecular Cell Biology 2010, 2(5):264-75.
11. Ou X, Zhang B, Zhang L, Zhao G, Ding X. Characterization of rrdA, a TetR family protein gene involved in the regulation of secondary metabolism in Streptomyces coelicolor. Applied and Environmental Microbiology 2009, 75(7):2158-65.
12. Ou X, Zhang B, Zhang L, Dong K, Liu C, Zhao G, Ding X. SarA influences the sporulation and secondary metabolism in Streptomyces coelicolor M145. Acta Biochimica et Biophysica Sinica 2008, 40(10):877-82.
13. Zhang L, Ou X, Zhao G, Ding X. Highly efficient in vitro site-specific recombination system based on streptomyces phage phiBT1 integrase. Journal of Bacteriology 2008, 190(19):6392-7.