Title & Institution: Professor, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University

Email: kovit.pat@mahidol.ac.th

Topic in NCKU Research Week: Alteration of B-cell subsets and their fates during acute dengue infection

Abstract:

B-cells play a major role in both protective immunity and immunopathology during dengue viral (DENV) infection. While rapid and massive virus-specific plasmablast responses with high numbers of antibody secreting cells (ASCs) are observed, little is known about the regulation of these cells and other B-cell subsets as well as their fates and distribution. In this study, peripheral mononuclear cells obtained from the patients throughout the acute infection period were stained for B cell subsets of naïve, resting memory (RM), tissue memory (TM), activated memory (AM), ASC and plasmablasts with a panel of fluorochrome-conjugated monoclonal antibodies against CD3, CD14, CD19, CD20, CD21, CD27, CD38, CD45, CD138 and some interesting homing molecules and analyzed by using polychromatic flow cytometer.  Expression of pro-apoptotic CD95 molecules was also determined by activation of these B-cell subsets with dengue non-structural protein 1 (NS1).  Resullts showed significant increase in the frequencies of TM and ASC expressing trafficking molecules of inflamed tissues and various organs during DENV infection. In contrast, the frequencies of naïve and RM B-cells in the patients were considerably decreased, while AM cells remained unchanged. However, these changes were not different in both dengue fever and dengue hemorrhagic fever, suggesting that such alterations of B cell subsets was not associated with disease severity. Interestingly, B-cell apoptosis showed significantly increase in the frquencies of CD95 expression in all B-cell subsets except ASCs when compared to the normal controls. This study provides insight into the distribution and mobilization of B-cell subsets. Alteration of CD95 expression induced by NS1 protein in certain B-cell subsets suggesting a potential mechanism of apoptotic regulation on B-cell subsets during the ongoing of DENV infection.

Personal Profile: Kovit Pattanapanyasat received his B.Sc and MSc in Biochemistry, (1974, 1977) from Chulalongkorn University, Bangkok, Thailand.  He received a Dip. Bio. Med. Method, (1985) and a Ph.D. in Haematology (1987) from the University of Wales College of Medicine, Cardiff, U.K. He has been on the Faculty of Medicine Siriraj Hospital, Mahidol University since 1980. He was appointed as a Professor in 1997 and is now Mahidol University’s Emeritus Professor and head of the Siriraj Center of Research Excellence in Microparticle and Exosome in Diseases (SiCORE MED) at the Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. Professor Kovit principal research interest has always been in the use of flow cytometry to study immuno-pathophysiology of thalassemia and infectious diseases i.e. dengue, malaria, and HIV, all of which are the diseases that have a great impact on the public health and economic burden in Thailand. He and his research team have published more than 200 articles in the peer reviewed journals.

Website link to personal research profile:  https://www.si.mahidol.ac.th/th/department/microbiology/microbiology_index-1.asp