Phyu Thwe Soe1, Jariya Hanthamrongwit2, Chutiphon Saelee2, Soe Paing Kyaw3, Prasong Khaenam4, Saradee Warit5, Nusara Satproedprai6, Surakameth Mahasirimongkol6, Hideki Yanai7, Patchanee Chootong2, Chaniya Leepiyasakulchai8. 1. Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand; Department of Medical Laboratory Technology, University of Medical Technology, Mandalay, Myanmar. 2. Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand. 3. Clinical Pathology Laboratory, (1000) Bedded General Hospital, Nay Pyi Taw, Myanmar. 4. Center of Standardization and Product Validation, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand. 5. Industrial Tuberculosis Team, IMMBRG, National Center for Genetic Engineering and Biotechnology (BIOTEC), NSTDA, Pathum Thani, Thailand. 6. Genomic Medicine and Innovation Support Division, Department of Medical Sciences, Ministry of Public Health, Thailand. 7. Department of Clinical Laboratory, Fukujuji Hospital, Japan Anti-Tuberculosis Association (JATA), Tokyo, Japan. 8. Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand. Electronic address: chaniya.lee@mahidol.edu.
Abstract
OBJECTIVE: To elucidate the antigenic potential of dormancy-associated antigens Rv2659c and Rv3128c of Mycobacterium tuberculosis by examining the persistence of specific IgG and IgA memory B cells (MBCs) among patients with active tuberculosis (TB), household contacts with latent tuberculosis (LTBI), and an endemic healthy control group. METHODS: Fresh peripheral blood mononuclear cells from the three study groups were used to enumerate the numbers of IgG and IgA MBCs specific to recombinant protein Rv2659c and Rv3128c by ELISpot assay. The composition of MBC subsets IgA+ and IgG + was analyzed by flow cytometry. RESULTS: The number of IgA MBCs specific to antigen Rv2659c was significantly higher in the LTBI group than the TB group. In contrast, no significant difference was found in IgA or IgG MBCs against antigen Rv3128c. The number of IgA+ MBCs was significantly higher than that of IgG+ MBCs in the classical MBC subset of the LTBI group. CONCLUSION: The results indicated that the dormancy-associated antigen Rv2659c induced an IgA MBCs response in individuals with latent TB, and IgA+ classical MBCs formed a major portion of the MBCs subset. This new knowledge will be beneficial for the development of novel TB vaccines and their control of latent TB.
OBJECTIVE: To elucidate the antigenic potential of dormancy-associated antigens Rv2659c and Rv3128c of Mycobacterium tuberculosis by examining the persistence of specific IgG and IgA memory B cells (MBCs) among patients with active tuberculosis (TB), household contacts with latent tuberculosis (LTBI), and an endemic healthy control group. METHODS: Fresh peripheral blood mononuclear cells from the three study groups were used to enumerate the numbers of IgG and IgA MBCs specific to recombinant protein Rv2659c and Rv3128c by ELISpot assay. The composition of MBC subsets IgA+ and IgG + was analyzed by flow cytometry. RESULTS: The number of IgA MBCs specific to antigen Rv2659c was significantly higher in the LTBI group than the TB group. In contrast, no significant difference was found in IgA or IgG MBCs against antigen Rv3128c. The number of IgA+ MBCs was significantly higher than that of IgG+ MBCs in the classical MBC subset of the LTBI group. CONCLUSION: The results indicated that the dormancy-associated antigen Rv2659c induced an IgA MBCs response in individuals with latent TB, and IgA+ classical MBCs formed a major portion of the MBCs subset. This new knowledge will be beneficial for the development of novel TB vaccines and their control of latent TB.