[Functional Genomics Center Seminar ]
    
      
   ▶Subject: Staphylococcal cell wall glycopolymer functions as a novel antigen molecule of T cell subsets: a valuable vaccine candidate for MRSA infection
   
   ▶Speaker: Bok Luel Lee, Ph.D. (College of Pharmacy, Pusan National University )
           
   ▶Date: 4:00PM/Mar./17(Tue)/2015
          
   ▶Place: Life Science Bldg. #104

   *Abctract
         Staphylococcus aureus is one of the most frequent causes of serious infections in humans.
Recently, infections caused by community-associated methicillin-resistant S. aureus (MRSA) have been reported to be increasing in healthy children and young adults. Since an effective staphylococcal vaccine has not been developed yet, identification of novel staphylococcal vaccine candidates is urgently needed. Many recent studies demonstrated that both serum antibody-mediated humoral immunity and T-cell-mediated cellular immunity are required to establish protective immunity against MRSA infection, suggesting that development of these two immune responses is essential for effective vaccination against S. aureus infection. However, no vaccine candidate has been identified that elicits both humoral and cellular immune responses in a murine model. Recently, we have demonstrated that S. aureus wall component is recognized by mannose-binding lectin (MBL), a key component of human complement system, and human serum antibody. These studies suggest that staphylococcal cell wall derivatives may induce protective immunity against S. aureus infection. To test this hypothesis, we purified several staphylococcal cell wall glycopolymer derivatives from S. aureus mutant strains. Following intradermal immunization of C57BL/6J mice with purified cell wall glycopolymer derivatives, infection with USA300 MRSA strain was performed with intravenous inoculation. When serum antibody titer and bacterial loads were examined, one of the cell wall derivatives was found to induce production of antibody significantly, with corresponding reduction in abscess formation and decreased bacterial load in kidneys. Further investigation showed that intraperitoneal injection of the same staphylococcal cell wall derivative into C57BL/6J mice resulted in significantly increased T-cell subset s-mediated IL-17 production in peritoneal fluid. Taken together, our results demonstrate that our novel staphylococcal cell wall glycopolymer derivative induces both humoral immunity, as demonstrated by production of specific serum antibodies that promote opsonophagocytosis, as well as cellular immunity, as demonstrated by production of T-cell subset s-mediated IL-17, which promotes neutrophil recruitment and phagocytosis during early-stage MRSA infection. Also, our studies support that newly identified staphylococcal cell wall glycopolymer functions as an antigen molecule of T-cell subsets and this glycopolymer derivative is a novel vaccine candidate against MRSA infection.

   ▶Inquiry: Prof. Inhwan Hwang (279-2128)
         
     * This seminar will be given in English