Dendritic cell interactions with capsular polysaccharides from pathogenic streptococci: impact on innate and adaptive immune responses

点击翻译按钮获取中文摘要

Infection often occurs when the immune system fails to respond optimally to invading pathogens. Therefore, the quest to manipulate the immune system to generate effective immunity against pathogens can be considered as the 'grand challenge' of modern immunology. An integral player orchestrating this immunity is a rare but widely distributed network of cells called dendritic cells (DCs). DCs express pathogen recognition receptors to sense and respond to microbes or vaccines. Research in the last decade has shown a fundamental role for DCs in initiating and controlling the quality and strength of the immune response. However, little information is available regarding the role of DCs in the immune response to extracellular bacteria, most of which are covered by a shell of sugars, known as the polysaccharide capsule (CPS), that help bacteria hiding from the immune system. Two examples of these redoubtable bacteria are Group B Streptococcus (GBS), which is a leading cause of disease and mortality in newborns and pregnant women; and Streptococcus suis, an important swine pathogen worldwide, which can be transmitted to humans. Both pathogens cause severe invasive diseases. In my research plan, I propose to delineate the interactions of GBS and S. suis with DCs and other immune cells to identify mechanisms by which DCs can overcome the strategies used by encapsulated bacteria to evade the immune system and thus initiate a protective immune response. Data from these studies will provide new insights into the pathogenesis of the disease caused by encapsulated bacteria, thereby helping to advance the development of control measures against these important pathogens.