免疫化学分野

大阪大学 免疫学フロンティア研究センター 免疫化学研究室 / 微生物病研究所 免疫化学分野


Our department analyzes how pathogens such as viruses have acquired the ability to evade the immune system and how host immune systems have acquired resistance to various pathogens. In particular, we are elucidating a fundamental mechanism of host defense against various pathogens by analyzing various immune regulatory receptors. Of particular interest are 'paired receptors' that consist of activating and inhibitory receptors expressed on various immune cells (Figure 1). We have suggested that these 'paired receptors' have evolved with pathogens by identifying the host ligands and viral ligands they recognize. In addition, we have found that these receptors are also involved in viral entry into cells. These studies will help to elucidate fundamental mechanisms of immune evasion by pathogen and the host factors that influence resistance to various infections. This research will help to build the foundation required for the development of new vaccines and therapies for infectious diseases.

(1) Analysis of recognition by 'paired receptors' Immune cells express various receptors that consist of activating and inhibitory receptors that are highly homologous to each other. The inhibitory receptors recognize self-antigens such as MHC molecules. In contrast, the activating receptors generally do not recognize self-antigens and ligands for most of them have remained unclear. We have found that one of these 'paired receptors' recognizes cytomegalovirus protein and showed that 'paired receptors' play an important role in determining host resistance to pathogens (Figure 2). We are continuing to analyze the functions of these receptors to elucidate the interactions between pathogens and the host immune system.

(2) Entry mechanism of virus into cells As described above, several viruses, which show persistent infection, downregulate immune response by expressing ligands for inhibitory receptors. Interestingly, we have found that some viruses exploit inhibitory receptors to enter the cells. Interaction between immune receptors and viral proteins was found to play an important role in entry mechanism of herpes simplex virus (HSV) (Figure 3). Because there is a possibility that other viruses also use similar receptors to enter cells, we further investigate molecular.

paired receptorRecognition of cytomegalovirus-infected cells by inhibitory and activating paired receptors

Entry mechanism of virus into cells