Abstract

Natural killer (NK) cells large granular lymphocytes that play an important role in our immune system. They are known to recognize and kill tumour and virus-infected cells. Historically, they were named ‘natural killer’ because they have the ability to kill a target cell ‘naturally’, meaning that they kill in a spontaneous ‘non-specific’ manner without pre-conditioning. For this reason and others, unlike T and B cells, NK cells are classified as innate immune cells. Over the past two decades, our knowledge of NK cells has substantially improved. We have learned that NK cells are more related to T cells in comparison with other leukocytes in the innate immune system, meaning that NK cells have adaptive features and were able to recognize and kill a target cell specifically. Although our knowledge of NK cells has increased significantly, a lot about NK cells is yet to be discovered. In particular, the complete mechanism behind NK cell activation, which leads to killing of tumour or virus-infected cells, remains undefined. In my PhD project I study a group of activating receptors called Killer Immunoglobulin-like receptors (KIRs). Most ligands (a protein on the target cell that the receptor recognises) of activating KIRs are unknown. By using human cytomegalovirus (HCMV) infected cell as an infection model, I have potentially found a ligand for an activating KIR on these infected cells. This finding would represent a stepping stone in unravelling the complete mechanism behind NK cell activation. In this talk I will discuss my research and I will show you how I am trying to decipher this potential ligand.