Preparation of tumour ligand B7-H6 with coiled-coil tag and verifying of its binding to receptor NKp30

Natural killer cells (NK cells) are part of innate antitumor immunity. These cells have the capacity to prevent viral infection or malignant transformation without prior antigen sensitization. Activation of NK cells consist of different recognition strategies. Mechanism of activation is based on down-regulated expression of MHC gp I molecules on the cell surface. NK cells possess both activation and inhibitory receptors that transmit activation or inhibitory signals which determine if NK cells are activated or not, and thus whether the target cell will be lysed or spared. NKp30 is a type I transmembrane receptor which recognize the stress-induced cell surface ligand B7-H6. Interaction of these two proteins leads to the initiation of immune response. The main aim of this thesis is the preparation of cell ligand B7-H6 with coiled-coil peptide tag in human embryonic kidney cell lines HEK293 GnTI- and HEK293T. Successful preparation of B7-H6 with coiled-coil tag on its C-terminus was verified by mass spectrometry. Its interaction with natural cytotoxicity receptor NKp30 was also proven by sedimentation analysis. Key words: NK cells, recombinant expression, B7-H6, HEK293, coiled-coil (This thesis is written in Czech