What we do…
What do Natural Killer cells and T cells do in the body?
Natural Killer (NK) cells and T cells are important components in the body’s defense against viral infections and tumors. NK cells and cytotoxic T cells (CTL) which is a subtype of T-cells control abnormal cells in the body by migrating from cell to cell and scan their surfaces in search of protein molecules, ligands, suggesting that the cell is infected or transformed. T cells have surface proteins, called T cell receptors that are activated selectively only on contact with specific antigens, while NK cells have a number of receptors that can provide both activating and inhibitory signals. If a target cell is considered abnormal, a close cell–cell interaction is formed and the T-cell or NK cell secretes substances that eventually lead to death of the target cell.
The value of single cell studies!
Each individual’s set of T and NK cells are heterogeneous with respect to the composition and number of the various receptor proteins on the cell surface. In practice this means that each cell or subpopulation of T / NK cells can be more or less sensitive to activation. Traditional immunological experiments are performed on large populations of cells with results that reflect the average of thousands or millions of cells. This experimental set up is not always favorable since complications of immunologic nature could be caused by a small group of cells that behave abnormally. Conversely, presence of a specific T cell clone or a few NK cells with activity against, e.g. virus infected cell or tumor cells can be instrumental for fighting disease or killing residual leukemia cells after stem cell transplantation. Therefore, it is of critical importance to study the behavior of NK and T cells at the single-cell level.