Cytotoxic T cell
A cytotoxic (or TC) T cell is a T cell (a type of white blood cell) which has on its surface antigen receptors that can bind to fragments of antigens displayed by the Class I MHC molecules of infected somatic cells.
Once bound to an antigen, TC cells release the protein perforin[?], which forms pores in the target cell's plasma membrane; this causes ions and water to flow into the target cell, making it expand and eventually lyse[?].
Most TC cells have present on the cell surface the protein CD8[?], which is attracted to portions of the Class I MHC molecule. This affinity keeps the TC cell and the target cell bound closely together during antigen-specific activation. TC cells with CD8 surface protein are called CD8+ T cells.
See also: