A<unk>  (also known as<unk> ,<unk> , T-Killer cell or killer<unk>  belongs to a sub-group of T lymphocytes (a type of white blood cell) which are capable of inducing the death of infected somatic or tumor cells; they kill cells that are infected with viruses (or other pathogens), or are otherwise damaged or dysfunctional.  Most<unk> s express T-cell receptors <unk> Rs) that can recognize a specific antigenic peptide bound to  Class I MHC molecules, present on all nucleated cells, and a glycoprotein called CD8, which is attracted to non-variable portions of the Class I MHC molecule. The affinity between CD8 and the MHC molecule keeps the<unk>  cell and the target cell bound closely together during antigen-specific activation. CD8+<unk> s are recognized as<unk>  cells once they become activated and are generally classified as having a pre-defined<unk>  role within the immune system.
Cytotoxic T cell
Memory T cell
Reactive lymphocyte
Dendritic cell
Follicular dendritic cells
B cell
Osteoclast
Complement membrane attack complex