IMMUNOLOGY

Detailed explanation-1: -Armed effector cytotoxic CD8 T cells are essential in host defense against pathogens that live in the cytosol, the commonest of which are viruses. These cytotoxic T cells can kill any cell harboring such pathogens by recognizing foreign peptides that are transported to the cell surface bound to MHC class I molecules.

Detailed explanation-2: -They can act as “killer cells”, attacking cells which have been infected with a virus or another kind of pathogen, or they can act as “helper cells” by supporting B cells to produce antibodies.