AP BIOLOGY

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: -Cytotoxic T lymphocytes (CTLs) often called CD8+ T cells, are a critical component of the adaptive immune system and play an important role in immune defense against intracellular pathogens such as viruses and bacteria and against tumors [1].

Detailed explanation-3: -Cytotoxic T cells can be separated from other blood cells, grown in the laboratory, and then given to a patient to kill cancer cells. A cytotoxic T cell is a type of white blood cell and a type of lymphocyte. Also called cytotoxic T lymphocyte and killer T cell.

Detailed explanation-4: -CD8+ T cells (often called cytotoxic T lymphocytes, or CTLs) are very important for immune defence against intracellular pathogens, including viruses and bacteria, and for tumour surveillance.

Detailed explanation-5: -CD4 T cells are MHC-II restricted and pre-programmed for helper functions, whereas CD8 T cells are MHC I-restricted and pre-programmed for cytotoxic functions.