PATHOLOGY

Detailed explanation-1: -They use chemical messengers to activate other immune system cells in order to start the adaptive immune system (T helper cells). They detect cells infected by viruses or tumorous cells and destroy them (cytotoxic T cells).

Detailed explanation-2: -RB: T cells can play different roles. 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.

Detailed explanation-3: -T cells protect us from infection. T cells can wipe out infected or cancerous cells. They also direct the immune response by helping B lymphocytes to eliminate invading pathogens.

Detailed explanation-4: -There are two main classes of T cells-cytotoxic T cells and helper T cells. Effector cytotoxic T cells directly kill cells that are infected with a virus or some other intracellular pathogen.