What is the difference between Th1 and Th2 lymphocytes and why is it important?
It was discovered in the late Eighties [Mosmann & Coffman 1989] that there are two main types of T-helper cells: • Type-I T-helper cells, or Th1 cells, manufacture NO gas, which is used to destroy cells infected by intracellular invaders (fungus, [legitimate] virus, mycobacteria, etc). Th1 cells produce inflammatory cytokines that stimulate the cell-mediated immunity. Macrophages and natural killer cells also produce cytotoxic NO gas. If these immune cells are not protected by sufficient intracellular glutathione (“gas mask”), they can accidentally become “kamikaze” fighters and die from their own attack (gaseous NO spray). • Type-II T-cells, or Th2 cells, do not manufacture NO gas. Instead they are antibody-helper cells. They migrate to the lymph and stimulate the B-cells to make antibodies, as part of the humoral immunity. An excess of Th2 cells in the bloodstream due to AZT toxicity can give a misleading representation of the actual strength of the cell-mediated (Th1)immune defense.
