Immune Responses

This is a response of adapted immunity. Cell-mediated responses resist invaders that reproduce within body cells and can also destroy cells that have mutated or are creating mutated forms of molecules. Cells that destroy other cells become active in this immune response. Unfortunately, they can only neutralize cells that are either infected with or producing a specific antigen.

To start this process, macrophages take a sample of the invading antigen and take it to a killer T-cells which have already bound with an antigen attached to a Class I MHC molecule. The killer T-cells then find and destroy any cells that have the the identified antigen attachd to them. This eliminates both the invaders and any infected cells.

This response is also a part of adaptive immunity. During this response, antibodies appear in body fluids, including blood. These destroy antigens. Humoral immmune responses act against foreign invaders which act outside body cells. It prevents viruses from entering cells and resists toxins and bacteria.

There is a special order in which cells and molecules interact with each other in humoral immune responses. First, a macrophage takes a sample of the antigen and gives it to a Class II MHC Molecule, which in turn takes the antigen to a helper T-cell. The T-cell the binds the antigen, which stimulates other T-cells into dividing and secreting interleukins, which are stimulatory molecules. The interleukins activate antibodies. The antibodies then help to destroy and neutralize the antigen.