Describe how phagocytosis of a virus by a macrophage leads to the presentation of its antigens.

Describe how the presentation of this viral antigen leads to the secretion of antibodies against it.

Myelin is a protein-lipid substance produced by cells in the central nervous system. Multiple sclerosis (MS) is an auto-immune disease in which a person's immune system attacks their own myelin. MS causes muscle weakness, vision loss, and coordination difficulties. Scientists have identified a virus that produces a protein very similar to human myelin protein. Suggest how the immune response to this viral protein can result in the development of MS.