Then the macrophage takes the invader apart, and displays the viral antigens on its surface for other immune cells to read (Figure 3).

Antigens are proteins specific to each particular microorganism. The antigens act as an identity card that allows our immune system to recognize invader organisms that need to be eliminated (Figure 1).

After displaying the agent's antigens, the macrophage will send out a message to a T-helper cell to read and recognize the antigens (Figure 4).