Macrophage

What are Macrophages? A type of white blood that ingests (takes in) foreign material. Macrophages are key players in the immune response to foreign invaders such as infectious microorganisms.

Function of Macrophage Macrophages help destroy bacteria, protozoa, and tumor cells. They also release substances that stimulate other cells of the immune system. And they are involved in antigen presentation. To do this, they carry the antigen on their surface and present it to a T cells.

How can it be Identified They can be identified by specific expression of a number of proteins including CD14, CD11b, F4/80 (mice)/EMR1 (human), Lysozyme M, MAC-1/MAC-3 and CD68 by flow cytometry or immunohistochemical staining. They move by action of Amoeboid movement.

How does it work When a leukocyte enters damaged tissue through the endothelium of a blood vessel (a process known as the leukocyte extravasation), it undergoes a series of changes to become a macrophage. Monocytes are attracted to a damaged site by chemical substances through chemotaxis, triggered by a range of stimuli including damaged cells, pathogens and cytokines released by macrophages already at the site. At some sites such as the testis, macrophages have been shown to populate the organ through proliferation.

Structure of a Macrophage Cell

Life Cycle Macrophages are created in the bone marrow. Macrophages start being a type of cell called monocyte, then when the monocyte is mature it turns into a macrophage. Some monocytes go to specific areas of the body, such as the liver, where they mature into specialized macrophages which remain in place. Macrophages have a short life they don’t live longer than seven or eight months.

Importance Macrophages are very important in our bodies because they protect us from dangerous diseases. They are like security guards for the immune system. Some of them remain at regular areas where foreign material commonly enters the body, they scan the materials and look if they are dangerous or and when they discover something which might be dangerous, they will create enzymes to neutralize it so that it cannot continue replicating in the body. They also remove dead cells that may cause an inflammation.