Macrophage

Macrophage is a type of white blood cell that is part of the immune system. Macrophages are found in almost all tissues, where they patrol for potential harmful organisms and destroy them. They are one of the first lines of defense in the immune response.

Function

Macrophages have many roles in the immune system, including the removal of dead cells, the presentation of antigens, the destruction of cancer cells, and the stimulation of other immune cells. They are able to move around in tissue and reach sites of infection or damage quickly.

Types

There are several types of macrophages, including:

• Tissue macrophages which reside in specific organs (also known as fixed macrophages)
• Monocytes which circulate in the blood and can become macrophages when they enter tissues
• Dendritic cells which share many functions with macrophages but are considered a different type of cell

Role in disease

Macrophages play a role in many diseases, as they can become overactive or dysfunctional. This can lead to chronic inflammation, which is a factor in diseases such as atherosclerosis, rheumatoid arthritis, and cancer. In some cases, macrophages can be hijacked by pathogens and used to spread infection.

Research

Research into macrophages is ongoing, with a focus on understanding how they function and how they can be manipulated to treat disease. This includes research into how macrophages can be 'reprogrammed' to attack cancer cells, or to reduce inflammation in autoimmune diseases.

See also

• Immune system
• White blood cell
• Inflammation
• Cancer

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  Cytology of a macrophage
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  Giemsa Stain Macrophage Illustration
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  Phagocytosis
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  Gram stain of a macrophage with ingested S. epidermidis bacteria
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  Macrophage
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  Micrograph of a melanophage
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  J774 Cells with Conidia in Liquid Media
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  Alveolar Macrophages with Conidia in Liquid Medium