Azurophilic granule

Azurophilic granules are a type of granule found in neutrophils, which are a type of white blood cell. They are named for their affinity for azure dyes, and are also known as primary granules.

Structure and Composition

Azurophilic granules are large, dense granules that are easily visible under a light microscope. They are composed of a variety of proteins, including myeloperoxidase, defensin, lysozyme, and elastase. These proteins are involved in the neutrophil's ability to kill and digest pathogens.

Function

The primary function of azurophilic granules is to aid in the destruction of pathogens. When a neutrophil encounters a pathogen, it engulfs the pathogen in a process called phagocytosis. The azurophilic granules then fuse with the phagosome, releasing their contents and killing the pathogen.

In addition to their role in pathogen destruction, azurophilic granules also play a role in inflammation. The proteins they release can attract other immune cells to the site of infection, amplifying the immune response.

Clinical Significance

Abnormalities in azurophilic granules can lead to a variety of diseases. For example, a lack of myeloperoxidase, one of the proteins found in azurophilic granules, can lead to a condition called myeloperoxidase deficiency, which can result in increased susceptibility to fungal and bacterial infections.

In addition, mutations in the gene that encodes elastase can lead to a condition called neutrophil elastase deficiency, which can result in severe congenital neutropenia, a condition characterized by a low number of neutrophils.

See Also

• Neutrophil granulocyte
• Granule (cell biology)
• Phagocytosis
• Inflammation