The innate immune system responds quickly to infection, with neutrophils (a type of white blood cells) being the first responders. Neutrophils enter the site of infection and begin to phagocytose (take up) pathogens. Once engulfed, the neutrophils must then degrade the captured pathogens–a process known as intracellular killing. One method of intracellular killing which takes place in the phagolysosomes of neutrophils involves the reaction of<unk>  with hydrogen peroxide (H2O2) acquired in the cells from NADPH oxidase through the respiratory bursts. This reaction generates several acidic products including hypochlorous acid (HClO), which can break down pathogens. Bacteria such as Pseudomonas aeruginosa and fungi such as Candida albicans are killed in this manner. Neutrophils are also involved in killing extracellular pathogens (pathogens outside of the cell) through the release of NETs. These NETs contain<unk> , among other antimicrobial proteins. Once released outside of the cell, NETs trap pathogens and may in some cases kill them. Although<unk>  is not required for all NET formation/release, NETs are only formed and released in response to Candida albicans when<unk>  is present.<unk>  proteins in NETs can still react with H2O2 to form HClO and break down some extracellular pathogens. In<unk>  deficient individuals, this extracellular pathogen killing doesn’t typically occur. Finally, during infection, neutrophils can migrate to the lymph nodes, where they deposit<unk> . Although the mechanisms of this process aren’t well understood, there is evidence that this extracellular<unk>  interacts with dendritic cells (cells of the adaptive immune system) in the lymph nodes, leading to a decrease in adaptive immune system activity in response to infection.
Myeloperoxidase deficiency
MBL deficiency
Leukocyte adhesion deficiency
Adenosine deaminase deficiency
Adenosine deaminase 2 deficiency
Leukocyte adhesion molecule deficiency
Neutrophil-specific granule deficiency
Primary immunodeficiency