Azurophilic

These more mature cell types are incapable of division and are identified by their nuclear morphology, granule content and accumulation of glycogen particles. In a mature neutrophil there are 200-300 granules, with the specific granules being about twice as abundant as azurophilic granules. 

The most abundant organelles within the cytoplasm are the granules, which are membrane-bound organelles containing an array of antimicrobial proteins. As discussed above ( 2.4), three major types have been identified to date azurophilic, specific and gelatinase-containing granules. Additionally, newly-described structures called secretory vesicles have been identified. 

Azurophil Specific Gelatinase- containing Secretory vesicle... 

The antimicrobial neutrophil proteins are located within intracellular granules. Approximately 30% of all neutrophil granules contain myeloperoxidase, and these azurophilic granules are the first granule types to be... 

The peroxidase-negative granules produced later in neutrophil development are termed secondary or specific granules (because they stain only with specific dyes). They are twice as abundant in the cytoplasm of the mature neutrophil as the azurophilic granules. Specific granules contain much of the lysozyme, lactoferrin, vitamin-B 12-binding protein, adhesin receptors, fMet-Leu-Phe receptors, and cytochrome b.245. 

BPI has been purified and characterised from both human and rabbit neutrophils, and the two proteins from these different species are highly homologous the first 17 amino-terminal amino acids are 80% homologous and the two molecules are immunologically cross-reactive. BPI is tightly associated with the azurophilic granule for two reasons ... 

Cathepsin G, a cationic, glycosylated protein of relative molecular mass -27 kDa, exists in four isoforms (25-29 kDa) that are identical in amino acid sequence but differ in levels of glycosylation. It is a component of azurophilic granules and present in human neutrophils at 1.5-3 jug/106 cells, but at lower levels in monocytes. cDNA has been cloned and sequenced (and the amino acid sequence predicted), and the gene has been localised to chromosome 14ql 1.2. The gene comprises five exons and four introns, a structure similar to that of the elastase gene. 

Lysozyme is a 14.4-kDa cationic protein (pi > 10) with the ability to kill a wide range of Gram-positive bacteria. It is present in both azurophilic and specific granules of neutrophils and is also found in the granules of monocytes and macrophages, in blood plasma, tears, saliva and airway secretions. In human neutrophils it is present at 1.5-3 jug/106 cells. Since its discovery in 1922 by Fleming, it has been widely studied by protein biochemists, and its three-dimensional structure has been precisely defined. It exerts its ef-... 

In order to function efficiently, myeloperoxidase must be translocated from its intracellular location, the azurophilic granule, to the site of NADPH oxi-... 

Circulating neutrophils of patients with CHS contain giant azurophilic and specific granules that form during haematopoiesis, and stem cells with these abnormalities are seen in the marrow. Chemotaxis, degranulation and bactericidal activity of circulating neutrophils are all impaired (often delayed), and these defects, coupled with the neutropenia that may occur, result in increased susceptibility to infections. Lymphocyte and NK cell functions are also defective. 

Lymphocytes White blood cells formed in the body s lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each) those with characteristics of neither major class are called null cells. [NIH]... 

Morphology Lymphocytes possess a large nucleus with little to no basophilic cytoplasm. Differences are seen in the nuclear (N) to cytoplasmic ratio, the degree of cytoplasmic staining with histological dyes and the presence or absence of azurophilic granules. 

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