Title: Neutrophilic granulocytes in peripheral blood smear (human)
Description: Stain: May-Grünwald-Giemsa (MGG).
The three neutrophilic granulocytes display segmented and lobulated nuclei. The lobes are connected with thin chromatin strands (→). The cytoplasm is ample filled with fine, dust-like granules and the majority are specific granules filled with enzymes such as lysozyme, collagenase, and elastase. These granules do not stain strongly with either basic or acidic dyes in contrast to the so-called azurophilic granules which contain enzymes and microbicidal substances.
Background: Neutrophils (and also macrophages) express cell surface receptors that recognize microbes which are subsequently ingested and degraded in phagolysosomes. Samples of receptors are mannose receptors and scavenger receptors, receptors for opsonins (Ig and complement factors), Toll-like receptors (TLR’s), G protein–coupled receptors .The actual killing mechanism for microbes consists of generation of reactive oxygen intermediates (ROI’s, respiratory burst), and reactive nitric oxid intermediates (iNOS). In addition they can release also cytokines (TNF, IL-12) to enhance inflammation reaction. See also POJA-L-604.
Keywords/Mesh: blood, bone marrow, neutrophilic granulocyte, histology, POJA collection