Phagocyte Chemiluminescence

Phagocytes form an essential defence against microbial infection and have an important role in debridement following tissue injury. In human subjects, there are essentially two classes of phagocyte: polymorphnuclear leukocytes (PMNL) and mononuclear phagocytes, both derived from myelomonocytic bone marrow cells. PMNL circulate in the bloodstream, and are subdivided into neutrophils, eosinophils, and basophiles. Mononuclear phagocytes circulate in the blood as monocytes as a heterogeneous population, a proportion of which becomes tissue macrophages (e.g., Kupffer cells in liver, microgha in brain). While blood-borne PMNL and monocytes are easily accessible for study, many tissue macrophages are difficult to obtain for in vitro chemiluminescence. Although methods of obtaining relatively pure populations of tissue macrophages exist, all tend to activate the cells to a variable degree, which impedes interpretation of any results obtained. Most in vitro macrophage studies are therefore conducted with monocyte-derived cells, although alveolar (lung) and peritoneal macrophages can be studied by direct sampling with minima1 preparation.