好中球の機能

Abstract

Neutrophils play a central role in host defence. They are produced in the bone marrow and egress into the vascular space at the rate of 1 × 109/kg of body weight per day and may be enhanced in the presence of an inflammatory stimulus. They stay in the vascular space for about 10 hours, then emigrate to tissue where they work as a guard against invading pathogenic microorganisms for a few days. The most important function of neutrophils is their phagocytic and killing activity against pathogenic microorganisms. The cellular response to microbial invasion can be divided into a number of stages, chemotaxis, phagocytosis (ingestion), intracellular killing and degranulation. Neutrophils must perform all of these steps to exhibit normal microbicidal activity. The major subjects of the recent research on neutrophil function are as follows: the adhesion between neutrophils and endothelium, intracellular signal transduction and the generation of oxygen radicals that play a key role in microbial killing. Researches on cytokines also offered important informations for analysing the regulatory mechanism of neutrophil function. It will be necessary to analyse the regulatory mechanism of neutrophil function in vivo and the role of neutrophils in the pathogenesis of some diseases in the future.