PHENOTYPIC HETEROGENEITY OF NEUTROPHILS: NEW ANTIMICROBIC CHARACTERISTICS AND DIAGNOSTIC TECHNOLOGIES

Abstract

Introduction. Neutrophils are the most numerous subpopulation of leukocytes circulating in the blood; they constitute the first line of defence of the innate link of the immune system.Aim. To generalize basic concepts about phenotypic and functional heterogeneity of neutrophils.General findings. According to contemporary concepts, this type of blood cells performs not only antimicrobial functions, but also participates in capture and destruction of various microorganisms, including such processes as phagocytosis and intracellular degradation, degranulation and formation of extracellular neutrophilic traps after the detection of microorganisms. Neutrophils are considered to be a phenotypically heterogeneous pool of blood cells featuring a significant functional variability. Under pathological conditions, they can differentiate into discrete subpopulations with va rious phenotypic and functional characteristics. They are capable of interaction with macrophages, natural killers, dendritic and mesenchymal stem cells, B and T lymphocytes or platelets. In addition, neutrophils exhibit vector properties with respect to cancerous tumours. They possess a high morphological and functional variability, being modulators of both inflammation and active triggers of immune responses. A search for molecular markers able to efficiently differentiate neutrophil phenotypes and establish the degree of their diagnostic specificity for various pathologies is of a particular importance.