Tissue-resident natural killer cells: Features of functioning in the uterus and decidual membrane [Тканерезидентные натуральные киллеры: особенности функционирования в матке и децидуальной оболочке]

Natural killers are a heterogeneous population of innate immune lymphocytes, among which in recent years 2 categories of cells have been distinguished - circulating (cNK) and tissue-resident (trNK). The circulating pool of these cells is now fairly well characterized: these are cells of bone marrow origin with predominantly cytolytic activity, predominanly CD56dimCD16+ phenotype and a high level of perforin and granzymes expression. The tissue-resident pool has not yet been sufficiently studied, but a number of its features have been established: the ability to differentiate in tissues, the predominance of the CD56brightCD16- phenotype, the ability to produce high levels of certain regulatory cytokines (IFN-γ, TNFα, GM-CSF), the nature of the expression of receptors specific to class I histocompatibility molecules, etc. One of the most important features of trNKs is that their properties correspond to the specific organ where they are localized. This review is devoted to the characteristics of the natural killer cells of the uterus (uNK) and the decidual membrane (dNK) during pregnancy, the features of their origin, phenotype, cytokine production and the set of implemented functions. © 2021 Meditsina Publishers. All rights reserved.