Epstein-Barr virus latent gene EBNA-1 genetic diversity among transplant patients compared with patients with infectious mononucleosis

CHANGES IN SUBSET COMPOSITION AND PHAGOCYTIC ACTIVITY OF MONOCYTES IN CHILDREN WITH INFECTIOUS MONONUCLEOSIS UNDER EXPOSURE TO GM-CSF IN VITRO

The aim of the study was to investigate the features of changes in the subset composition of monocytes and their phagocytic activity in children with infectious mononucleosis (IM) under the influence of granulocyte-macrophage colony-stimulating factor (GM-CSF) in vitro. We examined 84 children aged 3 to 11 years with Epstein-Barr virus (EBV) infection. EBV infection was diagnosed on the basis of clinical signs of IM, a positive test for EBV DNA in blood lymphocytes and results of ELISA tests (EBV-VCAIgM (+), EBV-EA-DIgG (+)). The control group consisted of 40 practically healthy children of the same age range. Monocytes were obtained by the standard method of adhesion to plastic from mononuclear cells isolated from heparinized venous blood by density gradient centrifugation. The isolated monocytes were divided into two samples: control (without GM-CSF) and experimental (50 ng of GM-CSF per 1 ml of cell suspension). The subset composition and phagocytic activity of monocytes in both samples were determined by flow cytometry after incubation for 1 hour at 37C in a CO2-incubator. It was found that in children against the background of the development of IM, the subpopulation composition of monocytes in the blood changes and their phagocytic activity is impaired. It was found that the subset composition and phagocytic activity of the blood monocytes changed in children against the background of the development of IM. Changes in the subset composition of monocytes against the background of acute IM did not depend on the age group of children (3-6 and 7-11 years) and were characterized by an increase in the number of pro-inflammatory (intermediate) monocytes and a decrease in the content of anti-inflammatory (non-classical) monocytes. Features of violation of the phagocytic activity of the monocytes in children with IM depended on age. The phagocytic activity of all three subsets of the monocytes was reduced in children with IM 3-6 years old while children with IM 7-11 years old had reduced phagocytic activity only of intermediate and non-classical monocytes. The effect of GM-CSF in vitro on monocytes in patients with IM, regardless of the age of children, led to a significant increase in the level of anti-inflammatory monocytes while the phagocytic activity of cells changed less. An increase in the phagocytic number for classical monocytes after incubation with GM-CSF in vitro was noted in children with IM at the age of 3-6 years while the phagocytic index of this fraction of monocytes remained unchanged. The level of the phagocytic index increased only in classical monocytes of children with IM aged 7-11 years. The presented results determine the scientific and clinical value of studying the mechanisms of the effect of GM-CSF on cells of the immune system and prove that this cytokine can be used in a new immunotherapeutic strategy for the treatment of IM.

[Epstein-Barr viral infection is a global epidemiological problem]

The number of studies devoted to Epstein-Barr viral infection (EBV infection) has been growing in recent years. However, they all relate to the clinical aspects of this problem. Epidemiology issues remain practically unexplored. A review of domestic and foreign publications has shown that at the present stage there is a high intensity of the epidemic process of EBV infection both in Russia and abroad. The main indicators of unfavorable epidemiological situation are the ubiquitous spread of the pathogen and the increase in the incidence of infectious mononucleosis in recent years. The deterioration of the epidemic situation of EBV infection is influenced by changes in the immunological reactivity of various population groups due to the spread of HIV, HBV, HCV, the causative agent of tuberculosis and SARS-CoV-2. The above makes it possible to classify the problem as a global one and determines the need for the rapid implementation of the system of epidemiological surveillance of EBV infection and optimization of the complex of preventive and anti-epidemic measures. Reducing the burden of EBV is possible only with the consolidated participation of specialists of various profiles.