Введение. При клинической манифестации туберкулеза легких альвеолярные макрофаги накапливают микобактерии и перестают выполнять свои эффекторные функции. Это связано с конверсией их провоспалительного фенотипа М1 в противовоспалительный М2, что способствует хронизации инфекции. Научная гипотеза исследования предполагает влияние цитокинового статуса организма на поляризацию моноцитов в крови в процессе их миграции к очагу воспаления, определяя дифференцировку и пути активации макрофагов в тканях. Цель исследования - оценка иммунофенотипа моноцитов крови и исследование in vitro уровня секреции иммунорегуляторных цитокинов мононуклеарными лейкоцитами периферической крови у больных с различными клиническими формами туберкулеза легких. Методика. Обследовано 65 пациентов с впервые выявленным туберкулезом легких. Материалом исследования служили венозная кровь и мононуклеарные лейкоциты периферической крови. Исследование иммунофенотипа моноцитов проводили методом проточной цитометрии (цитофлуориметр Cytoflex, Becman Coulter, США) в цельной крови с использованием моноклональных антител («eВioscience», США). Обработку полученных данных проводили с помощью программы «CytExpert 2.0». Определяли количество клеток экспрессирующих поверхностные маркеры: CD14, CD163, CD204 и HLA-DR. Содержание цитокинов (IL-2, IL-10, TGFβ) в супернатантах клеточных культур оценивали с помощью твердофазного иммуноферментного анализа (ELISA). Результаты. Полученные результаты позволяют предположить, что при общем снижении численности циркулирующих CD14-позитивных моноцитов крови у больных туберкулезом легких, независимо от его клинической формы сохраняется высокая экспрессия маркеров активации клеток как по провоспалительному фенотипу М1 (HLA-DR-позитивные моноциты), так и противовоспалительному фенотипу М2 (CD163-позитивные моноциты). При диссеминированной форме заболевания повышается количество противовоспалительных CD204-позитивных моноцитов, предшественников М2-макрофагов, что свидетельствует о доминировании супрессорного типа иммунного ответа. Анализ цитокинового статуса in vitro показал, что течение болезни сопровождается угнетением эффекторных иммунных реакций и повышением уровня противовоспалительных цитокинов. Выявленные изменения в равной степени могут быть как причиной, так и следствием дефицита секреции IL-2. Показано также, что уровень секреции медиаторов с супрессорными эффектами (IL-10, TGFβ) меняется в зависимости от клинической формы заболевания и чувствительности возбудителя к противотуберкулезным препаратам: гиперсекреция IL-10 отмечается у больных с инфильтративным лекарственно-чувствительным, а TGFβ - при диссеминированном лекарственно-устойчивом туберкулезе легких. Заключение. Особенности дифференциации моноцитов крови у больных туберкулезом легких позволили прийти к заключению, что предшественники макрофагов - моноциты, уже в кровотоке начинают экспрессировать маркеры, характерные для разных по функциям М1- и М2-макрофагов, c поляризацией в направлении М2-иммунофенотипа. Следовательно, при развитии туберкулеза легких реализуются механизмы цитокиновой регуляции, подавляющие активацию врожденного иммунитета, что, возможно, является причиной хронизации воспалительного процесса в легких и формирования иммунодефицита индуцированного Mycobacterium tuberculosis. In clinical manifestation of pulmonary tuberculosis, alveolar macrophages perform as a reservoir where they accumulate mycobacteria and lose their effector functions due to the pathological conversion of macrophage pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype, which provides transition to chronic infection. The study hypothesis suggested that the cytokine status, as evaluated by leukocyte secretion of cytokines in vitro, influences the monocyte polarization in the blood during their migration to the inflammatory focus, thereby determining differentiation and pathways of macrophage activation in tissues. The aim of this work was to assess the immunophenotype of blood monocytes and the in vitro secretion of immunoregulatory cytokines by mononuclear peripheral blood leukocytes from patients with different clinical forms of pulmonary tuberculosis taking into account the pathogen sensitivity to major anti-tuberculosis drugs. Methods. 65 patients with newly diagnosed pulmonary tuberculosis were evaluated. The study material was venous blood and peripheral blood mononuclear leukocytes. Monocyte immunophenotype was determined in whole blood by flow cytometry on a Cytoflex flow cytometer (Becman Coulter, USA) with monoclonal antibodies (eBioscience, USA). Results were processed with a CytExpert 2.0 software. The number of cells expressing surface markers, CD14, CD163, CD204 and HLA-DR, was determined. Content of cytokines (IL-2, IL-10, TGFβ) in supernatants of cell cultures was measured by enzyme-linked immunosorbent assay (ELISA). Results of the study were processed with a SPSS v.11.0 standard software package. Results. The study results suggested that with an overall decrease in the number of circulating CD14-positive blood monocytes in patients with pulmonary tuberculosis regardless of its clinical form, high expression of cell activation markers remained both for the pro-inflammatory M1 phenotype (HLA-DR-positive monocytes) and the anti-inflammatory M2 phenotype (CD163-positive monocytes). In disseminated tuberculosis, the number of anti-inflammatory CD204-positive monocytes, M2 macrophage precursors, increases indicating predomination of the immunosuppressive response. In vitro analysis of the cytokine status showed that tuberculosis progression is accompanied by inhibition of effector immune responses and increases in anti-inflammatory cytokine concentrations in vitro. These changes may be equally either a cause or a consequence of deficient IL-2 secretion. We also found that the secretion of mediators with suppressor effects (IL-10, TGFβ) varied depending on both the clinical form of tuberculosis and the pathogen sensitivity to anti-TB drugs; IL-10 hypersecretion was observed in patients with drug-sensitive, infiltrative tuberculosis whereas TGFβ hypersecretion was observed in disseminated, drug-resistant tuberculosis. Conclusion. Features of blood monocyte differentiation in patients with pulmonary tuberculosis allowed us to conclude that monocytes, the macrophage precursors, start expressing markers for different functions of M1 and M2 macrophages with polarization toward the M2 immunophenotype already in the bloodstream. Therefore, in the development of pulmonary tuberculosis, cytokine regulation mechanisms become involved in suppressing the activation of innate immunity, which possibly causes chronic inflammation in the lungs and formation of Mtb-induced immunodeficiency.
In the present time, incidence of pulmonary tuberculosis (TB) becomes broader, due to spreading resistance of Mycobacterium tuberculosis (MBT) to anti-tuberculosis drugs and infection with highly virulent strains of M. tuberculosis. The MBT antigens can cause dysfunction of the receptors and modulate the cytokine secreting function of immunocompetent cells. Polymorphic genes of pro-inflammatory cytokines involved in the mechanisms of defense responses of innate immunity, determine the degree of resistance to individual mycobacterial infection, as well as severity and duration of the disease in cases of clinical manifestations. The aim of the study was to investigate the connections between allelic polymorphisms of IL2, IFNG and TNFA genes and changes in secretion of the corresponding pro-inflammatory cytokines IL-2, IFNγ, and TNFα in vitro in patients with the newly diagnosed pulmonary tuberculosis (TB), depending on the clinical form of the disease.A total of 334 patients (220 men and 114 women) aged 23 to 50 years with newly diagnosed infiltrative and disseminated TB were enrolled into the study. The control group consisted of 183 healthy donors (130 men and 53 women) of corresponding age. The material of the research included DNA extracted from the whole blood and supernatants of culture suspensions of mononuclear leukocytes isolated from venous blood in healthy volunteers and patients with TB. The evaluation of cytokines secretion was performed by measuring their concentration in the blood mononuclear cell culture supernatants. using enzyme-linked immunosorbent assay (ELISA). To study polymorphic regions of cytokine genes, a polymerase chain reaction (PCR) was applied. Analysis of the obtained data was carried out by means of the program Statistica for Windows Version 6.0 (StatSoft Inc., USA).It was found that the imbalance of secretion of pro-inflammatory cytokines in TB patients was associated with the polymorphic variants of genes of these cytokines. It was found that the hypo-secretion of IL-2 is determined by the carriage of the G allele and genotype GG (T-330G) of the IL2 gene in both the control group and in patients with TB, regardless of the clinical form. In patients with DTB carriers of the homozygous genotype TT (T-330G) of the IL2gene, increased protein secretion was established. The maximum secretion of TNFб was recorded in patients with the AA genotype (G-308A) of the TNFA gene in the control group and in ITB patients; the minimum concentration of TNFα was associated with the carrier of the homozygous GG genotype (G-308A) of the TNFA gene in all the examined groups. In patients with ITB and DTB, an increase in IFNγ secretion by mononuclear blood leukocytes is not associated with the carrier of polymorphism +874A/T of the IFNG gene.Reduced secretion of IL-2 and TNFα in TB patients is associated with polymorphisms of their genes – (T-330G) of IL2 gene and (G-308A) of TNFA gene, respectively. The polymorphism (+874A/T) of the IFNG gene does not have a modulatory effect on the secretion of IFNγ in patients with TB, regardless of clinical form of the disease.
The aim of the work is to establish general regularities and features of differentiation of blood monocytes into 4 subpopulations in diseases associated with circulatory and respiratory hypoxia. Materials and methods. 18 patients with ischemic heart disease (IHD), 12 patients with ischemic cardiomyopathy (ICMP), 14 patients with chronic obstructive pulmonary disease (COPD), 15 patients with newly diagnosed infiltrative pulmonary tuberculosis (PTB) and 12 healthy donors were examined. In whole blood, we determined the relative number of different subpopulations of monocytes by flow cytometry. The results were analyzed by statistical methods. Results. It is shown that an increase in the number of classical (80.56 [77.60; 83.55]%) and the deficit of intermediate (10.38 [9.36; 11.26]%), non-classical (6.03 [5.24; 6.77]%) and transitional (2.14 [1.41; 3.92] %) monocytes in the blood is determined in patients with COPD when compared with the group of healthy donors ( p < 0.05). In groups of patients with PTB and IHD, an increase in the number of intermediate monocytes (26.24 respectively [22.38; 42.88] % and 25.27 [15.78; 31.39]%) and the lack of transitional cells (1.77 [1.36; 3.74]% and 2.68 [2.63; 4.0]%) at the normal content of classical and non-classical forms of monocytes ( p < 0.05) is detected. In patients with ICMP, a decrease in the number of non-classical monocytes (up to 5.05 [4.08; 6.58]%) is combined with the normal cell content of other subpopulations ( p < 0.05). The interrelation between the number of classical and intermediate monocytes in patients with COPD ( r = –0.63; p < 0.05), PTB ( r = –0.72; p < 0.01), IHD ( r = –0.59; p < 0.05), ICMP ( r = –0.58; p < 0.05) was established. Conclusion. In COPD associated with generalized hypoxia, an increase in the number of classical monocytes is combined with a deficiency of their other subpopulations in the blood. In PTB and IHD, antigenic stimulation of the immune system mediates accelerated differentiation of monocytes from classical to intermediate forms with a decrease in the number of transitional cells regardless of the etiology of the disease (infectious or non-infectious) and the type of hypoxia (respiratory or circulatory).
This literature review is devoted to the analysis of the role of macrophages in the immunopathogenesis of infectious lung diseases of bacterial etiology. The article summarizes information about the origin of macrophages, their phenotypic and functional heterogeneity. The mechanisms of impaired protective function of innate immunity are associated with the polarization of the program of maturation and activation of macrophages in the direction to tolerogenic or immunoregulatory cells with phenotype of M2. Alveolar macrophages perform a variety of functions (from pro-inflammatory to regenerative) in the development of inflammation in the respiratory organs. Their inherent plasticity suggests that the same macrophages can change their phenotype and function depending on the microenvironment in the inflammatory focus at different stages of the disease. Understanding the mechanisms that regulate macrophage plasticity will be an important step towards realizing the potential of personalized immunomodulatory therapy.