Impaired Phagocytic Activity Research Articles

Regulatory effects of antioxidants on indoxyl sulfate-enhanced intracellular oxidation and impaired phagocytic activity in differentiated U937 human macrophage cells.

Indoxyl sulfate (IS), a uremic toxin, is a physiologically active sulfated metabolite, specifically in kidney failure patients. Our previous studies have shown that IS downregulates phagocytic immune function in a differentiated HL-60 human macrophage cell model. However, it remains unclear whether IS exerts similar effects on macrophage function in other cell types or in lipopolysaccharide (LPS)-sensitive immune cell models. Therefore, this study aimed to investigate the effects of IS on intracellular oxidation levels and phagocytic activity in a differentiated U937 human macrophage cell model, both in the absence and presence of LPS. Our results demonstrated that IS significantly increases intracellular oxidation levels and decreases phagocytic activity, particularly in cells activated by LPS. Furthermore, we found that 2-acetylphenothiazine, an NADH oxidase inhibitor, attenuates the effects of IS in LPS-activated macrophage cells. Representative antioxidants, trolox, α-tocopherol, and ascorbic acid, significantly mitigated the effects of IS on the macrophages responding to LPS.

Exposure to microplastics renders immunity of the thick-shell mussel more vulnerable to diarrhetic shellfish toxin-producing harmful algae

Despite both microplastics (MPs) and harmful algae blooms (HABs) may pose a severe threat to the immunity of marine bivalves, the toxification mechanism underlying is far from being fully understood. In addition, owing to the prevalence and sudden occurrence characteristics of MPs and HABs, respectively, bivalves with MP-exposure experience may face acute challenge of harmful algae under realistic scenarios. However, little is known about the impacts and underlying mechanisms of MP-exposure experience on the susceptibility of immunity to HABs in bivalve mollusks. Taking polystyrene MPs and diarrhetic shellfish toxin-producing Prorocentrum lima as representatives, the impacts of MP-exposure on immunity vulnerability to HABs were investigated in the thick-shell mussel, Mytilus coruscus. Our results revealed evident immunotoxicity of MPs and P. lima to the mussel, as evidenced by significantly impaired total count, phagocytic activity, and cell viability of haemocytes, which may result from the induction of oxidative stress, aggravation of haemocyte apoptosis, and shortage in cellular energy supply. Moreover, marked disruptions of immunity, antioxidant system, apoptosis regulation, and metabolism upon MPs and P. lima exposure were illustrated by gene expression and comparative metabolomic analyses. Furthermore, the mussels that experienced MP-exposure were shown to be more vulnerable to P. lima, indicated by greater degree of deleterious effects on abovementioned parameters detected. In general, our findings emphasize the threat of MPs and HABs to bivalve species, which deserves close attention and more investigation.

Chitosan alleviates ovarian aging by enhancing macrophage phagocyte-mediated tissue homeostasis

BackgroundAge-related changes in the ovarian microenvironment are linked to impaired fertility in women. Macrophages play important roles in ovarian tissue homeostasis and immune surveillance. However, the impact of aging on ovarian macrophage function and ovarian homeostasis remains poorly understood.MethodsSenescence-associated beta-galactosidase staining, immunohistochemistry, and TUNEL staining were used to assess senescence and apoptosis, respectively. Flow cytometry was employed to evaluate mitochondrial membrane potential (MMP) and apoptosis in granulosa cells lines (KGN), and macrophages phagocytosis. After a 2-month treatment with low molecular weight Chitosan (LMWC), ovarian tissues from mice were collected for comprehensive analysis.ResultsCompared with the liver and uterus, the ovary displayed accelerated aging in an age-dependent manner, which was accompanied by elevated levels of inflammatory factors and apoptotic cells, and impaired macrophage phagocytic activity. The aged KGN cells exhibited elevated reactive oxygen species (ROS) and apoptotic levels alongside decreased MMP. H2O2-induced aging macrophages showed reduced phagocytosis function. Moreover, there were excessive aging macrophages with impaired phagocytosis in the follicular fluid of patients with diminished ovarian reserve (DOR). Notably, LMWC administration alleviated ovarian aging by enhancing macrophage phagocytosis and promoting tissue homeostasis.ConclusionsAging ovarian is characterized by an accumulation of aging and apoptotic granulosa cells, an inflammatory response and macrophage phagocytosis dysfunction. In turn, impaired phagocytosis of macrophage contributes to insufficient clearance of aging and apoptotic granulosa cells and the increased risk of DOR. Additionally, LMWC emerges as a potential therapeutic strategy for age-related ovarian dysfunction.

An insight into the pathophysiology of mucormycosis: Lesson learnt during COVID pandemic

Mucormycosis, a lethal fungal infection caused by Rhizopus oryzae, has gained significant attention due to its association with the COVID-19 pandemic. The causal relationship between COVID-19 and mucormycosis is not yet fully understood. This narrative review focuses on the pathophysiology of mucormycosis, particularly in the context of COVID-19. Mucormycosis primarily affects immunocompromised individuals and is commonly observed in diabetic patients with COVID-19 who receive high doses of corticosteroids. The most common presentation of mucormycosis in COVID-19 is rhino-orbital-cerebral mucormycosis. Early diagnosis and prompt initiation of treatment, including extensive surgical intervention and appropriate antifungal therapy, are crucial in preventing fatal complications. The global prevalence of mucormycosis varies widely, with a higher incidence in developing countries such as India. Diabetes mellitus remains the leading risk factor globally, while COVID-19 and corticosteroid therapy also predispose immunocompromised patients to mucormycosis. The impaired phagocytic activity in immunosuppressed individuals and the ability of Mucorales to acquire iron from the host play significant roles in the pathogenesis of mucormycosis. Endothelial damage and thrombosis, along with hyperglycemia, acidosis, and increased serum iron levels observed in COVID-19, contribute to the aggressive nature of mucormycosis in these patients. The review emphasizes the need for further research to establish a causal association between COVID-19, corticosteroid therapy, and mucormycosis, and highlights the importance of understanding the underlying mechanisms to improve the management and outcomes of patients with this devastating fungal infection.

Neutrophil exhaustion and impaired functionality in psoriatic arthritis patients.

Neutrophils (polymorphonuclear leukocytes, PMNs) are the most abundant subtype of white blood cells and are among the main actors in the inflammatory response. Psoriatic arthritis (PsA) is a chronic inflammatory disease affecting both the axial and peripheral joints. Typically associated with psoriasis, PsA can also affect multiple systems and organs, including the nails and entheses. Despite the involvement of PMNs in PsA, their specific role in the disease remains poorly understood. This study aimed to characterize the biological functions of PMNs and neutrophil-related mediators in PsA patients. 31 PsA patients and 22 healthy controls (HCs) were prospectively recruited. PMNs were isolated from peripheral blood and subjected to in vitro stimulation with lipopolysaccharide (LPS), N-Formylmethionyl-leucyl-phenylalanine (fMLP), tumor necrosis factor (TNF), phorbol 12-myristate 13-acetate (PMA), or control medium. Highly purified peripheral blood PMNs (>99%) were evaluated for activation status, reactive oxygen species (ROS) production, phagocytic activity, granular enzyme and neutrophil extracellular traps (NETs) release. Serum levels of matrix metalloproteinase-9 (MMP-9), myeloperoxidase (MPO), TNF, interleukin 23 (IL-23), and interleukin 17 (IL-17) were measured by ELISA. Serum Citrullinated histone H3 (CitH3) was measured as a NET biomarker. Activated PMNs from PsA patients displayed reduced activation, decreased ROS production, and impaired phagocytic activity upon stimulation with TNF, compared to HCs. PMNs from PsA patients also displayed reduced granular enzyme (MPO) and NET release. Serum analyses revealed elevated levels of MMP-9, MPO, TNF, IL-23, IL-17, and CitH3 in PsA patients compared to HCs. Serum CitH3 levels positively correlated with MPO and TNF concentrations, and IL-17 concentrations were positively correlated with IL-23 levels in PsA patients. These findings indicate that PMNs from PsA patients show reduced in vitro activation and function, and an increased presence of neutrophil-derived mediators (MMP-9, MPO, TNF, IL-23, IL-17, and CitH3) in their serum. Taken together, our findings suggest that PMNs from PsA patients exhibit an "exhausted" phenotype, highlighting their plasticity and multifaceted roles in PsA pathophysiology.

CRISPR Correction of the GBA Mutation in Human-Induced Pluripotent Stem Cells Restores Normal Function to Gaucher Macrophages and Increases Their Susceptibility to Mycobacterium tuberculosis.

Gaucher disease (GD) is an autosomal recessive lysosomal storage disorder caused by mutations in the β-glucocerebrosidase (GCase) GBA gene, which result in macrophage dysfunction. CRISPR (clustered regularly interspaced short palindromic repeats) editing of the homozygous L444P (1448T→C) GBA mutation in type 2 GD (GBA-/-) human-induced pluripotent stem cells (hiPSCs) yielded both heterozygous (GBA+/-) and homozygous (GBA+/+) isogenic lines. Macrophages derived from GBA-/-, GBA+/- and GBA+/+ hiPSCs showed that GBA mutation correction restores normal macrophage functions: GCase activity, motility, and phagocytosis. Furthermore, infection of GBA-/-, GBA+/- and GBA+/+ macrophages with the Mycobacterium tuberculosis H37Rv strain showed that impaired mobility and phagocytic activity were correlated with reduced levels of bacterial engulfment and replication suggesting that GD may be protective against tuberculosis.

Effects of intravenous immunoglobulin on the negatively transformed subpopulations of neutrophilic granulocytes in newborns with congenital pneumonia and neonatal sepsis

Today, the diagnosis and treatment of severe infectious and inflammatory diseases in newborns, e.g., congenital pneumonia (CP) and neonatal sepsis (NS), present difficult problems. Searching sensitive and specific severity markers of bacterial inflammatory process as well as early and effective treatment are crucial for the outcome and prognosis of these life-threatening diseases. The aim of our study was to assess the effects of intravenous immunoglobulin (IVIG) injections on the negatively transformed subpopulations of neutrophilic granulocytes (NG) СD64-CD16+СD32+СD11b+, СD64+CD16+СD32+СD11b+ and evaluation of their functional activity in newborns with CP and NS. We have observed 38 full-term newborn patients. Group 1 included 19 infants with CP, including 11 children who received conventional therapy and IVIG (group 1.1), and 8 children treated at conventional protocols (group 1.2). Group 2 included 19 children with NS, including 12 children who underwent conventional therapy and IVIG treatment (group 2.1), and 7 children who were subject to conventional therapy (group 2.2). The comparison group consisted of 22 healthy full-term newborns. Testing of NG population included the following parameters: counting the numbers of NG subpopulations which simultaneously expressed CD11b CD64, CD32, CD16, as well as their phenotypic patterns, with regard of the receptor expression density (MFI) using flow cytometric techniques. Moreover, we determined phagocytic and microbicidal activity of the granulocytes. We have revealed negative transformation of СD64-CD16+СD32+СD11b+ and СD64+CD16+СD32+СD11b+ subpopulations of neutrophilic granulocytes in newborns with CP and NS, The diagnostic significance of increased СD64+CD16+СD32+СD11b+NG subpopulation was more pronounced with increasing severity of bacterial infection and inflammatory process, i.e., 18.7-fold in CP, 52.3-fold in NS, along with predominant decrease in expression of appropriate membrane receptors. These phenotypic changes were associated with impaired phagocytic and killing activity of NG. The effect of IVIG on the impaired mechanisms of antibacterial immunity is associated not only with alleviation of IgG deficiency, but also with positive remodeling of negatively transformed subpopulations of СD64-CD16+СD32+СD11b+NG and СD64+CD16+СD32+СD11b+NG, improved effector functions of NG, especially in cases of CP. Thus, following IVIG treatment, a reduced number of СD64-CD16+СD32+СD11b+NG subpopulations was fully recovered in CP, while it increased 1.5 times in NS, and the content of diagnostically significant СD64+CD16+СD32+СD11b+NG subpopulation showed a significantly decrease, both in CP (2-fold) and in NS (2.6-fold). However, this index remained higher than the content of this subpopulation in healthy newborns. At the same time, we have noted the restorative or modulatory effects by changing density of trigger molecules in NG subpopulations. Limitation of the negative NG transformation in their functionally significant subpopulations in newborns with CAP and NS was accompanied by positive clinical effects, i.e., optimization of antibiotic therapy, reduced duration of treatment, and improved mortality rates.

Histamine Signaling Is Essential for Tissue Macrophage Differentiation and Suppression of Bacterial Overgrowth in the Stomach.

Histamine in the stomach traditionally is considered to regulate acid secretion but also has been reported to participate in macrophage differentiation, which plays an important role in tissue homeostasis. Therefore, this study aimed to uncover the precise role of histamine in mediating macrophage differentiation and in maintaining stomach homeostasis. Here, we expand on this role using histidine decarboxylase knockout (Hdc-/-) mice with hypertrophic gastropathy. In-depth invivo studies were performed in Hdc-/- mice, germ-free Hdc-/- mice, and bone-marrow-transplanted Hdc-/- mice. The stomach macrophage populations and function were characterized by flow cytometry. To identify stomach macrophages and find the new macrophage population, we performed single-cell RNA sequencing analysis on Hdc+/+ and Hdc-/- stomach tissues. Single-cell RNA sequencing and flow cytometry of the stomach cells of Hdc-/- mice showed alterations in the ratios of 3 distinct tissue macrophage populations (F4/80+Il1bhigh, F4/80+CD93+, and F4/80-MHC class IIhighCD74high). Tissue macrophages of the stomachs of Hdc-/- mice showed impaired phagocytic activity, increasing the bacterial burden of the stomach and attenuating hypertrophic gastropathy in germ-free Hdc-/- mice. The transplantation of bone marrow cells of Hdc+/+ mice to Hdc-/- mice recovered the normal differentiation of stomach macrophages and relieved the hypertrophic gastropathy of Hdc-/- mice. This study showed the importance of histamine signaling in tissue macrophage differentiation and maintenance of gastric homeostasis through the suppression of bacterial overgrowth in the stomach.

Neutrophil-Specific Knockdown of β2 Integrins Impairs Antifungal Effector Functions and Aggravates the Course of Invasive Pulmonal Aspergillosis.

β2-integrins are heterodimeric surface receptors that are expressed specifically by leukocytes and consist of a variable α (CD11a-d) and a common β-subunit (CD18). Functional impairment of CD18, which causes leukocyte adhesion deficiency type-1 results in an immunocompromised state characterized by severe infections, such as invasive pulmonary aspergillosis (IPA). The underlying immune defects have largely been attributed to an impaired migratory and phagocytic activity of polymorphonuclear granulocytes (PMN). However, the exact contribution of β2-integrins for PMN functions in-vivo has not been elucidated yet, since the mouse models available so far display a constitutive CD18 knockout (CD18-/- or CD18hypo). To determine the PMN-specific role of β2-integrins for innate effector functions and pathogen control, we generated a mouse line with a Ly6G-specific knockdown of the common β-subunit (CD18Ly6G cKO). We characterized CD18Ly6G cKO mice in-vitro to confirm the PMN-specific knockdown of β2-integrins. Next, we investigated the clinical course of IPA in A. fumigatus infected CD18Ly6G cKO mice with regard to the fungal burden, pulmonary inflammation and PMN response towards A. fumigatus. Our results revealed that the β2-integrin knockdown was restricted to PMN and that CD18Ly6G cKO mice showed an aggravated course of IPA. In accordance, we observed a higher fungal burden and lower levels of proinflammatory innate cytokines, such as TNF-α, in lungs of IPA-infected CD18Ly6G cKO mice. Bronchoalveolar lavage revealed higher levels of CXCL1, a stronger PMN-infiltration, but concomitantly elevated apoptosis of PMN in lungs of CD18Ly6G cKO mice. Ex-vivo analysis further unveiled a strong impairment of PMN effector function, as reflected by an attenuated phagocytic activity, and a diminished generation of reactive oxygen species (ROS) and neutrophil-extracellular traps (NET) in CD18-deficient PMN. Overall, our study demonstrates that β2-integrins are required specifically for PMN effector functions and contribute to the clearance of A. fumigatus by infiltrating PMN, and the establishment of an inflammatory microenvironment in infected lungs.

Copper Oxide Nanoparticles Stimulate the Immune Response and Decrease Antioxidant Defense in Mice After Six-Week Inhalation.

Copper oxide nanoparticles (CuO NPs) are increasingly used in various industry sectors. Moreover, medical application of CuO NPs as antimicrobials also contributes to human exposure. Their toxicity, including toxicity to the immune system and blood, raises concerns, while information on their immunotoxicity is still very limited. The aim of our work was to evaluate the effects of CuO NPs (number concentration 1.40×106 particles/cm3, geometric mean diameter 20.4 nm) on immune/inflammatory response and antioxidant defense in mice exposed to 32.5 µg CuO/m3 continuously for 6 weeks. After six weeks of CuO NP inhalation, the content of copper in lungs and liver was significantly increased, while in kidneys, spleen, brain, and blood it was similar in exposed and control mice. Inhalation of CuO NPs caused a significant increase in proliferative response of T-lymphocytes after mitogenic stimulation and basal proliferative activity of splenocytes. CuO NPs significantly induced the production of IL-12p70, Th1-cytokine IFN-γ and Th2-cytokines IL-4, IL-5. Levels of TNF-α and IL-6 remained unchanged. Immune assays showed significantly suppressed phagocytic activity of granulocytes and slightly decreased respiratory burst. No significant differences in phagocytosis of monocytes were recorded. The percentage of CD3+, CD3+CD4+, CD3+CD8+, and CD3-CD19+ cell subsets in spleen, thymus, and lymph nodes did not differ between exposed and control animals. No changes in hematological parameters were found between the CuO NP exposed and control groups. The overall antioxidant protection status of the organism was expressed by evaluation of GSH and GSSG concentrations in blood samples. The experimental group exposed to CuO NPs showed a significant decrease in GSH concentration in comparison to the control group. In summary, our results indicate that sub-chronic inhalation of CuO NPs can cause undesired modulation of the immune response. Stimulation of adaptive immunity was indicated by activation of proliferation and secretion functions of lymphocytes. CuO NPs elicited pro-activation state of Th1 and Th2 lymphocytes in exposed mice. Innate immunity was affected by impaired phagocytic activity of granulocytes. Reduced glutathione was significantly decreased in mice exposed to CuO NPs.

Targeting AURKA in treatment of peritoneal tumor dissemination in gastrointestinal cancer

Intraperitoneal (i.p.) tumor dissemination and the consequent malignant ascites remain unpredictable and incurable in patients with gastrointestinal (GI) cancer, and practical advances in diagnosis and treatment are urgently needed in the clinical settings. Here, we explored tumor biological and immunological mechanisms underlying the i.p. tumor progression for establishing more effective treatments.We established mouse tumor ascites models that murine and human colorectal cancer cells were both i.p. and subcutaneously (s.c.) implanted in mice, and analyzed peritoneal exudate cells (PECs) obtained from the mice. We then evaluated anti-tumor efficacy of agents targeting the identified molecular mechanisms using the ascites models. Furthermore, we validated the clinical relevancy of the findings using peritoneal lavage fluids obtained from gastric cancer patients.I.p. tumor cells were giant with large nuclei, and highly express AURKA, but less phosphorylated TP53, as compared to s.c. tumor cells, suggesting polyploidy-like cells. The i.p. tumors impaired phagocytic activity and the consequent T-cell stimulatory activity of CD11b+Gr1+PD1+ myeloid cells by GDF15 that is regulated by AURKA, leading to treatment resistance. Blocking AURKA with MLN8237 or siRNAs, however, abrogated the adverse events, and induced potent anti-tumor immunity in the ascites models. This treatment synergized with anti-PD1 therapy. The CD11b+PD1+ TAMs are also markedly expanded in the PECs of gastric cancer patients.These suggest AURKA is a determinant of treatment resistance of the i.p. tumors. Targeting the AURKA-GDF15 axis could be a promising strategy for improving clinical outcome in the treatment of GI cancer.

Altered Polarization and Impaired Phagocytic Activity of Lung Macrophages in People With Human Immunodeficiency Virus and Chronic Obstructive Pulmonary Disease.

People with human immunodeficiency virus (PWH) have an increased risk of developing chronic obstructive pulmonary disease (COPD). We phenotyped lung macrophages in 4 subgroups-M1 (CD40+CD163-), M2 (CD40-CD163+), double positives (CD40+CD163+), and double negatives and (CD40-CD163-)-and we determined their phagocytic capacity in PWH with and without COPD. People with human immunodeficiency virus with COPD have more double-negative macrophages (84.1%) versus PWH without (54.3%) versus controls (23.9%) (P=.004) and reduced phagocytosis (P=.012). Double-negative macrophages had the worst phagocytic capacity (P<.001). People with human immunodeficiency virus with COPD have an abundance of nonpolarized macrophages, which have poor phagocytic capacity and therefore predispose PWH to increased risk of disease progression.

ДИФФЕРЕНЦИРОВАННАЯ ТРАНСФОРМАЦИЯ ФЕНОТИПА СУБПОПУЛЯЦИЙ НЕЙТРОФИЛЬНЫХ ГРАНУЛОЦИТОВ ПРИ ВИРУСНО-ВИРУСНЫХ И ГНОЙНЫХ БАКТЕРИАЛЬНЫХ ИНФЕКЦИЯХ У ИММУНОКОМПРОМЕТИРОВАННЫХ ДЕТЕЙ

Children with clinical signs of immunocompromise have impaired functioning of the immune system. At the same time, the state of subpopulations of multifunctional neutrophil granulocytes (NG), which provide antiviral and antibacterial protection, in such patients has been poorly studied. Objective of the study: to assess the features of the transformation of the phenotype of the three most significant subpopulations of NG, their association with impaired phagocytic and microbicidal activity in immunocompromised children with atypical viral-viral co-infections and bacterial infections, and to clarify their differential diagnostic significance. Materials and methods of research: the phenotypes of NG subpopulations expressing CD64, CD32, CD16, CD11b receptors, phagocytic and microbicidal activity of NG were studied in the peripheral blood of 43 immunocompromised children of both sexes aged of 5–9 years old suffering from recurrent ARVI, atypical chronic mono – or mixed herpes virus infections (HVI) and purulent bacterial infection. 3 study groups were formed: 1st – repeated ARVI/HVI mono, 2nd – repeated ARVI/HVI mixed, 3rd – minor purulent infection (MPI) and a comparison group (20 apparently healthy children). Results: different differentiated transformation of the phenotype of functionally significant subpopulations of NG associated with impaired functional activity of NG as well as with the incidence of viral co-infections (repeated ARVI and recurrent HVI mixed) and the severity of clinical manifestations of MPI has been identified in the studied groups. Conclusion. Еvaluation of the features of transformation of phenotype of NG subpopulations, their effector functions in immunocompromised children with atypical viral-viral co-infections and purulent bacterial infections, will allow in the future to optimize the methods of target immunotherapy aimed at remodulating the negatively transformed phenotype of NG subpopulations, correcting their dysfunctions and, thereby, significantly increase the clinical effectiveness of therapeutic and preventive measures.

Активность фагоцитоза у больных атопическим дерматитом c подтвержденной контаминацией кожи дрожжами рода Candida spp

Фагоцитоз является неотъемлемой частью защиты организма от патогенов: его нарушения обусловливают развитие сопутствующих заболеваний и осложнений у больных атопическим дерматитом (АтД). Цель работы - оценка активности фагоцитоза у больных АтД c подтвержденной контаминацией кожи грибками рода Candida и определение экспрессии рецепторов нейтрофилов, необходимых для осуществления завершенного фагоцитоза. Методика. В исследовании приняли участие 70 больных АтД и 22 донора, все подписывали форму информированного согласия. Работа с кровью людей проводилась по международным правилам. Наличие контаминации микроскопическими грибками верифицировали методом полимеразо-цепной реакции в реальном времени (ПЦР). Нейтрофилы периферической крови выделяли на градиенте Перколла в интерфазе между 81% и 70%, отмывали, переводили в полную среду и анализировали ex vivo на активность фагоцитоза с дрожжами Candida tropicalis. Клетки обрабатывали антителами к рецепторам, а также пропидиумом иодидом, и анализировали на проточном цитометре FACSCalibur. Статистическую обработку результатов проводили по программе ANOVA. Результаты. Было установлено нарушение фагоцитарной активности нейтрофилов у больных АтД с сопутствующим поражением кожи грибками, что коррелировало с тяжестью течения АтД и статистически значимо отличалось от показателей больных АтД, не контаминированных возбудителями микозов. Экспрессия рецепторов, ассоциированных с фагоцитозом, различалась у больных АтД в зависимости от наличия или отсутствия Candida spp. Заключение. Установлены нарушения фагоцитарной активности нейтрофилов у больных АтД с верифицированной контаминацией кожи Candida spp., а также различия в экспрессии рецепторов фагоцитоза по сравнению с больными АтД без контаминации кожи дрожжами рода Candida.Phagocytosis is an integral part of the body defense against pathogens. Disturbance of phagocytosis results in development of concomitant diseases and complications in patients with atopic dermatitis (AD). The aim of this study was to measure the activity of phagocytosis in AD patients with fungal contamination of skin and to determine the expression of neutrophil receptors required for completing phagocytosis. Methods. 70 patients with AD and 22 donors participated in this study and signed an informed consent form. All experiments were performed in compliance with international rules for work with human biological materials. The presence of fungi on the skin was verified using the polymerase chain reaction in real time (PCR). Peripheral blood neutrophils were isolated on the Percoll gradient in the interphase between 81% and 70%, washed, transferred to the complete medium, and analyzed ex vivo for phagocytosis activity using yeast Candida tropicalis as a model system. Neutrophils were stained with monoclonal antibodies to the phagocytosis receptor and propidium iodide for DNA visualization and analyzed on a FACSCalibur flow cytometer. Statistical analysis was performed using ANOVA. Results. Impaired neutrophil phagocytic activity was found in AD patients with concomitant fungal contamination of the skin, which correlated with severity of AD and statistically significantly differed from that in AD patients without contamination with Candida spp. pathogens. The expression of phagocytosis-associated receptors varied in AD patients depending on the presence or absence of Candida spp. contaminants. Conclusion. Disordered neutrophil phagocytic activity was found in AD patients with verified Candida spp. contamination; the expression of phagocytosis receptors was different from that in AD patients without Candida contamination of the skin.

IL-15 and GM-CSF stimulated macrophages enhances phagocytic activity in ENU induced leukemic mice.

Murine splenic macrophage plays a decisive role in host immunity through phagocytosis against pathogens. It was reported that, macrophages also involves in phagocytosis of some tumour cells upon its activation initiated by certain cytokines produced by other immune cell or by indigenously treated. In this study, we have investigated the killing of leukemic blast cells by macrophages upon stimulated with IL-15 and GM-CSF alone or in combination in ENU challenged leukemic murine model. Along with, the release of TNF-α, IL-12 and IFN-γ by macrophages were assayed by ELISA. NO production by macrophages was also investigated. The molecular expressions like GM-CSF and TLRs were investigated for better understand of macrophage-leukemic cell interaction. Result shows that in disease condition macrophages have poor phagocytic activities which may be due to less release of TNF-α, IL-12 and IFN-γ by macrophages. This impaired phagocytic activity in leukemic mice was increase upon stimulation with IL-15 and GM-CSF.

Features of immune status in patients with various clinical forms of oral lichen planus

Oral mucosal lesions hold one of the lead places in the structure of dental diseases. Oral lichen planus (OLP) considered as a multifactorial disease is of top priority among dermatoses of oral mucosa and red lip border. Diverse putative concepts behind developing lichen planus pathogenesis are discussed including immunoallergic, viral, genetic and membrane-destructive theories. However, an immune theory is thought to play a crucial role in developing lichen planus. Despite documented induction of immune mechanisms, complex interaction between pathological process and normal defense response as well as stirred interest to it, multiple aspects of immunological conflict in lichen planus remain unclear. Few data describing altered immune parameters depending on clinical picture of lichen planus are currently available that suggested to perform the study aimed at examining immune status in patients with various forms of oral lichen planus. There were enrolled 286 oral lichen planus patients (248 females and 38 males), aged 2784 years. Based on clinical picture, all OLP patients were divided into 6 groups: a typical type, exudative-congestive, erosive-ulcerous, hyperkeratotic, atypical, bullous type. An immune status in peripheral blood samples was evaluated by analyzing innate defense mechanisms as well as humoral and cellular immunity. Multiple altered immune parameters characterized by impaired phagocytic capture and metabolic activity, disimmunoglobulinemia, altered ratio of major immunocompetent cell types and subsets were documented during the study. Moreover, OLP patients with typical, hyperkeratotic, exudative hyperemic, atypical and erosive ulcerous forms were found to have increased amount of CD4+ helper T cells associated with a self-sustained immune response due to suppressed elimination of pathogenic agents consequently resulting in developing autoimmune process. While analyzing immune status in OLP patients, it allowed to find a relationship between dysphagocytosis signs, impaired humoral and cellular immunity as well as various clinical forms of the disease. Thus, it suggests imbalanced mechanisms responsible for pathogen elimination might play a role in OLP pathogenesis, including infectious agents being involved in its development.

Reduced transient receptor potential vanilloid 2 expression in alveolar macrophages causes COPD in mice through impaired phagocytic activity

BackgroundDefective phagocytosis in alveolar macrophages is associated with chronic obstructive pulmonary disease (COPD). Transient receptor potential cation channel subfamily V member 2 (TRPV2), a type of nonselective cation channel pertinent to diverse physiological functions, regulates macrophage phagocytosis. However, the role of TRPV2 in COPD remains poorly understood. Here, we explored the role of TRPV2 in the development of COPD.MethodsMacrophage TRPV2 expression and phagocytosis function were measured in MH-S cells (a murine alveolar macrophage cell line) and a cigarette smoke exposure mouse model.ResultsTRPV2 expression and phagocytosis function were reduced when MH-S cells were exposed to cigarette smoke extract (CSE). TRPV2 knockdown by siRNA decreased phagocytosis in MH-S cells. Consistently, TRPV2 expression was reduced in alveolar macrophages prepared from bronchoalveolar lavage samples of mice which were exposed to cigarette smoke for 2 months. In addition, the alveolar space was progressively enlarged during development in TRPV2 knockout (TRPV2KO) mice. Moreover, exposure to cigarette smoke for 2 months significantly induced alveolar space enlargement in TRPV2KO mice, but not in wild-type (WT) mice. The phagocytic function of alveolar macrophages from TRPV2KO mice was reduced, compared with macrophages from WT mice.ConclusionsTRPV2 expression is profoundly downregulated in alveolar macrophages at early time points of cigarette smoke exposure. Reduced TRPV2-mediated phagocytic function renders the lung susceptible to cigarette smoke-induced alveolar space enlargement. TRPV2 may provide a therapeutic target for COPD induced by cigarette smoke.

Azithromycin promotes alternatively activated macrophage phenotype in systematic lupus erythematosus via PI3K/Akt signaling pathway

Alternatively activated macrophages have been reported to be helpful to alleviate systematic lupus erythematosus (SLE), and azithromycin could serve as an immunomodulator by promoting alternatively activated macrophage phenotype. However, the effect of azithromycin in SLE and the involved mechanism remain undetermined. The aim of this study is to characterize azithromycin and the underlying mechanism contributing to SLE therapy. First, we compared monocytes from SLE patients and matched healthy donors, and found monocytes from SLE patients exhibited more CD14+CD86+ cells, impaired phagocytic activity, and elevated interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α (the classical activated phenotype), which could be blocked by azithromycin. On the contrary, there were fewer CD14+CD163+ cells in SLE patients, accompanied by decreased arginase (Arg)-1 and found in inflammatory zone (Fizz)-1 (the alternatively activated phenotype). And IL-10, the crucial immune regulatory factor secreted by alternatively activated monocytes/macrophages, also showed a decreased trend in SLE patients. In addition, all these markers were up-regulated after azithromycin treatment. Next, we used activated lymphocyte-derived-DNA to imitate SLE macrophages in vitro to investigate the possible mechanism involved. Azithromycin showed the same effect in imitated SLE macrophages, with distinct Akt phosphorylation at 30 min and 12 h. After inhibiting Akt phosphorylation by LY294002, the down-regulation of CD80, IL-1β, IL-6, and TNF-α caused by azithromycin raised again, meanwhile, the up-regulation of CD206, Arg-1, Fizz-1, and IL-10 due to azithromycin was abolished. Additionally, insulin-like growth factor 1 (IGF-1), the specific agonist of Akt, played a similar role to azithromycin in imitated SLE macrophages. Taken together, our data indicated a novel role of azithromycin in alleviating SLE by promoting alternatively activated macrophage phenotype, and the PI3K/Akt signaling pathway was involved. Our findings provide a rationale for further investigation of novel therapeutic strategy for SLE patients.

Immune system-mediated atherosclerosis caused by deficiency of long non-coding RNAMALAT1in ApoE−/−mice

The immune system is considered a key driver of atherosclerosis, and beyond proteins and microRNAs (miRs), long non-coding RNAs (lncRNAs) are implicated in immune control. We previously described that lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is involved in cardiac innate immunity in a myocarditis model. Here, we investigated the impact of MALAT1 deficiency upon atherosclerosis development. Heterozygous MALAT1-deficient ApoE-/- mice displayed massive immune system dysregulation and atherosclerosis within 2 months even when kept on normal diet. Aortic plaque area (P < 0.05) and aortic root plaque size (P < 0.001) were increased in MALAT1-deficient vs. MALAT1-wildtype ApoE-/- mice. Serum levels of interferon-γ (IFN-γ), tumour necrosis factor (TNF), and interleukin 6 (IL6) were elevated (P < 0.001) in MALAT1-deficient animals. MALAT1-deficient bone marrow-derived macrophages showed enhanced expression of TNF (P = 0.001) and inducible NO synthase (NOS2) (P = 0.002), suppressed MMP9 (P < 0.001), and impaired phagocytic activity (P < 0.001) upon lipopolysaccharide stimulation. RNA-sequencing revealed grossly altered transcriptomes of MALAT1-deficient splenocytes already at baseline, with massive induction of IFN- γ, TNF, NOS2, and granzyme B; CC and CXC chemokines and CCR8; and innate immunity genes interferon-induced protein with tetratricopeptide repeats (IFIT)1/3, interferon-induced transmembrane protein (IFITM)1/3, ISG15. Multiple miRs were up to 45-fold upregulated. Further, selective ablation of the cytosolic part of the MALAT1 system only, the enzymatically MALAT1-derived mascRNA, resulted in massive induction of TNF (P = 0.004) and IL6 (P = 0.028) in macrophages. Northern analysis of post-myocardial infarction patient vs. control peripheral blood mononuclear cells showed reduced (P = 0.005) mascRNA in the patients. CHART-enriched RNA-sequencing reads at the genomic loci of MALAT1 and neighbouring nuclear enriched abundant transcript (NEAT1) documented direct interaction between these lncRNA transcripts. The data suggest a molecular circuit involving the MALAT1-mascRNA system, interactions between MALAT1 and NEAT1, and key immune effector molecules, cumulatively impacting upon the development of atherosclerosis. It appears reasonable to look for therapeutic targets in this circuit and to screen for anomalies in the NEAT1-MALAT1 region in humans, too, as possible novel disease risk factors.

Image Monitoring of the Impaired Phagocytic Activity of Kupffer Cells and Liver Oxygen Saturation in a Mouse Cholangitis Model Using Contrast-Enhanced Ultrasound Imaging and Photoacoustic Imaging

Bile duct ligation (BDL) can cause cholangitis, which is known to induce impaired Kupffer cell (KC) function and increased oxygen consumption in a mouse model. It is important to monitor changes in KC function and tissue oxygen saturation, both of which are critical factors in the progression of cholangitis. The purpose of this study is to investigate the impaired phagocytic activity of KC and liver oxygen saturation (sO2) in a mouse cholangitis model using contrast-enhanced ultrasound imaging (CEUS) and photoacoustic imaging (PAI). A mouse cholangitis model was created by ligation of the common bile duct (CBDL, n = 20), and the left intrahepatic bile duct (BDL-L, n = 19), both of which were compared with the non-ligation groups—right lobe measurement group after left intrahepatic bile duct ligation (BDL-R, n = 19) and the control group (n = 14). The echogenicity and sO2 were measured by CEUS and PAI and the KC fraction was assessed at 1, 2 and 4 wk after ligation. We found a significantly lower echogenicity of the Kupffer phase in the CBDL and BDL-L groups compared with that in the control and BDL-R groups at 2 wk (p < .01). The CBDL and BDL-L groups showed a lower echogenicity than that of the BDL-R group at 4 wk (p < .01). We found a significantly lower sO2 of the CBDL and BDL-L groups compared with that of the control and BDL-R groups at 4 wk (p < .01). The CBDL and BDL-L groups showed a higher KC fraction than that of the BDL-R and control groups at each time point (p < .01). In conclusion, our study suggests that the Sonazoid CEUS and PAI could be a useful tool for monitoring impaired KC phagocytic activity and the liver hypoxic state.