Phagocytic Activity Of Macrophages Research Articles

Effect of velvet antler on the immune activity of cyclophosphamide-induced immunosuppressed mice

ABSTRACT To study the antioxidant and immune protection activity of velvet antler (VA) in cyclophosphamide-induced immunocompromised mice, BALB/c mice were intragastrically administered 100, 300, or 500 mg/(kg·d) VA for 30 days, and were intraabdominally injected with cyclophosphamide to create a hypoimmune murine model. Cellular immunity, macrophage phagocytic activity, natural killer (NK) cell activity, white blood cell count, splenic lymphocyte subsets and the mRNA expression levels of serum cytokines were analysed. We found that the IC50 for removing 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS), OH, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals of VA were 0.476, 4.33, and 37.92 mg/mL, respectively. VA could enhance innate and adaptive immunity of mice by improving cellular immunity, macrophage phagocytic ability, and NK cell activity; promoting the production of IL-4, IFN-γ, TNF-α and other cytokines; increasing the content and ratio of lymphocyte subsets. These results indicate that VA has good antioxidant activity and can improve the immune function of cyclophosphamide-induced immunodeficient mice.

Immunomodulatory Potency Etlingera rubroloba A.D. Poulsen Fruit Ethanol extract against Macrophage Phagocytic Activity and CD4 Levels in Wistar Male Rats

Etlingera rubroloba A.D. Poulsen is an endemic plant in Southeast Sulawesi and taxonomic affinity with Etlingera elatior (Jack) R. M. Smith. The fruit of E. elatior has been reported to provide immunomodulatory activity by increasing the phagocytic activity of macrophage cells. This study aimed to determine the immunomodulatory potency of the E. rubroloba fruit ethanol extract with parameters of phagocytic activity and CD4 levels. This study used 24 male Wistar rats divided into 6 treatment groups, namely normal, negative (Na-CMC 0.5%), positive (Phylantii extract 0.135 mg/kgbw), extract dose I (200), dose II (300), and dose III (400) mg/kgBW. The treatment was given 3 mL each orally for seven days. All mice (except the normal group) were infected with 0.5 mL of Staphylococcus aureus intraperitoneally on the eighth day. The data were statistically analyzed by measuring macrophage phagocytic activity microscopically using Giemsa staining and CD4 levels using the sandwich ELISA method. The results showed that dose 300 mg/KgBW demonstrated the highest average percentage of macrophage cell phagocytic activity and CD4 level, which were 80.5% and 227.49 ng/mL, respectively. They were higher than the positive control treatment. Based on the results of Tukey's post hoc statistical test, all treatment groups had significant differences from the positive control group in both parameters (P<0.05). This study concludes that the ethanolic extract of the fruit of E. rubroloba dose of 300 mg/kgbw has potential as an immunomodulator where increased phagocytic activity is associated with increased CD4 levels.

THE EFFECT OF MORINGA LAM LEAF EXTRACT ON PHAGOCYTOSIS ACTIVITY OF MACROPHAGES, ROS, NO, IFN-γ, AND IL-10 ON PBMC IN ADULT PULMONARY TUBERCULOSIS PATIENTS INDUCED BY ESAT-6 IN-VITRO

Introduction: Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (MTB). MTB can inhibit phagolysosomal fusion, so it’s difficult to eliminate, and the BCG vaccine didn’t contain ESAT-6/CFP-10, which caused therapy and immunization couldn’t be optimal in eradicating TB. An immunomodulator is needed to improve the immune system, especially from natural ingredients. A Moringa oleifera plant is known to have immunomodulatory properties because of its nutrients, flavonoids, polyphenols, saponins,alkaloids, and steroids.
 Material and Methods: This study aims to determine the effect of the M. oleifera leaf extract (MLE) on the phagocytic activity of macrophages, ros, no, Ifn-γ, and IL-10 induced by ESAT-6 in the Peripheral Blood Mononuclear Culture (PBMC) pulmonary TB patients. The research was carried out on PBMC from the blood of six pulmonary TB patients with a post-test-only control group design. The samples were divided into three groups: negative control group, positive control group (induced with ESAT-6), and intervention groups (induced with ESAT-6 and MLE at doses of 1 μg/mL, 2.5 μg/mL, 10 μg/mL, and 25 μg/mL).
 Results: MLE with a dose of 1 μg/mL significantly increased macrophages’ phagocytic activity, ros/no, Ifn-γ, and decreased IL-10 levels (p < 0.05) as compared to the control group, whereas at a dose of ≥ 2.5 μg/mL, it decreased macrophages phagocytic activity, ros/no, Ifn-γ, and increased IL-10 levels.
 Discussion: These indicate that MLE at a low dose had immunostimulant activity, but at a higher dose showed immunosuppressive and anti-inflammatory activity.

Effect of ESAT-6 on Phagocytosis Activity, ROS, NO, IFN-γ, and IL-10 in Peripheral Blood Mononuclear Cells of Pulmonary Tuberculosis Patients

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (MTB) that lives intracellularly. MTB can inhibit lysosomal enzymes and phagolysosomal fusion, which is challenging to eliminate. These are due to ESAT-6/CFP-10 originating from the RD1 region genome that expresses the Esx-1 type VII secretion system. Esx-1 encodes Esx-A (ESAT-6) and Esx-B (CFP-10), potential vaccine candidates still under research and development. ESAT-6/CFP-10 is predicted to affect macrophage phagocytic activity, IFN-γ, ROS/NO, and IL-10 levels. Several studies have begun to focus on the ESAT-6 antigen due to the high levels of ESAT-6 antibody found in pleural effusion and granuloma fluid. They can last up to 1 year compared to CFP-10 in experimental animals. This study aimed to analyze the effect of ESAT-6 on the phagocytic activity of macrophages, ROS/NO, IFN-γ, and IL-10 in peripheral blood mononuclear cells (PBMCs) cultures of pulmonary TB patients. It is experimental laboratory research with a post-test-only control group design with PBMCs from October 2019 to December 2020 in the Aretha Laboratory Bandung. There were two groups: the negative group (without ESAT-6) and the positive group (with ESAT-6). Six subjects were sampled at the Pindad Hospital in Bandung, and the research was carried out at the Aretha Laboratory in Bandung. Statistical analysis using paired t test. There was a significant difference between the negative and positive groups (p<0.05). ESAT-6 can decrease macrophage phagocytic activity, intracellular ROS/NO, and IFN-γ but increase IL-10 levels.

Abstract 5196: CD47 Blockade potentiates immunotherapy of durvalumab against cutaneous T cell lymphoma

Abstract Immune checkpoint (IC) blockade for programmed cell death 1 (PD1) and PD-Ligand 1 (PD-L1) has shown promising and durable therapeutic outcomes in cutaneous T-cell lymphoma (CTCL), but resistance and/or relapses are common. While research focused on improving adaptive immune functions in CTCL, we investigated the role of 1) the “do not eat me signal” (CD47), and PD-L1, as a dual (innate and adaptive IC)-targeting strategy in CTCL. RNA sequencing and flow cytometric analysis showed that CTCL tumor cells and CTCL cell lines (MyLa, Hut78, HH, and H9 cells) overexpressed CD47 and PD-L1 compared with healthy control, and CD47 positively correlated with PD-L1 in CTCL patients. Overexpression of CD47 and PD-L1 was induced by high MYC expression in CTCL tumor cells lines. In addition, the signal-regulatory protein (SIRP)α receptor for CD47 and PD-L1 were significantly more abundant on macrophages, dendritic cells and natural killer cells in CTCL patients than healthy control by flow cytometric analysis. Furthermore, the RNA sequencing data indicated that the M2 macrophages, immature dendritic cells, and inhibitory receptors expressed natural killer cells in CTCL patients were higher than in healthy control. Notably, TTI-621 (SIRPαFc) treatment decreased M2 macrophage, immature dendritic cells, and inhibitory receptors expressed natural killer cells in CTCL patients at the end of the treatment, compared to baseline. In vitro, TTI-621 treatment increased the macrophage phagocytic activity compared to untreated control. Moreover, TTI-621 synergized with an anti-PD-L1 antibody (durvalumab) to reprogram M2-like TAMs, induced by MyLa supernatant, to M1-like phenotypes. The simultaneous blockade of both CD47 and PD-L1 inhibited growth of CTCL cell lines more potently than each single antibody alone or blank control in vitro. Enhanced CD8+ T cell mediated killing was detected using a chromium-release assay following dual blockade of in CTCL cell lines, suggesting anti-CD47 and anti-PD-L1 may synergistically facilitate elimination of CTCL tumor cells through specific pathways. RNA-sequencing analysis indicated that these effects were mediated by cell death related pathways such as apoptosis, autophagy, and necroptosis. Collectively, our findings demonstrated that CD47 and PD-L1 are critical regulators of innate and adaptive immune surveillance in CTCL and that dual targeting of CD47 and PD-L1 will provide insight into tumor immunotherapy to improve tumor control in CTCL. Citation Format: Zhen Han, Mingye Feng, Xiwei Wu, Chingyu Su, Yate-Ching Yuan, Hanjun Qin, James F. Sanchez, Jasmine Zain, Steven T. Rosen, Christiane Querfeld. CD47 Blockade potentiates immunotherapy of durvalumab against cutaneous T cell lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5196.

Immunomodulatory and Anticancer Activities of Barley Bran Grown in Jordan: An in vitro and in vivo Study.

The Mediterranean diet is regarded as one of the most healthful dietary patterns in the world, owing to a combination of foods high in antioxidants and anticancer constituents. Barley bran is one of the components of the Mediterranean diet. It has nutritional and beneficial effects in different pathological conditions. Many studies were achieved to assess the nutritious values of barley bran, but there is no research indicating immunomodulatory and anticancer activities of barley bran grown in Jordan. The present study aims to examine and assess the potential immunomodulatory and anti-tumor activities of ethanol, n-hexane, aqueous/methanol, and water extracts obtained from barley bran. The Maceration method was utilized to prepare ethanol, n-hexane, aqueous/methanol, and water extracts. Various phytochemical groups were determined by using qualitative phytochemical tests. The antiproliferative activity of extracts was determined against MCF-7, HCT-116, A549, and EMT6/p by the MTT assay. The Folin-Ciocalteu reagent was used to detect the total phenolic content in extracts. Furthermore, immunomodulatory activity was assessed by determining the effect of extracts on splenocytes proliferation in the presence and absence of mitogens. The nitro blue tetrazolium assay and the neutral red method were used to assess the effect of each extract on the phagocytic activity of macrophages and pinocytosis, respectively. For the in vivo part, three different concentrations (10, 20, and 30% w/v) of barley bran were used to test the prophylactic effect in four Balb/C mice groups inoculated with EMT6/p cell-line subcutaneously. Also, serum samples were collected to assess the effect on cytokines (IFN-gamma, IL-2, IL-4, and IL-10). Barley bran extracts inhibited cancer cell proliferation. According to immunoassays, n-hexane and aqueous/methanol extracts could significantly rise lymphocyte proliferation and pinocytosis activity of macrophages. The activity of phagocytosis was increased by n-hexane and ethanol extracts. For the in vivo part, the average tumor size and weight of mice given the 30% barley bran group was significantly reduced (p < 0.05) compared with the control group. During our study, higher levels of TH1 cytokines (IFN- γ, IL-2) and lower levels of TH2 cytokine (IL-4) and T regulatory cytokine (IL-10) were obtained due to consumption of barley bran in food. Barley bran can be used as a prophylactic agent because it has anti-cancer and immunomodulatory activities.

Loss of Autotaxin inhibits Toll‐like receptor4‐mediated immune mechanisms and promote spontaneous colitis in Il10‐ko mice

Autotaxin (Atx) is a secreted enzyme converting lysophosphatidylcholine (LPC) and sphingosyl‐phosphorylcholine into lysophosphatidic acid and sphingosine 1‐phosphate, respectively. Given the high affinity of LPC to cholesterol and the enrichment of cholesterol and sphingolipids in lipid rafts wherein LPS sensor Toll‐like receptor 4 (TLR4) and its co‐receptor CD14 reside, we hypothesized that Atx deficiency inhibits TLR4‐mediated innate and adaptive immunity; thereby, accelerating the susceptibility to microbe‐induced intestinal inflammation.To study this hypothesis, we generated myeloid cell lineage‐restricted Atx‐knockout (ko) mice (Atx‐dME/dME) to investigate TLR4‐mediated immune and inflammatory responses and examined LPS‐receptor complex formation through fluorescence resonance energy transfer technique, confocal microscopy, and flow cytometry. Phagocytic activity of macrophages was assessed. Lamina propria CD4+ T cells and bacterial load in the intestinal mucosa were examined. An impact of Atx deficiency in inflammatory bowel diseases (IBD) was investigated using Atx‐dME/dME;Il10‐/‐ mice that have both Atx‐deletion in myeloid cells and a global Il10 deletion. We examined the serum samples from IBD patients.With peritoneal macrophages from Atx‐dME/dME mice, we identified that Atx‐ko disrupted the integrity of lipid rafts at the plasma membrane, resulting in the inhibition of TLR4 complex formation. Accordingly, the recruitment of adaptor molecules to TLR4 was suppressed, and TLR4‐mediated responses were substantially reduced in Atx‐ko macrophages. TLR4‐induced innate immunity such as phagocytosis was attenuated in Atx‐ko macrophages. The activation of CD4+ effector T cells and regulatory T cells was diminished in the lamina propria lymphocytes of Atx‐dME/dME mice compared to that of Atx‐wt littermates. Consequently, Atx‐dME/dME mice had a higher bacterial prevalence in the intestinal mucosa compared to controls. Just like the notion that commensal microbes translocated from the lumen into the intestinal mucosa can elicit spontaneous colitis in Il10‐/‐ mice, combining Atx‐dME/dME with Il10‐/‐ mice (Atx‐dME/dME;Il10‐/‐) did accelerate spontaneous colitis development. Atx‐dME/dME;Il10‐/‐ mice had gross inflammation occurring throughout the colon, massive neutrophil infiltration and necrosis in the colonic mucosa, and increased mortality (Log‐rank P=0.0046), while Atx‐wt;Il10‐/‐ littermates are normal. Notably, ATX serum protein level was lower in UC (n=26) and CD (n=34) patients compared to the level in normal subjects (n=26) (P&lt;0.001), indicating an association of reduced ATX levels with intestinal inflammation.Collectively, we found that Atx deficiency suppresses TLR4‐mediated innate and adaptive immune mechanisms; thereby accelerating the susceptibility to microbe‐induced gut inflammation.

Mesenchymal stromal cells application for experimental genital tuberculosis combination therapy

BACKGROUND: Cell therapy is a promising trend in treating characterized by inflammation and sclerosis diseases such as genital tuberculosis, marked by pelvic inflammatory disease and uterine tube occlusion.&#x0D; AIM: Efficacy evaluation of combined mesenchymal stem cells and specific polychemotherapy treatment of the experimental genital tuberculosis.&#x0D; MATERIALS AND METHODS: Chinchilla rabbits (n = 27) were divided on 4 groups. Group 1 (n = 6) comprised control group, healthy animals. Group 2 (n = 7) infected with genital tuberculosis, without treatment. Group 3 (n = 7) infected with genital tuberculosis, treated with anti-tuberculous drugs only. Group 4 (n = 7) infected with genital tuberculosis, treated with anti-tuberculous drugs and mesenchymal stem cells. Culture of M. tuberculosis Erdman in dose 107 CFU/0.2 ml was injected under the left uterine tube serosa for the genital tuberculosis modelling. For treatment efficacy evaluation following tests were used: full blood count, blood chemistry, hysterosalpingography, diagnostic laparoscopy, peritoneal macrophage phagocytic activity assessment.&#x0D; RESULTS: Infected with genital tuberculosis animals had leukocytosis, elevated C-reactive protein, swelled and occluded uterine tubes. Treated with anti-tuberculous drugs and mesenchymal stem cells rabbits had lower white blood cell count (8.18 1.39 109/L vs 9.32 1.36 109/L, р 0.05) and C-reactive protein (1.1 0.8 mg/L vs 2.2 1.2 mg/L, р 0.01) compared to animal treated with anti-tuberculous drugs only. Animals in group 4 had also increased peritoneal macrophage phagocytic activity. Treated with mesenchymal stem cells animals had unobstructed uterine tubes, stabilized adhesive process within small pelvis with reparative process prevalence.&#x0D; CONCLUSIONS: Mesenchymal stem cells combined with anti-tuberculous drugs therapy favors reparative process in uterine tubes in genital tuberculosis.

M13 phage coated surface elicits an anti-inflammatory response in BALB/c and C57BL/6 peritoneal macrophages

Bacteriophages are one of the viral components of the human microbiome. M13 phages have recently been considered for immunotherapy because they can be detected by immune cells and stimulated immune responses. Macrophages are essential innate immune cells that respond to stimuli and direct subsequent immune responses. Therefore, it is crucial to evaluate the immunomodulatory effect of phage on macrophage function. For this purpose, peritoneal macrophages from BALB/c and C57BL/6 mice were cultured on the M13 phage, M13 phage-RGD, gelatin-coated, and un-coated wells. Then macrophages were examined for morphological characteristics, L. arginine metabolism, redox potential, inflammatory cytokine production, and phagocytic activity after two and seven days of culture. We observed that M13 phage-coated surfaces induced anti-inflammatory cytokines production and reduced inflammatory cytokines level of BALB/c and C57BL/6 macrophages at the steady-state and post LPS stimulation. In addition, L. arginine metabolism and phagocytic activity of macrophages were directed to the M2 phenotype by induction of arginase-1 and efferocytosis in the M13 phage-containing groups, respectively. The present study confirms the M13 phage's ability to polarize macrophages toward the M2 phenotype. However, using M13 phage in treating inflammatory diseases in animal models could determine their immunotherapy capacity in the future.

The dual role of mesenchymal stem cell-derived exosomes modulates the phagocytic activity of macrophages and promotes cardiac recovery after heart attack

The dual role of mesenchymal stem cell-derived exosomes modulates the phagocytic activity of macrophages and promotes cardiac recovery after heart attack

Modulation of functional activity of heat-stressed chicken macrophages by poultry-derived probiotic lactobacilli

This study investigated the potential role of lactobacilli in mitigating the negative effects of heat stress on the functional activity of chicken macrophages. Macrophage-like MQ-NCSU cells were incubated at 40 and 44 °C in the presence or absence of a single or a mixture of different poultry-derived Lactobacillus spp., including Lactobacillus animalis, L. acidophilus, L. reuteri, and L. crispatus. Macrophage activation was evaluated by measuring nitric oxide (NO) production, phagocytic activity, and the transcription levels of cytokines, chemokine, and Toll-like receptors (TLRs). Macrophages exposed to heat stress exhibited increased production of NO, diminished expression of interleukin (IL)-1β and IL-12p40, and elevated expression of TLR2 and TLR4, whereas no significant alterations in the phagocytic activity of macrophages were observed. Conversely, treatment of macrophages with probiotic lactobacilli counteracted the effects associated with heat stress. This was evidenced by a notable enhancement in macrophage phagocytic activity, NO production and expression of IL-1β, IL-12p40, IL-18, and chemokine CXCL8, coupled with a reduction in TLR2 and TLR4 expression. These findings suggest that probiotic lactobacilli could be given to chickens to mitigate the negative effects of heat stress on their innate immune system. However, further studies are required to validate the observed effects in an in vivo model.

The functions of clusterin in renal mesenchymal stromal cells: Promotion of cell growth and regulation of macrophage activation

Clusterin (CLU) increases resistance to renal ischemia-reperfusion injury and promotes renal tissue repair. However, the mechanisms underlying of the renal protection of CLU remain unknown. Mesenchymal stromal cells (MSCs) may contribute to kidney cell turnover and injury repair. This study investigated the in vitro functions of CLU in kidney mesenchymal stromal cells (KMSCs). KMSCs were grown in plastic culture plates. Cell surface markers, apoptosis and phagocytosis were determined by flow cytometry, and CLU protein by Western blot. There were no differences in the expression of MSC markers (positive: CD133, Sca-1, CD44, CD117 and NG2, and negative: CD34, CD45, CD163, CD41, CD276, CD138, CD79a, CD146 and CD140b) and in the trilineage differentiation to chondrocytes, adipocytes and osteocytes between wild type (WT) and CLU knockout (KO) KMSCs. CLU was expressed intracellularly and secreted by WT KMSCs, and it was up-regulated by hypoxia. CLU did not prevent hypoxia-induced cell apoptosis but promoted cell growth in KMSC cultures. Furthermore, incubation with CLU-containing culture medium from WT KMSCs increased CD206 expression and phagocytic capacity of macrophages. In conclusion, our data for the first time demonstrate the function of CLU in the promotion of KMSCs proliferation, and it may be required for KMSCs-regulated macrophage M2 polarization and phagocytic activity.

Polysaccharides from Spores of Cordyceps cicadae Protect against Cyclophosphamide-Induced Immunosuppression and Oxidative Stress in Mice

This study investigated the purification, preliminary structure and in vivo immunomodulatory activities of polysaccharides from the spores of Cordyceps cicadae (CCSP). The crude CCSP was purified by diethylaminoethyl (DEAE)-cellulose and Sephadex G-100 chromatography, affording CCSP-1, CCSP-2 and CCSP-3 with molecular weights of 1.79 × 106, 5.74 × 104 and 7.93 × 103 Da, respectively. CCSP-2 consisted of mannose and glucose, while CCSP-1 and CCSP-3 are composed of three and four monosaccharides with different molar ratios, respectively. CCSP-2 exhibited its ameliorative effects in cyclophosphamide-induced immunosuppressed mice through significantly increasing spleen and thymus indices, enhancing macrophage phagocytic activity, stimulating splenocyte proliferation, improving natural killer (NK) cytotoxicity, improving bone marrow suppression, regulating the secretion of cytokines and immunoglobulins, and modulating antioxidant enzyme system. These results indicate that CCSP-2 might be exploited as a promising natural immunomodulator.

Влияние пептидного препарата «Бурсанатал» на клетки барьерных тканей

An important condition for the normal existence of the body, protecting it from intoxication and maintaining homeostasis is the ability of barrier tissues to maintain plasticity and the ability to adapt to external influences. In turn, the physiological properties of external and internal barriers depend on the functional activity of their constituent cells. The influence of the tissue peptide preparation "Bursanatal", isolated by enzymatic hydrolysis from the lymphoid tissue of the Fabricius bag of broiler chickens, on the viability and morphofunctional characteristics of cells of barrier tissues: skin fibroblasts, macrophages of the mucous membranes of the respiratory and digestive apparatus was studied. An increase in the viability of all studied cell types was established, as well as an increase in the lysosomal and phagocytic activity of macrophages, without a significant effect on their enzymatic properties. The most pronounced changes in the morphological and functional properties of cells were observed when exposed to a 10% concentration of the drug "Bursanatal".

Syk promotes phagocytosis by inducing reactive oxygen species generation and suppressing SOCS1 in macrophage-mediated inflammatory responses.

ObjectiveInflammation, a vital innate immune response against infection and injury, is mediated by macrophages. Spleen tyrosine kinase (Syk) regulates inflammatory responses in macrophages; however, its role and underlying mechanisms are uncertain.Materials and MethodsIn this study, overexpression and knockout (KO) cell preparations, phagocytosis analysis, confocal microscopy, reactive oxygen species (ROS) determination, mRNA analysis, and immunoprecipitation/western blotting analyses were used to investigate the role of Syk in phagocytosis and its underlying mechanisms in macrophages during inflammatory responses.ResultsSyk inhibition by Syk KO, Syk-specific small interfering RNA (siSyk), and a selective Syk inhibitor (piceatannol) significantly reduced the phagocytic activity of RAW264.7 cells. Syk inhibition also decreased cytochrome c generation by inhibiting ROS-generating enzymes in lipopolysaccharide (LPS)-stimulated RAW264.7 cells, and ROS scavenging suppressed the phagocytic activity of RAW264.7 cells. LPS induced the tyrosine nitration (N-Tyr) of suppressor of cytokine signaling 1 (SOCS1) through Syk-induced ROS generation in RAW264.7 cells. On the other hand, ROS scavenging suppressed the N-Tyr of SOCS1 and phagocytosis. Moreover, SOCS1 overexpression decreased phagocytic activity, and SOCS1 inhibition increased the phagocytic activity of RAW264.7 cells.ConclusionThese results suggest that Syk plays a critical role in the phagocytic activity of macrophages by inducing ROS generation and suppressing SOCS1 through SOCS1 nitration during inflammatory responses.

The effect of the imbalance of the neurotransmitter systems of the dorsal hippocampus on the activity of alveolar macrophages and lung surfactant

The purpose of the study. The paper analyzes the metabolism of surfactant lipids and phagocytic activity of alveolar macrophages with an imbalance of the neurotransmitter systems of the dorsal hippocampus. Materials and methods. Male rats were microinjected with L-glutamate and GABA into the dorsal hippocampus bilaterally by stereotactic coordinates. Studies included determination of surfactant lipid fractions (thin-layer chromatography method), total phospholipids and their surface-active properties (Wilhelmi method), phospholipase activity, evaluation of endopulmonary cytogram, phagocytic index, and phagocytic number. Results. It was found that the introduction of L-glutamate was accompanied by an increase in phospholipids in the surfactant due to «inert» fractions of phosphatidylserine, phosphatidylinositol, and a low-active fraction of phosphatidylethanolamine against the background of a decrease in the intensity of phospholipase hydrolysis and the ability of macrophages to phagocytosis. The introduction of GABA led to redistribution of phospholipid fractions toward a decrease in phosphatidylcholine surfactant and an increase in the proportion of lysophosphatidylcholine under conditions of phospholipase activation and macrophage phagocytic activity. Conclusions The imbalance of the glutamate and GABAergic systems of the hippocampus has a multidirectional effect on the composition of surfactant lipids, the ability of alveolar macrophages to phagocytosis, and is characterized by the deterioration of the surface-active properties of the lungs.

The role of vitamin D deficiency in antituberculous protection

BACKGROUND. The main task of modern phthysiology is a comprehensive search for ways to optimize the etiotropic and the pathogenetic treatment of tuberculosis (TB). The search for improved treatment in addition to etiotropic antimicrobial therapy lies in the plane of improving pathogenetic therapy. Analysis of the available scientific sources suggests that the efficacy of TB treatment can be improved by adding vitamin D to the pathogenetic treatment, as vitamin D metabolites support the innate immune response to Mycobacterium tuberculosis.&#x0D; OBJECTIVE. To determine the role of vitamin D in the immunopathogenesis of the inflammatory response in pulmonary TB and to assess the prospects of its impact on improving the effectiveness of treatment by analyzing information from available scientific sources on this topic.&#x0D; MATERIALS AND METHODS. The study was performed for the period December 2020 – August 2021. The search was conducted by&#x0D; Keywords:&#x0D; pulmonary tuberculosis, vitamin D, mechanism of action, pathogenesis, treatment. Access to various full-text and abstract databases was used as the main source of research.&#x0D; RESULTS AND DISCUSSION. A large number of studies conducted so far prove the link between vitamin D deficiency and the occurrence of pulmonary TB. Vitamin D receptors have been found to be present on various surfaces of immune cells, including T and B cells, indicating that they need vitamin D to perform cellular functions. Vitamin D has been shown to increase the phagocytic activity of macrophages, and that monocytes incubated with cholecalciferol (vitamin D3) metabolites induce anti-TB activity. A number of studies have shown that vitamin D increases the body’s production of the antimicrobial/antimycobacterial peptide LL-37, a member of the cathelicidin petelide family. Therefore, the narrowly analyzed analysis according to the literature suggests that in the conditions of full vitamin D status of the human body the course of TB will be favorable, and in case of vitamin D deficiency – which is primarily associated with genetic polymorphisms, the course of TB may be unfavorable.&#x0D; CONCLUSIONS. Vitamin D functionates as one of the activators of macrophages and plays a role in the immune defense of the human body against mycobacterial TB. The inclusion of vitamin D in the program of complex treatment of TB infection is promising, as it enhances the production of antimicrobial/antimycobacterial peptide LL-37. It can be used as one of the components of TB prevention in children.

TRPA1-mediated effects on the functional activity of macrophages under the exposure with cigarette smoke and cinnamaldehyde

Introduction. Being the leading cause of COPD, smoking represents a major health problem. Upon entering the respiratory tract, cigarette smoke comes into contact with various cells, including macrophages expressing on their surface TRPA1 receptors, which are sensitive to the main pathogenic compounds formed during tobacco combustion.Aim. To study the functional activity of TRPA1 channels on macrophages in terms of cell responses to cigarette smoke and the TRPA1 agonist cinnamaldehyde (CA). Materials and methods. The experimental conditions included exposure of monocyte-derived macrophages to CA (100 μM), 4% cigarette smoke extract (CSE) and 4% CSE after pretreatment with TRPA1 selective antagonist (HC-030031 100 μM). The concentration of cytokines in the culture medium, the expression of TRPA1 on the cell surface, as well as the phagocytic activity of macrophages were analyzed by flow cytometry.Results. We found that 60.2 (49.6; 71.8)% of cells expressed TRPA1 and their number increased after exposure with CA. CSE significantly inhibited CXCL10 production from 1121.3 (295.7; 3154.6) pg/ml to 187.9 (113.8; 398.3) pg/ml (p=0.04), which was partially prevented by blocking TRPA1 (692.4 [428.6; 2916.6] pg/ml, p=0.04). Similar to CSE, CA also caused a decrease in CXCL10 concentration (189.2 [111.7; 311.3] pg/ml, p=0.03). Among other observations, there was an increase in the concentration of IL-1β after the exposition with HC-030031, as well as a decrease in TNF-α, IFN-γ and IL-12p70 after the treatment with CA. CSE caused a minor inhibition in phagocytic cells number, which was not prevented by TRPA1 blocking. CA, on the contrary, increased the phagocytic activity of macrophages. The initial expression of TRPA1 had a negative correlation with the dynamics of CXCL10 in response to CSE and CA but a positive correlation with the number of phagocytic cells after exposition with CA (ρ=0.81, p=0.005). Conclusions. TRPA1 expressed on macrophages apparently mediate an anti-inflammatory effect in terms of produced cytokines but increase phagocytic activity of the cells. TRPA1 are also major receptors involved in the diminished CXCL10 production by macrophage under exposition with cigarette smoke

Methyl and Isopropyl N-Methylanthranilates Affect Primary Macrophage Function - An Insight into the Possible Immunomodulatory Mode of Action.

To complement the knowledge on the anti-inflammatory activity of methyl and isopropyl N-methylanthranilates, two natural products with panacea-like properties, we investigated their effects on thioglycolate-elicited macrophages by evaluating macrophage ability to metabolize MTT, macrophage membrane function, and macrophage myeloperoxidase and phagocytic activities. Moreover, two additional aspects of the inflammatory response of these compounds, their inhibitory activity on xanthine oxidase and catalase, were studied. It was found that these two compounds regulate elicited macrophage functions, most probably by interfering with the function of cell membranes and changing the reducing cellular capacity or enzyme activity of macrophages. Nonetheless, no significant inhibitory action either towards xanthine oxidase or catalase was found, suggesting that the inhibition of these enzymes is not involved in the anti-inflammatory mode of action of these two esters.

Suppression of Extracellular Vesicle CD47 Induces Systemic Anti-DLBCL Immunity

Purpose:Tumor cells evade the immune surveillance by up-regulating surface expression of CD47, which interacts with SIRPa on macrophages to elicit the immune checkpoint response. Anti-CD47 antibody (IBI188) has shown promise in treating tumors, including Diffuse large B cell lymphoma (DLBCL). The objective response rate among DLBCL was 73% (ClinicalTrials.gov number, NCT02953509.). The basis of differential therapeutic success between patients remains unknown. Extracellular vesicles (EVs) carry bioactive molecules that influence the immune system. CD47 has be found on surface of EVs. The purpose of this study is to explore whether EV CD47 contributes to immunosuppression and is associated with anti-CD47 response in DLBCL.Methods: 1.Kaplan-Meier curves and Cox regression models were used to analyze PFS and OS. The area under the ROC curve (AUC) was used to assess the predicted validity of the National Comprehensive Cancer Network-International Prognostic Index (NCCN-IPI) model and the NCCN-IPI+ CD47 model.2.Immunofluorescence experiment was used to detect the infiltration of M1 and M2 subtype macrophages in DLBCL tumor tissue. M1 and M2 macrophages were generated from peripheral blood mononuclear cells obtained from healthy donors. Immunoelectron microscopy, flow cytometry and western blot were performed to detect CD47 on the surface of the EVs derived from DLBCL cells. The activity of macrophage phagocytosis of DLBCL cells was detected by confocal-based phagocytosis assay and flow cytometry-based phagocytosis assay.3.In DLBCL xenografts, the IBI188 antibody was a macrophage immune checkpoint inhibitor blocking CD47 that induces tumor-cell phagocytosis.4.Peripheral blood mononuclear cells from DLBCL patients and healthy donors was collected for EVs purification and subsequent detection of human CD47 proteins by ELISA.Results 1.The elevated expression of CD47 in DLBCL is significantly correlated with poor PFS and OS in a univariate analysis, and is statistically significant after adjusting for the NCCN-IPI in the univariate and multivariate analysis (Figure 1A, B). AUC analysis with cross-validation showed that the combination of the CD47 signature and NCCN-IPI had a better prediction of PFS and OS than without the CD47 signature (Figure 1C). Thus, CD47 in DLBCL can be used as a biomarker of prognosis and developed the prognostic stratification of DLBCL patients.2.EV CD47 derived from DLBCL cells has the same membrane topology as the cell surface CD47, with its extracellular domain exposed on the surface of the EVs (Figure 1D-G). Moreover, EV CD47 could function similarly to cell-surface CD47 in the suppression of macrophage phagocytosis of DLBCL cells (Figure 1H, I). DLBCL cells that had higher levels of cellular CD47 protein packaged greater amounts of CD47 into EVs, and these EVs displayed an increased binding to SIRPa of macrophages, thus inhibiting macrophage-mediated phagocytosis of DLBCL cells (Figure 1J-O).3.Antibodies against human CD47 specifically identified human CD47 on the circulating exosomes from mice bearing DLBCL xenografts but not the control mice. The level of circulating EV CD47 positively correlated with tumor size. Injection of EVs derived from DLBCL cells promoted the growth of tumors, whereas pre-treatment of the EVs with anti-CD47 antibodies (IBI188), but not IgG isotype or CD63-blocking antibodies, inhibited the effect (Figure 1P, Q).4.The presence of CD47 in the EVs isolated from the plasma of DLBCL patients, and the level of CD47 on the circulating EVs was significantly higher in DLBCL patients than that in healthy donors (Figure 1R, S). The receiver ROC curve shows that the level of circulating EV CD47 could distinguish DLBCL patients from healthy donors.ConclusionOur studies suggest that the EV CD47-SIRPa interaction may represent a critical mechanism by which DLBCL cells escape immune-mediated clearance. Our study also raises the possibility that disrupting the interaction between the EV CD47 and macrophage SIRPa is a mechanism in the CD47-SIRPa blockade-based therapies. Moreover, high levels of circulating EV CD47 would follow and correlate positively with the phagocytic activity of macrophages, and reflect the presence of a successful anti-tumor immunity elicited by the anti-CD47 therapy. Together, these findings show that EV CD47 represents an unexplored therapeutic target, which could overcome resistance to current CD47 antibody approaches. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.