Do chemokine/chemokine receptor axes play paramount parts in trafficking and oriented locomotion of monocytes/macrophages toward the lungs of COVID-19 infected patients? A systematic review.

The COVID-19 (coronavirus disease 2019) is a well-defined viral infection, resulting from SARS-CoV-2 (severe acute respiratory syndrome- coronavirus-2). The innate immune system serves as the first line of defense to limit viral spreading and subsequently stimulate adaptive immune responses by the prominent aids of its cellular and molecular arms. Monocytes are defined as the most prominent innate immune cells (IICs) that are reactive against invading pathogens. These cells support host protection against the virus that is mediated by several non-specific mechanisms such as phagocytosis, producing antiviral enzymes, and recruitment of immune cells toward and into the infected tissues. They have the ability to egress from blood and migrate to the SARS-CoV-2 infected regions by the aid of some defense-related functions like chemotaxis, which is mediated by chemical compounds, e.g., chemokines. Chemokines, in addition to their related ligands are categorized within the most important and deserved agents involved in oriented trafficking of monocytes/macrophages towards and within the lung parenchyma in both steady state and pathological circumstances, including COVID-19-raised infection. However, the overexpression of chemokines could have deleterious effects on various organs through the induction of cytokine storm and may be the most important leading mechanisms in the pathogenesis of COVID-19. Authors have aimed the current review article to describe present knowledge about the interplay between monocytes/macrophages and SARS-CoV-2 with a focus on the ability of IICs to migrate and home into the lung of COVID-19 patients through various chemokine-chemokine receptor axes to promote our understanding regarding this disease.

The Alleviating Impacts of Quercetin on Inflammation and Oxidant-antioxidant Imbalance in Rats with Allergic Asthma.

Asthma is an inflammatory disease of the airways. We assessed the anti-inflammatory and antioxidative impacts of quercetin, a plant derivative, on inflammatory and oxidative indices in lung tissue and serum of rats with asthma.Asth ma was induced by ovalbumin. Rats were divided into 4 groups: control, asthma+vehicle (Receieved normal saline), asthma+dexamethasone, and asthma+quercetin. After asthma induction, quercetin (50 mg/kg) and dexamethasone (2.5 mg/kg) were injected intraperitoneally once daily for 1 week. On day 50, lung histopathology indices; inflammatory factors; tissue gene expression, including GATA Binding Protein 3 (Gata-3), Tbx21 (T-bet), Transforming growth factor-ß (TGF-ß), Il10 (IL-10), Il1b (IL-1ß), Il6 (IL-6), Acta2 (α-SMA), and Tnf (TNF-α); and oxidative stress indices (malondialdehyde [MDA], catalase [CAT], glutathione peroxidase [GPX], superoxide dismutase [SOD], and total antioxidant capacity [TAC]) in tissue and serum, were evaluated. The results showed that quercetin reduced Gata3, Tnf, Tgfb1, Il1b, and Acta2 gene expression and increased Tbx21 gene expression following asthma. Quercetin also improved oxidative stress by decreasing MDA levels and increasing TAC, CAT, SOD, and GPX levels in serum and lung tissue. Furthermore, quercetin decreased IL6 and TNFα levels and increased IL10 levels in lung tissue after asthma was treated with quercetin. Quercetin ameliorates oxidative stress and inflammation caused by asthma, especially at the tissue level. Therefore, quercetin can be considered a potent antiasthmatic agent.

Interferon-γ-Treated Mesenchymal Stem Cells Modulate the T Cell-Related Chemokines and Chemokine Receptors in an Animal Model of Experimental Autoimmune Encephalomyelitis.

BACKGROUND: Mesenchymal stem cells (MSCs) modulate immune responses, and their immunomodulatory potential can be enhanced using inflammatory cytokines. Here, the modulatory effects of IFN-γ-licensed MSCs on expression of T cell-related chemokines and chemokine receptors were evaluated using an experimental autoimmune encephalomyelitis (EAE) model. MATERIAL AND METHODS: EAE was induced in 3 groups of C57bl/6 mice and then treated with PBS, MSCs and IFN-γ-treated MSCs. The EAE manifestations were registered daily and finally, the brain and spinal cords were isolated for histopathological and gene expression studies. RESULTS: The clinical scores were lowered in MSCs and IFN-γ-licensed MSCs groups, however, mice treated with IFN-γ-licensed MSCs exhibited lower clinical scores than MSCs-treated mice. Leukocyte infiltration into the brain was reduced after treatment with MSCs or IFN-γ-licensed MSCs compared to untreated group (P<0.05 and P<0.01, respectively). In comparison with untreated EAE mice, treatment with MSCs reduced CCL20 expression (P<0.001) and decreased CXCR3 and CCR6 expression (P<0.02 and P<0.04, respectively). In comparison with untreated EAE mice, treatment with IFN-γ-licensed MSCs reduced CXCL10, CCL17 and CCL20 expression (P<0.05, P<0.05, and P<0.001, respectively) as well as decreased CXCR3 and CCR6 expression (P<0.002 and P<0.02, respectively), whilst promoting expression of CCL22 and its receptor CCR4 (P<0.0001 and P<0.02, respectively). In comparison with MSC-treated group, mice treated with IFN-γ-licensed MSCs exhibited lower CXCL10 and CCR6 expression (P<0.002 and P<0.01, respectively), whereas greater expression of CCL22 and CCR4 (P<0.0001 and P<0.01, respectively). CONCLUSION: Priming the MSC with IFN-γ can be an efficient approach to enhance the immunomodulatory potential of MSCs.

Metabolic Regulation of T cell Activity: Implications for Metabolic-Based T-cell Therapies for Cancer

Immunometabolism is an emerging field in tumor immunotherapy. Understanding the metabolic competition for access to the limited nutrients between tumor cells and immune cells can reveal the complexity of the tumor microenvironment and help develop new therapeutic approaches for cancer. Recent studies have focused on modifying the function of immune cells by manipulating their metabolic pathways. Besides, identifying metabolic events, which affect the function of immune cells leads to new therapeutic opportunities for treatment of inflammatory diseases and immune-related conditions. According to the literature, metabolic pathway such as glycolysis, tricarboxylic acid cycle, and fatty acid metabolism, significantly influence the survival, proliferation, activation, and function of immune cells and thus regulate immune responses. In this paper, we reviewed the role of metabolic processes and major signaling pathways involving in T-cell regulation and T-cell responses against tumor cells. Moreover, we summarized the new therapeutics suggested to enhance anti-tumor activity of T cells through manipulating metabolic pathways.

Increased expression of PD-1 in CD8 + CD3 + T cells correlates with EBV viral load in MS patients.

Multiple sclerosis (MS) is one of the common autoimmune diseases. The exact etiology of MS is still unclear, but recent studies have shown the possibility of infectious agent involvement such as Epstein-Barr virus (EBV) in MS pathophysiology. In this study, CD3 + CD8 + T cells of 25 new case MS patients were compared with healthy donors for expression of exhaustion marker, PD-1, using flow cytometry. Also, the expression of the EBV gene, BRCF-1, in PBMCs was analyzed using real-time PCR. Results revealed a lower frequency of CD3 + CD8 + T cells in MS patients. Also, increased expression of PD-1 was observed on CTLs which correlated with higher viral loads. Therefore, a lower frequency of CD8 + T cells but a higher exhaustion marker in MS patients reveals a new mechanism of EBV pathogenesis in MS development. The results suggest that inefficient immune control of EBV in patients with MS may cause exacerbation of the disease. Future studies on the mechanism of T cell exhaustion and chronic infections may aid in a better understanding of the disease and the design of effective therapies.

The immunoregulatory and neuroprotective effects of human adipose derived stem cells overexpressing IL-11 and IL-13 in the experimental autoimmune encephalomyelitis mice.

Multiple sclerosis (MS) is an inflammatory demyelination disease in the central nervous system (CNS) characterized by incomplete endogenous remyelination in the chronic phase. A shift of the balance between pro and anti-inflammatory cytokines is one of the important markers in the pathogenesis of MS. This study aimed to evaluate the effects of human adipose derived stem cells (hADSCs) overexpressing interleukin 11 and interleukin 13 (IL-11, 13-hADSCs) on the experimental autoimmune encephalomyelitis (EAE), an animal model of MS.12 days after immunization of C57Bl/6 female mice with MOG35-55 and initial clinical symptoms appearance, the IL-11, 13-hADSCs were injected via the tail vein into the EAE mice. Then, the mice were sacrificed at 30 days post-immunization (DPI) and the spinal cords of experimental groups were extracted for histopathological and real-time RT-PCR studies.The results indicated that the clinical scores and mononuclear cells infiltration into the spinal cords of EAE mice were significantly reduced in mice treated with IL-11, 13-hADSCs. Likewise, the remyelination and oligodendrogenesis were significantly enhanced in the mentioned treatment group. Real-time results demonstrated that pro/anti-inflammatory cytokine genes expression was reversed in IL-11, 13-hADSCs treatment group in comparison to the untreated EAE group.Expression of IL-11 as a neurotrophic cytokine and IL-13 as an anti-inflammatory cytokine by hADSCs could increase the immunomodulatory and neuroprotective effects of hADSCs and be a powerful candidate in stem cell therapy for future treatment of MS.

Effect of Treatment with Thyme Extract on Urinary Levels of Melatonin in an Experimental Autoimmune Encephalomyelitis Mouse Model.

BACKGROUND: Thymus vulgaris, or thyme belongs to the Lamiaceae family of aromatic plant species and has established antioxidant and anti-inflammatory properties. We examined the association between thyme extract treatment to recovered urinary levels of melatonin, a hormone with neuroprotective effects, in mice induced with EAE. METHODS: Eight B6 mice induced with EAE were randomized into two groups and exposed to either 50 mg/kg of thyme extract or PBS. After EAE induction, mice were injected i.p every other day from day 0 to 21. Four B6 mice without EAE were considered the healthy control group. Urine samples were collected consecutively for two 24 h periods on day 19 and 20. We examined whether thyme extract treatment modified urinary melatonin sulfate concentration (ng/mL) in EAE-induced mice using an ELISA. RESULTS: The clinical score and body weight in thyme-treated EAE group were significantly lower in comparison to the EAE control group at indicated time points. The urinary melatonin concentration was significantly lower in the EAE control group compared to the healthy mice. There was no significant difference between thyme-treated and EAE groups regarding the urine melatonin concentration. CONCLUSION: Our results show that exposing EAE mice to thyme extract improved their clinical symptoms, however, there was no significant effect on urinary melatonin concentration.

Therapeutic effects of extracellular vesicles from human adipose-derived mesenchymal stem cells on chronic experimental autoimmune encephalomyelitis.

Since in cell therapy, there are always concerns about immune rejection, genetic disability, and malignancies, special attention has been paid to extracellular vesicles (EVs) which are secreted by mesenchymal stem cells (MSCs). In the present study, we assessed and compared the therapeutic effects of human adipose-derived mesenchymal stem cells (hADSC) and hADSC-EVs from adipose tissue on experimental autoimmune encephalomyelitis (EAE). After induction of EAE in C57Bl/6 mice, they were treated with hADSCs, hADSC-EVs, or vehicle intravenously. The clinical score of all mice was recorded every other day. Mice were killed at Day 30 and splenocytes were isolated for proliferation assay and determination of the frequency of Treg cells by flow cytometry. Leukocyte infiltration by hematoxylin and eosin, percentages of demyelination areas by luxol fast blue, and mean fluorescence intensity of oligodendrocyte transcription factor 2 (OLIG2) and myelin basic protein (MBP) by immunohistochemistry were assessed in the spinal cord. Our results showed that the maximum mean clinical score and myelin oligodendrocyte glycoprotein-induced proliferation of splenocytes in hADSC- and hADSC-EV-treated mice were significantly lower than the control mice (p < .05). We also demonstrated that the frequency of CD4+ CD25+ Foxp3+ cells was significantly higher in the spleen of hADSC-treated mice than EAE control mice (p = .023). The inflammation score and the percentages of demyelination areas in hADSC- and hADSC-EV-treated groups significantly declined compared with the untreated control group (p < .05). We also showed that there was no significant difference in MFI of MBP and OLIG2 in the spinal cord of studied groups. Overall, we suggest that intravenous administration of hADSC-EVs attenuates the induced EAE through diminishing proliferative potency of T cells, mean clinical score, leukocyte infiltration, and demyelination in a chronic model of multiple sclerosis.

Beneficial effects of Thymus vulgaris extract in experimental autoimmune encephalomyelitis: Clinical, histological and cytokine alterations.

The imbalance between pro and anti-inflammatory cytokines plays an important role in the pathogenesis of multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Thymus vulgaris (thyme) as a traditional medicinal plant has been reported to exert antimicrobial, antioxidant, and anti-inflammatory effects. Therefore, this study evaluated the modulatory effects of Thymus vulgaris on the clinical symptoms, histopathological scores, and the production of some anti-inflammatory (TGF-ß, IL-4, and IL-10) and pro-inflammatory (IFN-γ, IL-6 and IL-17) cytokines in EAE model. EAE was induced by MOG35-55 peptide and mice were treated intra-peritoneally (i.p) with phosphate buffered saline (PBS) in the control group or thyme extract (50 or 100 mg/kg of body weight, every other day) in thyme-treated EAE groups, from day 0 to +21 of post MOG immunization. Mice were sacrificed at day 22, and splenocytes were isolated and re-stimulated in vitro with MOG in order to measure the cytokine production and proliferation of re-stimulated cells by enzyme linked immunosorbent assay (ELISA) method and WST-1 reagent, respectively. The clinical symptoms and histopathological scores of the CNS were lower in thyme-treated than EAE control group. Furthermore, the production of IFN-γ and IL-6 by splenocytes was lower in thyme-treated EAE than in the control group. The production of IL-10 and TGF-ß increased in mice treated with thyme extract compared to the control group. In this study, we showed for the first time that the immunomodulatory effects of Thymus vulgaris in EAE model. Thus, the possible therapeutic potential of thyme for treatment of MS could be considered in future research.

Carvacrol ameliorates experimental autoimmune encephalomyelitis through modulating pro- and anti-inflammatory cytokines.

AIM: The inflammatory process is a key step in multiple sclerosis (MS) development. Carvacrol exhibits various anti-inflammatory properties. We aimed to assess the Carvacrol effects on clinical manifestations and production of pro-inflammatory (IFN-γ, IL-6 and IL-17) and anti-inflammatory (TGF-ß, IL-4, and IL-10) cytokines in experimental autoimmune encephalomyelitis (EAE) as MS animal model. MAIN METHODS: EAE mice were treated with 5, 10 mg/kg dose of Carvacrol or vehicle, as the control EAE group, every other day until day-21 post EAE induction. On day22, the leukocyte infiltration within the CNS was estimated using hematoxylin-eosin staining. The cytokine production by splenocytes was determined after in vitro stimulating with myelin oligodendrocyte protein (MOG). KEY FINDINGS: The EAE clinical scores in 5 and 10 mg/kg Carvacrol-treated mice were lower than untreated group (P < 0.001 and P < 0.01, respectively). The amounts of IFN-γ and IL-6 production by splenocytes of 5 and 10 mg/kg Carvacrol-administered mice were lower than control group (P < 0.001, and P < 0.01 for IFN-γ respectively; P ˂ 0.05 for IL-6). Splenocytes of 5 and 10 mg/kg Carvacrol-treated mice produced higher levels of TGF-ß than untreated mice (P < 0.001). in splenocytes of 5 mg/kg Carvacrol-treated group the IL-10 production was higher while IL-17 secretion was lower than control group (both with P < 0.01). SIGNIFICANCE: Carvacrol exhibits modulatory effects on expression of pro- and anti-inflammatory cytokines. It ameliorates EAE clinical and pathological consequences and therefore its potentials may be considered in treating MS patients.

Ferula gummosa gum induces apoptosis via ROS mechanism in human leukemic cells.

Ferula species known for its oleo-resins that are recognized valuable industrial crops and food products. In this study, we examined the level of cellular oxidants, cytotoxicity, apoptosis and differentiation induced by oleo resin gum from Ferula gummosa (30-250 µg/mL), as well as Arsenic trioxide (50 µM, as positive control), in leukemic (NB4 and HL-60 cells) and normal polymorph nuclear cells during 72 h. Resazurin assay was used to determine cell viability following treatment with F. gummosa (30-250 µg/mL). Intracellular reactive oxygen species was measured by fluorimetry using carboxy 2', 7'-dichlorofluorescein diacetate. Apoptotic cells were evaluated using PI staining of DNA fragmentation by flow cytometry (sub-G1 peak). Differentiation of cells evaluated by Giemsa staining and Nitro Blue Tetrazolium reduction. F. gummosa showed a concentration-dependent suppression in cell survival with IC50 values of 41.8 µg/mL for HL60 and 59.2 µg/mL for NB4 cells after 72 h treatment. ROS formation and apoptotic cells were concentration-dependently increased following treatment with F. gummosa, similar to As2O3. F. gummosa did not induce differentiation of leukemic cells towards granulocytic pattern. The resin did not have toxic effect on PMN cells (<800 µg/mL). In conclusion, the present study demonstrated that F. gummosa induced apoptosis through ROS mechanism on leukemic cells as a concentration and time dependent manner. The precise signaling pathway by which F. gummosa induce apoptosis needs further research.

Toll-like receptor 2: An important immunomodulatory molecule during Helicobacter pylori infection.

Toll like receptors (TLRs) are an essential subset of pathogen recognition receptors (PRRs) which identify the microbial components and contribute in the regulation of innate and adaptive immune responses against the infectious agents. The TLRs, especially TLR2, TLR4, TLR5 and TLR9, participate in the induction of immune response against H. pylori. TLR2 is expressed on a number of immune and non-immune cells and recognizes a vast broad of microbial components due to its potential to form heterodimers with other TLRs, including TLR1, TLR6 and TLR10. A number of H. pylori-related molecules may contribute to TLR2-dependent responses, including HP-LPS, HP-HSP60 and HP-NAP. TLR2 plays a pivotal role in regulation of immune response to H. pylori through activation of NF-κB and induction of cytokine expression in epithelial cells, monocytes/macrophages, dendritic cells, neutrophils and B cells. The TLR2-related immune response that is induced by H. pylori-derived components may play an important role regarding the outcome of the infection toward bacterial elimination, persistence or pathological reactions. The immunomodulatory and immunoregulatory roles of TLR2 during H. pylori infection were considered in this review. TLR2 could be considered as an interesting therapeutic target for treatment of H. pylori-related diseases.

Pulsed Dilution Method for the Recovery of Aggregated Mouse TNF-α.

BACKGROUND: The expression of mouse tumor necrosis factor alpha (TNF-α) in Escherichia coli is a favorable way to get high yield of protein; however, the formation of cytoplasmic inclusion bodies, which is the consequence of insoluble accumulated proteins, is a major obstacle in this system. To overcome this obstacle, we used a pulsed dilution method to convert the product to its native conformation. METHODS: Reducing agent and guanidine hydrochloride were used to solubilize inclusion bodies formed after TNF-(α) expression. Then, the refolding procedure was performed by pulsed dilution of the denatured protein into a refolding buffer. The properly-folded protein was purified by metal affinity chromatography. RESULTS: SDS-PAGE showed a 19.9 kDa band related to the mature TNF-(α) protein. The protein was recognized by anti-mouse TNF-(α) on western blots. The final concentration of the purified recombinant TNF-(α) was 62.5 µg/mL. CONCLUSIONS: Our study demonstrates the efficiency of this method to produce a high yield of folded mature TNF- (α).

A linkage and association analysis study in the multidrug resistance gene 1 (mdr1) in renal patients.

Several investigations demonstrated that the polymorphisms of multidrug resistance gene (MDR1) gene contribute to interindividual variability in bioavailability and tissue distribution of its substrates. Genotyping of closely spaced single-nucleotide polymorphism (SNP) markers frequently yields highly correlated data, owing to extensive linkage disequilibrium (LD) between markers. The product of multidrug resistance gene (P-gp) is an important molecule, which regulating the bioavailability of many drugs, including calcineurin inhibitors. It also reported that some MDR1 gene polymorphisms (such as 3435C>T) was associated with significantly reduced intestinal P-gp expression in T/T homozygotes. The aim of this study is to develop genotyping assays for polymorphisms of the MDR1 gene, which are believed to have functional properties and to assess the distribution of variant alleles in renal patients (UK Caucasoid). A total of ten polymorphisms in the MDR-1 gene were selected for analysis. Haplotype assays were performed by using EH programme in 172 individuals. The following possible haplotype was apparent (G-41, C-145, C-129, C+139, C+1236, G+2677, G+2956, C+3435, C+4030 and A+4036). This finding suggests the importance of haplotype assignment for the MDR1 gene.