Association study between killer immunoglobulin-like receptor polymorphisms and susceptibility to COVID-19 disease: a systematic review and meta-analysis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a known virus that leads to a respiratory disease called coronavirus disease 19 (COVID-19). Natural killer (NK) cells, as members of innate immunity, possess crucial roles in restricting viral infections, including COVID-19. Their functions and development depend on receiving signals through various receptors, of which killer cell immunoglobulin-like receptors (KIRs) belong to the most effective ones. Different studies investigated the association between KIR gene content and susceptibility to COVID-19. Since previous studies have yielded contradictory results, we designed this meta-analysis study to draw comprehensive conclusions about COVID-19 risk and KIR gene association. According to PRISMA guidelines, a systematic search was performed in the electronic databases to find all studies investigating KIR gene contents in COVID-19 patients before March 2023. Any association between KIR genes and COVID-19 risk was determined by calculating pooled odds ratio (OR) and 95% confidence interval (CI). After applying the inclusion and exclusion criteria, 1673 COVID-19 patients and 1526 healthy controls from eight studies were included in this meta-analysis. As the main results, we observed a positive association between the 2DL3 (OR = 1.48, 95% CI = 1.17-1.88, P < 0.001) and susceptibility to COVID-19 and a negative association between the 2DP1 and the risk for COVID-19 (OR = 0.48, 95% CI = 0.23-0.99, P = 0.049). This meta-analysis demonstrated that KIR2DL3, as a member of iKIRs, might be associated with an increased risk of COVID-19 disease.

Alterations in metabolic pathways: a bridge between aging and weaker innate immune response

Aging is a time-dependent progressive physiological process, which results in impaired immune system function. Age-related changes in immune function increase the susceptibility to many diseases such as infections, autoimmune diseases, and cancer. Different metabolic pathways including glycolysis, tricarboxylic acid cycle, amino acid metabolism, pentose phosphate pathway, fatty acid oxidation and fatty acid synthesis regulate the development, differentiation, and response of adaptive and innate immune cells. During aging all these pathways change in the immune cells. In addition to the changes in metabolic pathways, the function and structure of mitochondria also have changed in the immune cells. Thereby, we will review changes in the metabolism of different innate immune cells during the aging process.

Activating KIR/HLA-I combinations as a risk factor of adult B-ALL

B-cell acute lymphoblastic leukemia (B-ALL), the most predominant type of ALL, is less common and incurable among adults. Regarding the pivotal role of NK cells in immune surveillance against hematological malignancies, studying the effective factors in regulating their function, particularly KIRs as the most important NK cell receptors and HLA-I molecules as their main ligands, is of importance. Since NK responses against malignant lymphoblasts are influenced by KIR signals, we did a case-control study on 154 adult patients with B-ALL and 181 healthy controls to investigate the correlation of KIR/HLA-I combinations with susceptibility to B-ALL in Iranians. The genotyping of KIR genes and HLA-I alleles was performed by PCR-SSP with 11 and 9 primer pairs, respectively. Our data revealed an increased frequency of activating (a)KIRs and aKIR/HLA-I combinations in our patients: KIR3DS1 (p = 0.009, OR = 1.81), Bx genotype (p = 0.038, OR = 1.81), KIR3DS1(+)/HLA-Bw4Thr80(+) (p = 0.004, OR = 3.61), and KIR3DS1(+)/HLA-B Bw4(+) (p = 0.037, OR = 1.76). The presence of inhibitory (i)KIRs in the absence of their cognate HLA-I ligands was also more frequent among the patients. However, the frequency of inhibitory combinations was more common in controls: KIR2DL1(+)/HLA-C2(+) (p = 0.027, OR = 0.57), KIR2DL2/3(+)/HLA-C1(+) (p = 0.004, OR = 0.5), and KIR3DL2(+)/HLA-A3/A11(+) (p = 0.0012, OR = 0.46). To sum up, the less inherited iKIR/HLA-I combinations might make individuals more susceptible to B-ALL because of inefficient education of NK cells.

IFN-γ, IL-17, IL-22+ CD4+ subset in patients with hepatitis C virus and correlation with clinical factor

BACKGROUND

CD4+ T cell responses in HCV infection have a crucial role in the immunopathology of hepatitis C virus (HCV) infection. Our aim was to investigate the frequency of Th1, Th17, and Th22 cells in HCV-infected patients and elucidate their role in the progression of the disease.

METHODS

Twenty-six HCV-infected patients and 26 healthy individuals were recruited. Peripheral blood mononuclear cells (PBMCs) were stained to separate CD4, IFN-γ, IL-17, and IL-22 producing cells using flow cytometry.

RESULTS

Results showed that the mean expression of IL-22 in CD4+ T cells was significantly lower in HCV-infected patients compared to healthy controls. About correlation with clinical factor and T subsets, a negative correlation between the frequency of CD4+ IFN-γ+ cells and Thyroxine level (T4) was observed in the patients. The data showed a positive link between thyroid-stimulating hormone (TSH), cholesterol levels, and the frequency of Th17 cells. In addition, a positive correlation was seen between serum creatinine level with both Th1 and Th17. Ultimately, it was found that there was a positive link between viral burden and IL-17+ IL-22+ cells and a negative correlation between viral load and pure Th22.

CONCLUSIONS

Our findings indicate that Th22 cells may play a part in the immunopathology of HCV and show the associations between Thelper subsets and the clinical signs of the disease.

Investigation of the frequencies of various B cell populations in non-responder healthcare workers in comparison with responders to hepatitis B virus vaccination

BACKGROUND

Hepatitis B is a major global health problem. More than 90% of hepatitis B-vaccinated immunocompetent adults become fully immune. The main purpose of vaccination is immunization. Whether non-responders have a lower percentage of total or antigen-specific memory B cells in comparison with responders is still controversial. We aimed to assess and compare the frequency of various B cell subpopulations in non-responders and responders.

METHODS

Fourteen responders and 14 non-responders of hospital healthcare workers were enrolled in this study. We used flow cytometry to evaluate various CD19+ B cell subpopulations using fluorescent-labeled antibodies against CD19, CD10, CD21, CD27 and IgM and ELISA to evaluate total anti-HBs antibodies.

RESULTS

We found no significant differences in the frequency of various B cell subpopulations between the non-responder and responder groups. Furthermore, the frequency of the isotype-switched memory B cell population was significantly higher in the atypical memory B cell subset compared with the classical memory B cell subset in the responder and total groups (p=0.010 and 0.003, respectively).

CONCLUSIONS

Responders and non-responders to HBsAg vaccine had comparable memory B cell populations. Whether anti-HBs Ab production has a correlation with the level of class switching in B lymphocytes in healthy vaccinated individuals needs further investigation.

Frequency of B-Cell Subpopulations in Low Responders in Comparison with High Responders to Hepatitis B Vaccine Among Health Care Workers

Vaccination is the most effective way to prevent Hepatitis B (HB) infection. The goal of vaccination is to induce immunological memory. Hence, determining the frequency of memory B-cell (MBC) subsets is an important indicator of vaccine efficacy. This study aimed to evaluate the frequency of different B-cell subpopulations and the expression of PD-1 on B-cell subsets in low responders (LR) and high responders (HR) to HB vaccine. According to our findings, the expression level of PD-1 was significantly higher on atypical MBC (atMBC) than that of naive B cell and classical MBC (cMBC) in LR and HR groups. Moreover, cMBCs had a significant higher PD-1 expression than naive B cells in LR group. No significant differences were found in the frequency of various B-cell subpopulations and the expression level of PD-1 on B-cell subsets between LR and HR groups. We observed a negative correlation between age and HBsAb titer and a positive correlation between age and PD-1 expression level on cMBC in LR group. It can be concluded that inadequate specific memory B-cell response, rather than total memory B-cell deficiency, may be implicated in low responsive rate to HB vaccine in healthy individuals.

Targeting TRIM29 As a Negative Regulator of CAR-NK Cell Effector Function to Improve Antitumor Efficacy of These Cells: A Perspective

Natural killer (NK) cells are among the most important cells in innate immune defense. In contrast to T cells, the effector function of NK cells does not require prior stimulation and is not MHC restricted. Therefore, chimeric antigen receptor (CAR)-NK cells are superior to CAR-T cells. The complexity of the tumor microenvironment (TME) makes it necessary to explore various pathways involved in NK cell negative regulation. CAR-NK cell effector function can be improved by inhibiting the negative regulatory mechanisms. In this respect, the E3 ubiquitin ligase tripartite motif containing 29 (TRIM29) is known to be involved in reducing NK cell cytotoxicity and cytokine production. Also, targeting TRIM29 may enhance the antitumor efficacy of CAR-NK cells. The present study discusses the negative effects of TRIM29 on NK cell activity and genomic deletion or suppression of the expression of TRIM29 as a novel approach to optimize CAR-NK cell-based immunotherapy.

Immune responses in mildly versus critically ill COVID-19 patients

The current coronavirus pandemic (COVID-19), caused by SARS-CoV-2, has had devastating effects on the global health and economic system. The cellular and molecular mediators of both the innate and adaptive immune systems are critical in controlling SARS-CoV-2 infections. However, dysregulated inflammatory responses and imbalanced adaptive immunity may contribute to tissue destruction and pathogenesis of the disease. Important mechanisms in severe forms of COVID-19 include overproduction of inflammatory cytokines, impairment of type I IFN response, overactivation of neutrophils and macrophages, decreased frequencies of DC cells, NK cells and ILCs, complement activation, lymphopenia, Th1 and Treg hypoactivation, Th2 and Th17 hyperactivation, as well as decreased clonal diversity and dysregulated B lymphocyte function. Given the relationship between disease severity and an imbalanced immune system, scientists have been led to manipulate the immune system as a therapeutic approach. For example, anti-cytokine, cell, and IVIG therapies have received attention in the treatment of severe COVID-19. In this review, the role of immunity in the development and progression of COVID-19 is discussed, focusing on molecular and cellular aspects of the immune system in mild vs. severe forms of the disease. Moreover, some immune- based therapeutic approaches to COVID-19 are being investigated. Understanding key processes involved in the disease progression is critical in developing therapeutic agents and optimizing related strategies.

The frequency of CD4+ and CD8+ circulating T stem cell memory in type 1 diabetes

Introduction

Methods

Results

Conclusion

Targeting T Cell Metabolism as a Novel Approach for Treatment of MS: With a Focus on PFKFB3 Inhibitors

Abstract:

Multiple sclerosis (MS) is one of the organ-specific autoimmune diseases in which immune cells invade the neurons in the central nervous system (CNS) due to loss of tolerance to self-antigens. Consequently, inflammation and demyelination take place in the central nervous system. The pathogenesis of MS is not completely understood. However, it seems that T cells, especially Th17 cells, have an important role in the disease development. In recent years, studies on manipulation of metabolic pathways with therapeutic targets have received increasing attention and have had promising results in some diseases such as cancers. Glycolysis is a central metabolic pathway and plays an important role in the differentiation of T CD4+ cell toward its subsets, especially the Th17 cells. This suggests that manipulation of glycolysis, by for example using appropriate safe inhibitors of this pathway, can represent a means to affect the differentiation of T CD4+, thus reducing inflammation and disease activity in MS patients. Hence, in this study we aimed to discuss evidence showing that using inhibitors of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3(PFKFB3), as the main regulator of glycolysis, may exert beneficial effects on MS patients.

Comparison of the Antibody Responses Following Vaccination with AstraZeneca and Sinopharm

BACKGROUND

Vaccines are the most effective way to prevent Coronavirus 2 severe acute respiratory syndrome (SARS-CoV-2).

OBJECTIVES

To compare the antibody response of healthy individuals vaccinated with either the AstraZeneca (ChAdOx1 nCoV-19) or the Sinopharm (BBIBP-CorV) vaccine, in those who had no prior infection with SARS-CoV-2.

METHODS

Thirty seven participants were included, of which 17 were administered the AstraZeneca (ChAdOx1 nCoV-19) vaccine, while 20 were given the Sinopharm (BBIBP-CorV) vaccine. SARS-CoV-2 neutralizing antibody and anti-receptor-binding domain (RBD) IgG levels were checked 4 weeks after giving the first and the second dose of either vaccine using the enzyme-linked immunosorbent assay (ELISA) technique.

RESULTS

The AstraZeneca (ChAdOx1 nCoV-19) vaccine exhibited a higher levels of anti-(RBD) IgG compared with the Sinopharm (BBIBP-CorV) in both the first (14.51 μg/ml vs. 1.160 μg/ml) and the second (46.68 μg/ml vs. 11.43 μg/ml) doses. About neutralizing Abs, the titer of the antibody was higher in the AstraZeneca (ChAdOx1 nCoV-19) recipients than in the Sinopharm (BBIBP-CorV) subjects after the first (7.77 μg/ml vs. 1.79 μg/ml, p < 0.0001) and the second dose (10. 36 μg/ml vs. 4.88 μg/ml, p < 0.0001).

CONCLUSIONS

Recipients vaccinated with two doses of the AstraZeneca (ChAdOx1 nCoV-19) had superior quantitative antibody levels than Sinopharm (BBIBP-CorV)-vaccinated subjects. These data suggest that a booster dose may be needed for the Sinopharm (BBIBP-CorV) recipients, to control the COVID-19 pandemic.

Lower frequency of T stem cell memory (TSCM) cells in hepatitis B vaccine nonresponders

Despite the availability of an effective vaccine and antiviral treatments, hepatitis B is still a global public health problem. Hepatitis B vaccination can prevent the disease. Vaccination induces long-lasting protective immune memory, and the identification of memory cell subsets can indicate the effectiveness of vaccines. Here, we compared the frequency of CD4⁺ memory T cell subsets between responders and nonresponders to HB vaccination. Besides, the frequency of IFN-γ⁺ memory T cells was compared between studied groups. Study participants were grouped according to their anti-HBsAb titer. For restimulation of CD4⁺ memory T cells, peripheral blood mononuclear cells (PBMCs) were cultured in the presence of HBsAg and PHA for 48 h. Besides, PMA, ionomycin, and brefeldin were added during the last 5 h of incubation to induce IFN-γ production. Flow cytometry was used for analysis. There was a statistically significant difference in the frequency of CD4⁺CD95⁺, CD4⁺CD95^Hi, and CD4⁺CD95^low/med T stem cell memory (T_SCM) cells between responder and nonresponder groups. However, the comparison of the frequency of memory T cells producing IFN-γ showed no differences. Our results identified a possible defect of immunological CD4⁺ memory T cell formation in nonresponders due to their lower frequency of CD4⁺ T_SCM cells.

Accelerated co-cultured dendritic cell (acDC) loaded with autologous apoptotic bodies might be a promising approach for antigen delivery

Antigens derived from engulfed apoptotic bodies that are presented by dendritic cells can amplify Ag-specific T-cells. Accelerated co-cultured DC (acDC) strategy keeps lymphocytes in contact with differentiating DCs. Therefore, Ag-specific T-cell activation can occur during DC maturation. Our aim was to prepare DCs by acDC method and check the subsequent engulfment of the apoptotic body by acDC. We have proposed that this method could be feasible if we transfect the apoptotic bodies with the antigen. DCs were prepared using acDC method and their maturation markers were confirmed by flow cytometry. Ultraviolet was used for inducing apoptosis in the PBMCs and induction of apoptosis checked by propidium iodide and 7-aminoactinomycin D staining. Flow cytometry and immunohistochemistry were used for checking the uptake of apoptotic bodies by the DCs. The alloreactivity against apoptotic bodies was examined by enzyme-linked immunospot (ELISPOT) assay. Results showed that 40.4% of DCs could efficiently engulf the apoptotic bodies. The results indicated that acDC method is capable to isolate a high yield of DCs, and these cells could properly engulf the apoptotic bodies, more works should be performed to use this method for Ag discovery through delivering the Ag by apoptotic bodies into the DCs.

Comparison of the clinical features and outcome of children with hemophagocytic lymphohistiocytosis (HLH) secondary to visceral leishmaniasis and primary HLH: a single-center study

Background

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of excessive inflammation. We aimed to describe the clinical and laboratory findings of HLH patients secondary to Visceral leishmaniasis (VL) and their treatment outcome during a 4-year follow-up period compared to primary HLH.

Method

Forty children with primary HLH confirmed by genetic study and 20 children with HLH secondary to VL confirmed by a blood or bone marrow polymerase chain reaction from 2014 to 2018 in Shiraz, Fars province, Southern Iran, were enrolled.

Results

The median age at diagnosis was 11.5 months (range 1–170), and 56.7% were male. Fever and splenomegaly were the most frequent clinical presentations. 93.3% of the subjects had an HScore > 169, which had a good correlation with HLH-2004 criteria (r = 0.371, P = 0.004). Patients with primary HLH experienced more thrombocytopenia (P = 0.012) and higher alanine transaminase (P = 0.016), while patients with VL-associated HLH had higher ferritin (P = 0.034) and erythrocyte sedimentation rate (P = 0.011). Central nervous system (CNS) involvement occurred in 38.3% of patients. The mortality rate was higher in patients with CNS disease (61% vs. 35%, P = 0.051). The 3-yr overall survival rate was 35.9%. (24% in primary HLH and 100% in VL-associated HLH, P < 0.001). In Cox regression analysis, platelet count < 100,000/ μ l (hazard ratio 4.472, 95% confidence interval 1.324–15.107, P = 0.016) correlated with increased mortality in patients with primary HLH.

Conclusion

VL is a potential source of secondary HLH in regions with high endemicity. Treatment of the underlying disease in VL-associated HLH is sufficient in most cases, with no need to start etoposide-based chemotherapy.

Correlation between IL-28 polymorphism and spontaneous clearance in HCV patients: systematic review and meta-analysis

Hepatitis C virus (HCV) is a serious global health issue. Nearly 20% of HCV patients spontaneously clear the virus. While some studies have shown an association of spontaneous clearance (SC) of the virus with interleukin (IL) 28B single-nucleotide polymorphisms (SNPs), others did not show such a relationship. Thus, the purpose of the present study was to investigate the association of IL28B polymorphisms (12979860 SNP) with SC of HCV infection. Upon initial screening of the databases, a total of 545 articles were retrieved, of which 22 studies that met predefined eligibility criteria were entered into the meta-analysis. Odds ratios (ORs) with confidence intervals (95% CI), heterogeneity, publication bias, and sensitivity analysis were assessed. According to the meta-analysis results, a significant association was observed between the rs12979860 SNP and SC of HCV infection. The results indicated that the ORs of SC from hepatitis C virus infection were 2.75 times higher in those with cytokine gene polymorphisms (95% CI, 2.23 to 3.38). Moreover, it was found that the prevalence of rs12979860 CC was 0.33 with 95 CI 0.28-0.38 in genotype 1 and was 0.40 with 95 CI 0.34-0.47 in other genotypes. Our meta-analysis results suggest that IL28B rs12979860 CC is a strong predictor for SC of hepatitis C infection in PEG IFN-a/RBV-treated patients.

Comparison of the clinical features and outcome of children with hemophagocytic lymphohistiocytosis (HLH) secondary to visceral leishmaniasis and primary HLH: a single-center study

Background

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of excessive inflammation. We aimed to describe the clinical and laboratory findings of HLH patients secondary to Visceral leishmaniasis (VL) and their treatment outcome during a 4-year follow-up period compared to primary HLH.

Method

Forty children with primary HLH confirmed by genetic study and 20 children with HLH secondary to VL confirmed by a blood or bone marrow polymerase chain reaction from 2014 to 2018 in Shiraz, Fars province, Southern Iran, were enrolled.

Results

The median age at diagnosis was 11.5 months (range 1–170), and 56.7% were male. Fever and splenomegaly were the most frequent clinical presentations. 93.3% of the subjects had an HScore > 169, which had a good correlation with HLH-2004 criteria (r = 0.371, P = 0.004). Patients with primary HLH experienced more thrombocytopenia (P = 0.012) and higher alanine transaminase (P = 0.016), while patients with VL-associated HLH had higher ferritin (P = 0.034) and erythrocyte sedimentation rate (P = 0.011). Central nervous system (CNS) involvement occurred in 38.3% of patients. The mortality rate was higher in patients with CNS disease (61% vs. 35%, P = 0.051). The 3-yr overall survival rate was 35.9%. (24% in primary HLH and 100% in VL-associated HLH, P < 0.001). In Cox regression analysis, platelet count < 100,000/ μ l (hazard ratio 4.472, 95% confidence interval 1.324–15.107, P = 0.016) correlated with increased mortality in patients with primary HLH.

Conclusion

VL is a potential source of secondary HLH in regions with high endemicity. Treatment of the underlying disease in VL-associated HLH is sufficient in most cases, with no need to start etoposide-based chemotherapy.

Aryl hydrocarbon receptor engagement during redox alteration determines the fate of CD4+ T cells in C57BL/6 mice

The preservation of the redox homeostasis is critical for cell survival and functionality. Redox imbalance is an essential inducer of several pathological states. CD4⁺ /helper T cells are highly dependent on the redox state of their surrounding milieu. The potential of the aryl hydrocarbon receptor (AhR) engagement in controlling CD4⁺ T-cell fate during redox alteration is still challenging. C57BL/6 mice were treated with AhR agonist 6-formylindolo[3,2-b]carbazole (FICZ), AhR antagonist CH223191, an inhibitor of glutathione biosynthesis buthionine sulfoximine (BSO), and the antioxidant N-acetylcysteine (NAC) alone or in combination. Six days later, splenocytes were evaluated for the expression of the redox-related genes and the possible changes in T-cell subsets. FICZ like BSO significantly elevated the expression of HMOX1, GCLC, and GCLM genes but it failed to increase the expression of the Nrf2 gene. Moreover, FICZ + BSO increased while FICZ + CH223191 or NAC decreased the expression of these genes. FICZ also significantly increased Th1 cell numbers but decreased Tregs in a dose-dependent manner. Furthermore, a high dose of FICZ + CH223191 + NAC significantly enhanced Th1, Th17, and Treg cells but its low dose in such a situation increased Th2 and Th17 while decreased Treg cells. AhR engagement during redox alteration can determine the fate of CD4 + T cells, so, AhR agonists or antagonists might be useful in assessing immune responses. However, these results need further verifications in vitro and in animal models of various diseases.

Leishmanial apolipoprotein A-I expression: a possible strategy used by the parasite to evade the host's immune response

Apolipoprotein A-I (apo A-I) represents the main component of the Trypanosome lytic factor (TLF) which contributes to the host innate immunity against Trypanosoma and Leishmania. These parasites use complex and multiple strategies such as molecular mimicry to evade or subvert the host immune system. Previous studies have highlighted the adaptation mechanisms of TLF-resistant Trypanosoma species. These data might support the hypothesis that Leishmania parasites (amastigote forms in macrophages) might express apo A-I to bypass and escape from TLF action as a component of the host innate immune responses. The anti-inflammatory property of apo A-I is another mechanism that supports our idea that apo A-I may play a role in Leishmania parasites allowing them to bypass the host innate immune system.

Proportion of T follicular helper cells in peripheral blood of rheumatoid arthritis patients: a systematic review and meta-analysis

Introduction:Alterations in the levels and activity of Tfh may lead to impaired immune tolerance and autoimmune diseases. The aim of this study was to investigate the proportion and types of Tfh cells in the peripheral blood (PB) of RA patients.Areas covered:Comprehensive databases were searched for studies evaluating the proportion of Tfh cells in the PB of patients with RA compared to healthy control (HCs).The proportion of Tfh cells in RA patients was significantly higher than in HCs (SMD 0.699, [0.513, 0.884], p < 0.0001). Furthermore, Tfh cells proportion in untreated-RA and early-RA patients was markedly greater than HCs, when comparisons done without considering the definition markers, and also when Tfh cells were defined by the specified definition markers. While the proportion of Tfh cells by all definitions was higher in active-RA compared to HCs, analysis of two definitions, CD4⁺CXCR5⁺ and CD4⁺CXCR5⁺ICOS⁺, didn't show significant differences. Furthermore, higher proportion of Tfh cells defined by all definitions and a specified definition (CD4⁺CXCR5⁺PD-1^high) was observed when S⁺RA compared to S^-RA patients.Expert opinion:The results demonstrate that circulating Tfh are highly elevated in RA patients highlights its potential use as a biomarker and a target for RA therapy.

The role of FOXP3 rs3761548 and rs2294021 polymorphisms in pediatrics acute lymphoblastic leukemia: association with risk and response to therapy

FOXP3 X-linked gene has crucial roles in the development and function of regulatory T cells. We investigated the association of FOXP3 rs3761548, rs3761549 and rs2294021 single nucleotide polymorphisms (SNPs) with acute lymphoblastic leukemia (ALL) susceptibility and response to therapy. Genotyping was performed in 247 patients and 210 healthy subjects. We observed a higher frequency of rs3761548 A carriers and rs2294021 C carriers (p < 0.04) in male patients, and lower frequencies of rs3761548 AC genotype (p = 0.04) and rs2294021 CT genotype (p = 0.01) in female patients compared to controls. ACC (p = 0.04) and ATC haplotypes (p = 0.002) were associated with susceptibility to ALL. There was a significant correlation between the genotypes of rs3761548 and rs2294021 SNPs with event-free survival (EFS) and overall survival (OS). The rs3761548 A genotype in male patients was associated with increased risk of relapse (p < 0.0001), shorter EFS, increased death rate (p = 0.002) and shorter OS compared to C genotype (p = 0.001). Similar significant results were observed for the relation of rs2294021 C genotype with response to therapy in male patients. In females, patients with rs3761548 AC genotype had longer EFS (p = 0.02) and those with rs2294021 CT had longer EFS and OS (p < 0.005). According to haplotype analysis, patients carrying ACC or ATC haplotypes had the highest number of WBCs and shorter EFS or OS, and patients with CCT haplotype had the lowest number of WBCs and longer EFS or OS. These results provided evidence for the impact of these polymorphisms on susceptibility and response to therapy in children with ALL.

Identification of immunoreactive proteins in secretions of Leishmania infantum promastigotes: an immunoproteomic approach

Background

In the Mediterranean region, Leishmania infantum is the main cause of visceral leishmaniasis. Dogs with canine visceral leishmaniasis are an important reservoir of visceral leishmaniasis. Control of canine visceral leishmaniasis could disrupt transmission of visceral leishmaniasis to humans. The secreted antigens of Leishmania promastigotes are potential stimuli of the host immune system. Proteomic techniques facilitate the identification of new protein markers.

Aims

This study aimed to identify immunoreactive proteins in the secretions of L. infantum promastigotes which could be possible targets for the diagnosis and treatment of canine visceral leishmaniasis and the development of vaccines against the disease.

Methods

Secretions of L. infantum promastigotes were obtained from the cultivation of 6 × 10⁹ promastigotes in serum- free RPMI-1640 medium during a period of 72 h. After deionization and lyophilization, two-dimensional gel electrophoresis was used for protein separation followed by Western blotting. Thirteen common and repeatable immunoreactive spots were analysed by mass spectrometry.

Results

Nine proteins were identified by spectrometry. Most of these proteins were involved in metabolism pathways, survival and pathogenicity of Leishmania parasites. Phospholipase C, immune inhibitor A, chitin-binding protein and a single peptide match to chain A crystal structure of selenomethionine were observed in the secretions of L. infantum promastigotes.

Conclusions

The proteins identified in metabolism pathways, survival and pathogenicity of Leishmania parasites are possible targets that could be used for the diagnosis and treatment of canine visceral leishmaniasis and the development of vaccines against the disease in the future.

Variations in IL-22, IL-27 and IL-35 serum levels in untreated and treated hepatitis C patients

BACKGROUND

Hepatitis C virus (HCV) is the leading cause of chronic liver diseases including hepatic fibrosis, cirrhosis, and hepatocellular carcinoma. We aimed to assess serum levels of interleukin (IL)-22, IL-27 and IL-35 in patients with hepatitis C and healthy controls to investigate their possible relationship with viral genotypes and liver enzyme levels.

METHOD

A total of 30 newly diagnosed hepatitis C patients with no history of antiviral therapy and 30 healthy individuals participated in this study. Serum levels of IL-22, IL-27 and IL-35 were determined by ELISA in peripheral blood samples from patients prior to and following treament with pan-genotypic direct-acting anti-viral therapy. Serum levels of alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP) were measured to determine any possible association between hepatic enzymes and cytokine serum levels concentrations.

RESULT

The results show elevated serum levels of of IL-35 in HCV-infected patients compared to treated cases and healthy controls, whereas there was no significant difference in IL-22 and IL-27 serum levels among the three groups. Additionally, the cytokine levels were not significantly correlated with certain genotypes and levels of liver enzymes.

CONCLUSION

Our findings indicate a potential role for IL-35 in chronic HCV infection and therapeutic management of patients with hepatitis C infection.

Chitin binding protein as a possible RNA binding protein in Leishmania parasites

Leishmaniasis includes a broad spectrum of pathological outcomes in humans caused by protozoan parasites from the genus Leishmania. In recent years, proteomic techniques have introduced novel proteins with critical functions in Leishmania parasites. Based on our report of a Chitin binding protein (CBP) in our previous immunoproteomic study, this article suggests that CBP might be an RNA binding protein (RBP) in Leishmania parasites. RBPs, as key regulatory factors, have a role in post-transcriptional gene regulation. The presence of RBPs in Leishmania parasites has not been considered so far; however, this study aims to open a new venue regarding RBPs in Leishmania parasites. Confirming CBP as an RBP in Leishmania parasites, exploring other RBPs and their functions might lead to interesting issues in leishmaniasis. In fact, due to the regulatory role of RBPs in different diseases including cancers and their further classification as therapeutic targets, the emerging evaluation of CBP and RBPs from Leishmania parasites may allow the discovery of novel and effective drugs against leishmaniasis.

Therapeutic Effect of Carvacrol-loaded Albumin Nanoparticles on Arthritic Rats

Rheumatoid arthritis (RA) is one of the most common autoimmune diseases. Carvacrol, an important natural terpenoid product in aromatic plants such as thyme, has shown anti-inflammatory effects in animal models of arthritis. However, its poor water solubility and high volatility have limited its application. In the present study in order to overcome this problem, we encapsulated carvacrol in the bovine serum albumin (BSA) nanoparticles and examined its therapeutic and immunomodulatory effects in adjuvant-induced arthritis (AIA). Carvacrol-loaded BSA nanoparticles were prepared by desolvation method. Nanoparticles had encapsulation efficiency (EE) of 67.7 ± 6.9% and loading capacity (LC) of 26.6 ± 2%. The size of particles was 148 ± 25 nm and they had monomodal distribution. After arthritis induction, the rats were treated intraperitoneally with nanoparticle for every 3 days until day 28. The treatment of the rats with 375 mg/mL carvacrol-loaded BSA nanoparticle significantly decreased clinical severity score (27.5 ± 9.8%, p = 0.008), erythrocyte sedimentation rate (33.4 ± 10%, p = 0.02), nitric oxide production (82.3 ± 2.6%, p = 0.004) and interleukin (IL)-17 gene expression (55.1 ± 8.2%, p = 0.003) compared to the untreated arthritic group. A higher reduction in inflammation severity in arthritic rats treated with carvacrol-loaded BSA in comparison to those treated with carvacrol alone was observed. In conclusion, encapsulation of carvacrol in nanoparticles reduced arthritis signs and release of NO and IL-17 inflammatory cytokine and therefore is suggested to be considered as a good approach for improving the therapeutic applications of carvacrol in RA.

Pyrin and Hematopoietic Interferon-Inducible Nuclear Protein Domain Proteins: Innate Immune Sensors for Cytosolic and Nuclear DNA

The innate immune system is the first line of defense against microbial pathogens. The response of innate immunity is initiated by molecules known as pattern recognition receptors (PRRs). Such responses are often triggered by nucleic acids that are delivered to the cytoplasm or nucleus of cells. The ability to recognize foreign nucleic acids in these two locations is an important defense mechanism of the human innate immune system. Several PRRs are located in the cytosol or nucleus and detect foreign DNAs. The pyrin and hematopoietic interferon-inducible nuclear (PYHIN) domain protein is a family of PRRs that includes interferon-inducible protein 16, absent in melanoma 2, PYHIN 1 (or interferon-inducible protein X, as it is also known), myeloid cell nuclear differentiation antigen, and pyrin domain only protein 3. These nuclear and cytosolic sensors play an essential part in host defense of intracellular pathogens. In addition, members of the PYHIN family are critical regulators of immune response, apoptosis, cell growth, differentiation, and transcription. In this review, we summarize important characteristics of these innate immune sensors and their roles in several diseases. A better understanding of the role of DNA sensors in the nucleus and cytoplasm will lead to the development of novel therapeutic approaches to control infections and associated diseases.

The Effects of Type 2 Diabetes Mellitus on Organ Metabolism and the Immune System

Metabolic abnormalities such as dyslipidemia, hyperinsulinemia, or insulin resistance and obesity play key roles in the induction and progression of type 2 diabetes mellitus (T2DM). The field of immunometabolism implies a bidirectional link between the immune system and metabolism, in which inflammation plays an essential role in the promotion of metabolic abnormalities (e.g., obesity and T2DM), and metabolic factors, in turn, regulate immune cell functions. Obesity as the main inducer of a systemic low-level inflammation is a main susceptibility factor for T2DM. Obesity-related immune cell infiltration, inflammation, and increased oxidative stress promote metabolic impairments in the insulin-sensitive tissues and finally, insulin resistance, organ failure, and premature aging occur. Hyperglycemia and the subsequent inflammation are the main causes of micro- and macroangiopathies in the circulatory system. They also promote the gut microbiota dysbiosis, increased intestinal permeability, and fatty liver disease. The impaired immune system together with metabolic imbalance also increases the susceptibility of patients to several pathogenic agents such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Thus, the need for a proper immunization protocol among such patients is granted. The focus of the current review is to explore metabolic and immunological abnormalities affecting several organs of T2DM patients and explain the mechanisms, whereby diabetic patients become more susceptible to infectious diseases.

T cell responses to an HLA-A2-restricted adipophilin peptide correlate with BMI in patients with atherosclerosis

Introduction

Atherosclerosis is an inflammatory disease causing a vast array of cardiovascular diseases. Adipophilin has been reported to be highly expressed in atherosclerotic lesions. This study investigated the possible existence of auto-reactive T cells against an HLA-A02-restricted adipophilin-derived peptide as well as peptides from Epstein-barr virus (EBV), Cytomegalovirus (CMV) and influenza (Flu) virus in patients with atherosclerosis.

Methods

HLA-A02 expression on peripheral blood mononuclear cells (PBMCs) was examined by flow cytometry. PBMCs from HLA-A02 individuals were stimulated with adipophilin, CMV, EBV, and Flu peptides at a concentration of 10 µM. Interferon (IFN)-γ production was evaluated in the culture supernatant using a commercial ELISA test.

Results

The levels of IFN-γ production against an HLA-A02-restricted adipophilin peptide and peptides from CMV, EBV, and Flu revealed no statistically significant differences between patients and healthy controls. However, we found a positive correlation between IFN-γ production against adipophilin and Body mass index (BMI) of patients (R = 0.8, P = 0.003), whereas no significant correlation was found in healthy controls (R = -0.267, P = 0.378). No correlation between BMI and IFN-γ production against CMV, EBV, or Flu peptides was found.

Discussion

Atherosclerotic patients with higher BMIs might have greater numbers of T cells against adipophilin that is highly expressed in atherosclerotic plaques. Therefore, autoimmune reactions may have a greater role in the development of atherosclerosis in individuals with higher BMI.

IL-18 in Blood Serum of Hepatitis C Patients Might be of Predictive Value for Individual Outcomes

OBJECTIVE

Pro- inflammatory cytokines including Interleukin (IL)-18 have been shown to be involved in the clearance of Hepatitis C virus (HCV) infection. However, changes in the balance of pro- and anti-inflammatory cytokines production during the immune response, can elicit a variety of liver damages. Therefore, it is of interest to study IL-18 serum levels in hepatitis patients and its correlation with HCV infection.

METHODS

Twenty-nine newly diagnosed HCV+ patients with no history of antiviral therapy, and 17 healthy controls, were enrolled in our study. Biochemical markers of liver disease were evaluated by biochemistry assay kits. Serum concentrations of IL-18 were determined with the ELISA method before and after treatment with pangenotypic direct-acting antivirals (DAAs) treatment.

RESULTS

Our results showed statistically significant difference in serum levels of IL-18 in HCV+ patients (692.261 ± 48.76) compared to healthy controls (520.00 ± 44.73) (P=0.021). However, there was no significant difference in IL-18 serum levels between the treated group compared to untreated patients (P=0.74). No significant correlations were detected between the level of IL-18 and liver enzyme levels.

CONCLUSION

According to our study, IL-18 might be a disease marker associated with HCV infection; however, this conclusion requires further investigation.

Decreased levels of interleukin 27 in the serum of vitiligo patients

BACKGROUND

Vitiligo is a common skin disorder in which melanocytes are destroyed by auto-reactive immune responses. The loss of melanocytes results in the appearance of depigmented areas in different parts of the body. Cytokines have remarkable roles in the pathogenesis of vitiligo, such as IL-1, IL-6, and TNF-α; interleukin 27 (IL-27) is a new member of the IL-6/IL-12 family, mainly released by activated antigen-presenting cells. IL-27 has been suggested to function as a pro-inflammatory as well as an anti-inflammatory cytokine. Altered concentrations of IL-27 have been shown in various auto-immune diseases such as multiple sclerosis, rheumatoid arthritis, and psoriasis. No studies have been conducted to determine the expression of this cytokine in vitiligo patients.

OBJECTIVE

The objective of this study was to determine the serum concentration of IL-27 in vitiligo patients and compare it with normal individuals.

METHODS

The serum concentration of IL-27 in 79 vitiligo patients was evaluated in comparison to 45 healthy controls using ELISA assay.

RESULTS

Results showed decreased concentration of IL-27 in vitiligo patients as compared with healthy subjects (p=0.026). Furthermore, no correlation between IL-27 concentrations and disease parameters such as vitiligo severity and the extension of the depigmented area was observed.

STUDY LIMITATION

A larger sample size would be more recommended for this study.

CONCLUSION

The reduction in the serum levels of IL-27 in vitiligo patients compared to normal subjects suggested the possible anti-inflammatory role of this cytokine in vitiligo. Thus, IL-27 may be considered as a new target for the manipulation of the immune system in vitiligo patients.

Leishmanial selenoproteins and the host immune system: towards new therapeutic strategies?

Optimum levels of selenoproteins are essential for starting and managing the host immune responses against pathogens. According to the expression of selenoproteins in Leishmania parasites, and since high levels of selenoproteins lead to adverse effects on immune cells and their functions, Leishmania parasites might then express selenoproteins such as selenomethionine in their structure and/or secretions able to challenge the host immune system. Finally, this adaptation may lead to evasion of the parasite from the host immune system. The expression of selenoproteins in Leishmania parasites might then induce the development of infection. We therefore suggest these molecules as new therapeutic candidates for the treatment of leishmaniasis.

Pro-inflammatory Effects of Influenza Type A Virus PB1-F2 Protein-derived Peptide in Lipopolysaccharide-treated Macrophages

Influenza A virus (IAV) has the potential to cause pandemics with considerable health and socio-economic burdens. A viral protein, polymerase basic 1- frame2 (PB1-F2), as a virulence factor, has pro-apoptotic activity and contributes to viral pathogenesis by delaying viral clearance and inducing inflammation. Macrophages are susceptible to IAV infection and produce high levels of inflammatory cytokines and chemokines. In the present study, the pro-inflammatory effects of PB1-F2 derived peptide was evaluated by measuring the expression of key inflammatory mediators in murine macrophage cell line J774.1. PB1-F2 treated macrophages were examined for nitric oxide (NO) production, inflammatory cytokines, and enzymes expression and pro-inflammatory cytokines secretion using Griess reagent, real-time polymerase chain reaction (PCR) and ELISA, respectively. Our results have shown that PB1-F2 peptide at non-cytotoxic concentrations (0.1-0.8 µmol/mL) had no effect on NO production. When applied to Lipopolysaccharide (LPS)-treated macrophages, PB1-F2 peptide at 0.8 μmol/mLincreasedinducible NO synthase (iNOS), cyclooxygenase (COX)-2, and interleukin (IL)-6 genes expression to 2.02, 3.81, and 3.65 folds, respectively. PB1-F2 at concentrations of 0.4 and 0.8 µm/mL increased tumor necrosis factor (TNF)-α transcription by 4.15 and 5.55 fold. At posttranslational level, TNF-α increased from 166.5±13.88 in LPS-treated cells to 773.6±95.27 and 1485±76.31 at concentrations of 0.4 and 0.8 μmol/mL in PB1-F2 peptide, respectively. However, PB1-F2 Peptide did not have any significant effect on IL-6 production. These findings suggest that PB1-F2 peptide may partly exert its enhancing role in viral pathogenicity through the induction of inflammatory mediators in macrophages. Hence, targeting PB1-F2 peptide would be helpful in the reduction of viral infection complications.

ASSOCIATION OF FOXP3 GENE VARIANTS WITH RISK OF HASHIMOTO'S THYROIDITIS AND CORRELATION WITH ANTI-TPO ANTIBODY LEVELS

CONTEXT

Regulatory T cells (Tregs) have critical roles in preventing autoimmune diseases such as Hashimoto's thyroiditis (HT). Forkhead box P3 (Foxp3), the master transcription factor of Tregs, plays a pivotal role in Treg function.

OBJECTIVE

Herein, we investigated the association of two single nucleotide polymorphisms (SNPs) of the Foxp3 gene with HT development.

METHODS AND STUDY DESIGN

A total of 129 HT patients and 127 healthy subjects were genotyped for rs3761548 (-3279 A/C) and rs3761549 (-2383 C/T) in the Foxp3 gene, using polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

Genotypic and allelic distribution of rs3761548 SNP showed a significant association with HT. The CC genotype was observed in 37.2% of patients versus 22.1% of the controls [P<0.008, odds ratio (OR): 2.1; 95% confidence interval (CI): 1.2-3.6] and the AC genotype in 41.1% of patients compared to 54.3% of the controls (P<0.025, OR: 2.1; CI: 1.2-3.6). In addition, higher frequency of C allele in patients compared to controls (P=0.05, OR: 1.4; 95% CI: 0.9-2) suggested that patients with the CC genotype and C allele had increased susceptibility to HT. There were significantly higher serum levels of anti-thyroid peroxidase (ATPO) antibody in patients with the rs3761548 CC genotype (1156±163 IU/mL) compared to the other genotypes (≈582-656 IU/mL; P<0.004). We observed a greater frequency of the AC genotype in patients who had decreased ATPO antibody levels (P=0.02).

CONCLUSIONS

The association of the rs3761548 SNP with risk of HT and its influence on ATPO antibody levels suggested an important role for Foxp3 in the biology and pathogenesis of HT.

Influence of forkhead box protein 3 polymorphisms (rs2232365, rs3761548) with the outcome of pregnancy: A meta-analysis

Dysfunction of regulatory T cells (Tregs) may contribute to certain immune-related pregnancy complications. Forkhead box protein 3 (FOXP3) is the key transcription factor of Treg. We performed a systematic review and meta-analysis to evaluate the possible association between FOXP3 polymorphisms -924A/G (rs2232365) and -3279C/A (rs3761548) and immune-related pregnancy complications. After reviewing 78 fully published studies, 10 studies fulfilled previously defined eligibility criteria and were used for meta-analysis. Two single nucleotide polymorphisms showed a significant correlation with increased or reduced risk for immune-related pregnancy complications. For rs3761548, women with allele A were significantly at a higher risk than women carrying allele C (odds ratio = 1.29, 95% confidence interval: 1.20-1.38; p = 0.001). For rs2232365, women with GG or AG genotype were at a higher risk than women with genotype AA, thereby, allele G was significantly associated with a higher risk than allele A. Our meta-analysis supports the notion that immune-related pregnancy complications might be linked to genetic variations in the FOXP3 gene.

Tumor Cell Death via Apoptosis and Improvement of Activated Lymphocyte Cytokine Secretion by Extracts from Euphorbia Hebecarpa and Euphorbia Petiolata

Background: Immunomodulatory materials from natural herbs and the characterization of their immune enhancement effects may have tremendous potential as cancer treatment. The aim of the present study was to investigate the apoptosis-inducing activities of Euphorbia hebecarpa Boiss and Euphorbia petiolata Banks & Sol. plant extracts and their effects on cytokine secretion by lymphocytes. Materials and Methods: We assessed the apoptosis-inducing effect of the plants’ hexane extracts on previously determined sensitive cell lines (HeLa for E. hebecarpa and K562 for E. petiolata) by flow cytometry and measurement of caspase 3 activation. The apoptosis-related gene expressions were examined by real-time PCR. The effects of the extracts on lymphocyte proliferation and cytokine secretion were examined. Results: Flow cytometry analysis showed that the inhibitory effect of the extracts on tumor cell growth was due to cell apoptosis. The plant extracts at the 100 μg/ml dose induced apoptosis in HeLa (98.5 ± 0.1%) and K562 (57.7 ± 1.9%) cells. The extracts increased caspase 3 activation (≈2-fold>control). Real-time PCR showed Fas and Bax gene upregulation and Bcl-2 downregulation, which resulted in an increased Bax/Bcl-2 expression ratio. The extracts increased lymphocyte proliferation and increased levels of IFN-γ production in the presence and absence of mitogen (p < 0.05). They significantly increased IL-4 and decreased IL-10 secretion by mitogen-stimulated lymphocytes. E. hebecarpa also increased IL-17 release. Conclusion: These results have shown that both extracts possess antitumor activity by inducing apoptosis, possibly through both intrinsic and extrinsic pathways. In addition, they induced secretion of different T helper subset related cytokines that are effective in the immune response against cancer.

An immunoproteomic approach to identifying immunoreactive proteins in Leishmania infantum amastigotes using sera of dogs infected with canine visceral leishmaniasis

Visceral leishmaniasis (VL), the most severe form of leishmaniasis, is caused by Leishmania donovani and Leishmania infantum. The infected dogs with canine visceral leishmaniasis (CVL) are important reservoirs for VL in humans, so the diagnosis, treatment and vaccination of the infected dogs will ultimately decrease the rate of human VL. Proteomics and immunoproteomics techniques have facilitated the introduction of novel drug, vaccine and diagnostic targets. Our immunoproteomic study was conducted to identify new immunoreactive proteins in amastigote form of L. infantum. The strain of L. infantum (MCAN/IR/07/Moheb-gh) was obtained from CVL-infected dogs. J774 macrophage cells were infected with the L. infantum promastigotes. The infected macrophages were ruptured, and pure amastigotes were extracted from the macrophages. After protein extraction, two-dimensional gel electrophoresis was employed for protein separation followed by Western blotting. Western blotting was performed, using symptomatic and asymptomatic sera of the infected dogs with CVL. Thirteen repeatable immunoreactive spots were identified by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Some, including prohibitin, ornithine aminotransferase, annexin A4, and apolipoprotein A-I, have been critically involved in metabolic pathways, survival, and pathogenicity of Leishmania parasites. Further investigations are required to confirm our identified immunoreactive proteins as a biomarker for CVL.

The Importance of Checking Leishmania Promastigotes Viability in the Proteomics Analysis of Secretions

OBJECTIVE

The aim of the present study was to compare the efficacy of checking the viability of Leishmania promastigote by flow cytometry using propidium iodide (PI) and microscopic method using trypan blue (TB) before proteomics analysis of the secretions.

METHODS

The promastigotes (6×109) of Leishmania infantum in the exponential growth phase were transferred to serum-free media. Then, the viability of promastigotes was checked and compared with flow cytometry and microscopic method at 0, 2, 3, 4, 5, and 72 h.

RESULTS

Flow cytometry did not show many dead cells at 0 to 4 h, and the viability was approximately 98%. The percentage of the dead promastigotes increased to 8% at 5 h and 17% at 72 h. Meanwhile, the microscopic method using TB did not show any dead cell after 4 and 72 h, and the viability was 100%.

CONCLUSION

The present study confirms the importance of flow cytometry using PI in checking the viability of Leishmania promastigotes, especially before the proteomics analysis of the secretions. It also shows that flow cytometry using PI is more sensitive than microscopic method using TB.

Investigation of Dracocephalum kotschyi Plant Extract on the Effective Inflammatory Transcription Factors and Mediators in Activated Macrophages

BACKGROUND

Dracocephalum kotschyi is traditionally used for its anti-inflammatory effects. We aimed to investigate the effects of ethyl acetate extract of D. kotschyi on the expression of key inflammatory mediators and main signaling molecules involved in the regulation of inflammation.

METHODS

Lipopolysaccharide (LPS)-stimulated J774.1 mouse macrophages were cultured in the presence of the plant extract and examined by the real time-PCR for gene expressions of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2. Cytokine levels and phosphorylated forms of stressactivated protein kinases/c-Jun N-terminal kinase (SAPK/JNK), signal transducer and activator of transcription (STAT)-3, p38, IκB-α and nuclear factor (NF)-κB p65 were determined using ELISA.

RESULTS

The extract significantly reduced the expression of key mediators of inflammation. iNOS expression level decreased from 138±8.5 fold in LPS-only treated cells to 6.5±2.6 fold after treatment with 25 µg/ml of the extract (p<0.001). Similarly, COX-2 expression decreased from 632 ±98.8 fold in control to 124 ±24.6 fold (p<0.01). Treatment of cells with the extract significantly reduced IL-1β and TNF-α cytokines at both gene and protein expression levels. The extract at 25 µg/ml caused significant decreases in phospho- SAPK/JNK and phospho-STAT3 levels in macrophages (p<0.01). Proteins of phospho-p38, NFκB-p65 and phospho-NF-κB p65 had a reduced level in treated cells (p<0.05). No significant change in phospho-IκB level was observed.

CONCLUSION

These findings suggested that D. kotschyi with inhibition of NF-κB, SAPK/JNK, STAT-3 and p-38 might have reduced the expression levels of key inflammatory mediators and thus possibly have potential beneficial impact on inflammatory diseases.

An update on immune dysregulation in obesity-related insulin resistance

Obesity is associated with chronic low-grade inflammation of the adipose tissue (AT) that might develop into systemic inflammation, insulin resistance (IR) and an increased risk of type 2 diabetes mellitus (T2DM) in severe obese rodents and humans. In the lean state, small normal adipocytes and AT macrophages interact with each other to maintain metabolic homeostasis but during obesity, enlarged adipocytes secrete inflammatory mediators and express immune receptors to recruit immune cells and aggravate the inflammation. The better understanding of the obesity-related inflammatory milieu and the sequential events leading to IR could be helpful in designing new preventive and therapeutic strategies. The present review will discuss the cellular and molecular abnormalities participating in the pathogenesis of obesity in obese individuals as well as high-fat diet (HFD)-fed mice, a mouse model of obesity.

A multicenter-based study on epidemiology, antibiotic susceptibility and risk factors of toxigenic Clostridium difficile in hospitalized patients in southwestern Iran

Clostridium difficile (recently Clostridioides difficile) is a leading cause of hospital- and antimicrobial-associated diarrhea (AAD). The present study was carried out to investigate the prevalence of toxigenic C. difficile, antibiotic resistance and its associated risk factors in Iranian hospitalized patients. This cross-sectional study was conducted from October 2017 to June 2018 in three teaching hospitals in southwestern Iran. During this period, a total of 215 non duplicated nosocomial AAD samples were collected from the hospitalized patients older than two years of age. Presumptive C. difficile isolates were identified by standard microbiologic methods and confirmed by specific PCR primers. The minimum inhibitory concentrations (MICs) were determined by the agar dilution method. PCR was carried out to determine the presence of toxin genes (tcdA, and tcdB). In all, from the 215 diarrheal samples, the frequency of C. difficile culture-positive samples was 21.4% (n = 46). Of the 46 C. difficile isolates, 43 carried both toxins, two isolates only had the tcdB gene, and one was negative for both toxins. Overall, all isolates of C. difficile were susceptible to metronidazole and vancomycin. The MIC50/MIC90 of metronidazole and vancomycin were 0.75/2 μg/mL, 0.25/0.75 μg/mL, respectively. The findings of this study show the prevalence of CDI in hospitalized patients in southwestern Iran, highlighting the importance of active surveillance of CDI in hospitals. Meanwhile, all of the tested isolates were susceptible to metronidazole and vancomycin, which encourages the use of these antibiotics as the drug of choice for initial treatment of CDI in our region.

Recombinant NS3 Protein Induced Expression of Immune Modulatory Elements in Hepatic Stellate Cells During Its Fibrotic Activity

There is a growing body of studies that show the important role of NS3 protein from hepatitis C virus in fibrosis. However, mechanisms of the effects of this protein on immune modulation of stellate cells remain to be investigated. Herein, the effect of NS3 protein on the expression level of suppressor of cytokine signaling (SOCS)1/3 and interleukin-24 (IL-24)-related genes was investigated in hepatic stellate cell (HSC), LX-2. Recombinant NS3 protein was added to LX-2 HSC culture. Leptin and standard medium treatments were also included in experiments as positive and negative controls, respectively. Total RNA was extracted from each well at 6, 12, and 24 h after NS3 addition. The expression levels of the fibrotic (transforming growth factor beta 1 [TGF-β], alpha-smooth muscle actin [α-SMA], and COL1A1), inflammatory (IL-6 and IL-24), IL-20R, IL-22R, and immunosuppressive genes (SOCS1 and SOCS3) were evaluated by real-time polymerase chain reaction (PCR). Recombinant NS3 protein induced activated phenotypes of LX-2 with a significant increase in the expression level of α-SMA COL1A1 (p < 0.0001) and TGF-β. Moreover, this exposure led to a meaningful elevation in the expression of IL-6. Furthermore, compared with leptin (control), after the stellate cell treatment with NS3, SOCS1 and SOCS3 gene expression induced at a comparable level. Compared with the control sample, the NS3 protein significantly increased the expression level of IL-24 and its related receptors, IL-20R and IL-22R. This study not only confirmed the previously proved inflammatory and fibrotic effect of this protein but also indicated that high expression levels of SOCS1, SOCS3, and IL-24 have a significant effect on HSC activation. Therefore, these two molecules can be used as a potential therapeutic target candidate.

Inhibition of LPS-induced inflammatory responses by Satureja hortensis extracts in J774.1 macrophages

Macrophages are among the main cells involved in generation of inflammation. To investigate the anti-inflammatory effect of Satureja hortensis (summer savory), lipopolysaccharide (LPS)-activated J774.1 macrophages were treated with various extracts, and the expression and release of various inflammatory molecules by macrophages were examined. We showed that dichloromethane and hexane extracts reduced nitric oxide (NO) production more efficiently than other extracts. Both extracts decreased gene expression of inducible NO synthase (iNOS) (<0.44 fold of control), cyclooxygenase (COX)-2 (<0.29 fold), interleukin (IL)-1β (<0.41 fold), IL-6 (<0.25 fold) and tumor necrosis factor (TNF)-α (<0.2 fold). The extracts reduced IL-6 and IL-1β proteins production from macrophages. Surface intensity of expression of intercellular adhesion molecule (ICAM)-1 decreased to 845 ± 28.1 (dichloromethane) and 715 ± 48.6 (hexane) compared to the control (902 ± 73.1). These findings showed that Satureja hortensis, by influencing macrophages and related mediators, could contribute to reduction of inflammation and might be useful as an anti-inflammatory agent.

Anti-inflammatory activity of Echium amoenum extract on macrophages mediated by inhibition of inflammatory mediators and cytokines expression

Echium amoenum (Boraginaceae) is an important remedy used for various illnesses. In this study, we investigated the anti-inflammatory effects of E. amoenum in the J774.1A macrophage cell line. We prepared ethyl acetate, dichloromethane and hexane extracts from E. amoenum flowers and examined their possible cytotoxic effects using MTT assay. Lipopolysaccharide (LPS)-stimulated macrophages were treated with the extracts after which we measured nitric oxide (NO) production by Griess method. Inducible NO synthase (iNOS), cyclooxygenase-2 (COX2), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 gene expressions were examined by real time-PCR. IL-1β and IL-6 cytokine levels were measured by enzyme-linked immunosorbent assay (ELISA). The hexane extract with a half maximal inhibitory concentration (IC₅₀) of 39.8 μg/mL most effectively reduced NO production. Real time-PCR analysis indicated reduced levels of iNOS ((0.05 ± 0.006 relative fold change (RFC)) and COX2 (0.06 ± 0.002 RFC) gene expressions with the 100 μg/mL hexane extract (P < 0.001). IL1-β, TNF-α, and IL-6 gene expression levels decreased at all concentrations of the extract (less than ≈ 0.28 RFC). Treatment of LPS-stimulated cells with 100 μg/mL of the extract reduced IL-1β secretion to 27.9 ± 0.21 pg/mL and IL-6 to 555 ± 166 pg/mL. In conclusion, E. amoenum hexane extract showed the greatest reduction in macrophage NO secretion compared to other extracts. This extract could modulate the inflammatory mode of the macrophages by causing reductions in iNOS and COX2 enzymes as well as IL-1β, IL-6, and TNF-α cytokine levels. The results of this study have shown the anti-inflammatory effects of this plant. Further studies regarding its therapeutic potential in inflammatory disorders are recommended.

Effect of MicroRNA-21 Transfection on In-vitro Differentiation of Human Naive CD4+ T Cells to Regulatory T Cells

Regulatory T cells (Tregs) are important components of the immune system that modulate responses of other cells. These cells are involved in peripheral tolerance mechanisms, so defect in development and function of these cells can result in autoimmune disease. Increasing evidence supports the role of microRNAs-21 (miR-21) in the regulation of forkhead box P3 (Foxp3) expression in Tregs. We aimed to determine whether miR-21 transfection to naive CD4+ T cells can be useful in generation of iTregs in-vitro. We investigated in-vitro differentiation of miR-21-transfected naive CD4+ T cells to iTregs and compared these iTregs to cytokine-differentiated iTregs and control group. We showed that expression of Foxp3, transforming growth factor beta (TGF-β), and interleukin-10 (IL-10) are increased in iTregs generated after miR-21 transfection in comparison with cytokine-differentiated iTregs and control group. Our findings demonstrate that miR-21 has positive role in in-vitro generation of induced regulatory T-cells (iTregs).