The effects of killer cell immunoglobulin-like receptor (KIR) genes on susceptibility to severe COVID-19 in the Iranian population.

BACKGROUND: Variations in the innate and adaptive immune response systems are linked to variations in the severity of COVID-19. Natural killer cell (NK) function is regulated by sophisticated receptor system including Killer-cell immunoglobulin-like receptor (KIR) family. We aimed to investigate the impact of possessing certain KIR genes and genotypes on COVID19 severity in Iranians. KIR genotyping was performed on 394 age/sex matched Iranians with no underlying conditions who developed mild and severe COVID- 19. The presence and/or absence of 11 KIR genes were determined using the PCR with sequence specific primers (PCR-SSP). RESULTS: Patients with mild symptoms had higher frequency ofKIR2DS1 (p = 0.004) and KIR2DS2 (p = 0.017) genes compared to those with severe disease. While KIR3DL3 and deleted variant of KIR2DS4 occurred more frequently in patients who developed a severe form of the disease. In this study, a significant increase of and B haplotype was observed in the Mild group compared to the Severe group (respectively, p = 0.002 and p = 0.02). Also, the prevalence of haplotype A was significantly higher in the Severe group than in the Mild group (p = 0.02). CONCLUSIONS: These results suggest that the KIR2DS1, KIR2DS, and B haplotype maybe have a protective effect against COVID-19 severity. The results also suggest the inhibitory gene KIR2DL3 and haplotype A are risk factors for the severity of COVID-19.

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.

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.

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.

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.

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.

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.

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.

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.

Inhibition of interferon-γ production and T-bet expression by menthol treatment of human peripheral blood mononuclear cells.

Context: Mentha longifolia (L.) Huds., has shown anti-inflammatory effects. Objective: To evaluate the immunomodulatory effects of menthol, the major constituent of Mentha longifolia on T cells as the main cells affecting the inflammatory responses. Methods: Effect of menthol on: proliferation and viability of the peripheral blood human mononuclear cells (PBMCs) by BrdU and propidium iodide (PI) staining, respectively, interferone (IFN)γ and interleukin (IL)-4 cytokine production in lymphocytes stimulated with phytohemagglutinin (PHA) and phorbol myristate acetate/calcium ionophore (PMA/CI) by ELISA; intracellular staining of CD4+ cells for IFNγ expression by flow cytometry and gene expressions of T heper (Th) cell transcription factors was measured using real time-PCR. Results: Menthol dose-dependently inhibited lymphocytes proliferation from 88.7% at 50 µg/ml to 3.63% at 800 µg/ml (p < .05). According to the results of PI staining, this inhibitory effect was not due to cell death. Menthol dose-dependently decreased IFNγ but not IL-4 production in culture of PHA- and PMA/CI-stimulated lymphocytes to more than 80% at 800 µg/ml. In flow cytometry analysis, menthol reduced the number of IFN-γ-expressing CD4+T cells stimulated either with PHA or PMA/CI. Treatment of PBMCs with 800 µg/ml of menthol decreased levels of T-bet from 14.5 ± 2.26 fold in untreated control to 2.76 ± 1.74 fold (p < .001). Foxp-3 expression decreased to nearly half, but GATA3 did not significantly change. Ratios of T-bet to GATA3 and T-bet to Foxp3 gene expressions were dose-dependently declined. Conclusion: Decreased IFNγ expression plus T-bet down-regulation suggested the inhibitory effect of menthol on Th1 cells differentiation and hence imply its possible therapeutic usefulness in inflammatory diseases.

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)-1ß (<0.41 fold), IL-6 (<0.25 fold) and tumor necrosis factor (TNF)-α (<0.2 fold). The extracts reduced IL-6 and IL-1ß 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.

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.

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.

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.

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.

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.

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.

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.

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

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 occur 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 disease development. In recent years, studies on the 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+ cells to their subsets, especially Th17 cells. This suggests that manipulation of glycolysis, 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 therapeutic effects on MS patients.