Lymphopenia associated with survivin and its downstream pathway in COVID-19 serving as a potential route in COVID-19 pathogenesis.

PURPOSE: Starting in 2019, coronavirus disease 2019 (COVID-19) caused an epidemic that was growing rapidly and has harmed millions of people globally. It has been demonstrated that survivin regulates lymphocyte survival, a main route involved in COVID-19 pathogenesis. Survivin belongs to the inhibitor of apoptosis protein (IAP) family, and its primary functions comprise regulating mitosis and inhibiting apoptosis. Since lower survivin expression has been shown to increase the sensitivity of lymphocytes to apoptotic induction, we looked into the function of survivin and its corresponding pathways in COVID-19 pathogenesis. MATERIALS AND METHODS: The expression of survivin, X-linked inhibitor of apoptosis protein (XIAP), caspases 3, 7, 9, and poly (ADP-ribose) polymerase (PARP) was evaluated at both mRNA and protein levels in peripheral blood mononuclear cells (PBMCs) derived from healthy donors and patients with severe and moderate COVID-19 by qRT-PCR and Western blotting, respectively. Then, we enforced apoptosis to COVID-19 patient-derived lymphocytes, and the percent was assessed by flow cytometry. RESULTS: Survivin and XIAP were less expressed in PBMCs derived from COVID-19 patients as apoptosis inhibitors than PARP, cleaved-PARP, caspase 9, and cleaved caspases 3 and 7, according to the results of real-time PCR and Western blot analysis. Additionally, according to the flow cytometry results, the down-regulation of survivin served as a potential factor in the lymphocyte depletion observed in patients with COVID-19. CONCLUSION: The role of survivin and its related pathway was first discovered in the development of COVID-19 and may serve as a potential prognostic and therapeutic target.

Inhibition of ERAP1 represses HLA-B27 free heavy chains expression on polarized macrophages and interrupts NK cells activation and function from ankylosing spondylitis.

BACKGROUND: We aimed to assess if Endoplasmic reticulum aminopeptidase 1 (ERAP1) polymorphisms might impress Human leukocyte antigen (HLA)-B27-free heavy chains (FHCs) expression on macrophages and eventually NK cell activation in Ankylosing spondylitis (AS). METHODS: Blood samples were obtained from 10 HLAB27+ patients with protective and 10 HLAB27+ patients with non-protective genotype. Monocytes were isolated and polarized toward M1 and M2 macrophages. ERAP1 was inhibited in macrophages, which were then co-cultured with autologous NK cells. RESULTS: Expression of HLA-B27-FHCs on M1 and M2 macrophages was reduced in patients with protective ERAP1 genotype. Co-culturing ERAP1-inhibited M1 macrophages and NK cells from patients with protective genotype resulted in downmodulation of CD69 and CD107a markers on NK cells and reduced number of IFN-γ+ NK cells compared to that of patients with non-protective genotypes. CONCLUSION: Inhibition of ERAP1 activity, by diminishing NK activation, may have therapeutic value in treating AS patients.

MicroRNA-155 acts as a potential prognostic and diagnostic factor in patients with ankylosing spondylitis by modulating SOCS3.

BACKGROUND: Ankylosing spondylitis (AS) is a progressive inflammatory disease. Our primary objective was to explore the role of miR-155 and its targeted factors in AS pathogenesis. METHODS AND RESULTS: PBMCs were isolated from 30 AS patients and 30 healthy individuals using the Ficoll-hypaque isolation approach. The expression of miR-155 and its associated targets, including Suppressor Of Cytokine Signaling 3 (SOCS3), STAT3, and IL-21, were determined using qT-qPCR. Then, PBMCs were cultured, and the effect of miR-155, SOCS3 siRNA (to suppress its expression), pEFSOCS3 (enforced expression), and their combination were investigated by qRT-PCR and western blotting. We also treated the cultured PBMCs with Brefeldin A, a potent inhibitor of cytokine secretion, to determine its effect on IL-21 expression and secretion. In addition, the association between miR-155 and patients' clinicopathological features was examined. The results showed that miR-155, IL-21, and STAT3 were increased in patients with AS, while SOCS3 had decreasing expression trend. It was also determined that miR-155 alleviates SOCS3 expression and increases IL-21 and STAT3 expression; it had a prominent effect when combined with SOCS3 siRNA. Besides, we showed that simultaneous transfection of miR-155 and pEFSOCS3 had no significant effect on IL-21 and STAT3 expression, revealing that miR-155 could alleviate the enforced expression of SOCS3. It was also proven that Brefledine A led to IL-21 up-regulation or accumulation while relieving its secretion. Also, a significant correlation between miR-155 and pathological features of AS patients was found. CONCLUSION: miR-155 acts as a potential prognostic and diagnostic biomarker. Its up-regulation leads to the down-regulation of SOCS3 and increased expression of IL-21 and STAT3 as characteristic of TH-17 lymphocytes, leading to worsening inflammatory conditions in patients with AS.

Association of the matrix metalloproteinases (MMPs) family gene polymorphisms and the risk of coronavirus disease 2019 (COVID-19); implications of contribution for development of neurological symptoms in the COVID-19 patients.

BACKGROUND: Seemingly, the Matrix metalloproteinases (MMPs) play a role in the etiopathogenesis of coronavirus disease 2019 (COVID-19). Here in this study, we determined the association of MMP9 rs3918242, MMP3 rs3025058, and MMP2 rs243865 polymorphisms with the risk of COVID-19, especially in those with neurological syndrome (NS). METHODS: We enrolled 500 patients with COVID-19 and 500 healthy individuals. To genotype the target SNPs, the Real-time allelic discrimination technique was used. To determine serum levels of MMPs, Enzyme-linked immunosorbent assay (ELISA) was exerted. RESULTS: The MMP9 gene rs3918242 and MMP3 gene rs3025058 SNP were significantly associated with increased COVID-19 risk and susceptibility to COVID-19 with NS. The serum level of MMP-9 and MMP-3 was significantly higher in COVID-19 cases compared with the healthy controls. Serum MMP-9 and MMP-3 levels were also higher in COVID-19 subjects with NS in comparison to the healthy controls. The polymorphisms in MMP genes were not associated with serum level of MMPs. CONCLUSION: MMP9 and MMP3 gene polymorphisms increases the susceptibility to COVID-19 as well as COVID-19 with neurologic syndrome, but they probably have no role in the regulation of serum MMP-9 and MMP-3 levels.

Survivin; a novel therapeutic target that correlates with survival of autoreactive T lymphocytes obtained from patients with ankylosing spondylitis.

Ankylosing spondylitis (AS) is progressive immune-mediated arthritis. Persistent autoreactivity of T cells with an up-regulated Survivin expression is strongly implicated in AS immunopathogenesis. Besides, Survivin can inhibit proapoptotic caspase 9 activations. Moreover, microRNAs are small non-coding RNAs that are dysregulated in various diseases, in which their altered expression could modulate Survivin expression. The primary goal of this study was to assess the role of Survivin and its-targeting microRNAs in the immunopathogenesis of AS disease. For this aim, peripheral blood mononuclear cells (PBMCs) were isolated from 15 patients with AS and healthy matched controls using Ficoll-Hypaque. T cells were obtained using the magnetic-activated cell sorting (MACS) method. After that, the expression levels of Survivin, Caspase 9, and specific miRNAs were determined using qT-qPCR. Also, the expression of Survivin and Caspase 9 at protein levels was determined by western blotting. Then, the isolated T cells were co-cultured with interleukin (IL)-2 and muromonab-CD3 (OKT-3) for active-induced cell death (AICD) induction, Survivin siRNA for inhibition of Survivin expression, and their combination to assess the implication of Survivin expression in autoreactive T lymphocytes' resistance to apoptosis by determining the rate of apoptosis by Flowcytometry assay. The results showed that Survivin was up-regulated while Caspase 9 was downregulated in patients with AS. It was also revealed that microRNAs that directly or indirectly target the Survivin mRNA were dysregulated in patients with AS. It was also revealed that T cells obtained from AS patients were more resistant to apoptosis induction than those obtained from healthy people. In summary, the results obtained from this study showed that dysregulation of Survivin and Survivin-targeting miRNAs in T lymphocytes obtained from AS patients contribute to their resistance to apoptosis, suggesting the future development of targeted therapies for AS.

The role of immune regulatory molecules in rheumatoid arthritis: Implication for etiopathogenesis and prospective for treatment.

Rheumatoid arthritis (RA) is considered an autoimmune chronic disorder and the most common inflammatory arthropathy. Disease progression in RA begins with asymptomatic autoimmune responses in cases with a genetic or environmental predisposition, that alters to arthralgia phase as autoantibodies reach the joints and subjects begin demonstrating nonspecific musculoskeletal presentations lacking any clinical symptoms of synovial inflammation. After that, patients' symptoms develop to undifferentiated arthritis (UA)/idiopathic arthritis (IA) whenever the subjects progress to clinical synovitis systemic comorbidities affecting the vasculature, metabolism, and bone, and eventually with augmented immune cell infiltration, IA/UA patients progress to clinically classifiable RA. RA is mainly correlated with different immune cells and each of them contributes variously to the pathogenesis of the disease. The pathogenesis of RA is altered by the contribution of both T and B cells in an autoimmune irregularity. Modulation of the immune responses occurs through regulatory and inhibitory molecules that control activation of the adaptive system as well as immune hemostasis. To confine the exorbitant T cell-associated inflammatory reactions, the immune system provides a system of inhibitory feedbacks, collectively named immune checkpoints. In this review, we aimed to discuss about inhibitory members of immune checkpoint molecules, including programmed cell death 1 (PD-1)/PD-L1, cytotoxic-T-lymphocyte-antigen-4, lymphocyte activation gene-3, T cell immunoglobulin-3, V-domain Ig suppressor of T cell activation, B- and T-lymphocyte attenuator, and T cell immunoglobulin and ITIM domain and their role in RA.

NK cells - Dr. Jekyll and Mr. Hyde in autoimmune rheumatic diseases.

Natural killer (NK) cells belong to innate immune system that are large granular lymphocytes differentiating from the common lymphoid progenitors. These cells were first identified by their functional response against tumor cells and virus-infected cells. That notwithstanding, NK cells are able to affect both adaptive and innate immune arms and modulate a wide range of immune cells. As a consequence, NK cells are capable of bridging between the innate and adaptive immune responses. The effector cytokines as well as direct cell-cell cytotoxicity by NK cells have been shown to be involved in the regulation of the immune responses and might participate in the etiopathogenesis of several disorders, particularly autoimmune rheumatic diseases (AIRDs), such as Ankylosing spondylitis (AS), Rheumatoid arthritis (RA), Systemic lupus erythematosus (SLE), Behcet's disease (BD), Systemic sclerosis (SSc), and psoriasis. Nonetheless, NK cells demonstrate both harmful and protective functions during autoimmune diseases pathogenesis based on the subset of NK cell as well as disease microenvironment and disease phase or genetic/environmental stimuli. Here in this review, we intend to go through the recent findings in the etiology and pathogenesis of AIRDs and discuss about their clinical potential to be utilized as targets for the sake of therapy in the context of such disorders.

Dysregulation of Survivin-Targeting microRNAs in Autoimmune Diseases: New Perspectives for Novel Therapies.

It has been well established that the etiopathogenesis of diverse autoimmune diseases is rooted in the autoreactive immune cells' excessively proliferative state and impaired apoptotic machinery. Survivin is an anti-apoptotic and mitotic factor that has sparked a considerable research interest in this field. Survivin overexpression has been shown to contribute significantly to the development of autoimmune diseases via autoreactive immune cell overproliferation and apoptotic dysregulation. Several microRNAs (miRNAs/miRs) have been discovered to be involved in survivin regulation, rendering the survivin-miRNA axis a perspective target for autoimmune disease therapy. In this review, we discuss the role of survivin as an immune regulator and a highly implicated protein in the pathogenesis of autoimmune diseases, the significance of survivin-targeting miRNAs in autoimmunity, and the feasibility of targeting the survivin-miRNA axis as a promising therapeutic option for autoimmune diseases.

microRNAs: Small molecules with a large impact on colorectal cancer.

Colorectal cancer (CRC) accounts for one of the main cancer-related mortality and morbidity worldwide. The molecular mechanisms of CRC development have been broadly investigated and, over the last decade, it has become evident that aberrant transcription of microRNAs (miRNAs), a class of small, noncoding RNA molecules, has a significant role in the inception and promotion of CRC. In the involved tissues of CRC, the transcription profile of miRNAs is modulated, and their expression templates are related with prognosis, diagnosis, and treatment outcomes. Here, in the current review, we attempted to discuss the latest information regarding the aberrantly expressed miRNAs in CRC and the advantages of utilizing miRNAs as biomarkers for early diagnosis and prognosis of CRC as well as potential therapeutic application. The effect of miRNAs involved in various signaling pathways, primarily p53, EGFR, Wnt, and TGF-ß pathways, was clarified.

Cardiotoxicity of immune checkpoint inhibitors: An updated review.

The immune checkpoint molecules are involved in the regulation of T cells in order to prevent them from attacking to sell tissues and play a role in the immune response homeostasis. Application of the immune checkpoint inhibitors (ICIs) has provided a promising therapeutic approach in pathologies where the immune system is suppressed. The extended utilization of ICIs in several cancers has caused immune-related side effects in the cardiovascular system like cardiomyopathy and myocarditis. Cardiac toxicity, one of the main side effects of the ICIs-based therapeutic approach, has less been concerned; however, during the last years, many cases of fatal heart failure and myocarditis have been reported in patients treated with ICIs. In this review article, we attempted to discuss the cardiac adverse effects of inhibiting different immune checkpoint molecules.

The Role of the IL-33/ST2 Immune Pathway in Autoimmunity: New Insights and Perspectives.

Interleukin (IL)-33, a member of IL-1 cytokine family, is produced by various immune cells and acts as an alarm to alert the immune system after epithelial or endothelial cell damage during cell necrosis, infection, stress, and trauma. The biological functions of IL-33 largely depend on its ligation to the corresponding receptor, suppression of tumorigenicity 2 (ST2). The pathogenic roles of this cytokine have been implicated in several disorders, including allergic disease, cardiovascular disease, autoimmune disease, infectious disease, and cancers. However, alerted levels of IL-33 may result in either disease amelioration or progression. Genetic variations of IL33 gene may confer protective or susceptibility risk in the onset of autoimmune diseases. The purpose of this review is to discuss the involvement of IL-33 and ST2 in the pathogenesis of a variety of autoimmune disorders, such as autoimmune rheumatic, neurodegenerative, and endocrine diseases.

Fetomaternal Immune Tolerance: Crucial Mechanisms of Tolerance for Successful Pregnancy in Humans.

For many years, the question of how the maternal immune system tolerates the foreign fetus has remained unanswered, and numerous studies have considerably attempted to elucidate underlying mechanisms for fetomaternal tolerance. This review aimed at discussing various significant mechanisms in fetomaternal compatibility. At the fetomaternal interface, in addition to having efficient control against infections, innate and adaptive maternal immune systems selectively prevent fetal rejection. In general, understanding the complex mechanisms of fetomaternal tolerance is critical for immunologic tolerance induction and spontaneous abortion prevention in high-risk populations. Different cells and molecules, such as regulatory T-cells, dendritic cells, decidua cells, IDO, Class I HLA molecules, TGF-ß, and IL-10, induce maternal immune tolerance in the fetus in numerous ways. The findings on fetomaternal immune tolerance have remained controversial and require further research.

MicroRNAs Targeting Programmed Cell Death Protein 1 (PD-1) Promote Natural Killer Cell Exhaustion in Rheumatoid Arthritis.

 Natural killer (NK) cells play a role in the pathogenesis of rheumatoid arthritis (RA). Upregulated levels of programmed cell death protein 1 (PD-1) is a sign of exhausted NK cells that could be regulated by microRNAs (miRNAs). In this investigation, we determined PD­1 expression on NK cells (as a representation of NK cell exhaustion) in RA patients and evaluated if miRNAs are involved in the modulation of PD-1 expression in NK cells. Peripheral blood specimens were obtained from 40 RA patients and 20 healthy subjects. NK cells were isolated by negative selection from a pool of peripheral blood mononuclear cells. The frequency of PD-1-expressing NK cells and the expression of PD-1 on NK cells were analyzed by flow cytometry. Real-time PCR was used to measure the expression levels of PD-1 mRNA and miRNAs in the NK cells. The percentage of the PD-1-expressing NK cells and Mean fluorescence intensity (MFI) of PD-1 expression on the NK cells were significantly higher in the RA cases compared to the controls. The mRNA expression of PD-1 was significantly upregulated in NK cells from RA patients compared to healthy subjects. The expression levels of miR-28, miR-138, and miR-4717 were significantly downregulated in the NK cells from RA patients compared to the healthy group. In RA, miRNAs probably regulate the NK cell exhaustion process through driving PD-1 expression.

Cytotoxicity and Immunogenicity Evaluation of Synthetic Cell-penetrating Peptides for Methotrexate Delivery.

Methotrexate (MTX) is one of the most effective therapeutics to treat different types of solid tumors; however, it suffers low permeability limiting its bioavailability and cellular uptake. To tackle this, we aim to design and fabricate different types of cell-penetrating peptides (CPPs) to improve the intracellular uptake of MTX without causing any immunogenic response. CPPs were synthesized by the solid-phase peptide synthesis method. Peptide-MTX conjugates were prepared via covalent binding of peptide and drug molecule. CPPs and peptide-E8 nanoparticles were characterized using zeta-sizer and scanning electron microscopy. Cytotoxicity of CPPs and peptide-MTX conjugates was evaluated by MTT assay. An enzyme-linked immunosorbent assay was employed to assess the IL-6 and TNF-α cytokine release profile. Amongst all sequences, W4R4-MTX possessed the highest loading efficiency (97%) and drug to peptide percentage (24.02%). The lowest loading efficiency (36%) and drug to peptide percentage (8.76%) were seen for NGRWK-MTX conjugates. The NGRWR peptide and NGRWR-E8 nanoparticles had acceptable size (~100 nm) with spherical and rod-like structures, respectively. The selected CPPs and peptide-MTX conjugates did not show any cytotoxicity or immunogenicity. The fabricated peptides are represented as promising carriers to improve the intracellular delivery of MTX to cancer cells with low immunogenic and cytotoxic effects on normal cells.

PD-1/PD-L1 blockade: Prospectives for immunotherapy in cancer and autoimmunity.

Immune checkpoint blockade therapy (ICBT) has become a successful cancer treatment approach in the field of cancer immunotherapy. Blockade of programmed death 1 (PD-1) and programmed death-ligand 1 (PD-L1) with monoclonal antibodies have been known as successful examples of cancer immunotherapy in recent years. Although ICBT has been shown to be beneficial in cancers, such benefits have only been seen in a portion of cancer patients. In this regard, enhancing the therapeutic effects of inhibiting PD-1 and PD-L1 and reducing the side effects of this approach can be considered as a potential approach in a successful ICBT. In this review, we have highlighted new viewpoints regarding improving the therapeutic effect of PD-1 and PD-L1 blockades in cancer therapy. Besides, their expression levels as a biomarker with prognostic value, their role in intestinal microbiota modulation, combination therapy, and immune-related side effects (irAEs) have been discussed.

Matrix metalloproteinases are involved in the development of neurological complications in patients with Coronavirus disease 2019.

BACKGROUND: Evidence show that Matrix metalloproteinases (MMPs) have been associated with neurological complications in the viral infections. Here in the current investigation, we intended to reveal if MMPs are potentially involved in the development of neurological symptoms in the patients with Coronavirus disease 2019 (COVID-19). METHODS: The levels of MMPs, inflammatory cytokines, chemokines, and adhesion molecules were evaluated in the serum and cerebrospinal fluid (CSF) samples from 10 COVID-19 patients with neurological syndrome (NS) and 10 COVID-19 patients lacking NS. Monocytes from the CSF samples were treated with TNF-α and the secreted levels of MMPs were determined. RESULTS: The frequency of monocytes were increased in the CSF samples of COVID-19 patients with NS compared to patients without NS. Levels of inflammatory cytokines IL-1ß, IL-6, and TNF-α, chemokines CCL2, CCL3, CCL4, CCL7, CCL12, CXCL8, and CX3CL1, MMPs MMP-2, MMP-3, MMP-9, and MMP-12, and adhesion molecules ICAM-1, VCAM-1, and E-selectin were significantly increased in the CSF samples of COVID-19 patients with NS compared with patients without NS. Treatment of CSF-derived monocytes obtained from COVID-19 patients with NS caused increased production of MMP-2, MMP-3, MMP-9, and MMP-12. CONCLUSIONS: Higher levels of inflammatory cytokines might promote the expression of adhesion molecules on blood-CSF barrier (BCSFB), resulting in facilitation of monocyte recruitment. Increased levels of CSF chemokines might also help to the trafficking of monocytes to CSF. Inflammatory cytokines might enhance production of MMPs from monocytes, leading to disruption of BCSFB (and therefore further infiltration of inflammatory cells to CSF) in COVID-19 patients with NS.

Multi-facets of neutrophil extracellular trap in infectious diseases: Moving beyond immunity.

Neutrophil extracellular traps (NETs) are networks of extracellular chromosomal DNA fibers, histones, and cytoplasmic granule proteins. The release of NET components from neutrophils is involved in the suppression of pathogen diffusion. Development of NETs around target microbes leads to disruption of the cell membrane, eventuating in kind of cell death that is called as NETosis. The very first step in the process of NETosis is activation of Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase upon signaling by innate immune receptors. Afterwards, produced Reactive oxygen species (ROS) trigger protein-arginine deiminase type 4, neutrophil elastase, and myeloperoxidase to generate decondensed chromatin and disrupted integrity of nuclear membrane. Subsequently, decondensed chromatin is mixed with several enzymes in the cytoplasm released from granules, leading to release of DNA and histones, and finally formation of NET. Several reports have indicated that NETosis might contribute to the immune responses through limiting the dissemination of microbial organisms. In this review, we discuss recent advances on the role of neutrophils, NETs, and their implications in the pathogenesis of microbial infections. Additionally, the prospective of the NET modulation as a therapeutic strategy to treat infectious diseases are clarified.

Association of the genetic variants in the endoplasmic reticulum aminopeptidase 2 gene with ankylosing spondylitis susceptibility.

BACKGROUND: Genetic polymorphisms in the endoplasmic reticulum aminopeptidase gene ERAP2 has been attributed with the etiopathogenesis of ankylosing spondylitis (AS). Here we assessed the association of ERAP2 gene single nucleotide polymorphisms (SNPs) with AS predisposition in Iranian patients and determined their effect on the inflammatory state of the patients. METHODS: For genotyping of rs2548538, rs2287988, and rs17408150 SNPs using a real-time allelic discrimination approach, DNA was extracted from the whole blood of 250 AS patients and 250 healthy individuals. RNA of the peripheral blood mononuclear cells was separated, cDNA was synthesized, and transcriptional levels of cytokines, including interleukin (IL)-17A, IL-23, IL-10, and transforming growth factor-ß, were measured. Enzyme-linked immunosorbent assay was used to measure the serum concentration on the cytokines. RESULTS: Three ERAP2 gene SNPs were not associated significantly with AS risk. Nonetheless, rs2287988 and rs17408150 SNPs showed statistically significant association with susceptibility to the disease in those AS patients who were positive for human leukocyte antigen (HLA)-B27. Transcriptional level and serum concentration of IL-17A and IL-23 were higher, but those of IL-10 were lower in both AS patients and the HLA-B27-positive patient group relative to the control group. Nevertheless, ERAP2 gene SNPs in the HLA-B27-positive AS patients did not affect the transcription level and serum concentration of cytokines. CONCLUSIONS: ERAP2 gene rs2287988 and rs17408150 SNPs are associated with susceptibility to AS, but they are probably not determining the levels of IL-17A, IL-23, and IL-10 in this disease.

The role of myeloid-derived suppressor cells in rheumatoid arthritis: An update.

Rheumatoid arthritis (RA) is an autoimmune disease that generally affects the joints. In the late stages of the disease, it can be associated with several complications. Although the exact etiology of RA is unknown, various studies have been performed to understand better the immunological mechanisms involved in the pathogenesis of RA. At the onset of the disease, various immune cells migrate to the joints and increase the recruitment of immune cells to the joints by several immunological mediators such as cytokines and chemokines. The function of specific immune cells in RA is well-established. The shift of immune responses to Th1 or Th17 is one of the most essential factors in the development of RA. Myeloid-derived suppressor cells (MDSCs), as a heterogeneous population of myeloid cells, play a regulatory role in the immune system that inhibits T cell activity through several mechanisms. Various studies have been performed on the function of these cells in RA, which in some cases have yielded conflicting results. Therefore, the purpose of this review article is to comprehensively understand the pro-inflammatory and anti-inflammatory functions of MDSCs in the pathogenesis of RA.