SARS-CoV2 infection induce miR-155 expression and skewed Th17/Treg balance by changing SOCS1 level: A clinical study.

BACKGROUND: One of the regulators in severe acute respiratory syndrome coronavirus2 (SARS-CoV2) infection is miRNAs. In COVID-19 patients, immunological responses to SARS-CoV2 infection may be impacted by miR-155, a miRNA associated to inflammation. MATERIALS AND METHODS: Peripheral blood mononuclear cells (PBMCs) of 50 confirmed COVID-19 patients /Healthy Controls (HCs) was isolated by Ficoll. The frequency of T helper 17 and regulatory T cells was analyzed by flowcytometry. The RNA was extracted from each sample and after synthesis of c-DNA, the relative expression of miR-155, suppressor of cytokine signaling (SOCS-1), Signal transducer and activator of transcription 3(STAT3), and Fork Head Box Protein 3 (FoxP3) was evaluated by real-time PCR. The protein level of STAT3, FoxP3 and RORγT in the isolated PBMCs measured by western blotting. The serum level of IL-10, TGF-ß, IL-17 and IL21 was assessed by ELISA method. RESULTS: The population of Th17 cells showed a significant rise, whereas Treg cells reduced in COVID-19 cases. The master transcription factor of Treg (FoxP3) and Th17 (RORγT) relative expression showed the same pattern as flowcytometry. STAT3 level of expression at RNA and protein level increased in COVID-19 cases. FOXP3 and SOCS-1 proteins were down-regulated. The relative expression of miR-155, up-regulated in PBMC of COVID-19 patients and revealed a negative correlation with SOCS-1. The serum cytokine profile showed a reduction in TGF-ß, on the other hand an increase was seen in IL-17, IL-21 and IL-10 in COVID-19 cases toward control group. CONCLUSION: Based on the studies conducted in this field, it can be suggested that Th17/Treg in covid-19 patients can be affected by miR-155 and it can be considered a valuable diagnostic and prognostic factor in this disease.

Immune system-related soluble mediators and COVID-19: basic mechanisms and clinical perspectives.

During SARS-CoV-2 infection, an effective immune response provides the first line of defense; however, excessive inflammatory innate immunity and impaired adaptive immunity may harm tissues. Soluble immune mediators are involved in the dynamic interaction of ligands with membrane-bound receptors to maintain and restore health after pathological events. In some cases, the dysregulation of their expression can lead to disease pathology. In this literature review, we described current knowledge of the basic features of soluble immune mediators and their dysregulation during SARS-CoV-2 infections and highlighted their contribution to disease severity and mortality. Video Abstract.

A comprehensive evaluation of the immune system response and type-I Interferon signaling pathway in hospitalized COVID-19 patients.

BACKGROUND: The COVID-19 pandemic has become the world's main life-threatening challenge in the third decade of the twenty-first century. Numerous studies have been conducted on SARS-CoV2 virus structure and pathogenesis to find reliable treatments and vaccines. The present study aimed to evaluate the immune-phenotype and IFN-I signaling pathways of COVID-19 patients with mild and severe conditions. MATERIAL AND METHODS: A total of 100 COVID-19 patients (50 with mild and 50 with severe conditions) were enrolled in this study. The frequency of CD4 + T, CD8 + T, Th17, Treg, and B lymphocytes beside NK cells was evaluated using flow cytometry. IFN-I downstream signaling molecules, including JAK-1, TYK-2, STAT-1, and STAT-2, and Interferon regulatory factors (IRF) 3 and 7 expressions at RNA and protein status were investigated using real-time PCR and western blotting techniques, respectively. Immune levels of cytokines (e.g., IL-1ß, IL-6, IL-17, TNF-α, IL-2R, IL-10, IFN-α, and IFN-ß) and the existence of anti-IFN-α autoantibodies were evaluated via enzyme-linked immunosorbent assay (ELISA). RESULTS: Immune-phenotyping results showed a significant decrease in the absolute count of NK cells, CD4 + T, CD8 + T, and B lymphocytes in COVID-19 patients. The frequency of Th17 and Treg cells showed a remarkable increase and decrease, respectively. All signaling molecules of the IFN-I downstream pathway and IRFs (i.e., JAK-1, TYK-2, STAT-1, STAT-2, IRF-3, and IRF-7) showed very reduced expression levels in COVID-19 patients with the severe condition compared to healthy individuals at both RNA and protein levels. Of 50 patients with severe conditions, 14 had anti-IFN-α autoantibodies in sera. Meanwhile, this result was 2 and 0 for patients with mild symptoms and healthy controls, respectively. CONCLUSION: Our results indicate a positive association of the existence of anti-IFN-α autoantibodies and immune cells dysregulation with the severity of illness in COVID-19 patients. However, comprehensive studies are necessary to find out more about this context. Video abstract.

Reduction and exhausted features of T lymphocytes under serological changes, and prognostic factors in COVID-19 progression.

AIMS: Coronavirus disease 2019 (COVID-19) is a novel viral infection threatening worldwide health as currently there exists no effective treatment strategy and vaccination programs are not publicly available yet. T lymphocytes play an important role in antiviral defenses. However, T cell frequency and functionality may be affected during the disease. MATERIAL AND METHODS: Total blood samples were collected from patients with mild and severe COVID-19, and the total lymphocyte number, as well as CD4+ and CD8 + T cells were assessed using flowcytometry. Besides, the expression of exhausted T cell markers was evaluated. The levels of proinflammatory cytokines were also investigated in the serum of all patients using enzyme-linked immunesorbent assay (ELISA). Finally, the obtained results were analyzed along with laboratory serological reports. RESULTS: COVID-19 patients showed lymphopenia and reduced CD4+ and CD8 + T cells, as well as high percentage of PD-1 expression by T cells, especially in severe cases. Serum secretion of TNF-α, IL-1ß, and IL-2 receptor (IL-2R) were remarkably increased in patients with severe symptoms, as compared with healthy controls. Moreover, high levels of triglyceride (TG) and low density lipoprotein cholesterol (LDL-C), were correlated with the severity of the disease. CONCLUSION: Reduced number and function of T cells were observed in COVID-19 patients, especially in severe patients. Meanwhile, the secretion of proinflammatory cytokines was increased as the disease developed. High level of serum IL-2R was also considered as a sign of lymphopenia. Additionally, hypercholesterolemia and hyperlipidemia could be important prognostic factors in determining the severity of the infection.

Application of newly developed SARS-CoV2 serology test along with real-time PCR for early detection in health care workers and on-time plasma donation.

BACKGROUND: As the daily number of coronavirus infection disease 19 (COVID19) patients increases, the necessity of early diagnosis becomes more obvious. In this respect, we aimed to develop a serological test for specifically detecting anti-SARS-CoV2 antibodies. METHODS: We collected serum and saliva samples from 609 individuals who work at TBZMED affiliated hospitals in Tabriz, Iran, from April to June of 2020. Real-time PCR technique was used to detect SARS-CoV-2 genome using specific primers. An enzyme linked immunosorbent assay (ELISA) test was designed based on virus nucleocapsid (N), spike (S) and its receptor binding domain (RBD) protein, and the collected sera were subjected to IgM and/or IgG analysis. RESULT: Real-time PCR results showed that 66 people were infected with the SARS-CoV-2. Our designed ELISA kit showed 93.75% and 98% of sensitivity and specificity, respectively. In this study, 5.74% of participants had specific IgG against RBD, whereas the percentage for IgM positive individuals was 5.58%. Approximately the same results were observed for S protein. The number of positive participants for NP increased further, and the results of this antigen showed 7.38% for IgG and 7.06% for IgM. CONCLUSION: The ELISA test beside real-time PCR could provide a reliable serologic profile for the status of the disease progress and early detection of individuals. More importantly, it possesses the potential to identify the best candidates for plasma donation according to the antibody titers.

Prevalence of SARS-CoV-2 Specific Antibodies in Asymptomatic Hemodialysis Patients.

BACKGROUND: Since the outbreak of the new coronavirus pandemic, the importance of carrying out an infection check to prevent acquisition and transmission among end-stage renal disease patients (ESRD) under maintenance hemodialysis (MHD) has become a major concern in the health care system. Applying serology screening tests could enlighten the view with regards to disease prevalence in dialysis wards. METHODS: We subjected 328 end-stage renal disease patients to maintenance hemodialysis. After dividing patients into suspicious and non-suspicious groups for COVID-19 infection based on their clinical manifestation, they were investigated for SARS-CoV-2 specific IgM and IgG screening against nucleoprotein (NP), spike protein (SP), and receptor-binding domain (RBD), utilizing our recently developed ELISA tests. RESULTS: We found that approximately 10.1% of asymptomatically tested cases were antibody positive. Although IgG positivity showed a higher prevalence than IgM across all three virus antigen subunits, there were no significant differences among mentioned immunoglobulins of the studied groups. The most prevalent antibody was from the IgG subtype against virus nucleoprotein (NP), while the lowest prevalence was attributed to receptor-binding domain (RBD) IgM. CONCLUSION: High seropositive rate among asymptomatic end-stage renal disease patients, as a sample of high-risk population, reflected the importance of considering SARS-CoV-2 specific antibody screening for disease containment.

Immunomodulatory effects of nanocurcumin on Th17 cell responses in mild and severe COVID-19 patients.

In novel coronavirus disease 2019 (COVID-19), the increased frequency and overactivation of T helper (Th) 17 cells and subsequent production of large amounts of proinflammatory cytokines result in hyperinflammation and disease progression. The current study aimed to investigate the therapeutic effects of nanocurcumin on the frequency and responses of Th17 cells in mild and severe COVID-19 patients. In this study, 40 severe COVID-19 intensive care unit-admitted patients and 40 patients in mild condition were included. The frequency of Th17 cells, the messenger RNA expression of Th17 cell-related factors (RAR-related orphan receptor γt, interleukin [IL]-17, IL-21, IL-23, and granulocyte-macrophage colony-stimulating factor), and the serum levels of cytokines were measured in both nanocurcumin and placebo-treated groups before and after treatment. A significant decrease in the number of Th17 cells, downregulation of Th17 cell-related factors, and decreased levels of Th17 cell-related cytokines were found in mild and severe COVID-19 patients treated by nanocurcumin compared to the placebo group. Moreover, the abovementioned parameters were significantly decreased in the nanocurcumin-treated group after treatment versus before treatment. Curcumin could reduce the frequency of Th17 cells and their related inflammatory factors in both mild and severe COVID-19 patients. Hence, it could be considered as a potential modulatory compound in improving the patient's inflammatory condition.

Th17 and Treg cells function in SARS-CoV2 patients compared with healthy controls.

In the course of the coronavirus disease 2019 (COVID-19), raising and reducing the function of Th17 and Treg cells, respectively, elicit hyperinflammation and disease progression. The current study aimed to evaluate the responses of Th17 and Treg cells in COVID-19 patients compared with the control group. Forty COVID-19 intensive care unit (ICU) patients were compared with 40 healthy controls. The frequency of cells, gene expression of related factors, as well as the secretion levels of cytokines, were measured by flow cytometry, real-time polymerase chain reaction, and enzyme-linked immunosorbent assay techniques, respectively. The findings revealed a significant increase in the number of Th17 cells, the expression levels of related factors (RAR-related orphan receptor gamma [RORγt], IL-17, and IL-23), and the secretion levels of IL-17 and IL-23 cytokines in COVID-19 patients compared with controls. In contrast, patients had a remarkable reduction in the frequency of Treg cells, the expression levels of correlated factors (Forkhead box protein P3 [FoxP3], transforming growth factor-ß [TGF-ß], and IL-10), and cytokine secretion levels (TGF-ß and IL-10). The ratio of Th17/Treg cells, RORγt/FoxP3, and IL-17/IL-10 had a considerable enhancement in patients compared with the controls and also in dead patients compared with the improved cases. The findings showed that enhanced responses of Th17 cells and decreased responses of Treg cells in 2019-n-CoV patients compared with controls had a strong relationship with hyperinflammation, lung damage, and disease pathogenesis. Also, the high ratio of Th17/Treg cells and their associated factors in COVID-19-dead patients compared with improved cases indicates the critical role of inflammation in the mortality of patients.