B lymphocytes in COVID-19: a tale of harmony and discordance.

B lymphocytes play a vital role in the human defense against viral infections by producing specific antibodies. They are also critical for the prevention of infectious diseases by vaccination, and their activation influences the efficacy of the vaccination. Since the beginning of coronavirus disease 2019 (COVID-19), which became the main concern of the world health system, many efforts have been made to treat and prevent the disease. However, for the development of successful therapeutics and vaccines, it is necessary to understand the interplay between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, and the immune system. The innate immune system provides primary and nonspecific defense against the virus, but within several days after infection, a virus-specific immune response is provided first by antibody-producing B cells, which are converted after the resolution of disease to memory B cells, which provide long-term immunity. Although a failure in B cell activation or B cell dysfunction can cause a severe form of the disease and also lead to vaccination inefficiency, some individuals with B cell immunodeficiency have shown less production of the cytokine IL-6, resulting in a better disease outcome. In this review, we present the latest findings on the interaction between SARS-CoV-2 and B lymphocytes during COVID-19 infection.

Isolation and in vitro Expansion of Regulatory T Cells from ß-Thalassemia Major Kids and in vitro Evaluation of Their Plasticity and Inhibitory Effects in the Presence of Pro-Inflammatory Cytokines.

INTRODUCTION: Graft-versus-host disease (GvHD) is a life-threatening syndrome commonly associated with hematopoietic stem cell transplantation (HSCT). Preventing the incidence of GVHD after HSCT along with minimizing long-term immunosuppression is currently under investigation with regulatory T cells (Tregs). As Tregs are a low-frequency population and the yield of all memory Tregs is not sufficient for clinical application, an initial Treg expansion is essential. METHODS: Thirty milliliters of peripheral blood from the ß-thalassemia major (beta-TM) patients and healthy controls were obtained and Tregs were isolated using MACS. Isolated cells were cultured in the presence of rapamycin and rIL-2 followed by activated with anti-CD3/CD28-coated beads. To evaluate Treg plasticity, expanded Tregs were cultured in a medium containing IL1ß, IL6, TGFß, and IL2, with or without 500 nM rapamycin for 72 h. To assess the functional properties of Tregs, CFSE dilution assays were performed to evaluate the ability of in vivo expanded Tregs from beta-TM patients. Statistical analysis was performed using paired t-test and independent t-test, with the aid of SPSS version 12.0. p-value ≤0.05 was considered significant. RESULTS: The percentage of Tregs isolated from the control group was significantly higher than the Tregs isolated from patients (p-value = 0.01), which is probably due to the iron overload in beta-TM patients as a result of continuous blood transfusion. Also, the percentage of Tregs after 5 days of expansion had a significant increase in both groups compared to before expansion (p-value = 0.03). Our results also showed that the expansion of Tregs after 72 h in the presence of inflammatory cytokines and in the absence of rapamycin led to the increase in the intracellular expression of IL-17 (p-value = 0.01), while intracellular expression of IL-17 remained low following the addition of 100 nM rapamycin to the culture medium (pvalue = 0.073). The results of the functional evaluation of expanded Tregs showed relatively differences in both patient and control groups. Thus, expanded Tregs inhibited the proliferation of responder T cells in a dose-dependent manner in the control group (p-value = 0.028), while in the patient group this inhibitory effect was not significant (p-value = 0.055). CONCLUSION: Tregs isolated from beta-TM patients have poorer inhibitory performance than Tregs isolated from healthy individuals. Also, we concluded that rapamycin stabilizes the Treg population by inhibiting the production of IL-17, all necessitating the administration of appropriate immunosuppressive drugs in patients receiving Treg therapy.

Recent developments in SARS-CoV-2 vaccines: A systematic review of the current studies.

Designing and manufacturing efficient vaccines against coronavirus disease 2019 (COVID-19) is a major objective. In this systematic review, we aimed to evaluate the most important vaccines under construction worldwide, their efficiencies and clinical results in healthy individuals and in those with specific underlying diseases. We conducted a comprehensive search in PubMed, Scopus, EMBASE, and Web of Sciences by 1 December 2021 to identify published research studies. The inclusion criteria were publications that evaluated the immune responses and safety of COVID-19 vaccines in healthy individuals and in those with pre-existing diseases. We also searched the VAERS database to estimate the incidence of adverse events of special interest (AESI) post COVID-19 vaccination. Almost all investigated vaccines were well tolerated and developed good levels of both humoural and cellular responses. A protective and efficient humoural immune response develops after the second or third dose of vaccine and a longer interval (about 28 days) between the first and second injections of vaccine could induce higher antibody responses. The vaccines were less immunogenic in immunocompromised patients, particularly those with haematological malignancies. In addition, we found that venous and arterial thrombotic events, Bell's palsy, and myocarditis/pericarditis were the most common AESI. The results showed the potency of the SARS-CoV-2 vaccines to protect subjects against disease. The provision of further effective and safe vaccines is necessary in order to reach a high coverage of immunisation programs across the globe and to provide protection against infection itself.

Mesenchymal stem cells- derived exosomes inhibit the expression of Aquaporin-5 and EGFR in HCT-116 human colorectal carcinoma cell line.

BACKGROUND: Aquaporins are channel proteins, form pores in the membrane of biological cells to facilitate the transcellular and transepithelial water movement. The role of Aquaporins in carcinogenesis has become an area of interest. In this study, we aimed to investigate the effects of adipose-derived mesenchymal stem cells secreted exosomes on the expression of aquaporin 5 and EGFR genes in the HCT-116 tumor cell line. METHODS AND RESULTS: Surface antigenic profile of Ad-MSCs was evaluated using specific markers. Exosomes were purified from the Ad-MSc supernatant while the quality and the shape of isolated exosomes were assessed by western blot and transmission electron microscopy (TEM) respectively. HCT-116 cells were co-cultured with MSC-conditioned medium (MSC-CM) and/or with 100 µg/ml of MSC-derived exosomes for 48 h and. Real-time PCR was carried out to determine the expression of aquaporin5 and EGFR in HCT-116. Relative expression levels were calculated using the 2-ΔΔct method. Our result showed that AQP5 and EGFR mRNA levels were significantly reduced in CM and/or exosomes treated HCT116 compare to the control group (P-value < 0.05). CONCLUSION: The current study showed that MSC derived exosomes could inhibit expression of two important molecules involved in tumor progression. Hence it seems MSCs-derived exosomes may hold a hopeful future as drug delivery vehicles which need the furtherer investigation.

Intestinal Microbiota: Novel Personalized Cancer Immunotherapy in Colorectal Cancer.

The human colon harbors a diverse array of microorganisms that play fundamental roles in colorectal cancer (CRC). Increasing evidence indicates that dysbiosis of the intestinal microbiome has been associated with the development of CRC. Interaction between host genetics, intestinal microbiota, and lifestyle is well-indicated in the influence, prevention, and treatment of CRC. Various microbiome compositions have reported anticancer and/or anti-inflammatory properties. The presence of our microbiota is integral to our development, but a change in its composition can often lead to adverse effects, increasing the propensity for serious diseases like cancers. Recently, molecular detection and metabolomic techniques have increased our knowledge of the role of microbiota in promoting tumorigenesis. Dietary interventions may be appropriate to regulate the growth of beneficial microbiota in the gut. Metagenomic approaches along with immunology and metabolomics will obvious a new path for the treatment of CRC. In this study, we summarized recent advances in understanding the mechanisms involved in microbiota-related colorectal carcinoma, based on evidence from immunotherapy studies.

Emerging therapeutic potential of regulatory T (Treg) cells for rheumatoid arthritis: New insights and challenges.

Rheumatoid arthritis (RA) is an autoimmune-related disorder characterized by chronic inflammation. Although the etiopathogenesis of RA still remains to be clarified, it is supposed that the breakdown of immune self-tolerance may contribute to the development of RA. Thus, restoring of immune tolerance at the site of inflammation is the ultimate goal of RA treatment. Regulatory T cells (Treg cells) are the main suppressive cells that maintain tolerance and inhibit immunity against auto-antigen. Of note, recent studies demonstrated the efficacy of adoptive transfer of Treg cells in the modulation of the unwanted immune response, which makes them an ideal candidate to maintain immune homeostasis and restore antigen-specific tolerance in the case of RA and other autoimmune diseases. This review intends to submit recent finding of Treg cells-based therapies in RA with a focus on strategies applied to improve the therapeutic value of Treg cells to restore immune tolerance.

Genetically engineered mesenchymal stromal cells as a new trend for treatment of severe acute graft-versus-host disease.

Mesenchymal stem cells (MSCs) are a population of non-hematopoietic and self-renewing cells characterized by the potential to differentiate into different cell subtypes. MSCs have interesting features which have attracted a lot of attention in various clinical investigations. Some basic features of MSCs are including the weak immunogenicity (absence of MHC-II and costimulatory ligands accompanied by the low expression of MHC-I) and the potential of plasticity and multi-organ homing via expressing related surface molecules. MSCs by immunomodulatory effects could also ameliorate several immune-pathological conditions like graft-versus-host diseases (GVHD). The efficacy and potency of MSCs are the main objections of MSCs therapeutic applications. It suggested that improving the MSC immunosuppressive characteristic via genetic engineering to produce therapeutic molecules consider as one of the best options for this purpose. In this review, we explain the functions, immunologic properties, and clinical applications of MSCs to discuss the beneficial application of genetically modified MSCs in GVHD.

Nucleic Acids as Novel Therapeutic Modalities to Address Multiple Sclerosis Onset and Progression.

The issue of treating Multiple Sclerosis (MS) begins with disease-modifying treatments (DMTs) which may cause lymphopenia, dyspnea, and many other adverse effects. Consequently, further identification and evaluation of alternative treatments are crucial to monitoring their long-term outcomes and hopefully, moving toward personalized approaches that can be translated into clinical treatments. In this article, we focused on the novel therapeutic modalities that alter the interaction between the cellular constituents contributing to MS onset and progression. Furthermore, the studies that have been performed to evaluate and optimize drugs' efficacy, and particularly, to show their limitations and strengths are also presented. The preclinical trials of novel approaches for multiple sclerosis treatment provide promising prospects to cure the disease with pinpoint precision. Considering the fact that not a single treatment could be effective enough to cover all aspects of MS treatment, additional researches and therapies need to be developed in the future. Since the pathophysiology of MS resembles a jigsaw puzzle, researchers need to put a host of pieces together to create a promising window towards MS treatment. Thus, a combination therapy encompassing all these modules is highly likely to succeed in dealing with the disease. The use of different therapeutic approaches to re-induce self-tolerance in autoreactive cells contributing to MS pathogenesis is presented. A Combination therapy using these tools may help to deal with the clinical disabilities and symptoms of the disease in the future.

Cell therapy in transplantation: A comprehensive review of the current applications of cell therapy in transplant patients with the focus on Tregs, CAR Tregs, and Mesenchymal stem cells.

Organ transplantation is a practical treatment for patients with end-stage organ failure. Despite the advances in short-term graft survival, long-term graft survival remains the main challenge considering the increased mortality and morbidity associated with chronic rejection and the toxicity of immunosuppressive drugs. Since a novel therapeutic strategy to induce allograft tolerance seems urgent, focusing on developing novel and safe approaches to prolong graft survival is one of the main goals of transplant investigators. Researchers in the field of organ transplantation are interested in suppressing or optimizing the immune responses by focusing on immune cells including mesenchymal stem cells (MSCs), polyclonal regulatory Tcells (Tregs), and antigen-specific Tregs engineered with chimeric antigen receptors (CAR Tregs). We review the mechanistic pathways, phenotypic and functional characteristics of these cells, and their promising application in organ transplantation.

Serological and Molecular Tests for COVID-19: a recent update.

The COVID-19 pandemic is probably the most devastating worldwide challenge in recent century. COVID-19 leads to a mild to severe respiratory disease and affects different organs and has become a global concern since December 2019. Meanwhile, molecular biology and diagnostic laboratories played an essential role in diagnosis of the disease by introducing serological and molecular tests. Molecular-based techniques are reliable detection tools for SARS-CoV-2 and used for diagnosis of patients especially in the early stage of the disease. While, serological assays are considered as additional tools to verify the asymptomatic infections, tracing previous contacts of individuals, vaccine efficacy, and study the seroprevalance. The average time of the appearance of anti-SARS-CoV-2 antibodies in the patient's serum is 3-6 days after the onset of symptoms for both IgM and IgA and 10-18 days for IgG. Following the outbreak of COVID-19, FDA has approved and authorized a series of serological laboratory tests for early diagnosis. Serological assays have low-cost and provide fast results but have poor sensitivity in the early stage of the viral infection. Although the serological tests may not play an important role in the active case of COVID-19, it could be effective to determine the immunity of health care workers, and confirm late COVID-19 cases during the outbreak. In this review, we compared various laboratory diagnostic assays for COVID-19.

The immune system as a target for therapy of SARS-CoV-2: A systematic review of the current immunotherapies for COVID-19.

AIMS: The immune response is essential for the control and resolution of viral infections. Following the outbreak of novel coronavirus disease (COVID-19), several immunotherapies were applied to modulate the immune responses of the affected patients. In this review, we aimed to describe the role of the immune system in response to COVID-19. We also provide a systematic review to collate and describe all published reports of the using immunotherapies, including convalescent plasma therapy, monoclonal antibodies, cytokine therapy, mesenchymal stem cell therapy, and intravenous immunoglobulin and their important outcomes in COVID-19 patients. MATERIAL AND METHODS: A thorough search strategy was applied to identify published research trials in PubMed, Scopus, Medline, and EMBASE from Dec 1, 2019, to May 4, 2020, for studies reporting clinical outcomes of COVID-19 patients treated with immunotherapies along with other standard cares. KEY FINDINGS: From an initial screen of 80 identified studies, 24 studies provided clinical outcome data on the use of immunotherapies for the treatment of COVID-19 patients, including convalescent plasma therapy (33 patients), monoclonal antibodies (55 patients), interferon (31 patients), mesenchymal stem cell therapy (8 patient), and immunoglobulin (63 patients). Except for nine severe patients who died after treatment, most patients were recovered from COVID-19 with improved clinical symptoms and laboratory assessment. SIGNIFICANCE: Based on the available evidence, it seems that treatment with immunotherapy along with other standard cares could be an effective and safe approach to modulate the immune system and improvement of clinical outcomes.

Intravenous Immunoglobulin Therapy in Myocarditis.

Myocarditis is an inflammatory disease of the myocardium with lymphocyte infiltration and myocyte necrosis leading to a wide range of clinical presentations including heart failure, arrhythmia, and cardiogenic shock. Infectious and noninfectious agents may trigger the disease. The fact that immunosuppressive drugs are useful in several kinds of autoimmune myocarditis is proof of the autoimmune mechanisms involved in the development of myocarditis. Pathogenic mechanisms in myocardial inflammation are including inflammasome activation followed by myocyte destruction, myocarditis, and pericarditis. Intravenous immunoglobulin (IVIG) is a serum product made up of immunoglobulins, widely used in a variety of diseases. This product is effective in several immune-mediated pathologies. As well as the determined usage of IVIG in Kawasaki disease, IVIG may be useful in several kinds of heart failure including fulminant myocarditis, acute inflammatory cardiomyopathy, Giant Cell Myocarditis, and peripartum cardiomyopathy. Generally, IVIG is used in two different doses of low dose (200 to 400 mg/kg) and high dose (2 g/kg) regimen. The exact therapeutic effects of IVIG are not clear, however over the last decades, our knowledge about its mechanism of function has greatly enhanced. IVIG administration should be based on the accepted protocols of its transfusion. In this review article, we try to provide an overview of the different kinds of myocarditis, pathologic mechanisms and their common treatments and evaluation of the administration of IVIG in these diseases. Furthermore, we will review current protocols using IVIG in each disease individually.

Association between paraoxonase-1 gene Q192R and L55M polymorphisms and risk of gastric cancer: A case-control study from Iran.

The aim of the present study was to examine the relation between two paraoxonase1 (PON1) polymorphisms, Q192R and L55M and susceptibility to gastric cancer in an Iranian population. In this case-control study the PON1 polymorphisms were assessed in 90 gastric cancer patients and 90 healthy controls by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Regarding PON1 Q192R polymorphism, a significant increase in the R allele in the patient group compared with the controls (p value = 0.0006) While the Q allele was more frequent in the control group. No significant difference was found in the genotype or allele frequency of the L55M polymorphism between healthy individuals and patients with gastric cancer. Our results demonstrated the protective effect of Q allele against gastric cancer.