Simultaneous silencing of the A2aR and PD-1 immune checkpoints by siRNA-loaded nanoparticles enhances the immunotherapeutic potential of dendritic cell vaccine in tumor experimental models.

Following various immunotherapies, lack of proper anti-tumor immune responses is considered a significant problem in novel cancer therapeutic approaches. The expression of inhibitory checkpoint molecules on tumor-infiltrating T cells is one of the main reasons for the ineffectiveness of various immunotherapies. Therefore, we decided to inhibit two of the most important immune checkpoints expressed on tumor-associated T cells, PD-1 and A2aR. Ligation of PD-1 with PD-L1 and A2aR with adenosine significantly suppress T cell responses against tumor cells. Whitin tumors, specific inhibition of these molecules on T cells is of particular importance for successful immunotherapy as well as the elimination of treatment-associated side-effects. Thus, in this study, superparamagnetic iron oxide (SPION) nanoparticles (NPs) were covered by chitosan lactate (CL), functionalized with TAT peptide, and loaded with siRNA molecules against PD-1 and A2aR. Appropriate physicochemical properties of the prepared NPs resulted in efficient delivery of siRNA to tumor-derived T cells and suppressed the expression of A2aR and PD-1, ex vivo. T cell functions such as cytokine secretion and proliferation were considerably enhanced by the downregulation of these molecules which led to an increase in their survival time. Interestingly, treatment of CT26 and 4T1 mouse tumors with siRNA-loaded NPs not only inhibited tumor growth but also markedly increased anti-tumor immune responses and survival time. The results strongly support the efficacy of SPION-CL-TAT NPs loaded with anti-PD-1/A2aR siRNAs in cancer therapy and their further development for cancer patients in the near future.

Different T cell related immunological profiles in COVID-19 patients compared to healthy controls.

In various pathological conditions, cellular immunity plays an important role in immune responses. Amongimmunecells, T lymphocytes pdomotecellular and humoralresponses as well as innate immunity. Therefore, careful investigation of these cells has a significant impact on accurate knowledge in COVID-19diseasepathogenesis. In current research, the frequency and function of various T lymphocytes involved in immune responses examined in SARS-CoV-2 patients with various disease severity compared to normal subjects. In order to make an accurate comparison among patients with various disease severity, this study was performed on asymptomatic recovered cases (n = 20), ICU hospitalized patients (n = 30), non-ICU hospitalized patients (n = 30), and normal subjects (n = 20). To precisely evaluate T cells activity following purification, their cytokine secretion activity was examined. Similarly, immediately after purification of Treg cells, their inhibitory activity on T cells was investigated. The results showed that COVID-19 patients with severe disease (ICU hospitalized patients) not only had a remarkable increase in Th1 and Th17 but also a considerable decrease in Th2 and Treg cells. More importantly, as the IL-17 and IFN-γ secretion was sharply increased in severe disease, the secretion of IL-10 and IL-4 was decreased. Furthermore, the inhibitory activity of Treg cells was reduced in severe disease patients in comparison to other groups. In severe COVID-19 disease, current findings indicate when the inflammatory arm of cellular immunity is significantly increased, a considerable reduction in anti-inflammatory and regulatory arm occurred.

Angiotensin-converting enzyme as a new immunologic target for the new SARS-CoV-2.

The coronavirus disease 2019 (COVID-19) pandemic has affected the daily lives of millions of people worldwide and had caused significant mortality; hence, the assessment of therapeutic options is of great interest. The leading cause of death among COVID-19 patients is acute respiratory distress syndrome caused by hyperinflammation secondary to cytokine release syndrome (CRS). Cytokines, such as tumor necrosis factor-α, interleukin-6, interferon-γ and interleukin-10, are the main mediators of CRS. Based on recent evidence, the angiotensin-converting enzyme (ACE) II is known to be the target of the COVID-19 spike protein, which enables the virus to penetrate human cells. ACE II also possesses an anti-inflammatory role in many pathologies such as cardiovascular disease, hypertension, diabetes mellitus and other conditions, which are the main risk factors of poor prognosis in COVID-19 infection. Changes in tissue ACE II levels are associated with many diseases and hyperinflammatory states, and it is assumed that elevated levels of ACE II could aggravate the course of COVID-19 infection. Therefore, the use of renin-angiotensin-aldosterone system inhibitors (RASis) in COVID-19 patients could be hypothetically considered, though sufficient evidence is not presented by the scientific community. In this work, based on the most recent pieces of evidence, the roles of RAS and RASi in immunologic interactions are addressed. Furthermore, the molecular and immunologic aspects of RASi and their potential significance in COVID-19 are discussed.

Tumor-associated neutrophils as new players in immunosuppressive process of the tumor microenvironment in breast cancer.

Despite the conventional reputation of neutrophils to have antibacterial properties, recent studies have put emphasis and are interested in the role of neutrophils in the spread and treatment of cancer. It has been shown that the infiltration of neutrophils, either by exerting pro- or anti-tumoral effects, probably affects tumor prognosis. Tumor-associated neutrophils (TANs) probably participate in tumor promotion and development in different ways, such as increasing genomic instability, induction of immunosuppression, and increasing angiogenesis. Despite major advances in breast cancer treatment, it is the second leading cause of death in American women. It has been revealed that inflammation is a fundamental issue in the treatment of this cancer because tumor growth, invasion, metastasis, and vascularization can be affected by inflammatory factors. It is demonstrated that enhanced neutrophil to lymphocyte ratio probably contributes to the raised rate of mortality and decreased survival among breast cancer cases. The present review explores the biology of TANs, their suspected interactions in the breast cancer microenvironment, and their functions in preserving the tumor microenvironment and progression of tumors. Furthermore, their potential as therapeutic targets and clinical biomarkers has been discussed in this paper.

Epigenetic mechanisms shape the underlining expression regulatory mechanisms of the STAT3 in multiple sclerosis disease.

OBJECTIVES: Immunological tolerance is mediated by CD4+CD25+ regulatory T (Treg) cells. Studies have shown that thymic and peripheral generations of Treg cells depend on the CD28 signaling pathway. T helper 17 (Th17) cells are involved in the pathophysiology of various inflammatory diseases. Cytokines, such as interleukin (IL)-6 and TGF-ß, regulate the reciprocal development of Th17 and Treg cells. In CD4+ T cells, signal transducer and activator of transcription 3 (STAT3) play a critical role in the induction of Th17 cell differentiation and inhibition of Treg cell development. RESULTS: In this study, we investigated the STAT3 methylation and gene expression status in patients with MS. Our study demonstrated that the level of STAT3 methylation decreased in relapsing-remitting MS patient compared to control groups, which the decreases were statistically significant. STAT3 gene expression increased in patient group relative to healthy one, and the increases were found to be statistically significant. According to our findings, it can be suggested that DNA hypermethylation of STAT3 affects the gene expression. In addition, there is a strong and significant negative correlation between the methylation status and mRNA level of STAT3.

Innate and adaptive immune responses against coronavirus.

Coronaviruses (CoVs) are a member of the Coronaviridae family with positive-sense single- stranded RNA. In recent years, the CoVs have become a global problem to public health. The immune responses (innate and adaptive immunity) are essential for elimination and clearance of CoVs infections, however, uncontrolled immune responses can result in aggravating acute lung injury and significant immunopathology. Gaining profound understanding about the interaction between CoVs and the innate and adaptive immune systems could be a critical step in the field of treatment. In this review, we present an update on the host innate and adaptive immune responses against SARS-CoV, MERS-CoV and newly appeared SARS-CoV-2.

Targeting STAT3 in cancer and autoimmune diseases.

Signal transducer and activator of transcription 3 (STAT3) is a transcription factor that is activated downstream of a broad range of receptors particularly interleukin-6 (IL-6) family. STAT3 is the key regulator of cell proliferation, survival and apoptosis and is constitutively activated in most human cancers, indicating that it can be an important potential therapeutic target for cancer treatment. STAT3 also has important roles in lymphocyte biology, regulation of immune responses and autoimmunity. Considering the vital role of STAT3 in tumor progression and autoimmunity, scientists have focused to develop small molecules that suppress STAT3 function. In this review, we firstly discussed the predominant role of STAT3 in cancer and autoimmune diseases. Subsequently, we discussed the efficacy and therapeutic potential of different STAT3 inhibitors in cancer and autoimmune diseases in preclinical studies and clinical trials offering an insight into novel approaches for development of new STAT3 inhibitors.

Nanomedicine for improvement of dendritic cell-based cancer immunotherapy.

Dendritic cell (DC)-based cancer immunotherapy has shown impressive outcomes, including the development of the first FDA-approved anti-cancer vaccine. However, the clinical application of DC-based cancer immunotherapy is associated with various challenges. Promising novel tools for the administration of cancer vaccines has emerged from recent developments in nanoscale biomaterials. One current strategy to enhance targeted drug delivery, while minimizing drug-related toxicities, is the use of nanoparticles (NPs). These can be utilized for antigen delivery into DCs, which have been shown to provide potent T cell-stimulating effects. Therefore, NP delivery represents one promising approach for creating an effective and stable immune response without toxic side effects. The current review surveys cancer immunotherapy with particular attention toward NP-based delivery methods that target DCs.

Silencing of p68 and STAT3 synergistically diminishes cancer progression.

AIMS: Since several factors are involved in the tumorigenesis process, targeting only one factor most probably cannot overwhelm cancer progression. Therefore, it seems that combination therapy through targeting more than one cancer-related factor may lead to cancer control. The expression and function of p68 (DDX5; DEAD-Box Helicase 5) are dysregulated in various cancers. P68 is also a co-activator of many oncogenic transcription factors such as the signal transducer and activator of transcription-3 (STAT3), which contributes to cancer progression. This close connection between p68 and STAT3 plays an important role in the growth and development of cancer. MATERIALS AND METHODS: We decided to suppress the p68/STAT3 axis in various cancer cells by using Polyethylene glycol-trimethyl Chitosan-Hyaluronic acid (PEG-TMC-HA) nanoparticles (NPs) loaded with siRNA molecules. We assessed the impact of this combination therapy on apoptosis, proliferation, angiogenesis, and tumor growth, both in vitro and in vivo. KEY FINDINGS: The results showed that siRNA-loaded NPs notably suppressed the expression of p68/STAT3 axis in cancer cells, which was associated with blockade of tumor growth, colony formation, angiogenesis, and cancer cell migration. In addition to apoptosis induction, this combined therapy also reduced the expression of several tumor-promoting factors including Fibroblast growth factors (FGF), vascular endothelial growth factor (VEGF), transforming growth factor-ß (TGF-ß), matrix metallopeptidases-2 (MMP-2), MMP-9, hypoxia-inducible factor-(HIF-1α), interleukin-6 (IL-6), IL-33, Bcl-x, vimentin, and snail. SIGNIFICANCE: These findings indicate the potential of this nano-based anti-cancer therapeutic strategy for efficient cancer therapy which should be further investigated in future studies.

Regulatory T cells in breast cancer as a potent anti-cancer therapeutic target.

Despite marked advances in treatment approaches, breast cancer is still going to be more prevalent, worldwide. High levels of regulatory T (Treg) cells have repeatedly been demonstrated in circulation, lymph nodes, and tumor samples from patients with various cancer types. The transcription factor Forkhead box protein 3 (Foxp3)-expressing Treg cells have the high suppressive potential of the immune system and are fundamental in preserving immune homeostasis and self-tolerance. However, they enhance tumor development by curbing efficient anti-tumor immune mechanisms in malignancies. Moreover, the accumulation of Treg cells in breast tumors is related to the short overall survival of patients. Treg cell frequency has been applied as an independent predicting factor to diagnose patients with a high risk of relapse. Pulling out all populations of Treg cells to promote the efficacy of anticancer treatment methods may potentially lead to hazardous autoimmune disorders. Thus, realizing the exact structure of tumor-infiltrating Treg cells is pivotal to efficiently target Treg cells in tumors. There are exclusive and non-exclusive approaches to lower down and degrade the number/function of Treg cells. These approaches can include inhibiting tumoral migration, depletion, interference with function, and utilizing T cell plasticity. This review article attempts to clarify the implications concerning the involvement of Treg cells in breast cancer progression and discuss the current approaches in the treatment of this cancer via modulation of Treg cells function.

IL-21 and IL-21-producing T cells are involved in multiple sclerosis severity and progression.

Multiple sclerosis is a common neuroinflammatory disease of the central nervous system causing nervous system defects and severe physical disability. IL-21 is a proinflammatory cytokine produced mainly by Th-17 and Tfh cells which its exact role in MS was not yet clearly understood. In the present study we aimed to investigate the possible correlation of IL-21 gene expression, methylation, and its serum levels with MS severity and progression. The results showed that IL-21 mRNA level and serum level were significantly increased in patient group compared with control group (p = 0.02 and p < 0.0001 respectively). Moreover, we found a strong positive correlation between IL-21 mRNA levels and EDSS scores (r = 0.637, P < 0.0001), IL-21 mRNA levels and Progression Index (r = 0.540, P < 0.0001), IL-21 serum levels and EDSS scores (r = 0.617, P < 0.0001), and IL-21 serum levels and Progression Index (r = 0.527, P < 0.0001) in MS patients. Additionally, we found that the methylation level of IL-21 promoter region was decreased in patient group compared with the control group (p < 0.0001). We also found that methylation level of IL-21 gene promoter is negatively correlated with the IL-21 mRNA level (r = -0.263, p = 0.02), serum level (r = -0.249, p = 0.03), EDSS scores (r = -0.276, p = 0.01) and Progression Index (r = -0.430, p = 0.0001). Data showed that the increased percentages of IL-21-producing Tfh-like, Th-17 and Th1 cells in patients are positively correlated with MS severity and progression. The results of our study suggest a pro-inflammatory and booster role for IL-21 in the MS pathogenesis and progression.

The role of DEAD-box RNA helicase p68 (DDX5) in the development and treatment of breast cancer.

RNA helicase p68 or DEAD (Asp-Glu-Ala-Asp) box polypeptide 5 (DDX5) is a unique member of the highly conserved protein family, which is involved in a broad spectrum of biological processes, including transcription, translation, precursor messenger RNA processing or alternative splicing, and microRNA (miRNA) processing. It has been shown that p68 is necessary for cell growth and participates in the early development and maturation of some organs. Interestingly, p68 is a transcriptional coactivator of numerous oncogenic transcription factors, including nuclear factor-κß (NF-κß), estrogen receptor α (ERα), ß-catenin, androgen receptor, Notch transcriptional activation complex, p53 and signal transducer, and activator of transcription 3 (STAT3). Recent studies on the role of p68 (DDX5) in multiple dysregulated cellular processes in various cancers and its abnormal expression indicate the importance of this factor in tumor development. Discussion of the precise role of p68 in cancer is complex and depends on the cellular microenvironment and interacting factors. In terms of the deregulated expression of p68 in breast cancer and the high prevalence of this cancer among women, it can be informative to review the precise function of this factor in the breast cancer. Therefore, an attempt will be made in this review to clarify the tumorigenic function of p68 in association with its targeting potential for the treatment of breast cancer.

The significant role of interleukin-6 and its signaling pathway in the immunopathogenesis and treatment of breast cancer.

Despite remarkable improvements in cancer treatment approaches, breast cancer is still the main cause of cancer-related death in women. Its principal cause is the resistance of the cancer cells against conventional anticancer therapeutics, mainly in advanced disease stages. It has been shown that chronic inflammation in the tumor microenvironment facilitates tumor growth and induces resistance toward chemo- and radiotherapy. Overexpression of interleukin-6 (IL-6) cytokine in the tumor microenvironment has been demonstrated in numerous tumors including breast cancer. Tumor cells and tumor-associated fibroblasts are the major sources of IL-6 secretion in the tumor microenvironment. Several studies have demonstrated the immunopathogenic function of IL-6 and its signaling in the tumor growth, metastasis, and therapeutic resistance in the breast cancer. Therefore, it seems that targeting IL-6 and/or its receptor in combination with other potent anticancer therapies may be a potent therapeutic approach for breast cancer therapy.

Polymorphism of Foxp3 gene affects the frequency of regulatory T cells and disease activity in patients with rheumatoid arthritis in Iranian population.

Rheumatoid arthritis (RA) is a chronic autoimmune disease that mainly affects joints and characterized by chronic joint inflammation and infiltration of various immune cells in the synovium. Forkhead box P3 (Foxp3)-expressing regulatory T cells (Tregs) play a crucial role in preventing autoimmunity and undesirable T cell responses. However, there are controversial reports regarding the defective function or frequency of these cells in various studies, which may be in part related to different polymorphisms of FoxP3 and influence of ethnicity on these differences. Therefore, the main subject of this study was to evaluate the association of Foxp3 gene polymorphism and Treg frequency in Iranian patients with RA. Accordingly, 240 RA patients diagnosed according to American college of rheumatology 2010 criteria and 240 normal subjects were recruited for this study. Genomic DNA was genotyped for -3279 C/A Foxp3 gene SNP using the PCR-RFLP. The frequency of Tregs and serum levels of interleukin (IL)-10, transforming growth factor (TGF)-ß, anti-cyclic citrullinated peptide (CCP) and rheumatoid factor (RF) were determined by flow cytometry and ELISA methods, respectively. The results showed a significant association of Foxp3 -3279 A allele with augmented risk of RA in Iranian patients compared to wild-type allele. While the frequencies of CA and AA genotypes were significantly higher in patients, RA patients with AA genotype had a significant lower frequency of Tregs compared to patients with CC and CA genotypes. Consistently, TGF-ß and IL-10 significantly diminished in patients with AA genotype compared to patients with CA and CC genotypes. Our findings indicated that the AA genotype of Foxp3 in RA patients is associated with downregulation of Tregs and susceptibility to RA in the Iranian population.

Regulatory T and T helper 17 cells: Their roles in preeclampsia.

Regulatory T (Treg) cells have been identified as key immune regulators and are important to fetal survival within the maternal uterus. T helper 17 (Th17) cells have also emerged as a new subset of effector helper T cells and play significant roles in host defense against extracellular pathogens, autoimmune conditions, and inflammatory chronic diseases. Recent findings have provided strong support for the contribution of Th17 and Treg cells to successful pregnancy. Disorders of pregnancy such as preeclampsia (PE) and recurrent spontaneous abortion (RSA) are associated with low frequencies of Treg cells and high levels of Th17 cells. Here, we review current knowledge on Tregs and Th17 cells and shed light on their roles in both normal pregnancy and PE. We also discuss the imbalance between Th17 cells and Treg cells which is known as a major contributory factor in the pathophysiology of PE.

Natural killer T cells in Preeclampsia: An updated review.

Preeclampsia (PE), as a pregnancy-specific syndrome, has become one of the main causes of maternal and fetal mortality worldwide and is known as a major risk factor for preterm birth. PE is typically characterized by hypertension, significant proteinuria, and an excessive maternal systemic inflammatory response. Recent evidences provide support for the notion that Natural killer T (NKT) cells (a small, but significant immunoregulatory T cell subset of human peripheral blood lymphocytes) play pivotal roles in pregnancy. NKT cells with unique transcriptional and cytokine profiles exist in different peripheral tissues acting as mediators between the innate and adaptive immune systems. NKT cells secrete Interleukin-4 (IL-4) and Interferon-γ (IFN-γ) which might regulate the balance between Type 1T helper (Th1) and Type 2T helper (Th2) responses. During pregnancy, maternal immunity is biased towards type II cytokine production to inhibit the function of type I cytokines that could be harmful for the developing fetus. This shift to type II cytokines does not occur in preeclamptic patients. In this review, we discuss the numbers, phenotype, changes, and the functional activity of Natural killer T (NKT) cells during normal pregnancy and preeclampsia.