ABSTRACT
Background & Aim: With larger accessibility and increased number of patients being treated with CART cell therapy, real-world toxicity continues to remain a significant challenge to its widespread adoption. We have previously shown that allogeneic umbilical cord blood derived (UCB) regulatory T cells (Tregs) can resolve uncontrolled inflammation and can treat acute and immune mediated lung injury in a xenogenic model as well as in patients suffering from COVID-19 acute respiratory distress syndrome. The unique properties of UCB Tregs including: i) lack of plasticity when exposed to inflammatory micro-environments;ii) no requirement for HLA matching;iii) long shelf life of cryopreserved Tregs;and iv) immediate product availability for on demand treatment, makes them an attractive source for treating acute inflammatory syndromes. Therefore, we hypothesized that add-on therapy with UCB derived Tregs may resolve uncontrolled inflammation responsible for CART cell therapy associated toxicity. Methods, Results & Conclusion(s): UCB Tregs were added in 1:1 ratio to CART cells, where no interference in their ability to kill CD19+ Raji cells, was detected at different ratios : 8:1 (80.4% vs. 81.5%);4:1 (62.0% vs. 66.2%);2:1 (50.1% vs. 54.7%);1:1 (35.4% vs. 44.1%) (Fig 1A). In a xenogenic B cell lymphoma model, multiple injections of Tregs were administered after CART injection (Fig 1B), which did not impact distribution of CD8+ T effector cells (Fig 1C) or CART cells cells (Fig 1D) in different organs. No decline in the CAR T levels was observed in the Tregs recipients (Fig 1E). Specifically, no difference in tumor burden was detected between the two arms (Fig 2A). No tumor was detected in CART+Tregs in liver (Fig 2B) or bone marrow (Fig 2C). A corresponding decrease in multiple inflammatory cytokines in peripheral blood was observed in CART+Tregs when compared to CART alone (Fig 2D). Here we show "proof of concept" for add-on therapy with Tregs to mitigate hyper-inflammatory state induced by CART cells without interference in their on-target anti-tumor activity. The timing of Tregs administration after CART cells have had sufficient time for forming synapse with tumor cells allows for preservation of their anti-tumor cytotoxicity, such that the infused Tregs home to the areas of tissue damage to bind to the resident antigen presenting cells which in turn collaborate with Tregs to resolve inflammation. Such differential distribution of cells allow for a Treg "cooling blanket" and lays ground for clinical study. [Figure presented]Copyright © 2023 International Society for Cell & Gene Therapy
ABSTRACT
Problem: Environmental stress during pregnancy has known impacts on both maternal and fetal health. In terms of theCOVID-19 pandemic, the majority of published work has focused on the impact of the infection itself, without considering the potential immune impact of pandemic related-stress.We, therefore, assessed the impact of pandemic stress, independently of SARS-CoV-2 infection, on the circulating and placental immune profiles of pregnant individuals. Method(s): Placentas from 239 patients were collected at the Sainte- Justine Hospital, Montreal, Canada. Of these, 199 patients delivered during the pandemic and were exposed to pandemic stress with (+: 79) or without (-: 120) SARS-CoV-2 infection, the latter exposed to pandemic stress only. Pre-pandemic historic controls (uncomplicated pregnancies, Ctrl: 40), were also included. Placental biopsies were collected to assess cytokine levels by ELISAs and histopathological lesions. A sub-study with 35 pre-pandemic pregnancies (unexposed) and 20 who delivered during the pandemic (exposed) was also conducted. The latter (exposed/unexposed) were all uncomplicated pregnancies. We collected maternal blood prior to delivery for immunophenotyping, and plasma/peripheral blood mononuclear cells (PBMCs) were isolated. Inflammatory mediators in the plasma were quantified by ELISAs. Co-culture assays with PBMCs and human umbilical vein endothelial cells (HUVECs) were performed to assess endothelial activation. Demographical/obstetrical data were obtained through chart review. Result(s): SARS-CoV-2+ patients were multiethnic (63.4%), had higher pre-pregnancyBMI (28.9 vs. 24.8 inCtrl, P<.05), and elevated preterm birth rate (16.5% vs. 5.8% in SARS-CoV-2-, P < .05 and 0.0% in Ctrl, P < .01). In the placentas, we observed an increase in the levels of IL- 1Ra (P < .05) and CRP (P < .05) in both SARS-CoV-2 groups, while IL-6 (P = .0790) and MCP-1 (P < .001) were elevated solely in SARS-CoV- 2-. These changes were predominant in placentas with inflammatory lesions on histopathological analysis. Moreover, we observed elevated CD45+ cells (P < .001) in the placentas from both SARS-CoV-2 groups versus Ctrl. Considering that the differences we observed were important in the SARS-CoV-2- group, we performed a study solely on uncomplicated pregnancies, either exposed or unexposed to pandemic stress. At the systemic level, we observed a decrease in the percentage of Th2 cells (P < .001), leading to a pro-inflammatory Th1/Th2 imbalance in exposed individuals. Decreased Treg (P < .05) and Th17 (P < .05) versus unexposed was also observed. Surprisingly, decreased levels of circulating IL-6 (P < .05), MCP-1 (P < .01), and CRP (P<.05) were seen in exposed versus unexposed individuals. Finally,we observed increased secretion of ICAM, a marker of endothelial activation, solely in endothelial cells co-cultured with PBMCs from exposed individuals. Conclusion(s): Overall, placental inflammatory profiles differed between pregnant individuals exposed to pandemic stress with or without SARS-CoV-2 infection. Moreover, we observed that the pandemic stress exposed group presented a systemic pro-inflammatory bias. This highlights the need to understand the differences between the effects of pandemic-related stress and the added burden of SARS-CoV-2 infection itself on maternal and fetal health. Our work also supports an association between an increased risk of hypertension/ preeclampsia and SARS-CoV-2 infection that might be driven in part by pandemic-related stress.
ABSTRACT
CD4+CD25+FOXP3+regulatory T cells (Tregs) contribute to the maintenance of immune homeostasis and tolerance in the body. The expression levels and functional stability of FOXP3 control the function and plasticity of Tregs. Tregs critically impact infectious diseases, especially by regulating the threshold of immune responses to pathogenic microorganisms. The functional regulatory mechanism and cell-specific surface markers of Tregs in different tissues and inflammatory microenvironments have been investigated in depth, which can provide novel ideas and strategies for immunotherapies targeting infectious diseases.Copyright © 2021. All rights reserved.
ABSTRACT
Background & Aim: Immunocompromised patients are susceptible to high-risk opportunistic infections and malignant diseases. If available, most antiviral and antifungal drugs are quite toxic, relatively ineffective, and induce resistance in the long term. Methods, Results & Conclusion(s): We have previously demonstrated the safety of adoptive cell therapy for COVID-19 patients with CD45RA negative cells containing SARS-CoV-2-specific T cells from a donor, chosen based on HLA compatibility and cellular response to SARS-CoV-2 peptide pools. After finishing a Phase 2 randomized multicenter clinical trial (RELEASE, NCT04578210), we concluded that the infusion is safe, effective, accelerates lymphocyte recovery and shows hallmarks of an immune response. To use adoptive cell therapy to treat COVID-19 it would be necessary to develop a biobank of living drugs. For that, we examined the immune evolution performing a longitudinal analysis from previously SARS-CoV-2 infected and infection- naive individuals covering 21 months from infection. Cellular responses were maintained over time while humoral responses increased after vaccination but were gradually lost. Therefore, the best donors would be recovered individuals and two months after vaccination. We also evaluated the effect of dexamethasone (current standard of care treatment for COVID-19 and other infections involving lymphopenia) and Interleukin-15 (cytokine involved in T-cell maintenance and survival) on CD45RA negative. Dexamethasone did not alter cell functionality, proliferation or phenotype at a clinical-practice concentration, while interleukin-15 increased the memory T-cell and T-regulatory cell activation state, and interferon gamma release. Furthermore, we applied the adoptive passive transfer of CD45RA negative cells containing pathogen-specific memory T-cells to other infectious diseases characterized by sustained lymphopenia. We infused six immunocompromised patients with Cytomegalovirus, BK virus, Aspergillus, and Epstein-Barr virus lymphoproliferative disease. Patients experienced pathogen clearance, resolution of symptoms and lymphocyte increase. Transient microchimerism was detected in three patients. The use of CD45RA negative cells containing specific memory T cells of a third-party donor for treating severe pathogenic diseases in immunocompromised patients is feasible, safe, and effective, and has an advantage over other cell therapies such as lower costs and a less complex regulatory environment.Copyright © 2023 International Society for Cell & Gene Therapy
ABSTRACT
Background: A significant portion of individuals experience persistent symptoms months after SARS-CoV-2 infection, broadly referred to as Long COVID (LC). Although the frequencies of subsets of SARS-CoV-2-specific T cells have been shown to differ in individuals with LC relative to those with complete recovery, a deep dive into phenotypic and functional features of total and SARSCoV- 2-specific T cells from individuals with LC has yet to be performed. Method(s): Here, we used CyTOF to characterize the phenotypes and effector functions of T cells from LIINC cohort. The median age was 46, the cohort was 55.8% female, and 9/43 had been hospitalized. Participants were reported a median of 7 LC symptoms at 8 months. SARS-CoV-2-specific total antibody levels were also measured in concurrent sera. Manual gating was used to define T cell subsets, SPICE analyses for polyfunctionality, T cell clustering for phenotypic features, and linear regression for correlation. Permutation tests, Student's t tests, and Welch's t test were used for statistical analysis. Result(s): SARS-CoV-2 total antibody responses were elevated in the LC group (p=0.043), and correlated with frequencies of SARS-CoV-2-specific T cells in those without LC (r=0.776, p< 0.001) but not those with LC. While the frequencies of total SARS-CoV-2-specific CD4+ and CD8+ T cells were similar between individuals with and without LC, those from individuals without LC tended to be more polyfunctional (co-expressing IFNgamma, TNFalpha, IL2, and/or MIP1beta). CD4+ T cells from individuals with LC harbored higher frequencies of Tcm (p=0.003), Tfh (p=0.037), and Treg subsets (p=0.0412), and preferentially expressed a variety of tissue homing receptors including CXCR4 and CXCR5 (p=0.037). SARS-CoV-2-specific CD4+ T cells producing IL6, albeit rare, were observed exclusively among those with LC (p=0.016). In addition, participants with LC harbored significantly higher frequencies of SARS-CoV-2-specific CD8+ T cells co-expressing exhaustion markers PD1 and CTLA4 (p=0.018). Conclusion(s): Long COVID is characterized by global phenotypic differences in the CD4+ T cell compartment in ways suggesting preferential migration of these cells to inflamed mucosal tissues. Individuals with LC also harbor higher numbers of exhausted SARS-CoV-2-specific CD8+ T cells, potentially implicating viral persistence. Finally, our data additionally suggest that individuals with LC may uniquely exhibit an uncoordinated T cell and antibody response during COVID-19 convalescence.
ABSTRACT
Background: The pathogenetic mechanisms behind the development of long- COVID (LC) are largely unknown. Because both plasma SARS-CoV-2 RNAemia and dysregulated immunity have been correlated with COVID-19 severity, we evaluated whether they are associated with LC. Method(s): We consecutively enrolled unvaccinated hospitalized COVID-19 patients during acute-COVID-19 (T0) in March-October 2020 who either developed LC at a follow-up visit 2-3 months from virologic clearance (T1) or did not. LC was defined as persistence >=2 months after recovery of >=1 symptom: anosmia, dysgeusia, fever, gastrointestinal symptoms, dyspnoea, fatigue, musculoskeletal pain, muscle weakness, brain fog. We measured: SARS-CoV-2 RNAemia (RT-qPCR, log10(copies/mL)), magnitude (ELISA, AUC) and functionality (pseudovirus neutralization, ID50;Fc-mediated functions, %ADCC) of SARS-CoV-2-specific antibodies, SARS-CoV-2-specific B and CD4-T-cells (Immunophenotype, AIM and ICS assays). Result(s): We enrolled 48 COVID-19 individuals, 38/48 (79.2%) developed LC (LC+) and 10 did not (LC-). LC+ and LC- had similar co-morbidities and symptoms in the acute phase (Fig.1A), and the majority showed a radiologically documented SARS-CoV-2 pneumonia. The SARS-CoV-2 RNAemia did not differ between groups at both time points. The levels of RBD-specific Abs, as well as their functionality, appeared to increase over time in the LC- group but not in the LC+ (Fig.1B-D). Similarly, a trend towards increased RBD-specific B-cells was observed over time in the LC- group but not in LC+ (Fig.1E). B-cell immunophenotyping showed a significant increase over time of classical memory B cells (MBCs) at the expenses of activated MBCs (Fig.1F-G) as well as an IgA class-switching in the LC- group compared to LC+ (Fig.1H-I). Furthermore, LC+ showed a faster decline of SARS-CoV-2-specific (CD69+CD137+) CD4- TEMRA and CD4-TEM (Fig.1L-M). Finally, IFN-gamma-producing TREG of LC- individuals increased over time (Fig.1N). Conclusion(s): Acutely ill, hospitalized COVID-19 patients developing LC feature a dysregulated SARS-CoV-2-specific humoral as well as B- and T-cell response, in both magnitude and functionality, suggesting a link between dysregulated SARS-CoV-2-specific adaptive immunity and LC development. The fine understanding of the factors contributing to such dysregulation in LC patients is strongly needed, that might further inform targeted therapeutic interventions. (Figure Presented).
ABSTRACT
Background: mRNA vaccines have proven useful in protecting vulnerable populations against SARS-CoV-2 infection. However, certain therapeutics, specifically those used in cancer treatment, reduce mRNA vaccine-induced humoral responses against SARS-CoV-2. The effects on T cell responses are not well characterized. Here, we evaluate SARS-CoV-2 spike-specific T cell responses over the course of one year in solid tumor patients in BC, Canada. Method(s): 18 female, solid-tumor patients from the BC Cancer Agency were enrolled in this prospective, cohort study, with 7 patients receiving cytotoxic chemotherapy and 11 patients receiving non-cytotoxic treatments. Whole blood was collected 1-month (T1) and one-year +/- 1-month (T2) post series completion (2 mRNA doses). Antigen-induced marker assays (AIM assays) were used to quantify CD4+ and CD8+ T cell responses, where whole blood was stimulated with ancestral or omicron SARS-CoV2 Spike peptide pools or unstimulated for 48 hours at 37degree C, fluorescently stained for activation markers CD25 and OX40 (CD4+ T cells) or CD69 and CD137 (CD8+ T cells), and analyzed using a 5-laser flow cytometer. Phenotyping of antigen-specific CD4+ T cells was done in parallel to assess the frequency of spike-specific Tregs, Th1, Th2, Th9, Th17, and Th17.1 cells. Result(s): All individuals had detectable levels of spike-specific CD4+ T cells at T2, while only 72.2% of individuals had detectable levels of spike-specific CD8+ T cells. Treatment type did not significantly impact the magnitude or phenotype of T cell responses, including those to Omicron. However, increased age was associated with decreased ancestral CD8+ T cell responses at T2. Further, ancestral and omicron responses were significantly different at T2, with decreased magnitude and altered phenotype of omicron-specific CD4+ T cells. Conclusion(s): Here, we report that solid tumor patients, treated with either chemotherapy or biologics, mount robust T cell immunity to SARS-CoV-2 following vaccination. Additional data is needed to determine if these responses correlate with antibody levels and clinical illness.
ABSTRACT
INTRODUCTION: Glioblastoma (GBM) is the most common and deadliest primary brain tumor, characterized by chemoradiation resistance and an immunosuppressive tumor microenvironment (TME). SARS-CoV-2, the COVID-19 virus, produces a significant proinflammatory response and a spectrum of clinical presentations after central nervous system infection. METHOD(S): Patient-derived GBM tissue, primary cell lines, and organoids were analyzed with immunohistochemistry and pixel-line intensity quantification. Data from tumor-bulk and single-cell transcriptomics served to describe the cell-specific expression of SARS-CoV-2 receptors in GBM and its association with the immune TME phenotype. Normal brain and iPSC-derived organoids served as controls. RESULT(S): We demonstrate that patient-derivedGBMtissue and cell cultures express SARS-CoV2 entry factors such as ACE2, TMPRSS2, and NRP1. NRP1 expression was higher in GBM than in normal brains (p<0.05), where it plays a crucial role in SARS-CoV-2 infection. NRP1 was expressed in a cell-type and phenotype-specific manner and correlated with TME infiltration of immunosuppressive cells: M2 macrophages (r = 0.229), regulatory T cells (r = 0.459), NK cells (r = -0.346), and endothelial cells (r = 0.288) (p < 0.05). Furthermore, gene ontology enrichment analysis showed that leukocyte migration and chemotaxis are among the top 5 biological functions mediated by NRP1 (p < 0.05). We found our GBM organoids recapitulate tumoral expression of SARSCoV- 2 entry factors, which varies based on distance from surface as surrogate of TME oxygenation (p < 0.05). CONCLUSION(S): GBM cancer cells and immune TME cells express SARS-CoV-2 entry factors. Glioblastoma organoids recapitulate this expression and allow for currently undergoing studies analyzing the effect of SARS-CoV-2 infection in GBM. Our findings suggest that SARSCoV- 2 could potentially target GBM, opening the door to future studies evaluating SARS-CoV-2-driven immune modulation.
ABSTRACT
Herbal plant extracts or purified phytocomponents have been extensively used to treat several diseases since ancient times. The Indian Ayurvedic system and Chinese traditional medicines have documented the medicinal properties of important herbs. In Ayurveda, the polyherbal formulation is known to exhibit better therapeutic efficacy compared to a single herb. This review focuses on six key ayurvedic herbal plants namely, Tinospora cordifolia, Withania somnifera, Glycyrrhiza glabra/Licorice, Zingiber officinale, Emblica officinalis and Ocimum sanctum. These plants possess specific phytocomponents that aid them in fighting infections and keeping body healthy and stress-free. Plants were selected due to their reported antimicrobial and anti-inflammatory effects in several diseases and effectiveness in controlling viral pathogenesis. An ad-vanced literature search was carried out using Pubmed and google scholar. Result(s): These medicinal plants are known to exhibit several protective features against various diseases or infections. Here we have particularly emphasized on antioxidant, anti-inflammatory, anti-microbial and immunomodulatory properties which are common in these six plants. Recent literature analysis has revealed Ashwagandha to be protective for Covid-19 too. The formulation from such herbs can exhibit synergism and hence better effectiveness against infection and related dis-eases. The importance of these medicinal herbs becomes highly prominent as it maintains the har-monious balance by way of boosting the immunity in a human body. Further, greater mechanistic analyses are required to prove their efficacy in fighting infectious diseases like Covid-19. It opens the arena for in-depth research of identifying and isolating the active components from these herbs and evaluating their potency to inhibit viral infections as polyherbal formulations.Copyright © 2023 Bentham Science Publishers.
ABSTRACT
Dysbiosis, especially in the gut plays a crucial role in the pathogenesis of a wide variety of diseases, including inflammatory bowel disease, colorectal cancer, cardiovascular disease, DDS obesity, diabetes and multiple sclerosis. At mucosal surfaces, mucosal polymeric immunoglobulin AIgAantibodies are known to be important to regulate the gut microbiota as well as to exclude infection induced by pathogenic bacteria or virus such as influenza and SARS-CoV-2severe acute respiratory syndrome coronavirus 2. Since the 1970 s, oral administration of IgA or IgG antibodies has been performed against infectious enteritis caused by pathogenic Escherichia coli or Clostridioides difficile. However, none of them has been successfully developed as an antibody drug up to now. Although IgA is well known to modulate the gut commensal microbiota, the therapeutic IgA drugs to treat dysbiosis has not been developed. Here, we discuss the advantages of therapeutic IgA antibodies.Copyright © 2022, Japan Society of Drug Delivery System. All rights reserved.
ABSTRACT
Background: Although many aspects of the COVID-19 disease have not yet been clarified, dysregulation of the immune system may play a crucial role in the progression of the disease. In this study, the lymphocyte subsets were evaluated in patients with different severities of COVID-19. Material(s) and Method(s): In this prospective study, the frequencies of peripheral lymphocyte subsets (CD3+, CD4+, and CD8+ T cells;CD19+ and CD20+ B cells;CD16+/CD56+ NK cells, and CD4+/CD25+/FOXP3+ regulatory T cells) were evaluated in 67 patients with confirmed COVID-19 on the first day of their admission. Result(s): The mean age of patients was 51.3 +/- 14.8 years. Thirty-two patients (47.8%) were classified as severe cases, and 11 (16.4%) were categorized as critical. The frequencies of blood lymphocytes, CD3+ cells, CD25+FOXP3+ T cells, and absolute count of CD3+ T cells, CD25+FOXP3+ T cells, CD4+ T cells, CD8+ T cells, and CD16+56+ lymphocytes were lower in more severe cases compared to the milder patients. The percentages of lymphocytes, T cells, and NK cells were significantly lower in the deceased patients. (p= 0.002 and p= 0.042, p=0.006, respectively). Conclusion(s): Findings of this cohort study demonstrated that the frequencies of CD4+, CD8+, CD25+FOXP3+ T cells, and NK cells differed in the severe cases of COVID-19. Moreover, lower frequency of T cells and NK cells could be predictors of mortality in these patients.Copyright © 2022, Shaheed Beheshti University of Medical Sciences and Health Services. All rights reserved.
ABSTRACT
The cellular and molecular hallmarks of aging include genomic instability, telomere attrition, epigenetic alterations, changes in intracellular signaling, cellular senescence, and mitochondrial dysfunction. These lead to complex remodeling and changes involving both the innate and adaptive immune systems. Besides age related changes in immune cells, the microenvironment in the lymphoid and non-lymphoid organs, as well as circulating factors interacting with the immune system also contribute to immunosenescence. Overall, immunosenescence is characterized by reduction of immune response, an increase in inflammatory and oxidation background (inflamm-aging), and production of autoantibodies. One of the most prominent age-related changes in the adaptive immune system is the decline in regenerative thymic capacity. Similar aging related defects have also been observed in stroma of the bone marrow. While lymphocytes in infants show a naive phenotype, memory phenotype predominates after midlife. Though immune responses against recall antigens may still be conserved, the ability to mount primary response against novel antigens declines with age. As a result, increased susceptibility to infections, and suboptimal vaccine response is observed in the elderly. Apart from functional alternation in immune cells, there is a low-grade persistent elevation in inflammatory molecules. Inflamm-aging may result from the accumulation of misfold proteins, compromised gut barrier function, chronic infection, obesity, etc. Furthermore, aging is associated with immune dysregulation, with defective resolution of immune response after activation, and impaired clearance of dead cells with sustained inflammation. Excessive inflammation not only impairs antigen specific immunity, but also leads to tissue damage. In fact, this may partly account for the increased mortality of COVID infection in the elderly. Apart from vulnerability to infection and weakened vaccine response, immunosenescence also plays an important role in cancer and autoimmunity in the elderly. Because of increased tissue damage and apoptosis, coupled with inflamm-aging, increased autoantibodies production is observed in the elderly. Nevertheless, there is an age-related increase in peripheral regulatory T cells. While there is an increase in autoimmunity with aging, this does not always translate into an increase in autoimmune disease. On the other hand, the increase in regulatory T cells, along with other immunosuppressive cells and the senescence associated proinflammatory environment, promotes tumor development and progression in the elderly. As immunosenescence has a significant impact on health and disease, better understanding on this process is crucial for research and development in the future geriatric health care.
ABSTRACT
In December 2019, the novel coronavirus strain SARS-CoV-2 caused an outbreak that quickly spread worldwide and led to the COVID-19 pandemic. COVID-19, the severe infectious disease caused by SARS-CoV-2, often presents with symptoms including fever, cough, and mental confusion and can cause the acute respiratory inflammatory disorder. Additionally, viral infection with SARS-CoV-2 is associated with mental health, neuronal degeneration, and psychiatric complications. With infection by the virus, cytokines are released by immune cells, causing acute systemic inflammation affecting the lungs. Lung damage can occur, resulting in hypoxia, brain damage, and mental health dysfunction. In addition, a cascade of inflammatory cytokines, including IL-1, IL-6, and TNF, are released, a phenomenon termed the "cytokine storm" that causes serious pathological damage to tissues and organs and mental health. This exaggerated production of cytokines leads to lymphopenia and disrupts the balance of Treg and Th17 cells, weakening the immune system. The elderly population is particularly at risk for damage associated with the "cytokine storm", which can affect neurological functions or result in death. Copyright © by BIOLIFE.
ABSTRACT
Background/Purpose: The 2019 outbreak of coronavirus disease COVID-19 causes immune system disruption. Recent studies reported that the decrease or depletion of regulatory T cell (Treg) may be responsible for overstimulation of the immune system and lung damage in patients with severe COVID-19. This study aims to find the molecular mechanisms and genetic biomarkers associated with Tregs in COVID-19, providing new ideas for the treatment of COVID-19. Method(s): RNA sequencing data of peripheral blood mononuclear cells (PBMC) from 252 COVID-19 infected patients and 69 healthy controls (HC) were obtained from the GEO database. The Tregs composition of COVID-19 samples was quantified using the CIBERSORT deconvolution method. The differential genes (DEGs) were identified by the limma R package. Gene co-expression network analysis (WGCNA) was used to identify the gene. Differentially expressed Tregs-related genes (DETregRGs) were obtained by intersecting DEGs with the highly related modular genes obtained in the previous step. The potential biological functions and pathways of DETregRGs were then explored. Protein-protein interaction (PPI) networks were subsequently constructed to identify hub genes. In addition, the prediction of small molecule drugs for the potential treatment of COVID-19 was made using the CMap database. Result(s): After the weighted gene co-expression network analysis (WGCNA), the turquoise module was highly correlated with Treg expression and a total of 134 DEGs was identified as DETregRGs. These genes were mainly involved in GO biological processes, such as the inflammatory response, and T cell differentiation of thymus. Then, 11 hub genes (including RPS12, RPL21, RPS3A, CD8B, CD3D, TRAT1, RPS6, CD3E, CD28, RPL3, and CD4) were ranked based on Molecular Complex Detection (MCODE) analysis. The TregRG score of COVID-19 patients showed significantly lower than HC, calculated by the 'singscore' algorithms. After the signature query of the CMap database, the KU-0063794, an mTOR inhibitor ranked second in the negative enrichment score, may restore immune system dysregulation caused by increased Th17 differentiation and decreased Treg differentiation during SARS-CoV- 2 infection. Conclusion(s): Our study examined in detail the molecular mechanisms underlying the inadequacy of Tregs in patients with COVID-19 infection. mTOR inhibitors may improve COVID-19 symptoms by expanding Tregs which may be one of the potential therapeutic methods that need further investigation. (Figure Presented).
ABSTRACT
Purpose: Kidney transplant (KT) recipients are more prone to developing lifethreatening forms of COVID-19 than the general population. Little is known about the immunological mechanisms underlying disease severity in these patients receiving T-cell targeting immunosuppressive drugs. We investigated the relationship between T cell responsiveness at the beginning of the infection and the risk to subsequently progress to respiratory failure. Method(s): We performed a multicentric prospective study in 45 KT recipients with a positive RT-PCR COVID-19 test and only mild symptoms at inclusion. Blood samples were collected at baseline directly in a cell culture system containing T cell stimuli. We assessed T cell responsiveness by computing the ratio between the levels of Th1, Th2, Th17 and Treg cytokines produced after polyclonal stimulation and the number of blood lymphocytes. We then used an unsupervised classification approach to stratify patients into low and high T cell responders and a penalized logistic regression to identify variables independently associated with progression to severe COVID-19. Result(s): Forty-five kidney transplant patients were included. Unsupervised clusterization identified 31 low and 14 high T cell responders. Patients who progressed to severe pneumonia were all low T cell responders (p=0.01). In multivariate analysis, we found that low T cell responsiveness at baseline was the main risk factor for subsequent progression to severe pneumonia. Conclusion(s): Low T cell reactivity in the early phase of COVID-19 is strongly associated with progression to severe pneumonia. This study provides new insights into the mechanisms underlying COVID-19 severity in organ transplant recipients and data of interest to clinicians managing immunosuppressive drugs in these patients.
ABSTRACT
Background: Besides the ability to induce antigen-specifc responses, vaccines can be endowed with immunomodulatory properties including the capacity to induce or downregulate regulatory T cells (Treg) that suppress adaptative and autoreactive immune responses (1). Objectives: We asked if an anti-SARS-CoV-2 mRNA vaccine could also induce an accumulation of Treg cells in patients with mixed cryoglobulinemia vasculitis (MCV), who have a defciency of Treg cells (2) and in healthy individuals. We also investigated immunologic variables possibly associated with a low immunogenic-ity of SARS-CoV-2 mRNA vaccine in patients with MCV (3). Methods: We analyzed peripheral blood lymphocyte subpopulations and anti-SARS-CoV-2 serological response in 24 patients with MCV and 9 Healthy donors (HD) before and after 2 weeks after the second dose of the Pfzer/BioNTech vaccine. Results: Among MCV patients we found 15 serological responders and 9 non-responders. All 5 seronegative patients treated recently with rituximab had <5 B cells/μ L, whereas the absolute B cell count was increased in 2 of 4 untreated patients due to monoclonal B cell lymphocytosis, with monoclonal cells representing more than 90% of B cells, associated with non-Hodgkin lymphoma. The percentage of pathologic CD21low B cells was signifcantly increased in seronegative patients. Before receiving the Pfzer/BioNTech vaccine, patients with MCV had a signifcantly reduced frequency of Treg cells among CD4+ T cells compared to HD. After the second dose of the vaccine, there was in MCV patients a signifcant increase in the percent and absolute count of Treg among CD4+ T cells Concerning the pre-vaccination distribution of T cells subpopulations, including the percentages and absolute counts of total CD3+, CD4+, CD8+, HLA-DR+ activated, Treg or CD56+ natural killer T cells, we could not reveal any pattern signifcantly associated with lack of serological response to vaccine. Conclusion: Our fndings show that lack of immunoreactivity in patients with MCV may be associated with expansion of pathologic B cells and that anti-SARS-CoV2 mRNA vaccine may induce an increase of Treg cells.
ABSTRACT
The relevance of the current epidemic situation of a new coronavirus infection is determined by new strains of the virus and the registration of cases of re-infection in COVID-19 survivors earlier. In this regard, the questions about the expediency and nature of vaccination of those who have been ill attract close attention, moreover it has affected the formation of the concept of “hybrid immunity”. The aim of this study was to analyze changes in the parameters of the immune system, reflecting their regulatory and functional potential, in response to the introduction of the peptide vaccine EpiVacCorona to persons who have suffered from the new coronavirus infection. To study the features of the formation of hybrid immunity, a retrospective analysis of the observation of 43 study participants was carried out. The inclusion criteria were data confirming COVID-19 in mild and moderate forms of the course in the period from six months to a year ago, a low level or absence of antibodies to the nucleocapsid protein SARS-CoV-2, a negative PCR result for the presence of the SARS-CoV-2 virus, the absence of comorbid pathology. The subpopulation composition, regulatory and functional potential of the immune system were determined by flow cytofluorimetry using a set of monoclonal antibodies corresponding to the goals. 21 days after the administration of a single dose of EpiVacCorona, antibodies to the vaccine peptide antigens were registered in all study participants at the highest coefficient of positivity values for the SARS-CoV-2-IgG-Vector test system used. In addition, there was a fourfold increase in the number of specific IgG to the N protein. A specific immune response to recombinant SARS-CoV-2 antigens was accompanied by a decrease in the circulation of the number of monocytes expressing TLR4, T helper cells expressing the interaction coreceptor with antigen-presenting cells, unconnected B memory with an increase in the number of B lymphocytes expressing the CD40 T-B coreceptor interaction molecule. The remaining differences in the functioning of the immune system identified in patients with COVID-19 before the vaccination in comparison with the control data have not changed. The differences consist in a decrease in the proportion of monocytes expressing HLA-DR, an increase in the expression of interaction molecules on T and B lymphocytes, an increase in the number of Treg, B1 cells, activated B lymphocytes with a decrease in the proportion of suppressor Breg and B memory. The totality of the presented data demonstrates that the COVID-19 infection that preceded vaccination in mild and moderate clinical course contributes to the formation of immunological memory, which made it possible to form a secondary immune response even to a single injection of peptide antigens of the virus.
ABSTRACT
Background & Aim: Due to its immunomodulatory potential, therapy based on the transfer of regulatory T cells (Tregs) has acquired great interest in the treatment of diseases in which it is necessary to restore immune homeostasis. Until now, autologous Treg cell therapy has proven to be safe, but the employment of blood as the source of Treg presents several limitations in terms of Treg recovery and the quality of the employed Tregs. Our group has developed a new technology to produce massive amounts of GMP Treg derived from the pediatric thymic tissue discarded in pediatric cardiac surgeries (thyTreg) that could overcome the main obstacles. Indeed, we are employing thyTreg cells with success in a clinical trial as autologous cell therapy in transplanted children. Given the large amounts of thyTreg that can be obtained from a single thymus, the main objective of this work is to evaluate the immunogenicity of thyTreg and confirm that its immature phenotype makes possible the allogeneic use of this cellular therapy in order to treat a range of immune diseases and patients. Methods, Results & Conclusion: The thyTreg obtained in the laboratory using the protocol developed by our group exhibit high viability (>90%) and high purity (>80%) in terms of CD25+FoxP3+ expression. ThyTreg have been observed to express low levels of immunogenicity markers (CD40L, CD80, CD86) by flow cytometry. Moreover, in vitro models of thyTreg co-culture with allogeneic peripheral blood mononuclear cells (PBMC) from healthy donors have been performed to i) determine if thyTreg generate an immunogenic response on PBMC, and ii) evaluate the capacity of thyTreg to suppress the proliferation of allogeneic PBMC. Even that the HLA disparity in the allogeneic cocultures between thyTreg and PBMC was high (13 of the 21 typed pairs had HLA <4/12 concordance), thyTreg did not induce the expression of activation markers (CD25, CD69) nor the proliferation or the production of pro-inflammatory cytokines (IFN-g) by allogeneic PBMCs. Moreover, thyTreg greatly inhibit the proliferation of allogeneic CD4 and CD8 T cells, reaching levels of around 70% inhibition of proliferation at a 1: 1 ratio. The results suggest that allogenic thyTreg are not immunogenic and are capable of exerting their suppressive function in an allogeneic context, indicating their possible off-the-shelf use as a treatment for transplant rejection, graft-versus- host disease, autoimmune diseases or the cytokine release syndrome characteristic of severe COVID-19 patients.
ABSTRACT
Rationale: The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has killed millions via the acute respiratory distress syndrome (ARDS). The early immune suppression of SARS-CoV-2 then subsequent inflammation suggests an unusual ability to cause immune dysregulation. Host transforming growth factor beta (TGF-β) is an immunesuppressing and profibrotic cytokine frequently “hijacked” by microbes to evade immune detection. We discovered a KRFK domain (a potent activating motif for latent TGF-β) in the SARS-CoV-2 nonstructural 15 (NSP15) protein. We hypothesized that this NSP15 protein causes immune dysregulation by activation of latent TGF-β and subsequent activation of immunosuppressive Tregulatory (Treg) cells, and that substantial TGF-β is present in the lungs of COVID-19 ARDS patients. Methods: We evaluated TGF-β1 concentrations in endotracheal aspirates (ETA) of 27 COVID-19 ARDS patients by ELISA. We produced recombinant SARS-CoV-2 NSP15 protein in E. coli and tested its ability to activate latent TGF-β1 using in vitro assays. TGF-β inhibitors were assessed for their ability to block effects. We obtained blood mononuclear cells from healthy subjects and isolated Tregs to assess their activation state via intracellular smad-2 phosphorylation (pSMAD2) using flow cytometry. Results: The KRFK domain was present in all SARS-CoV-2 variants. High concentrations of both active and total TGF-β1 were detected in ETA of COVID-19 ARDS patients (150 +/- 34 pg/ml active;1,819 +/- 304 pg/ml total) in a range previously shown to affect T cell function. NSP15 at 2.4 nM increased activation of latent TGF-β 12-fold (P < .001 vs. vehicle), compared to an 11% activation with the positive control thrombospondin-1 (TSP1;10 nM) (Figure). TGF-β receptor inhibitors blocked NSP15 effects on latent TGF-β activation and intracellular TGF-β1 signaling in a bioassay by over 95% (p<.01). At tested concentrations (25, 50, 100 nM) NSP15 increased Treg pSMAD2 levels via activation of latent TGF-β1, exceeding levels seen in Tregs stimulated with 400 pM of active TGF-β1 (+ control) (pSMAD2 + cells: vehicle 1.1%, active TGF-β1 43%, NSP15/latent TGF-β1 49-56%). Conclusions: High concentrations of active and total TGF-β1 are present in the lungs of COVID-19 ARDS patients, suggesting SARS-CoV-2 uses host TGF-β hijacking as a mechanism for immune evasion. The NSP15 protein of SARSCoV- 2 potently activates latent TGF-β, leading to Treg activation. TGF-β inhibitors are potent inhibitors of these NSP15 effects. A strategy to block NSP15-mediated effects with TGF-β inhibitors is an innovative therapy worthy of testing in animal models of COVID-19.