ABSTRACT
Immune responses are tightly regulated yet highly variable between individuals. To investigate human population variation of trained immunity, we immunized healthy individuals with Bacillus Calmette-Guérin (BCG). This live-attenuated vaccine induces not only an adaptive immune response against tuberculosis but also triggers innate immune activation and memory that are indicative of trained immunity. We established personal immune profiles and chromatin accessibility maps over a 90-day time course of BCG vaccination in 323 individuals. Our analysis uncovered genetic and epigenetic predictors of baseline immunity and immune response. BCG vaccination enhanced the innate immune response specifically in individuals with a dormant immune state at baseline, rather than providing a general boost of innate immunity. This study advances our understanding of BCG's heterologous immune-stimulatory effects and trained immunity in humans. Furthermore, it highlights the value of epigenetic cell states for connecting immune function with genotype and the environment.
Subject(s)
BCG Vaccine , Trained Immunity , Humans , Multiomics , Vaccination , Epigenesis, GeneticABSTRACT
Differences in susceptibility to immune-mediated diseases are determined by variability in immune responses. In three studies within the Human Functional Genomics Project, we assessed the effect of environmental and non-genetic host factors of the genetic make-up of the host and of the intestinal microbiome on the cytokine responses in humans. We analyzed the association of these factors with circulating mediators and with six cytokines after stimulation with 19 bacterial, fungal, viral, and non-microbial metabolic stimuli in 534 healthy subjects. In this first study, we show a strong impact of non-genetic host factors (e.g., age and gender) on cytokine production and circulating mediators. Additionally, annual seasonality is found to be an important environmental factor influencing cytokine production. Alpha-1-antitrypsin concentrations partially mediate the seasonality of cytokine responses, whereas the effect of vitamin D levels is limited. The complete dataset has been made publicly available as a comprehensive resource for future studies. PAPERCLIP.
Subject(s)
Cytokines/genetics , Cytokines/immunology , Gene-Environment Interaction , Adolescent , Adult , Aged , Aging , Animals , Arthritis/immunology , Blood/immunology , Body Mass Index , Female , Human Genome Project , Humans , Infections/immunology , Infections/microbiology , Infections/virology , Inflammation/immunology , Inflammation/microbiology , Leukocytes, Mononuclear/immunology , Macrophages/immunology , Male , Mice , Middle Aged , Seasons , Sex CharacteristicsABSTRACT
The antituberculosis vaccine Bacillus Calmette-Guérin (BCG) induces nonspecific protection against heterologous infections, at least partly through induction of innate immune memory (trained immunity). The amplitude of the response to BCG is variable, but the factors that influence this response are poorly understood. Metabolites, either released by cells or absorbed from the gut, are known to influence immune responses, but whether they impact BCG responses is not known. We vaccinated 325 healthy individuals with BCG, and collected blood before, 2 weeks and 3 months after vaccination, to assess the influence of circulating metabolites on the immune responses induced by BCG. Circulating metabolite concentrations after BCG vaccination were found to have a more pronounced impact on trained immunity responses, such as the increase in IL-1ß and TNF-α production upon Staphylococcus aureus stimulation, than on specific adaptive immune memory, assessed as IFN-γ production in response to Mycobacterium tuberculosis. Circulating metabolites at baseline were able to predict trained immunity responses at 3 months after vaccination and enrichment analysis based on the metabolites positively associated with trained immunity revealed enrichment of the tricarboxylic acid (TCA) cycle and glutamine metabolism, both of which were previously found to be important for trained immunity. Several new metabolic pathways that influence trained immunity were identified, among which taurine metabolism associated with BCG-induced trained immunity, a finding validated in functional experiments. In conclusion, circulating metabolites are important factors influencing BCG-induced trained immunity in humans. Modulation of metabolic pathways may be a novel strategy to improve vaccine and trained immunity responses.
Subject(s)
BCG Vaccine , Mycobacterium bovis , Antitubercular Agents , Glutamine , Humans , Immunity, Innate , Metabolome , Taurine , Tricarboxylic Acids , Tumor Necrosis Factor-alpha , VaccinationABSTRACT
The innate immune system can display heterologous memory-like responses termed trained immunity after stimulation by certain vaccinations or infections. In this randomized, placebo-controlled trial, we investigated the modulation of Bacille Calmette-Guérin (BCG)-induced trained immunity by BCG revaccination or high-dose BCG administration, in comparison to a standard dose. We show that monocytes from all groups of BCG-vaccinated individuals exerted increased TNFα production after ex-vivo stimulation with various unrelated pathogens. Similarly, we observed increased amounts of T-cell-derived IFNγ after M. tuberculosis exposure, regardless of the BCG intervention. NK cell cytokine production, especially after heterologous stimulation with the fungal pathogen Candida albicans, was predominantly boosted after high dose BCG administration. Cytokine production capacity before vaccination was inversely correlated with trained immunity. While the induction of a trained immunity profile is largely dose- or frequency independent, baseline cytokine production capacity is associated with the magnitude of the innate immune memory response after BCG vaccination.
Subject(s)
BCG Vaccine , Mycobacterium tuberculosis , Humans , Immunization, Secondary , Trained Immunity , Adaptive Immunity , Vaccination , Cytokines , Immunity, InnateABSTRACT
OBJECTIVE: Basic calcium phosphate (BCP) crystals can activate the NLRP3 inflammasome and are potentially involved in the pathogenesis of osteoarthritis (OA). In order to elucidate relevant inflammatory mechanisms in OA, we used a functional genomics approach to assess genetic variation influencing BCP crystal-induced cytokine production. METHOD: Peripheral blood mononuclear cells (PBMCs) were isolated from healthy volunteers who were previously genotyped and stimulated with BCP crystals and/or lipopolysaccharide (LPS) after which cytokines release was assessed. Cytokine quantitative trait locus (cQTL) mapping was performed. For in vitro validation of the cQTL located in anoctamin 3 (ANO3), PBMCs were incubated with Tamoxifen and Benzbromarone prior to stimulation. Additionally, we performed co-localisation analysis of our top cQTLs with the most recent OA meta-analysis of genome-wide association studies (GWAS). RESULTS: We observed that BCP crystals and LPS synergistically induce IL-1ß in human PBMCs. cQTL analysis revealed several suggestive loci influencing cytokine release upon stimulation, among which are quantitative trait locus annotated to ANO3 and GLIS3. As functional validation, anoctamin inhibitors reduced IL-1ß release in PBMCs after stimulation. Co-localisation analysis showed that the GLIS3 locus was shared between LPS/BCP crystal-induced IL-1ß and genetic association with Knee OA. CONCLUSIONS: We identified and functionally validated a new locus, ANO3, associated with LPS/BCP crystal-induced inflammation in PBMCs. Moreover, the cQTL in the GLIS3 locus co-localises with the previously found locus associated with Knee OA, suggesting that this Knee OA locus might be explained through an inflammatory mechanism. These results form a basis for further exploration of inflammatory mechanisms in OA.
Subject(s)
Osteoarthritis, Knee , Quantitative Trait Loci , Humans , Toll-Like Receptor 4/genetics , Leukocytes, Mononuclear , Genome-Wide Association Study , Lipopolysaccharides , Calcium Phosphates/pharmacology , Inflammation/genetics , Genomics , AnoctaminsABSTRACT
Different components of the immune response show large variability between individuals, but they also vary within the same individual because of host and environmental factors. In this study, we report an extensive analysis of the immune characteristics of 56 individuals over four timepoints in 1 single year as part of the Human Functional Genomics Project. We characterized 102 cell subsets using flow cytometry; quantified production of eight cytokines and two chemokines in response to 20 metabolic, bacterial, fungal, and viral stimuli; and measured circulating markers of inflammation. Taking advantage of the longitudinal sampling, both seasonal and nonseasonal sources of variability were studied. The circulating markers of inflammation IL-18, IL-18 binding protein, and resistin displayed clear seasonal variability, whereas the strongest effect was observed for α-1 antitrypsin. Cytokine production capacity also showed strong seasonal changes, especially after stimulation with the influenza virus, Borrelia burgdorferi, and Escherichia coli Furthermore, we observed moderate seasonality effects on immune cell counts, especially in several CD4+/CD8+ T cell subpopulations. Age of the volunteers was an important factor influencing IFN-γ and IL-22 production, which matched the strong impact of age on several T cell subsets. Finally, on average, genetics accounted for almost 50% of the interindividual variance not already explained by age, sex, and body mass index, although this varies strongly for different parameters. In conclusion, seasonality is an important environmental factor that influences immune responses, in addition to specific genetic and nongenetic host factors, and this may well explain the seasonal variation in the incidence and severity of immune-mediated diseases.
Subject(s)
Immunity/immunology , Adult , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Cytokines/immunology , Female , Flow Cytometry/methods , Humans , Inflammation/immunology , Male , SeasonsABSTRACT
Laboratory diagnosis of Lyme borreliosis (LB) is mainly based on serology, which has limitations, particularly in the early stages of the disease. In recent years there have been conflicting reports concerning a new diagnostic tool using the cytokine interferon-gamma (IFN-γ). Previous studies have generally found low concentrations of IFN-γ in early LB infection. The goal of this study is to investigate IFN-γ regulation during early LB and provide insights into the host response to B. burgdorferi. We performed in vitro experiments with whole blood assays and peripheral blood mononuclear cells (PBMCs) of LB patients and healthy volunteers exposed to B. burgdorferi and evaluated the IFN-γ response using ELISA and related interindividual variation in IFN-γ production to the presence of single nucleotide polymorphisms. IFN-γ production of B. burgdorferi-exposed PBMCs and whole blood was amplified by the addition of interleukin-12 (IL-12) to the stimulation system. This effect was observed after 24 h of B. burgdorferi stimulation in both healthy individuals and LB patients. The effect was highly variable between individuals, but was significantly higher in LB patients 6 weeks since the start of antibiotic treatment compared to healthy individuals. IL-12 p40 and IL-18 mRNA were upregulated upon exposure to B. burgdorferi, whereas IL-12 p35 and IFN-γ mRNA expression remained relatively unchanged. SNP Rs280520 in the downstream IL-12 pathway, Tyrosine Kinase 2, was associated with increased IFN-γ production. This study shows that IL-12 evokes an IFN-γ response in B. burgdorferi exposed cells, and that LB patients and healthy controls respond differently to this stimulation.
Subject(s)
Borrelia burgdorferi , Lyme Disease , Humans , Interferon-gamma , Interleukin-12 , Leukocytes, Mononuclear , RNA, MessengerABSTRACT
BACKGROUND: Older age is associated with increased severity and death from respiratory infections, including coronavirus disease 2019 (COVID-19). The tuberculosis BCG vaccine may provide heterologous protection against nontuberculous infections and has been proposed as a potential preventive strategy against COVID-19. METHODS: In this multicenter, placebo-controlled trial, we randomly assigned older adults (aged ≥60 years; nâ =â 2014) to intracutaneous vaccination with BCG vaccine (nâ =â 1008) or placebo (nâ =â 1006). The primary end point was the cumulative incidence of respiratory tract infections (RTIs) that required medical intervention, during 12 months of follow-up. Secondary end points included the incidence of COVID-19, and the effect of BCG vaccination on the cellular and humoral immune responses. RESULTS: The cumulative incidence of RTIs requiring medical intervention was 0.029 in the BCG-vaccinated group and 0.024 in the control group (subdistribution hazard ratio, 1.26 [98.2% confidence interval, .65-2.44]). In the BCG vaccine and placebo groups, 51 and 48 individuals, respectively tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with polymerase chain reaction (subdistribution hazard ratio, 1.053 [95% confidence interval, .71-1.56]). No difference was observed in the frequency of adverse events. BCG vaccination was associated with enhanced cytokine responses after influenza, and also partially associated after SARS-CoV-2 stimulation. In patients diagnosed with COVID-19, antibody responses after infection were significantly stronger if the volunteers had previously received BCG vaccine. CONCLUSIONS: BCG vaccination had no effect on the incidence of RTIs, including SARS-CoV-2 infection, in older adult volunteers. However, it improved cytokine responses stimulated by influenza and SARS-CoV-2 and induced stronger antibody titers after COVID-19 infection. CLINICAL TRIALS REGISTRATION: EU Clinical Trials Register 2020-001591-15 ClinicalTrials.gov NCT04417335.
Subject(s)
COVID-19 , Influenza, Human , Aged , BCG Vaccine , COVID-19/epidemiology , COVID-19/prevention & control , Cytokines , Humans , Pandemics/prevention & control , SARS-CoV-2 , VaccinationABSTRACT
The endocrine and the immune systems interact by sharing receptors for hormones and cytokines, cross-control and feedback mechanisms. To date, no comprehensive study has assessed the impact of thyroid hormones on immune homeostasis. By studying immune phenotype (cell populations, antibody concentrations, circulating cytokines, adipokines and acute-phase proteins, monocyte-platelet interactions and cytokine production capacity) in two large independent cohorts of healthy volunteers of Western European descent from the Human Functional Genomics Project (500FG and 300BCG cohorts), we identified a crucial role of the thyroid hormone thyroxin (T4) and thyroid-stimulating hormone (TSH) on the homeostasis of lymphocyte populations. TSH concentrations were strongly associated with multiple populations of both effector and regulatory T cells, whereas B-cell populations were significantly associated with free T4 (fT4). In contrast, fT4 and TSH had little impact on myeloid cell populations and cytokine production capacity. Mendelian randomization further supported the role of fT4 for lymphocyte homeostasis. Subsequently, using a genomics approach, we identified genetic variants that influence both fT4 and TSH concentrations and immune responses, and gene set enrichment pathway analysis showed enrichment of fT4-affected gene expression in B-cell function pathways, including the CD40 pathway, further supporting the importance of fT4 in the regulation of B-cell function. In conclusion, we show that thyroid function controls the homeostasis of the lymphoid cell compartment. These findings improve our understanding of the immune responses and open the door for exploring and understanding the role of thyroid hormones in the lymphocyte function during disease.
Subject(s)
B-Lymphocytes/immunology , T-Lymphocyte Subsets/immunology , T-Lymphocytes, Regulatory/immunology , Thyrotropin/metabolism , Thyroxine/metabolism , Adolescent , Adult , CD40 Antigens/metabolism , Cells, Cultured , Cohort Studies , Female , Homeostasis , Humans , Immunophenotyping , Lymphocyte Activation , Male , Signal Transduction , Young AdultABSTRACT
OBJECTIVE: Metabolic dysregulation and inflammation are important consequences of obesity and impact susceptibility to cardiovascular disease. Anti-inflammatory therapy in cardiovascular disease is being developed under the assumption that inflammatory pathways are identical in women and men, but it is not known if this is indeed the case. In this study, we assessed the sex-specific relation between inflammation and metabolic dysregulation in obesity. Approach and Results: Three hundred two individuals were included, half with a BMI 27 to 30 kg/m2 and half with a BMI>30 kg/m2, 45% were women. The presence of metabolic syndrome was assessed according to the National Cholesterol Education Program-ATPIII criteria, and inflammation was studied using circulating markers of inflammation, cell counts, and ex vivo cytokine production capacity of isolated immune cells. Additionally, lipidomic and metabolomic data were gathered, and subcutaneous fat biopsies were histologically assessed. Metabolic syndrome is associated with an increased inflammatory profile that profoundly differs between women and men: women with metabolic syndrome show a lower concentration of the anti-inflammatory adiponectin, whereas men show increased levels of several pro-inflammatory markers such as IL (interleukin)-6 and leptin. Adipose tissue inflammation showed similar sex-specific associations with these markers. Peripheral blood mononuclear cells isolated from men, but not women, with metabolic syndrome display enhanced cytokine production capacity. CONCLUSIONS: We identified sex-specific pathways that influence inflammation in obesity. Excessive production of proinflammatory cytokines was observed in men with metabolic syndrome. In contrast, women typically showed reduced levels of the anti-inflammatory adipokine adiponectin. These different mechanisms of inflammatory dysregulation between women and men with obesity argue for sex-specific therapeutic strategies.
Subject(s)
Health Status Disparities , Inflammation Mediators/blood , Inflammation/etiology , Metabolic Syndrome/etiology , Obesity/complications , Adiponectin/blood , Aged , Aged, 80 and over , Biomarkers/blood , Body Mass Index , Cells, Cultured , Female , Humans , Inflammation/blood , Inflammation/diagnosis , Interleukin-6/blood , Leptin/blood , Leukocytes, Mononuclear/metabolism , Male , Metabolic Syndrome/blood , Metabolic Syndrome/diagnosis , Metabolomics , Middle Aged , Obesity/blood , Obesity/diagnosis , Risk Factors , Sex FactorsABSTRACT
OBJECTIVES: Acute gouty arthritis is caused by endogenously formed monosodium urate (MSU) crystals, which are potent activators of the NLRP3 inflammasome. However, to induce the release of active interleukin (IL)-1ß, an additional stimulus is needed. Saturated long-chain free fatty acids (FFAs) can provide such a signal and stimulate transcription of pro-IL-1ß. In contrast, the short-chain fatty acid butyrate possesses anti-inflammatory effects. One of the mechanisms involved is inhibition of histone deacetylases (HDACs). Here, we explored the effects of butyrate on MSU+FFA-induced cytokine production and its inhibition of specific HDACs. METHODS: Freshly isolated peripheral blood mononuclear cells (PBMCs) from healthy donors were stimulated with MSU and palmitic acid (C16.0) in the presence or absence of butyrate or a synthetic HDAC inhibitor. Cytokine responses were measured with ELISA and quantitative PCR. HDAC activity was measured with fluorimetric assays. RESULTS: Butyrate decreased C16.0+MSU-induced production of IL-1ß, IL-6, IL-8 and IL-1ß mRNA in PBMCs from healthy donors. Similar results were obtained in PBMCs isolated from patients with gout. Butyrate specifically inhibited class I HDACs. The HDAC inhibitor, panobinostat and the potent HDAC inhibitor, ITF-B, also decreased ex vivo C16.0+MSU-induced IL-1ß production. CONCLUSIONS: In agreement with the reported low inhibitory potency of butyrate, a high concentration was needed for cytokine suppression, whereas synthetic HDAC inhibitors showed potent anti-inflammatory effects at nanomolar concentrations. These novel HDAC inhibitors could be effective in the treatment of acute gout. Moreover, the use of specific HDAC inhibitors could even improve the efficacy and reduce any potential adverse effects.
Subject(s)
Antioxidants/pharmacology , Arthritis, Gouty , Butyrates/pharmacology , Cytokines/drug effects , Enzyme Inhibitors/pharmacology , Histone Deacetylase Inhibitors/pharmacology , Palmitic Acid/pharmacology , RNA, Messenger/drug effects , Uric Acid/pharmacology , Adult , Carbamates/pharmacology , Crystallization , Cytokines/genetics , Cytokines/metabolism , Enzyme-Linked Immunosorbent Assay , Female , Histone Deacetylases , Humans , Hydroxamic Acids/pharmacology , Indoles/pharmacology , Interleukin-1beta/drug effects , Interleukin-1beta/genetics , Interleukin-1beta/metabolism , Interleukin-6/metabolism , Interleukin-8/drug effects , Interleukin-8/metabolism , Leukocytes, Mononuclear , Male , Middle Aged , Panobinostat , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
OBJECTIVES: The study of the proinflammatory role of uric acid has focused on the effects of its crystals of monosodium urate (MSU). However, little is known whether uric acid itself can directly have proinflammatory effects. In this study, we investigate the priming effects of uric acid exposure on the cytokine production of primary human cells upon stimulation with gout-related stimuli. METHODS: Peripheral blood mononuclear cells (PBMCs) were harvested from patients with gout and healthy volunteers. Cells were pretreated with or without uric acid in soluble form for 24â h and then stimulated for 24â h with toll-like receptor (TLR)2 or TLR4 ligands in the presence or absence of MSU crystals. Cytokine production was measured by ELISA; mRNA levels were assessed using qPCR. RESULTS: The production of interleukin (IL)-1ß and IL-6 was higher in patients compared with controls and this correlated with serum urate levels. Proinflammatory cytokine production was significantly potentiated when cells from healthy subjects were pretreated with uric acid. Surprisingly, this was associated with a significant downregulation of the anti-inflammatory cytokine IL-1 receptor antagonist (IL-1Ra). This effect was specific to stimulation by uric acid and was exerted at the level of gene transcription. Epigenetic reprogramming at the level of histone methylation by uric acid was involved in this effect. CONCLUSIONS: In this study we demonstrate a mechanism through which high concentrations of uric acid (up to 50â mg/dL) influence inflammatory responses by facilitating IL-1ß production in PBMCs. We show that a mechanism for the amplification of IL-1ß consists in the downregulation of IL-1Ra and that this effect could be exerted via epigenetic mechanisms such as histone methylation. Hyperuricaemia causes a shift in the IL-1ß/IL-1Ra balance produced by PBMCs after exposure to MSU crystals and TLR-mediated stimuli, and this phenomenon is likely to reinforce the enhanced state of chronic inflammation.
Subject(s)
Cytokines/immunology , Epigenesis, Genetic/immunology , Gout/immunology , Leukocytes, Mononuclear/immunology , RNA, Messenger/metabolism , Toll-Like Receptor 2/immunology , Toll-Like Receptor 4/immunology , Uric Acid/immunology , Adult , Aged , Aged, 80 and over , Antioxidants/pharmacology , Case-Control Studies , Cytokines/drug effects , Cytokines/genetics , Enzyme-Linked Immunosorbent Assay , Epigenesis, Genetic/genetics , Gout/genetics , Histone Code , Histones/metabolism , Humans , Inflammation , Interleukin 1 Receptor Antagonist Protein/drug effects , Interleukin 1 Receptor Antagonist Protein/genetics , Interleukin 1 Receptor Antagonist Protein/immunology , Interleukin-10/genetics , Interleukin-10/immunology , Interleukin-1beta/drug effects , Interleukin-1beta/genetics , Interleukin-1beta/immunology , Interleukin-6/genetics , Interleukin-6/immunology , Leukocytes, Mononuclear/drug effects , Methylation , Middle Aged , Tumor Necrosis Factor-alpha/drug effects , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/immunology , Uric Acid/pharmacologyABSTRACT
Bacillus Calmette-Guérin vaccine is well known for inducing trained immunity in myeloid and natural killer cells, which can explain its cross-protective effect against heterologous infections. Although displaying functional characteristics of both adaptive and innate immunity, γδ T-cell memory has been only addressed in a pathogen-specific context. In this study, we aimed to determine whether human γδ T cells can mount trained immunity and therefore contribute to the cross-protective effect of the Bacillus Calmette-Guérin vaccine. We investigated in vivo induction of innate memory in γδ T cells by Bacillus Calmette-Guérin vaccination in healthy human volunteers by combining single-cell RNA sequencing technology with immune functional assays. The total number of γδ T cells and membrane markers of activation was not influenced by Bacillus Calmette-Guérin vaccination. In contrast, Bacillus Calmette-Guérin changed γδ T cells' transcriptional programs and increased their responsiveness to heterologous bacterial and fungal stimuli, including lipopolysaccharide and Candida albicans, as simultaneously characterized by higher tumor necrosis factor and interferon γ production, weeks after vaccination. Human γδ T cells in adults display the potential to develop a trained immunity phenotype after Bacillus Calmette-Guérin vaccination.
Subject(s)
BCG Vaccine , Mycobacterium bovis , Adult , Humans , Trained Immunity , Interferon-gamma , Immunity, Innate , VaccinationABSTRACT
The Bacille Calmette-Guerin (BCG) vaccine is a well-established inducer of innate immune memory (also termed trained immunity), causing increased cytokine production upon heterologous secondary stimulation. Innate immune responses are known to be influenced by season, but whether seasons impact induction of trained immunity is not known. To explore the influence of season on innate immune memory induced by the BCG vaccine, we vaccinated healthy volunteers with BCG either during winter or spring. Three months later, we measured the ex vivo cytokine responses against heterologous stimuli, analyzed gene expressions and epigenetic signatures of the immune cells, and compared these with the baseline before vaccination. BCG vaccination during winter induced a stronger increase in the production of pro-inflammatory cytokines by peripheral blood mononuclear cells (PBMCs) upon stimulation with different bacterial and fungal stimuli, compared to BCG vaccination in spring. In contrast, winter BCG vaccination resulted in lower IFNγ release in PBMCs compared to spring BCG vaccination. Furthermore, NK cells of the winter-vaccinated people had a greater pro-inflammatory cytokine and IFNγ production capacity upon heterologous stimulation. BCG had only minor effects on the transcriptome of monocytes 3 months later. In contrast, we identified season-dependent epigenetic changes in monocytes and NK cells induced by vaccination, partly explaining the higher immune cell reactivity in the winter BCG vaccination group. These results suggest that BCG vaccination during winter is more prone to induce a robust trained immunity response by activating and reprogramming the immune cells, especially NK cells. (Dutch clinical trial registry no. NL58219.091.16).
ABSTRACT
The measles, mumps, and rubella (MMR) vaccine protects against all-cause mortality in children, but the immunological mechanisms mediating these effects are poorly known. We systematically investigated whether MMR can induce long-term functional changes in innate immune cells, a process termed trained immunity, that could at least partially mediate this heterologous protection. In a randomized, placebo-controlled trial, 39 healthy adults received either the MMR vaccine or a placebo. Using single-cell RNA-Seq, we found that MMR caused transcriptomic changes in CD14+ monocytes and NK cells, but most profoundly in γδ T cells. Monocyte function was not altered by MMR vaccination. In contrast, the function of γδ T cells was markedly enhanced by MMR vaccination, with higher production of TNF and IFN-γ, as well as upregulation of cellular metabolic pathways. In conclusion, we describe a trained immunity program characterized by modulation of γδ T cell function induced by MMR vaccination.
Subject(s)
Mumps , Rubella , Child , Adult , Humans , Infant , Mumps/prevention & control , Measles-Mumps-Rubella Vaccine , Rubella/prevention & control , Metabolic Reprogramming , Trained Immunity , Vaccination , Antibodies, ViralABSTRACT
BACKGROUND: Endogenous steroid hormones have significant effects on inflammatory and immune processes, but the immunological activities of steroidogenesis precursors remain largely unexplored. METHODS: We conducted a systematic approach to examine the association between steroid hormones profile and immune traits in a cohort of 534 healthy volunteers. Serum concentrations of steroid hormones and their precursors (cortisol, progesterone, testosterone, androstenedione, 11-deoxycortisol and 17-OH progesterone) were determined by liquid chromatography-tandem mass spectrometry. Immune traits were evaluated by quantifying cellular composition of the circulating immune system and ex vivo cytokine responses elicited by major human pathogens and microbial ligands. An independent cohort of 321 individuals was used for validation, followed by in vitro validation experiments. FINDINGS: We observed a positive association between 11-deoxycortisol and lymphoid cellular subsets numbers and function (especially IL-17 response). The association with lymphoid cellularity was validated in an independent validation cohort. In vitro experiments showed that, as compared to androstenedione and 17-OH progesterone, 11-deoxycortisol promoted T cell proliferation and Candida-induced Th17 polarization at physiologically relevant concentrations. Functionally, 11-deoxycortisol-treated T cells displayed a more activated phenotype (PD-L1high CD25high CD62Llow CD127low) in response to CD3/CD28 co-stimulation, and downregulated expression of T-bet nuclear transcription factor. INTERPRETATION: Our findings suggest a positive association between 11-deoxycortisol and T-cell function under physiological conditions. Further investigation is needed to explore the potential mechanisms and clinical implications. FUNDING: Found in acknowledgements.
Subject(s)
Cortodoxone , Progesterone , Humans , Androstenedione , Steroids , PhenotypeABSTRACT
Background: Dexamethasone improves the survival of COVID-19 patients in need of supplemental oxygen therapy. Although its broad immunosuppressive effects are well-described, the immunological mechanisms modulated by dexamethasone in patients hospitalized with COVID-19 remain to be elucidated. Objective: We combined functional immunological assays and an omics-based approach to investigate the in vitro and in vivo effects of dexamethasone in the plasma and peripheral blood mononuclear cells (PBMCs) of COVID-19 patients. Methods: Hospitalized COVID-19 patients eligible for dexamethasone therapy were recruited from the general care ward between February and July, 2021. Whole blood transcriptomic and targeted plasma proteomic analyses were performed before and after starting dexamethasone treatment. PBMCs were isolated from healthy individuals and COVID-19 patients and stimulated with inactivated SARS-CoV-2 ex vivo in the presence or absence of dexamethasone and transcriptome and cytokine responses were assessed. Results: Dexamethasone efficiently inhibited SARS-CoV-2-induced in vitro expression of chemokines and cytokines in PBMCs at the transcriptional and protein level. Dexamethasone treatment in COVID-19 patients resulted in down-regulation of genes related to type I and II interferon (IFN) signaling in whole blood immune cells. In addition, dexamethasone attenuated circulating concentrations of secreted interferon-stimulating gene 15 (ISG15) and pro-inflammatory cytokines and chemokines correlating with disease severity and lethal outcomes, such as tumor necrosis factor (TNF), interleukin-6 (IL-6), chemokine ligand 2 (CCL2), C-X-C motif ligand 8 (CXCL8), and C-X-C motif chemokine ligand 10 (CXCL10). In PBMCs from COVID-19 patients that were stimulated ex vivo with multiple pathogens or Toll-like receptor (TLR) ligands, dexamethasone efficiently inhibited cytokine responses. Conclusion: We describe the anti-inflammatory impact of dexamethasone on the pathways contributing to cytokine hyperresponsiveness observed in severe manifestations of COVID-19, including type I/II IFN signaling. Dexamethasone could have adverse effects in COVID-19 patients with mild symptoms by inhibiting IFN responses in early stages of the disease, whereas it exhibits beneficial effects in patients with severe clinical phenotypes by efficiently diminishing cytokine hyperresponsiveness.
Subject(s)
COVID-19 , Interferon Type I , Humans , Cytokines , Leukocytes, Mononuclear , Ligands , Proteomics , SARS-CoV-2 , COVID-19 Drug Treatment , Tumor Necrosis Factor-alpha , Dexamethasone/pharmacology , Dexamethasone/therapeutic useABSTRACT
Background: Novel mRNA-based vaccines have been used to protect against SARS-CoV-2, especially in vulnerable populations who also receive an annual influenza vaccination. The TACTIC study investigated potential immune interference between the mRNA COVID-19 booster vaccine and the quadrivalent influenza vaccine, and determined if concurrent administration would have effects on safety or immunogenicity. Methods: TACTIC was a single-blind, placebo-controlled randomized clinical trial conducted at the Radboud University Medical Centre, the Netherlands. Individuals ≥60 years, fully vaccinated against COVID-19 were eligible for participation and randomized into one of four study groups: 1) 0.5 ml influenza vaccination Vaxigrip Tetra followed by 0.3 ml BNT162b2 COVID-19 booster vaccination 21 days later, (2) COVID-19 booster vaccination followed by influenza vaccination, (3) influenza vaccination concurrent with the COVID-19 booster vaccination, and (4) COVID-19 booster vaccination only (reference group). Primary outcome was the geometric mean concentration (GMC) of IgG against the spike (S)-protein of the SARS-CoV-2 virus, 21 days after booster vaccination. We performed a non-inferiority analysis of concurrent administration compared to booster vaccines alone with a predefined non-inferiority margin of -0.3 on the log10-scale. Findings: 154 individuals participated from October, 4, 2021, until November, 5, 2021. Anti-S IgG GMCs for the co-administration and reference group were 1684 BAU/ml and 2435 BAU/ml, respectively. Concurrent vaccination did not meet the criteria for non-inferiority (estimate -0.1791, 95% CI -0.3680 to -0.009831) and antibodies showed significantly lower neutralization capacity compared to the reference group. Reported side-effects were mild and did not differ between study groups. Interpretation: Concurrent administration of both vaccines is safe, but the quantitative and functional antibody responses were marginally lower compared to booster vaccination alone. Lower protection against COVID-19 with concurrent administration of COVID-19 and influenza vaccination cannot be excluded, although additional larger studies would be required to confirm this. Trial registration number: EudraCT: 2021-002186-17. Funding: The study was supported by the ZonMw COVID-19 Programme.
ABSTRACT
A growing number of studies show that innate immune cells can undergo functional reprogramming, facilitating a faster and enhanced response to heterologous secondary stimuli. This concept has been termed "trained immunity." We outline here a protocol to recapitulate this in vitro using adherent monocytes from consecutive isolation of peripheral blood mononuclear cells. The induction of trained immunity and the associated functional reprogramming of monocytes is described in detail using ß-glucan (from Candida albicans) and Bacillus Calmette-Guérin as examples. For complete details on the use and execution of this protocol, please refer to Repnik et al. (2003) and Bekkering et al. (2016).
Subject(s)
Cellular Reprogramming Techniques/methods , Immunity, Innate/immunology , Cellular Reprogramming/physiology , Cytokines/immunology , Humans , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/physiology , Monocytes/physiology , Mycobacterium bovis/physiology , beta-Glucans/pharmacologyABSTRACT
BCG vaccination protects not only against tuberculosis but also against heterologous infections. This effect differs between individuals, yet the factors responsible for this variation are unknown. BCG-induced nonspecific protection is, at least partially, mediated by innate immune reprogramming (trained immunity), which can be induced by the muramyl dipeptide (MDP) component of peptidoglycans. We aimed to study whether differential release of MDP in healthy individuals may explain variability of their response to BCG vaccination. Circulating MDP concentrations were increased up to three months after BCG vaccination. MDP concentrations at baseline, but not their increase postvaccination, positively correlated with the induction of trained immunity and not with mycobacteria-induced T-cell responses. Interestingly, MDP concentrations correlated with inflammatory markers in the circulation. In conclusion, circulating MDP concentrations are associated with the strength of trained immunity responses and thus influence the biological effects of BCG vaccination. This study increases our understanding about the role of MDP in BCG-induced trained immunity, which might help to optimize vaccine efficacy and explore novel applications of BCG vaccination.