ABSTRACT
Infectious agents contribute significantly to the global burden of diseases through both acute infection and their chronic sequelae. We leveraged the UK Biobank to identify genetic loci that influence humoral immune response to multiple infections. From 45 genome-wide association studies in 9,611 participants from UK Biobank, we identified NFKB1 as a locus associated with quantitative antibody responses to multiple pathogens, including those from the herpes, retro-, and polyoma-virus families. An insertion-deletion variant thought to affect NFKB1 expression (rs28362491), was mapped as the likely causal variant and could play a key role in regulation of the immune response. Using 121 infection- and inflammation-related traits in 487,297 UK Biobank participants, we show that the deletion allele was associated with an increased risk of infection from diverse pathogens but had a protective effect against allergic disease. We propose that altered expression of NFKB1, as a result of the deletion, modulates hematopoietic pathways and likely impacts cell survival, antibody production, and inflammation. Taken together, we show that disruptions to the tightly regulated immune processes may tip the balance between exacerbated immune responses and allergy, or increased risk of infection and impaired resolution of inflammation.
Subject(s)
Genetic Predisposition to Disease , Hypersensitivity , Inflammation , Humans , Genome-Wide Association Study , Hypersensitivity/genetics , Inflammation/genetics , NF-kappa B p50 Subunit/genetics , UK BiobankABSTRACT
We present EPISPOT, a fully joint framework which exploits large panels of epigenetic annotations as variant-level information to enhance molecular quantitative trait locus (QTL) mapping. Thanks to a purpose-built Bayesian inferential algorithm, EPISPOT accommodates functional information for both cis and trans actions, including QTL hotspot effects. It effectively couples simultaneous QTL analysis of thousands of genetic variants and molecular traits with hypothesis-free selection of biologically interpretable annotations which directly contribute to the QTL effects. This unified, epigenome-aided learning boosts statistical power and sheds light on the regulatory basis of the uncovered hits; EPISPOT therefore marks an essential step toward improving the challenging detection and functional interpretation of trans-acting genetic variants and hotspots. We illustrate the advantages of EPISPOT in simulations emulating real-data conditions and in a monocyte expression QTL study, which confirms known hotspots and finds other signals, as well as plausible mechanisms of action. In particular, by highlighting the role of monocyte DNase-I sensitivity sites from >150 epigenetic annotations, we clarify the mediation effects and cell-type specificity of major hotspots close to the lysozyme gene. Our approach forgoes the daunting and underpowered task of one-annotation-at-a-time enrichment analyses for prioritizing cis and trans QTL hits and is tailored to any transcriptomic, proteomic, or metabolomic QTL problem. By enabling principled epigenome-driven QTL mapping transcriptome-wide, EPISPOT helps progress toward a better functional understanding of genetic regulation.
Subject(s)
Algorithms , Computer Simulation , Epigenome , Models, Genetic , Mutation , Phenotype , Quantitative Trait Loci , Bayes Theorem , Chromosome Mapping , HumansABSTRACT
Leprosy is a chronic infection of the skin and peripheral nerves caused by Mycobacterium leprae. Despite recent improvements in disease control, leprosy remains an important cause of infectious disability globally. Large-scale genetic association studies in Chinese, Vietnamese and Indian populations have identified over 30 susceptibility loci for leprosy. There is a significant burden of leprosy in Africa, however it is uncertain whether the findings of published genetic association studies are generalizable to African populations. To address this, we conducted a genome-wide association study (GWAS) of leprosy in Malawian (327 cases, 436 controls) and Malian (247 cases, 368 controls) individuals. In that analysis, we replicated four risk loci previously reported in China, Vietnam and India; MHC Class I and II, LACC1 and SLC29A3. We further identified a novel leprosy susceptibility locus at 10q24 (rs2015583; combined p = 8.81 × 10-9; OR = 0.51 [95% CI 0.40 - 0.64]). Using publicly-available data we characterise regulatory activity at this locus, identifying ACTR1A as a candidate mediator of leprosy risk. This locus shows evidence of recent positive selection and demonstrates pleiotropy with established risk loci for inflammatory bowel disease and childhood-onset asthma. A shared genetic architecture for leprosy and inflammatory bowel disease has been previously described. We expand on this, strengthening the hypothesis that selection pressure driven by leprosy has shaped the evolution of autoimmune and atopic disease in modern populations. More broadly, our data highlights the importance of defining the genetic architecture of disease across genetically diverse populations, and that disease insights derived from GWAS in one population may not translate to all affected populations.
Subject(s)
Inflammatory Bowel Diseases , Leprosy , Humans , Child , Genome-Wide Association Study , Genetic Predisposition to Disease , Polymorphism, Single Nucleotide , Malawi , Mali , Leprosy/genetics , Nucleoside Transport Proteins/geneticsABSTRACT
BACKGROUND & AIMS: The pathogenesis of immune checkpoint inhibitor (ICI)-colitis remains incompletely understood. We sought to identify key cellular drivers of ICI-colitis and their similarities to idiopathic ulcerative colitis, and to determine potential novel therapeutic targets. METHODS: We used a cross-sectional approach to study patients with ICI-colitis, those receiving ICI without the development of colitis, idiopathic ulcerative colitis, and healthy controls. A subset of patients with ICI-colitis were studied longitudinally. We applied a range of methods, including multiparameter and spectral flow cytometry, spectral immunofluorescence microscopy, targeted gene panels, and bulk and single-cell RNA sequencing. RESULTS: We demonstrate CD8+ tissue resident memory T (TRM) cells are the dominant activated T cell subset in ICI-colitis. The pattern of gastrointestinal immunopathology is distinct from ulcerative colitis at both the immune and epithelial-signaling levels. CD8+ TRM cell activation correlates with clinical and endoscopic ICI-colitis severity. Single-cell RNA sequencing analysis confirms activated CD8+ TRM cells express high levels of transcripts for checkpoint inhibitors and interferon-gamma in ICI-colitis. We demonstrate similar findings in both anti-CTLA-4/PD-1 combination therapy and in anti-PD-1 inhibitor-associated colitis. On the basis of our data, we successfully targeted this pathway in a patient with refractory ICI-colitis, using the JAK inhibitor tofacitinib. CONCLUSIONS: Interferon gamma-producing CD8+ TRM cells are a pathological hallmark of ICI-colitis and a novel target for therapy.
Subject(s)
CD8-Positive T-Lymphocytes/drug effects , Colitis/chemically induced , Colon/drug effects , Immune Checkpoint Inhibitors/adverse effects , Immunologic Memory/drug effects , Interferon-gamma/metabolism , Memory T Cells/drug effects , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , CTLA-4 Antigen/antagonists & inhibitors , CTLA-4 Antigen/metabolism , Case-Control Studies , Colitis/drug therapy , Colitis/immunology , Colitis/metabolism , Colitis, Ulcerative/immunology , Colitis, Ulcerative/metabolism , Colon/immunology , Colon/metabolism , Cross-Sectional Studies , Gene Expression Profiling , Humans , Longitudinal Studies , Lymphocyte Activation/drug effects , Memory T Cells/immunology , Memory T Cells/metabolism , Phenotype , Piperidines/therapeutic use , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Programmed Cell Death 1 Receptor/metabolism , Prospective Studies , Pyrimidines/therapeutic use , RNA-Seq , Single-Cell Analysis , TranscriptomeABSTRACT
BACKGROUND: Immune checkpoint blockers (ICBs) activate CD8+ T cells, eliciting both anti-cancer activity and immune-related adverse events (irAEs). The relationship of irAEs with baseline parameters and clinical outcome is unclear. METHODS: Retrospective evaluation of irAEs on survival was performed across primary (N = 144) and secondary (N = 211) independent cohorts of patients with metastatic melanoma receiving single agent (pembrolizumab/nivolumab-sICB) or combination (nivolumab and ipilimumab-cICB) checkpoint blockade. RNA from pre-treatment and post-treatment CD8+ T cells was sequenced and differential gene expression according to irAE development assessed. RESULTS: 58.3% of patients developed early irAEs and this was associated with longer progression-free (PFS) and overall survival (OS) across both cohorts (log-rank test, OS: P < 0.0001). Median survival for patients without irAEs was 16.6 months (95% CI: 10.9-33.4) versus not-reached (P = 2.8 × 10-6). Pre-treatment monocyte and neutrophil counts, but not BMI, were additional predictors of clinical outcome. Differential expression of numerous gene pathway members was observed in CD8+ T cells according to irAE development, and patients not developing irAEs demonstrating upregulated CXCR1 pre- and post-treatment. CONCLUSIONS: Early irAE development post-ICB is associated with favourable survival in MM. Development of irAEs is coupled to expression of numerous gene pathways, suggesting irAE development in-part reflects baseline immune activation.
Subject(s)
Autoimmune Diseases/chemically induced , CD8-Positive T-Lymphocytes/drug effects , Immune Checkpoint Inhibitors/adverse effects , Melanoma/drug therapy , Aged , Aged, 80 and over , Antineoplastic Agents, Immunological/adverse effects , Antineoplastic Agents, Immunological/therapeutic use , Autoimmune Diseases/diagnosis , Autoimmune Diseases/epidemiology , Autoimmune Diseases/genetics , Autoimmunity/drug effects , Autoimmunity/genetics , CD8-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/pathology , Female , Gene Expression Regulation, Neoplastic/drug effects , Humans , Immune Checkpoint Inhibitors/therapeutic use , Immunotherapy/adverse effects , Male , Melanoma/immunology , Melanoma/mortality , Melanoma/pathology , Middle Aged , Neoplasm Metastasis , Prognosis , Progression-Free Survival , Retrospective Studies , Skin Neoplasms/drug therapy , Skin Neoplasms/immunology , Skin Neoplasms/mortality , Skin Neoplasms/pathology , Survival Analysis , Transcriptome/drug effects , Transcriptome/immunology , Treatment Outcome , United Kingdom/epidemiologyABSTRACT
Inappropriate activation or inadequate regulation of CD4+ and CD8+ T cells may contribute to the initiation and progression of multiple autoimmune and inflammatory diseases. Studies on disease-associated genetic polymorphisms have highlighted the importance of biological context for many regulatory variants, which is particularly relevant in understanding the genetic regulation of the immune system and its cellular phenotypes. Here we show cell type-specific regulation of transcript levels of genes associated with several autoimmune diseases in CD4+ and CD8+ T cells including a trans-acting regulatory locus at chr12q13.2 containing the rs1131017 SNP in the RPS26 gene. Most remarkably, we identify a common missense variant in IL27, associated with type 1 diabetes that results in decreased functional activity of the protein and reduced expression levels of downstream IRF1 and STAT1 in CD4+ T cells only. Altogether, our results indicate that eQTL mapping in purified T cells provides novel functional insights into polymorphisms and pathways associated with autoimmune diseases.
Subject(s)
Autoimmune Diseases/genetics , CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/metabolism , Quantitative Trait Loci/genetics , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Chromosome Mapping/methods , Diabetes Mellitus, Type 1/genetics , Gene Expression Regulation , Genetic Predisposition to Disease/genetics , Genome-Wide Association Study/methods , Genotype , HEK293 Cells , Humans , Interferon Regulatory Factor-1/genetics , Interleukin-27/genetics , Mutation , Polymorphism, Single Nucleotide , Ribosomal Proteins/genetics , STAT1 Transcription Factor/geneticsABSTRACT
Differential HLA-C levels influence several human diseases, but the mechanisms responsible are incompletely characterized. Using a validated prediction algorithm, we imputed HLA-C cell surface levels in 228 individuals from the 1000 Genomes dataset. We tested 68,726 SNPs within the MHC for association with HLA-C level. The HLA-C promoter region variant, rs2395471, 800 bp upstream of the transcription start site, gave the most significant association with HLA-C levels (p = 4.2 × 10-66). This imputed expression quantitative trait locus, termed impeQTL, was also shown to associate with HLA-C expression in a genome-wide association study of 273 donors in which HLA-C mRNA expression levels were determined by quantitative PCR (qPCR) (p = 1.8 × 10-20) and in two cohorts where HLA-C cell surface levels were determined directly by flow cytometry (n = 369 combined, p < 10-15). rs2395471 is located in an Oct1 transcription factor consensus binding site motif where the A allele is predicted to have higher affinity for Oct1 than the G allele. Mobility shift electrophoresis demonstrated that Oct1 binds to both alleles in vitro, but decreased HLA-C promoter activity was observed in a luciferase reporter assay for rs2395471_G relative to rs2395471_A on a fixed promoter background. The rs2395471 variant accounts for up to 36% of the explained variation of HLA-C level. These data strengthen our understanding of HLA-C transcriptional regulation and provide a basis for understanding the potential consequences of manipulating HLA-C levels therapeutically.
Subject(s)
HLA-C Antigens/biosynthesis , HLA-C Antigens/genetics , Octamer Transcription Factor-1/metabolism , Promoter Regions, Genetic/genetics , Algorithms , Alleles , Binding Sites/genetics , Datasets as Topic , Genome, Human/genetics , Genome-Wide Association Study , HeLa Cells , Humans , Polymorphism, Single Nucleotide/genetics , Quantitative Trait Loci/genetics , Transcription Initiation Site , Transcription, GeneticABSTRACT
The functional consequences of trait associated SNPs are often investigated using expression quantitative trait locus (eQTL) mapping. While trait-associated variants may operate in a cell-type specific manner, eQTL datasets for such cell-types may not always be available. We performed a genome-environment interaction (GxE) meta-analysis on data from 5,683 samples to infer the cell type specificity of whole blood cis-eQTLs. We demonstrate that this method is able to predict neutrophil and lymphocyte specific cis-eQTLs and replicate these predictions in independent cell-type specific datasets. Finally, we show that SNPs associated with Crohn's disease preferentially affect gene expression within neutrophils, including the archetypal NOD2 locus.
Subject(s)
Lymphocytes/cytology , Neutrophils/cytology , Polymorphism, Single Nucleotide , Quantitative Trait Loci , Cell Line , Crohn Disease/genetics , Gene Expression Regulation , Genome-Wide Association Study/methods , Humans , Lymphocytes/metabolism , Neutrophils/metabolism , Nod2 Signaling Adaptor Protein/genetics , Nod2 Signaling Adaptor Protein/metabolism , Phenotype , Principal Component Analysis , Reproducibility of ResultsABSTRACT
BACKGROUND: Non-typhoidal Salmonella (NTS) causes invasive and frequently fatal disease in African children. Existing strategies to prevent, diagnose, and treat NTS disease are inadequate. An improved understanding of the biology of invasive Salmonella infection will facilitate the development of novel NTS control measures. Despite evidence in mice and man showing a clear role for host genetics in NTS susceptibility, there are no published studies investigating host genetic susceptibility to NTS in African populations. METHODS: We conducted a genome-wide association study (SNP Array 6.0, Affymetrix, CA, USA) of NTS bacteraemia in Kenyan children, with replication in Malawian children. We assessed the function of NTS-associated variants in an expression quantitative trait locus (eQTL) dataset of interferon γ (IFNγ) and lipopolysaccharide-stimulated monocytes from 432 healthy European adults. Serum IFNγ (Bio-Plex immunoassay, Bio-Rad Laboratories, CA, USA) in Malawian NTS cases (n=106) during acute disease was correlated with genotype by linear regression. FINDINGS: After whole-genome imputation and quality control, 180 Kenyan cases and 2677 controls were included in an association analysis at 7â951â614 (additive model) and 4â669â537 (genotypic model) loci. After quality control, 143 Malawian cases and 336 controls were included in the replication analysis. An intronic variant in STAT4 was associated (recessive model) with NTS in both Kenyan and Malawian children (Kenya p=5·6â×â10(-9), Malawi p=0·02, combined p=1·4â×â10(-9); odds ratio 7·2, 95% CI 3·8-13·5). The NTS-associated variant was an eQTL for STAT4 expression in IFNγ-stimulated monocytes (p=9·59â×â10(-6)), the NTS risk allele being associated with lower STAT4 expression. In Malawian children with NTS bacteraemia, the same NTS risk allele was associated with lower serum concentrations of IFNγ (p=0·02) at presentation. INTERPRETATION: STAT4 is highly plausible as a susceptibility locus for invasive NTS disease. STAT4 mediates IFNγ release in T cells and natural killer cells in response to interleukin 12 (IL12). Individuals with rare mutations elsewhere in the IL12-IFNγ axis are at risk of disseminated NTS infection. We provide the first evidence, to our knowledge, of a host genetic determinant of NTS disease in African children, and of a STAT4 variant conferring susceptibility to an infectious disease in man. FUNDING: Wellcome Trust.
ABSTRACT
The human major histocompatibility complex (MHC) on chromosome 6p21 is a paradigm for genomics, showing remarkable polymorphism and striking association with immune and non-immune diseases. The complex genomic landscape of the MHC, notably strong linkage disequilibrium, has made resolving causal variants very challenging. A promising approach is to investigate gene expression levels considered as tractable intermediate phenotypes in mapping complex diseases. However, how transcription varies across the MHC, notably relative to specific haplotypes, remains unknown. Here, using an original hybrid tiling and splice junction microarray that includes alternate allele probes, we draw the first high-resolution strand-specific transcription map for three common MHC haplotypes (HLA-A1-B8-Cw7-DR3, HLA-A3-B7-Cw7-DR15, and HLA-A26-B18-Cw5-DR3-DQ2) strongly associated with autoimmune diseases including type 1 diabetes, systemic lupus erythematosus, and multiple sclerosis. We find that haplotype-specific differences in gene expression are common across the MHC, affecting 96 genes (46.4%), most significantly the zing finger protein gene ZFP57. Differentially expressed probes are correlated with polymorphisms between haplotypes, consistent with cis effects that we directly demonstrate for ZFP57 in a cohort of healthy volunteers (P = 1.2 × 10(-14)). We establish that alternative splicing is significantly more frequent in the MHC than genome-wide (72.5% vs. 62.1% of genes, P ≤ 1 × 10(-4)) and shows marked haplotypic differences. We also unmask novel and abundant intergenic transcription involving 31% of transcribed blocks identified. Our study reveals that the renowned MHC polymorphism also manifests as transcript diversity, and our novel haplotype-based approach marks a new step toward identification of regulatory variants involved in the control of MHC-associated phenotypes and diseases.
Subject(s)
Gene Expression Profiling/methods , Genetic Variation , Haplotypes , Major Histocompatibility Complex , Alleles , Alternative Splicing , Cells, Cultured , Chromosome Mapping , Diabetes Mellitus, Type 1/genetics , Genetic Predisposition to Disease , HLA-A Antigens/genetics , HLA-A Antigens/metabolism , Humans , Linkage Disequilibrium , Lupus Erythematosus, Systemic/genetics , Multiple Sclerosis/genetics , Oligonucleotide Array Sequence Analysis , Quantitative Trait Loci , Sequence Analysis, DNA , Transcription, GeneticABSTRACT
AIM: Sex chromosome aneuploidies increase the risk of spoken or written language disorders but individuals with specific language impairment (SLI) or dyslexia do not routinely undergo cytogenetic analysis. We assess the frequency of sex chromosome aneuploidies in individuals with language impairment or dyslexia. METHOD: Genome-wide single nucleotide polymorphism genotyping was performed in three sample sets: a clinical cohort of individuals with speech and language deficits (87 probands: 61 males, 26 females; age range 4 to 23 years), a replication cohort of individuals with SLI, from both clinical and epidemiological samples (209 probands: 139 males, 70 females; age range 4 to 17 years), and a set of individuals with dyslexia (314 probands: 224 males, 90 females; age range 7 to 18 years). RESULTS: In the clinical language-impaired cohort, three abnormal karyotypic results were identified in probands (proband yield 3.4%). In the SLI replication cohort, six abnormalities were identified providing a consistent proband yield (2.9%). In the sample of individuals with dyslexia, two sex chromosome aneuploidies were found giving a lower proband yield of 0.6%. In total, two XYY, four XXY (Klinefelter syndrome), three XXX, one XO (Turner syndrome), and one unresolved karyotype were identified. INTERPRETATION: The frequency of sex chromosome aneuploidies within each of the three cohorts was increased over the expected population frequency (approximately 0.25%) suggesting that genetic testing may prove worthwhile for individuals with language and literacy problems and normal non-verbal IQ. Early detection of these aneuploidies can provide information and direct the appropriate management for individuals.
Subject(s)
Aneuploidy , Dyslexia/epidemiology , Dyslexia/genetics , Language Development Disorders/epidemiology , Language Development Disorders/genetics , Sex Chromosomes , Adolescent , Child , Child, Preschool , Cohort Studies , Female , Genotype , Humans , Karyotyping , Male , Paternal Age , Polymorphism, Single Nucleotide , Prevalence , Young AdultABSTRACT
To better understand inter-individual variation in sensitivity of DNA methylation (DNAm) to immune activity, we characterized effects of inflammatory stimuli on primary monocyte DNAm (n = 190). We find that monocyte DNAm is site-dependently sensitive to lipopolysaccharide (LPS), with LPS-induced demethylation occurring following hydroxymethylation. We identify 7,359 high-confidence immune-modulated CpGs (imCpGs) that differ in genomic localization and transcription factor usage according to whether they represent a gain or loss in DNAm. Demethylated imCpGs are profoundly enriched for enhancers and colocalize to genes enriched for disease associations, especially cancer. DNAm is age associated, and we find that 24-h LPS exposure triggers approximately 6 months of gain in epigenetic age, directly linking epigenetic aging with innate immune activity. By integrating LPS-induced changes in DNAm with genetic variation, we identify 234 imCpGs under local genetic control. Exploring shared causal loci between LPS-induced DNAm responses and human disease traits highlights examples of disease-associated loci that modulate imCpG formation.
Subject(s)
CpG Islands , DNA Methylation , Epigenesis, Genetic , Monocytes , Adult , Female , Humans , Male , CpG Islands/genetics , DNA Methylation/drug effects , Epigenesis, Genetic/drug effects , Lipopolysaccharides/pharmacology , Monocytes/drug effects , Monocytes/metabolism , Monocytes/immunology , Middle Aged , AgedABSTRACT
We describe three cases of critical acute myositis with myocarditis occurring within 22 days of each other at a single institution, all within 1 month of receiving the initial cycle of the anti-PD-1 drug pembrolizumab. Analysis of T cell receptor repertoires from peripheral blood and tissues revealed a high degree of clonal expansion and public clones between cases, with several T cell clones expanded within the skeletal muscle putatively recognizing viral epitopes. All patients had recently received a COVID-19 mRNA booster vaccine prior to treatment and were positive for SARS-CoV2 Spike antibody. In conclusion, we report a series of unusually severe myositis and myocarditis following PD-1 blockade and the COVID-19 mRNA vaccination.
Subject(s)
Antibodies, Monoclonal, Humanized , COVID-19 , Myocarditis , Myositis , SARS-CoV-2 , Aged , Female , Humans , Male , Antibodies, Monoclonal, Humanized/adverse effects , Antibodies, Monoclonal, Humanized/therapeutic use , COVID-19/prevention & control , COVID-19/immunology , COVID-19 Vaccines/adverse effects , Immune Checkpoint Inhibitors/adverse effects , Immune Checkpoint Inhibitors/therapeutic use , Myocarditis/chemically induced , Myositis/chemically induced , SARS-CoV-2/immunology , Vaccination/adverse effects , Aged, 80 and overSubject(s)
Abiraterone Acetate/blood , Antineoplastic Agents/blood , Artifacts , Cytochrome P-450 Enzyme Inhibitors/blood , Prostatic Neoplasms/blood , Testosterone/blood , Abiraterone Acetate/therapeutic use , Antineoplastic Agents/therapeutic use , Cohort Studies , Cytochrome P-450 Enzyme Inhibitors/therapeutic use , Humans , Immunoassay , Limit of Detection , Male , Mass Spectrometry , Prostatic Neoplasms/drug therapyABSTRACT
Endotoxin tolerance is characterized by the suppression of further TNF release upon recurrent exposure to LPS. This phenomenon is proposed to act as a homeostatic mechanism preventing uncontrolled cytokine release such as that observed in bacterial sepsis. The regulatory mechanisms and interindividual variation of endotoxin tolerance induction in man remain poorly characterized. In this paper, we describe a genetic association study of variation in endotoxin tolerance among healthy individuals. We identify a common promoter haplotype in TNFRSF1B (encoding TNFR2) to be strongly associated with reduced tolerance to LPS (p = 5.82 × 10(-6)). This identified haplotype is associated with increased expression of TNFR2 (p = 4.9 × 10(-5)), and we find basal expression of TNFR2, irrespective of genotype and unlike TNFR1, is associated with secondary TNF release (p < 0.0001). Functional studies demonstrate a positive-feedback loop via TNFR2 of LPS-induced TNF release, confirming this previously unrecognized role for TNFR2 in the modulation of LPS response.
Subject(s)
Endotoxins/pharmacology , Haplotypes , Immune Tolerance/genetics , Lipopolysaccharides/pharmacology , TNF Receptor-Associated Factor 2/genetics , Animals , Cells, Cultured , Cohort Studies , Endotoxins/immunology , Endotoxins/metabolism , Feedback, Physiological , Genetic Markers , Genotype , Humans , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/metabolism , Lipopolysaccharides/immunology , Lipopolysaccharides/metabolism , Macaca , Pan troglodytes , Polymorphism, Single Nucleotide , Pongo , Quantitative Trait Loci , TNF Receptor-Associated Factor 2/biosynthesis , TNF Receptor-Associated Factor 2/physiology , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolismABSTRACT
IFNγ is an immune mediator with concomitant pro- and anti-tumor functions. Here, we provide evidence that IFNγ directly acts on intra-tumoral CD8 T cells to restrict anti-tumor responses. We report that expression of the IFNγ receptor ß chain (IFNγR2) in CD8 T cells negatively correlates with clinical responsiveness to checkpoint blockade in metastatic melanoma patients, suggesting that the loss of sensitivity to IFNγ contributes to successful antitumor immunity. Indeed, specific deletion of IFNγR in CD8 T cells promotes tumor control in a mouse model of melanoma. Chronic IFNγ inhibits the maintenance, clonal diversity and proliferation of stem-like T cells. This leads to decreased generation of T cells with intermediate expression of exhaustion markers, previously associated with beneficial anti-tumor responses. This study provides evidence of a negative feedback loop whereby IFNγ depletes stem-like T cells to restrict anti-tumor immunity. Targeting this pathway might represent an alternative strategy to enhance T cell-based therapies.
Subject(s)
Melanoma , T-Lymphocytes, Cytotoxic , Mice , Animals , T-Lymphocytes, Cytotoxic/metabolism , CD8-Positive T-Lymphocytes , Melanoma/therapy , Melanoma/drug therapy , Clone Cells/metabolismABSTRACT
Interleukin-6 (IL-6) is an important modulator of inflammation and immunity whose dysregulation is associated with a number of disease states. There is evidence of significant heritability in inter-individual variation in IL6 gene expression but the genetic variants responsible for this remain to be defined. We adopted a combined approach of mapping protein and expression quantitative trait loci in peripheral blood mononuclear cells using high-density single-nucleotide polymorphism (SNP) typing for approximately 2000 loci implicated in cardiovascular, metabolic and inflammatory syndromes to show that common SNP markers and haplotypes of LEP (encoding leptin) associate with a 1.7- to 2-fold higher level of lipopolysaccharide (LPS)-induced IL-6 expression. We subsequently demonstrate that basal leptin expression significantly correlates with LPS-induced IL-6 expression and that the same variants at LEP which associate with IL-6 expression are also major determinants of leptin expression in these cells. We find that variation involving two other genomic regions, CAPNS1 (encoding calpain small subunit 1) and ALOX15 (encoding arachidonate 15-lipoxygenase), show significant association with IL-6 expression. Although this may be a subset of all such trans-acting effects, we find that the same ALOX15 variants are associated with induced expression of tumour necrosis factor and IL-1beta consistent with a broader role in acute inflammation for ALOX15. This study provides evidence of novel genetic determinants of IL-6 production with implications for understanding susceptibility to inflammatory disease processes and insight into cross talk between metabolic and inflammatory pathways. It also provides proof of concept for use of an integrated expression phenotype mapping approach.
Subject(s)
Arachidonate 15-Lipoxygenase/genetics , Calpain/genetics , Genetic Variation , Interleukin-6/immunology , Leptin/genetics , Adult , Arachidonate 15-Lipoxygenase/immunology , Calpain/immunology , Cells, Cultured , Chromosome Mapping , Female , Gene Expression , Humans , Interleukin-6/genetics , Leptin/immunology , Leukocytes, Mononuclear/immunology , Male , Middle Aged , Phenotype , Young AdultABSTRACT
Leprosy is an infectious disease caused by the obligate intracellular pathogen Mycobacterium leprae and remains endemic in many parts of the world. Despite several major studies on susceptibility to leprosy, few genomic loci have been replicated independently. We have conducted an association analysis of more than 1,500 individuals from different case-control and family studies, and observed consistent associations between genetic variants in both TLR1 and the HLA-DRB1/DQA1 regions with susceptibility to leprosy (TLR1 I602S, case-control P = 5.7 x 10(-8), OR = 0.31, 95% CI = 0.20-0.48, and HLA-DQA1 rs1071630, case-control P = 4.9 x 10(-14), OR = 0.43, 95% CI = 0.35-0.54). The effect sizes of these associations suggest that TLR1 and HLA-DRB1/DQA1 are major susceptibility genes in susceptibility to leprosy. Further population differentiation analysis shows that the TLR1 locus is extremely differentiated. The protective dysfunctional 602S allele is rare in Africa but expands to become the dominant allele among individuals of European descent. This supports the hypothesis that this locus may be under selection from mycobacteria or other pathogens that are recognized by TLR1 and its co-receptors. These observations provide insight into the long standing host-pathogen relationship between human and mycobacteria and highlight the key role of the TLR pathway in infectious diseases.
Subject(s)
Genetic Predisposition to Disease/genetics , HLA-DR Antigens/genetics , Leprosy/genetics , Toll-Like Receptor 1/genetics , Gene Frequency , Genome-Wide Association Study , HLA-DQ Antigens/genetics , HLA-DQ alpha-Chains , HLA-DRB1 Chains , Humans , Leprosy/immunology , Mycobacterium leprae/immunology , Toll-Like Receptor 1/immunologyABSTRACT
Natural Killer cells are innate lymphocytes with central roles in immunosurveillance and are implicated in autoimmune pathogenesis. The degree to which regulatory variants affect Natural Killer cell gene expression is poorly understood. Here we perform expression quantitative trait locus mapping of negatively selected Natural Killer cells from a population of healthy Europeans (n = 245). We find a significant subset of genes demonstrate expression quantitative trait loci specific to Natural Killer cells and these are highly informative of human disease, in particular autoimmunity. A Natural Killer cell transcriptome-wide association study across five common autoimmune diseases identifies further novel associations at 27 genes. In addition to these cis observations, we find novel master-regulatory regions impacting expression of trans gene networks at regions including 19q13.4, the Killer cell Immunoglobulin-like Receptor region, GNLY, MC1R and UVSSA. Our findings provide new insights into the unique biology of Natural Killer cells, demonstrating markedly different expression quantitative trait loci from other immune cells, with implications for disease mechanisms.
Subject(s)
Autoimmune Diseases , Transcriptome , Autoimmune Diseases/genetics , Autoimmunity/genetics , Carrier Proteins , Gene Expression Profiling , Genome-Wide Association Study , Humans , Killer Cells, Natural , Polymorphism, Single NucleotideABSTRACT
Treatment with immune checkpoint blockade (ICB) frequently triggers immune-related adverse events (irAEs), causing considerable morbidity. In 214 patients receiving ICB for melanoma, we observed increased severe irAE risk in minor allele carriers of rs16906115, intronic to IL7. We found that rs16906115 forms a B cell-specific expression quantitative trait locus (eQTL) to IL7 in patients. Patients carrying the risk allele demonstrate increased pre-treatment B cell IL7 expression, which independently associates with irAE risk, divergent immunoglobulin expression and more B cell receptor mutations. Consistent with the role of IL-7 in T cell development, risk allele carriers have distinct ICB-induced CD8+ T cell subset responses, skewing of T cell clonality and greater proportional repertoire occupancy by large clones. Finally, analysis of TCGA data suggests that risk allele carriers independently have improved melanoma survival. These observations highlight key roles for B cells and IL-7 in both ICB response and toxicity and clinical outcomes in melanoma.