RESUMEN
Systemic Lupus Erythematosus (SLE) is characterized by B cells lacking IgD and CD27 (double negative; DN). We show that DN cell expansions reflected a subset of CXCR5- CD11c+ cells (DN2) representing pre-plasma cells (PC). DN2 cells predominated in African-American patients with active disease and nephritis, anti-Smith and anti-RNA autoantibodies. They expressed a T-bet transcriptional network; increased Toll-like receptor-7 (TLR7); lacked the negative TLR regulator TRAF5; and were hyper-responsive to TLR7. DN2 cells shared with activated naive cells (aNAV), phenotypic and functional features, and similar transcriptomes. Their PC differentiation and autoantibody production was driven by TLR7 in an interleukin-21 (IL-21)-mediated fashion. An in vivo developmental link between aNAV, DN2 cells, and PC was demonstrated by clonal sharing. This study defines a distinct differentiation fate of autoreactive naive B cells into PC precursors with hyper-responsiveness to innate stimuli, as well as establishes prominence of extra-follicular B cell activation in SLE, and identifies therapeutic targets.
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Subgrupos de Linfocitos B/inmunología , Linfocitos B/inmunología , Lupus Eritematoso Sistémico/inmunología , Receptor Toll-Like 7/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Subgrupos de Linfocitos B/metabolismo , Linfocitos B/metabolismo , Femenino , Redes Reguladoras de Genes/genética , Redes Reguladoras de Genes/inmunología , Humanos , Lupus Eritematoso Sistémico/genética , Lupus Eritematoso Sistémico/metabolismo , Masculino , Persona de Mediana Edad , Células Plasmáticas/inmunología , Células Plasmáticas/metabolismo , Receptor Toll-Like 7/genética , Receptor Toll-Like 7/metabolismo , Transcriptoma/genética , Transcriptoma/inmunología , Adulto JovenRESUMEN
OBJECTIVE: Axonal/neuronal damage has been shown to be a pathological finding that precedes neuropsychiatric manifestations in SLE. The objective of this study was to determine the presence of axonal dysfunction in childhood-onset SLE patients (cSLE) and to determine clinical, immunological and treatment features associated with its occurrence. METHODS: We included 86 consecutive cSLE patients [median age 17 (range 5-28) years] and 71 controls [median age 18 (5-28) years]. We performed proton magnetic resonance spectroscopic imaging using point resolved spectroscopy sequence over the superior-posterior region of the corpus callosum and signals from N-acetylaspartate (NAA), choline-based (CHO), creatine-containing (Cr), myo-inositol (mI), glutamate, glutamine and lactate were measured and metabolites/Cr ratios were determined. Complete clinical, laboratory and neurological evaluations were performed in all subjects. Serum IL-4, IL-5, IL-6, IL-10, IL-12, IL-17, TNF-α and INF-γ cytokine levels, antiribosomal P protein antibodies (anti-P) and S100ß were measured by ELISA using commercial kits. Data were compared by non-parametric tests. RESULTS: NAA/Cr ratios (P = 0.035) and lactate/Cr ratios (P = 0.019) were significantly decreased in cSLE patients when compared with controls. In multivariate analysis, IFN-γ levels [odds ratio (OR) = 4.1; 95% CI: 2.01, 7.9] and depressive symptoms (OR = 1.9; 95% CI: 1.1, 3.2) were associated with NAA/Cr ratio. Increased CHO/Cr was associated with the presence of cognitive impairment (OR = 3.4; 95% CI: 2.034, 5.078; P < 0.001). mI/Cr ratio correlated with cumulative glucocorticoids dosage (r = 0.361, P = 0.014). CONCLUSION: NAA and CHO ratios may be useful as biomarkers in neuropsychiatric cSLE. Longitudinal studies are necessary to determine whether they predict structural damage.
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Interferón gamma , Lupus Eritematoso Sistémico , Adolescente , Adulto , Ácido Aspártico/metabolismo , Encéfalo/metabolismo , Niño , Preescolar , Colina/análisis , Colina/metabolismo , Humanos , Interferón gamma/metabolismo , Ácido Láctico/metabolismo , Lupus Eritematoso Sistémico/diagnóstico , Imagen por Resonancia Magnética , Espectroscopía de Resonancia Magnética/métodos , Adulto JovenRESUMEN
BACKGROUND: Peripheral vascular diseases may induce chronic ischemia and cellular injury distal to the arterial obstruction. Cellular senescence involves proliferation arrest in response to stress, which can damage neighboring cells. Renal artery stenosis (RAS) induces stenotic-kidney dysfunction and injury, but whether these arise from cellular senescenceand their temporal pattern remain unknown. METHODS: Chronic renal ischemia was induced in transgenic INK-ATTAC and wild type C57BL/6 mice by unilateral RAS, and kidney function (in vivo micro-MRI) and tissue damage were assessed. Mouse healthy and stenotic kidneys were analyzed using unbiased single-cell RNA-sequencing. To demonstrate translational relevance, cellular senescence was studied in human stenotic kidneys. RESULTS: Using intraperitoneal AP20187 injections starting 1, 2, or 4 weeks after RAS, selective clearance of cells highly expressing p16Ink4a attenuated cellular senescence and improved stenotic-kidney function; however, starting treatment immediately after RAS induction was unsuccessful. Broader clearance of senescent cells, using the oral senolytic combination dasatinib and quercetin, in C57BL/6 RAS mice was more effective in clearing cells positive for p21 (Cdkn1a) and alleviating renal dysfunction and damage. Unbiased, single-cell RNA sequencing in freshly dissociated cells from healthy and stenotic mouse kidneys identified stenotic-kidney epithelial cells undergoing both mesenchymal transition and senescence. As in mice, injured human stenotic kidneys exhibited cellular senescence, suggesting this process is conserved. CONCLUSIONS: Maladaptive tubular cell senescence, involving upregulated p16 (Cdkn2a), p19 (Cdkn2d), and p21 (Cdkn1a) expression, is associated with renal dysfunction and injury in chronic ischemia. These findings support development of senolytic strategies to delay chronic ischemic renal injury.
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Senescencia Celular/fisiología , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Isquemia/fisiopatología , Riñón/fisiopatología , Insuficiencia Renal Crónica/fisiopatología , Quinasas p21 Activadas/metabolismo , Animales , Apoptosis/efectos de los fármacos , Caspasa 8/metabolismo , Senescencia Celular/efectos de los fármacos , Senescencia Celular/genética , Enfermedad Crónica , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Inhibidor p19 de las Quinasas Dependientes de la Ciclina/metabolismo , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Dasatinib/farmacología , Modelos Animales de Enfermedad , Activación Enzimática/efectos de los fármacos , Células Epiteliales/fisiología , Transición Epitelial-Mesenquimal , Expresión Génica , Factor de Crecimiento Similar a EGF de Unión a Heparina/genética , Humanos , Isquemia/etiología , Riñón/irrigación sanguínea , Riñón/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Osteopontina/genética , Inhibidores de Proteínas Quinasas/farmacología , Obstrucción de la Arteria Renal/complicaciones , Insuficiencia Renal Crónica/etiología , Insuficiencia Renal Crónica/patología , Análisis de Secuencia de ARN , Análisis de la Célula Individual , Tacrolimus/análogos & derivados , Tacrolimus/farmacología , Regulación hacia Arriba , Quinasas p21 Activadas/genéticaRESUMEN
Systemic lupus erythematosus (SLE) is a complex and heterogeneous systemic autoimmune disease associated with innate and adaptive immune dysregulation. SLE occurs primarily in females of childbearing age, with increased prevalence and severity in minority populations. Despite improvements in treatment modalities, SLE patients frequently experience periods of heightened disease activity and flare that can lead to permanent organ damage, increased morbidity, and early mortality. Such outcomes impair quality of life and inflict a significant socioeconomic burden. Predicting changes in SLE disease activity could allow for closer monitoring and preemptive treatment, but existing clinical, demographic and serologic markers have been only modestly predictive. Novel, proactive approaches to clinical disease management are thus critically needed. Panels of blood biomarkers can detect a breadth of immune pathway dysregulation that captures SLE heterogeneity and disease activity. Alterations in the balance of pro-inflammatory and regulatory soluble mediators have been associated with changes in clinical disease activity and are detectable several weeks prior to clinical flare occurrence. A soluble mediator score has been highly predictive of impending flare in both European American and African American SLE patients, and this score does not require a priori knowledge of specific pathway activation in the patient. We review current concepts of disease activity and flare in SLE, focusing on the potential of novel blood biomarkers to characterize and predict changes in disease activity. Measuring the disordered immune response in SLE in this way promises to improve disease management and prevent organ damage in SLE.
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Biomarcadores , Lupus Eritematoso Sistémico/diagnóstico , Lupus Eritematoso Sistémico/etiología , Brote de los Síntomas , Costo de Enfermedad , Citocinas/sangre , Citocinas/metabolismo , Manejo de la Enfermedad , Progresión de la Enfermedad , Susceptibilidad a Enfermedades/inmunología , Humanos , Mediadores de Inflamación/sangre , Mediadores de Inflamación/metabolismo , Lupus Eritematoso Sistémico/metabolismo , Lupus Eritematoso Sistémico/terapia , Prevalencia , Pronóstico , Índice de Severidad de la Enfermedad , Resultado del TratamientoRESUMEN
Cryopyrin-associated periodic syndromes (CAPS) are a group of autoinflammatory diseases associated with NLRP3 gain of function mutations. CAPS associated mutations are found predominantly in exon 3. The objective of this study is to describe a new variant on NRLP3 gene and its phenotype. Case report description of a new NRLP3 pathogenic variant and literature case-based search through INFEVERS database. A 21-year old male who presented multiple tonic-clonic seizures on his 3rd day of life. At age 2, he had recurrent central facial palsy, high fever (40 °C), painful and persistent oral ulcers, abdominal pain, nausea and vomiting, and delayed neuropsychomotor development, with polyarthritis in wrists and knees. Over the years, several symptoms were observed: livedo reticularis, Raynaud's phenomenon, positive pathergy test, heat allodynia, extremely painful genital ulcers, and sporadic conjunctivitis. Laboratory studies revealed persistently elevated inflammatory markers and serum amyloid protein A (30 µg/l). The genetic panel for autoinflammatory diseases revealed heterozygous mutation in the NLRP3, (c.2068G > C, p.E690Q) with 0% of frequency in the general population. The patient denies rash and did not have frontal bossing or patellar overgrowth. We found a positive familial history on mother and brother, who carried the same mutation. The patient was started on canakinumab which controlled his symptoms. Currently, 241 missense variants in the NLRP3 have been described. We presented a new mutation in exon 3 of the NRLP3 gene in a patient that fulfills clinical criteria for CAPS who had complete clinical response to Canakinumab, supporting the idea that this mutation is pathogenic.
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Síndromes Periódicos Asociados a Criopirina/genética , Proteína con Dominio Pirina 3 de la Familia NLR , Anticuerpos Monoclonales Humanizados/uso terapéutico , Síndromes Periódicos Asociados a Criopirina/diagnóstico , Síndromes Periódicos Asociados a Criopirina/tratamiento farmacológico , Diagnóstico Diferencial , Exones , Humanos , Masculino , Mutación , Fenotipo , Adulto JovenRESUMEN
INTRODUCTION: Immune checkpoint inhibitors (ICIs) are increasingly used to treat advanced cancer. Rheumatoid arthritis (RA) is associated with an increased risk of malignancies; however, patients with RA have been excluded from ICI trials. In this study, we evaluated risk of toxicity after initiation of ICI treatment in RA patients. METHODS: We conducted a single-institution, medical records review analysis to assess the incidence of immune-related adverse events (irAEs) and autoimmune disease (AID) flares among patients with AIDs treated with ICIs from 2011 to 2018. A subgroup analysis for RA patients was performed with frequencies of irAEs and AID flares reported. RESULTS: Twenty-two patients with RA who were treated with ICI for malignancy were identified. At the time of ICI initiation, 86% had inactive RA disease activity. Immune-related adverse events occurred in 7 (32%) of patients, with 2 (9%) developing grade 3 (i.e., severe) irAEs. Immune checkpoint inhibitors were temporarily discontinued because of irAEs in 5 patients (23%), and permanently in 1 patient. Rheumatoid arthritis flares occurred in 12 patients (55%). Of those, 10 (83%) received oral corticosteroids with an adequate treatment response. CONCLUSIONS: Our analysis suggests that irAEs following ICI treatment are not increased among RA patients compared with other cancer patients. Heightened RA disease activity during ICI treatment is common, but most adverse events are manageable with oral corticosteroids, and few require permanent ICI discontinuation. A close collaboration between the oncologist and rheumatologist is advisable when considering ICIs in patients with RA.
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Artritis Reumatoide , Enfermedades Autoinmunes , Neoplasias , Artritis Reumatoide/tratamiento farmacológico , Enfermedades Autoinmunes/tratamiento farmacológico , Humanos , Inhibidores de Puntos de Control Inmunológico , Inmunoterapia , Neoplasias/tratamiento farmacológico , Neoplasias/epidemiologíaRESUMEN
BACKGROUND/PURPOSE: High serum interferon alpha (IFN-α) is an important heritable phenotype in systemic lupus erythematosus (SLE) which is involved in primary disease pathogenesis. High vs. low levels of IFN-α are associated with disease severity and account for some of the biological heterogeneity between SLE patients. The aim of the study was to replicate and fine-map previously detected genetic associations with serum IFN-α in SLE. METHODS: We previously undertook a case-case genome-wide association study of SLE patients stratified by ancestry and extremes of phenotype in serum IFN-α. Single nucleotide polymorphisms (SNPs) in seven loci identified in this screen were selected for follow up in a large independent cohort of 1370 SLE patients (703 European-ancestry, 432 African ancestry, and 235 Amerindian ancestry). Each ancestral background was analyzed separately, and ancestry-informative markers were used to control for ancestry and admixture. RESULTS: We find a rare haplotype spanning the promoter region of EFNA5 that is strongly associated with serum IFN-α in both African-American and European-American SLE patients (ORâ¯=â¯3.0, pâ¯=â¯3.7â¯×â¯10-6). We also find SNPs in the PPM1H, PTPRM, and NRGN regions associated with IFN-α levels in European-American, Amerindian, and African-American SLE patients respectively. Many of these associations are within regulatory regions of the gene, suggesting an impact on transcription. CONCLUSION: This study demonstrates the power of molecular sub-phenotypes to reveal genetic factors involved in complex autoimmune disease. The distinct associations observed in different ancestral backgrounds emphasize the heterogeneity of molecular pathogenesis in SLE.
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Interferón-alfa/sangre , Lupus Eritematoso Sistémico/genética , Efrina-A5/genética , Estudio de Asociación del Genoma Completo , Haplotipos , Humanos , Lupus Eritematoso Sistémico/sangre , Polimorfismo de Nucleótido SimpleRESUMEN
Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are two common autoimmune rheumatic diseases that vary in severity, clinical presentation, and disease course between individuals. Molecular and genetic studies of both diseases have identified candidate genes and molecular pathways that are linked to various disease outcomes and treatment responses. Currently, patients can be grouped into molecular subsets in each disease, and these molecular categories should enable precision medicine approaches to be applied in rheumatic diseases. In this article, we will review key lessons learned about disease heterogeneity and molecular characterization in rheumatology, which we hope will lead to personalized therapeutic strategies.
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Enfermedades Autoinmunes , Medicina de Precisión , Enfermedades Reumáticas , Reumatología , Enfermedades Autoinmunes/diagnóstico , Enfermedades Autoinmunes/genética , Enfermedades Autoinmunes/inmunología , Humanos , Medicina de Precisión/métodos , Enfermedades Reumáticas/diagnóstico , Enfermedades Reumáticas/genética , Enfermedades Reumáticas/inmunología , Reumatología/métodosRESUMEN
Clinical manifestations of systemic lupus erythematosus (SLE) in female patients with polysomy X have been less characterized as compared to those in male patients. Here, we describe a 28-year-old woman with trisomy X (47,XXX) who developed SLE. She had polyarthritis, hemolytic anemia, and was positive for anti-nuclear and anti-dsDNA antibodies. We discuss the common SLE manifestations with female polysomy X and the possible link between the development of SLE and the presence of extra X-chromosomes.
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Lupus Eritematoso Sistémico/patología , Trastornos de los Cromosomas Sexuales del Desarrollo Sexual/complicaciones , Adulto , Cromosomas Humanos X/genética , Femenino , Humanos , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/genética , Lupus Eritematoso Sistémico/inmunología , Aberraciones Cromosómicas Sexuales , TrisomíaRESUMEN
Familial Mediterranean fever (FMF) is an autosomal recessive disease characterized by recurrent, acute, and self-limiting attacks of fever. Mutations in MEFV gene encoding pyrin account for FMF, but the high number of heterozygote patients with typical symptoms of the disease has driven a number of alternative aetiopathogenic hypotheses. The MEFV gene was knocked down in human myelomonocytic cells that express endogenous pyrin to identify deregulated microRNAs (miRNAs). Microarray analyses revealed 29 significantly differentially expressed miRNAs implicated in pathways associated with cellular integrity and survival. Implementation of in silico gene network prediction algorithms and bioinformatics analyses showed that miR-4520a is predicted to target genes implicated in autophagy through regulation of RHEB/mTOR signaling. Differential expression levels of RHEB were confirmed by luciferase reporter gene assays providing further evidence that is directly targeted by miR-4520a. Although the relative expression levels of miR-4520a were variable among FMF patients, the statistical expression of miR-4520a was different between FMF mutation carriers and controls (P = 0.0061), indicating an association between miR-4520a expression and MEFV mutations. Comparison between FMF patients bearing the M694V mutation, associated with severe disease, and healthy controls showed a significant increase in miR-4520a expression levels (P = 0.00545). These data suggest that RHEB, the main activator of mTOR signaling, is a valid target of miR-4520a with the relative expression levels of the latter being significantly deregulated in FMF patients and highly dependent on the presence of pyrin mutations, especially of the M694V type. These results suggest a role of deregulated autophagy in the pathogenesis of FMF. J. Cell. Physiol. 232: 1326-1336, 2017. © 2016 Wiley Periodicals, Inc.
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Fiebre Mediterránea Familiar/genética , Perfilación de la Expresión Génica , MicroARNs/genética , Mutación/genética , Pirina/genética , Adulto , Estudios de Casos y Controles , Línea Celular , Femenino , Redes Reguladoras de Genes , Humanos , Luciferasas/metabolismo , Masculino , MicroARNs/metabolismo , Proteínas de Unión al GTP Monoméricas/genética , Proteínas de Unión al GTP Monoméricas/metabolismo , Neuropéptidos/genética , Neuropéptidos/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteína Homóloga de Ras Enriquecida en el CerebroRESUMEN
Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease characterized by immune complex formation with multi-organ manifestations. Lupus nephritis (LN) is one of the most severe types of organ damage in SLE, and it clearly contributes to increased morbidity and mortality due to SLE. LN occurs more frequently and is more severe in non-European ancestral backgrounds, although the cause of this disparity remains largely unknown. Genetic factors play an important role in the pathogenesis of SLE. Although many SLE susceptibility genes have been identified, the genetic basis of LN is not as well understood. While some of the established general SLE susceptibility genes are associated with LN, recent discoveries highlight a number of genes with renal functions that are specifically associated with LN. Some of these genes associated with LN help to explain the disparity in the prevalence of nephritis between individuals with SLE, and also partially explain differences in LN between ancestral backgrounds. Moreover, not only the gene mutations, but also post-translational modifications seem to play important roles in the pathogenesis of LN. Overall it seems likely that a combination of general SLE susceptibility genes cooperate with LN specific risk genes to result in the genetic propensity for LN. In this review, we will outline the genetic contribution to LN and describe possible roles of LN susceptibility genes.
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Nefritis Lúpica/genética , Animales , Epigenómica , Predisposición Genética a la Enfermedad , Humanos , Incidencia , Nefritis Lúpica/epidemiología , Nefritis Lúpica/etnologíaRESUMEN
Efforts to identify lupus-associated causal variants in the FAM167A/BLK locus on 8p21 are hampered by highly associated noncausal variants. In this report, we used a trans-population mapping and sequencing strategy to identify a common variant (rs922483) in the proximal BLK promoter and a tri-allelic variant (rs1382568) in the upstream alternative BLK promoter as putative causal variants for association with systemic lupus erythematosus. The risk allele (T) at rs922483 reduced proximal promoter activity and modulated alternative promoter usage. Allelic differences at rs1382568 resulted in altered promoter activity in B progenitor cell lines. Thus, our results demonstrated that both lupus-associated functional variants contribute to the autoimmune disease association by modulating transcription of BLK in B cells and thus potentially altering immune responses.
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Lupus Eritematoso Sistémico/genética , Regiones Promotoras Genéticas , Transcripción Genética , Familia-src Quinasas/genética , Alelos , Cromosomas Humanos Par 8 , Ensayo de Cambio de Movilidad Electroforética , Femenino , Predisposición Genética a la Enfermedad , Haplotipos , Humanos , Masculino , Polimorfismo de Nucleótido SimpleRESUMEN
OBJECTIVE: We examined whether measures of vitamin D were associated with transitioning to systemic lupus erythematosus (SLE) in individuals at risk for SLE. METHODS: 436 individuals who reported having a relative with SLE but who did not have SLE themselves were evaluated at baseline and again an average of 6.3 (±3.9) years later. Fifty-six individuals transitioned to SLE (≥4 cumulative American College of Rheumatology criteria). 25-Hydroxyvitamin D (25[OH]D) levels were measured by ELISA. Six single-nucleotide polymorphisms in four vitamin D genes were genotyped. Generalised estimating equations, adjusting for correlation within families, were used to test associations between the vitamin D variables and the outcome of transitioning to SLE. RESULTS: Mean baseline 25[OH]D levels (p=0.42) and vitamin D supplementation (p=0.65) were not different between those who did and did not transition to SLE. Vitamin D deficiency (25[OH]D <20â ng/mL) was greater in those who transitioned compared with those who did not transition to SLE (46% vs 33%, p=0.05). The association between 25[OH]D and SLE was modified by CYP24A1 rs4809959, where for each additional minor allele increased 25[OH]D was associated with decreased SLE risk: zero minor alleles (adjusted OR: 1.03, CI 0.98 to 1.09), one minor allele (adjusted OR: 1.01, CI 0.97 to 1.05) and two minor alleles (adjusted OR: 0.91, CI 0.84 to 0.98). Similarly, vitamin D deficiency significantly increased the risk of transitioning to SLE in those with two minor alleles at rs4809959 (adjusted OR: 4.90, CI 1.33 to 18.04). CONCLUSIONS: Vitamin D status and CYP24A1 may have a combined role in the transition to SLE in individuals at increased genetic risk for SLE.
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Lupus Eritematoso Sistémico/sangre , Lupus Eritematoso Sistémico/genética , Deficiencia de Vitamina D/sangre , Vitamina D3 24-Hidroxilasa/genética , Vitamina D/análogos & derivados , 25-Hidroxivitamina D3 1-alfa-Hidroxilasa/genética , Adulto , Anciano , Alelos , Femenino , Predisposición Genética a la Enfermedad , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Receptores de Calcitriol/genética , Factores de Riesgo , Vitamina D/sangre , Proteína de Unión a Vitamina D/genéticaRESUMEN
OBJECTIVE: ATG16L1 is an autophagy gene known to control host immune responses to viruses and bacteria. Recently, a non-synonymous single-nucleotide polymorphism in ATG16L1 (Thr300Ala), previously identified as a risk factor in Crohn's disease (CD), was associated with more favourable clinical outcomes in thyroid cancer. Mechanisms underlying this observation have not been proposed, nor is it clear whether an association between Thr300Ala and clinical outcomes will be observed in other cancers. We hypothesised that Thr300Ala influences clinical outcome in human colorectal cancer (CRC) and controls innate antiviral pathways in colon cancer cells. DESIGN: We genotyped 460 patients with CRC and assessed for an association between ATG16L1 Thr300Ala and overall survival and clinical stage. Human CRC cell lines were targeted by homologous recombination to examine the functional consequence of loss of ATG16L1, or introduction of the Thr300Ala variant. RESULTS: We found an association between longer overall survival, reduced metastasis and the ATG16L1 Ala/Ala genotype. Tumour sections from ATG16L1 Ala/Ala patients expressed elevated type I interferons (IFN-I)-inducible, MxA, suggesting that differences in cytokine production may influence disease progression. When introduced into human CRC cells by homologous recombination, the Thr300Ala variant did not affect bulk autophagy, but increased basal production of type I IFN. Introduction of Thr300Ala resulted in increased sensitivity to the dsRNA mimic poly(I:C) through a mitochondrial antiviral signalling (MAVS)-dependent pathway. CONCLUSIONS: The CD-risk allele, Thr300Ala, in ATG16L1 is associated with improved overall survival in human CRC, generating a rationale to genotype ATG16L1 Thr300Ala in patients with CRC. We found that Thr300A alters production of MAVS-dependent type I IFN in CRC cells, providing a mechanism that may influence clinical outcomes.
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Adenocarcinoma/genética , Biomarcadores de Tumor/genética , Proteínas Portadoras/genética , Neoplasias Colorrectales/genética , Interferón Tipo I/metabolismo , Polimorfismo de Nucleótido Simple , Adenocarcinoma/metabolismo , Adenocarcinoma/mortalidad , Adulto , Anciano , Anciano de 80 o más Años , Proteínas Relacionadas con la Autofagia , Biomarcadores de Tumor/metabolismo , Línea Celular Tumoral , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/mortalidad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Análisis de SupervivenciaRESUMEN
Integrin alpha M (ITGAM; CD11b) is a component of the macrophage-1 antigen complex, which mediates leukocyte adhesion, migration and phagocytosis as part of the immune system. We previously identified a missense polymorphism, rs1143679 (R77H), strongly associated with systemic lupus erythematosus (SLE). However, the molecular mechanisms of this variant are incompletely understood. A meta-analysis of published and novel data on 28 439 individuals with European, African, Hispanic and Asian ancestries reinforces genetic association between rs1143679 and SLE [Pmeta = 3.60 × 10(-90), odds ratio (OR) = 1.76]. Since rs1143679 is in the most active region of chromatin regulation and transcription factor binding in ITGAM, we quantitated ITGAM RNA and surface protein levels in monocytes from patients with each rs1143679 genotype. We observed that transcript levels significantly decreased for the risk allele ('A') relative to the non-risk allele ('G'), in a dose-dependent fashion: ('AA' < 'AG' < 'GG'). CD11b protein levels in patients' monocytes were directly correlated with RNA levels. Strikingly, heterozygous individuals express much lower (average 10- to 15-fold reduction) amounts of the 'A' transcript than 'G' transcript. We found that the non-risk sequence surrounding rs1143679 exhibits transcriptional enhancer activity in vivo and binds to Ku70/80, NFKB1 and EBF1 in vitro, functions that are significantly reduced with the risk allele. Mutant CD11b protein shows significantly reduced binding to fibrinogen and vitronectin, relative to non-risk, both in purified protein and in cellular models. This two-pronged contribution (nucleic acid- and protein-level) of the rs1143679 risk allele to decreasing ITGAM activity provides insight into the molecular mechanisms of its potent association with SLE.
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Antígeno CD11b/genética , Predisposición Genética a la Enfermedad , Lupus Eritematoso Sistémico/genética , Monocitos/metabolismo , ARN Mensajero/genética , Alelos , Antígenos Nucleares/genética , Antígenos Nucleares/metabolismo , Antígeno CD11b/metabolismo , Cromatina/metabolismo , Cromatina/patología , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Femenino , Fibrinógeno/genética , Fibrinógeno/metabolismo , Regulación de la Expresión Génica , Frecuencia de los Genes , Humanos , Autoantígeno Ku , Lupus Eritematoso Sistémico/etnología , Lupus Eritematoso Sistémico/metabolismo , Lupus Eritematoso Sistémico/patología , Masculino , Monocitos/patología , Subunidad p50 de NF-kappa B/genética , Subunidad p50 de NF-kappa B/metabolismo , Oportunidad Relativa , Polimorfismo Genético , Unión Proteica , ARN Mensajero/metabolismo , Grupos Raciales , Riesgo , Transactivadores/genética , Transactivadores/metabolismo , Transcripción Genética , Vitronectina/genética , Vitronectina/metabolismoRESUMEN
OBJECTIVES: The relationship of immune dysregulation and autoantibody production that may contribute to systemic lupus erythematosus (SLE) pathogenesis is unknown. This study evaluates the individual and combined contributions of autoantibodies, type I interferon (IFN-α) activity, and IFN-associated soluble mediators to disease development leading to SLE. METHODS: Serial serum specimens from 55 individuals collected prior to SLE classification (average timespan=4.3â years) and unaffected healthy controls matched by age (±5â years), gender, race and time of sample procurement were obtained from the Department of Defense Serum Repository. Levels of serum IFN-α activity, IFN-associated mediators and autoantibodies were evaluated and temporal relationships assessed by growth curve modelling, path analysis, analysis of covariance and random forest models. RESULTS: In cases, but not matched controls, autoantibody specificities and IFN-associated mediators accumulated over a period of years, plateauing near the time of disease classification (p<0.001). Autoantibody positivity coincided with or followed type II IFN dysregulation, preceding IFN-α activity in growth curve models, with elevated IFN-α activity and B-lymphocyte stimulator levels occurring shortly before SLE classification (p≤0.005). Cases were distinguished by multivariate random forest models incorporating IFN-γ, macrophage chemoattractant protein (MCP)-3, anti-chromatin and anti-spliceosome antibodies (accuracy 93% >4â years pre-classification; 97% within 2â years of SLE classification). CONCLUSIONS: Years before SLE classification, enhancement of the type II IFN pathway allows for accumulation of autoantibodies and subsequent elevations in IFN-α activity immediately preceding SLE classification. Perturbations in select immunological processes may help identify at-risk individuals for further clinical evaluation or participation in prospective intervention trials.
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Autoanticuerpos/sangre , Interferón Tipo I/sangre , Interferón gamma/sangre , Lupus Eritematoso Sistémico/sangre , Adulto , Factor Activador de Células B/sangre , Estudios de Casos y Controles , Femenino , Humanos , Interferón-alfa/sangre , Lupus Eritematoso Sistémico/diagnóstico , Lupus Eritematoso Sistémico/inmunología , Masculino , Análisis Multivariante , Factores de TiempoRESUMEN
OBJECTIVE: Studies suggest that circulating type I interferon (IFN) may predict response to biological agents in rheumatoid arthritis (RA). Prediction of response prior to initiating therapy would represent a major advancement. METHODS: We studied sera from a test set of 32 patients with RA from the Auto-immune Biomarkers Collaborative Network Consortium and a validation set of 92 patients with RA from the Treatment Efficacy and Toxicity in Rheumatoid Arthritis Database and Repository registry. The test set included those with good response or no response to tumour necrosis factor (TNF) inhibitors at 14â weeks by European League Against Rheumatism criteria. The validation set included subjects with good, moderate or no response at 12â weeks. Total serum type I IFN activity, IFN-α and IFN-ß activity were measured using a functional reporter cell assay. RESULTS: In the test set, an increased ratio of IFN-ß to IFN-α (IFN-ß/α activity ratio) in pretreatment serum associated with lack of response to TNF inhibition (p=0.013). Anti-cyclic citrullinated peptide antibody titre and class of TNF inhibitor did not influence this relationship. A receiver-operator curve supported a ratio of 1.3 as the optimal cut-off. In the validation set, subjects with an IFN-ß/α activity ratio >1.3 were significantly more likely to have non-response than good response (OR=6.67, p=0.018). The test had 77% specificity and 45% sensitivity for prediction of non-response compared with moderate or good response. Meta-analysis of test and validation sets confirmed strong predictive capacity of IFN-ß/α activity ratio (p=0.005). CONCLUSIONS: Increased pretreatment serum IFN-ß/α ratio strongly associated with non-response to TNF inhibition. This study supports further investigation of serum type I IFN in predicting outcome of TNF inhibition in RA.
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Antirreumáticos/uso terapéutico , Artritis Reumatoide/sangre , Artritis Reumatoide/tratamiento farmacológico , Interferón-alfa/sangre , Interferón beta/sangre , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Bases de Datos Factuales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Pronóstico , Sistema de Registros , Sensibilidad y Especificidad , Resultado del Tratamiento , Adulto JovenRESUMEN
OBJECTIVES: Systemic lupus erythematosus (SLE; OMIM 152700) is characterised by the production of antibodies to nuclear antigens. We previously identified variants in complement receptor 2 (CR2/CD21) that were associated with decreased risk of SLE. This study aimed to identify the causal variant for this association. METHODS: Genotyped and imputed genetic variants spanning CR2 were assessed for association with SLE in 15 750 case-control subjects from four ancestral groups. Allele-specific functional effects of associated variants were determined using quantitative real-time PCR, quantitative flow cytometry, electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP)-PCR. RESULTS: The strongest association signal was detected at rs1876453 in intron 1 of CR2 (pmeta=4.2×10(-4), OR 0.85), specifically when subjects were stratified based on the presence of dsDNA autoantibodies (case-control pmeta=7.6×10(-7), OR 0.71; case-only pmeta=1.9×10(-4), OR 0.75). Although allele-specific effects on B cell CR2 mRNA or protein levels were not identified, levels of complement receptor 1 (CR1/CD35) mRNA and protein were significantly higher on B cells of subjects harbouring the minor allele (p=0.0248 and p=0.0006, respectively). The minor allele altered the formation of several DNA protein complexes by EMSA, including one containing CCCTC-binding factor (CTCF), an effect that was confirmed by ChIP-PCR. CONCLUSIONS: These data suggest that rs1876453 in CR2 has long-range effects on gene regulation that decrease susceptibility to lupus. Since the minor allele at rs1876453 is preferentially associated with reduced risk of the highly specific dsDNA autoantibodies that are present in preclinical, active and severe lupus, understanding its mechanisms will have important therapeutic implications.