Innate immunity to viral infection involves induction of the type I IFN response; however, dysfunctional regulation of this pathway leads to inappropriate inflammation. Here, we evaluated a ...nonconsanguineous family of mixed European descent, with 4 members affected by systemic inflammatory and autoimmune conditions, including lupus, with variable clinical expression. We identified a germline dominant gain-of-function mutation in TMEM173, which encodes stimulator of type I IFN gene (STING), in the affected individuals. STING is a key signaling molecule in cytosolic DNA-sensing pathways, and STING activation normally requires dimerization, which is induced by 2'3' cyclic GMP-AMP (cGAMP) produced by the cGAMP synthase in response to cytosolic DNA. Structural modeling supported constitutive activation of the mutant STING protein based on stabilized dimerization. In agreement with the model predictions, we found that the STING mutant spontaneously localizes in the Golgi of patient fibroblasts and is constitutively active in the absence of exogenous 2'3'-cGAMP in vitro. Accordingly, we observed elevated serum IFN activity and a type I IFN signature in peripheral blood from affected family members. These findings highlight the key role of STING in activating both the innate and adaptive immune responses and implicate aberrant STING activation in features of human lupus.
Immune checkpoint inhibitors (ICIs) are associated with immune-related adverse events (irAEs). Among them, ICIs-induced systemic sclerosis (SSc) is poorly known.
To better characterize this irAE, our ...comprehensive approach combined the description of ICIs-induced scleroderma cases, the systematic review of the literature and the analysis of VigiBase, the WHO pharmacovigilance database.
We identified two cases with underlying limited cutaneous SSc who presented a dramatic increase in the skin thickening following pembrolizumab, associated with scleroderma renal crisis in one case. In the literature, four cases of scleroderma and four cases of morphea have been reported with pembrolizumab or nivolumab. None following ipilimumab, atezolizumab or durvalumab were retrieved. Skin changes appeared or worsened more quickly with pembrolizumab than nivolumab, and had different patterns between both drugs. Patients with generalized skin changes required high-dose prednisone to improve skin thickening. Among the 2527 scleroderma cases identified in VigiBase, 35 were associated with ICIs. Nivolumab and pembrolizumab showed a disproportionality in scleroderma reporting. No disproportionality was found for ipilimumab, atezolizumab or durvalumab.
The risk of scleroderma or fibrosis extension in SSc patients should be considered when initiating anti-PD-1 agents. It suggests the role of PD-1/PD-L1 interaction in the pathophysiology of SSc.
Activation of the cyclic dinucleotide sensor stimulator of interferon (IFN) genes (STING) is critical for IFN and inflammatory gene expression during innate immune responses. However, the role of ...STING in adaptive immunity is still unknown. In this study, we show that STING activation reduces the proliferation of T lymphocytes. This activity was independent of TBK1 and IRF3 recruitment and of type I IFN but required a distinct C-terminal domain of STING that activates NF-κB. Inhibition of cell proliferation by STING required its relocalization to the Golgi apparatus and caused mitotic errors. T lymphocytes from patients carrying constitutive active mutations in
encoding STING showed impaired proliferation and reduced numbers of memory cells. Endogenous STING inhibited proliferation of mouse T lymphocytes. Therefore, STING, a critical innate sensor, also functions intrinsically in cells of the adaptive immune system to inhibit proliferation.
Dedicator of cytokinesis (DOCK) proteins play a central role in actin cytoskeleton regulation. This is highlighted by the DOCK2 and DOCK8 deficiencies leading to actinopathies and immune ...deficiencies. DOCK8 and DOCK11 activate CDC42, a Rho-guanosine triphosphate hydrolases involved in actin cytoskeleton dynamics, among many cellular functions. The role of DOCK11 in human immune disease has been long suspected but, to the best of our knowledge, has never been described to date. We studied 8 male patients, from 7 unrelated families, with hemizygous DOCK11 missense variants leading to reduced DOCK11 expression. The patients were presenting with early-onset autoimmunity, including cytopenia, systemic lupus erythematosus, skin, and digestive manifestations. Patients' platelets exhibited abnormal ultrastructural morphology and spreading as well as impaired CDC42 activity. In vitro activated T cells and B-lymphoblastoid cell lines from patients exhibited aberrant protrusions and abnormal migration speed in confined channels concomitant with altered actin polymerization during migration. Knock down of DOCK11 recapitulated these abnormal cellular phenotypes in monocytes-derived dendritic cells and primary activated T cells from healthy controls. Lastly, in line with the patients' autoimmune manifestations, we also observed abnormal regulatory T-cell (Treg) phenotype with profoundly reduced FOXP3 and IKZF2 expression. Moreover, we found reduced T-cell proliferation and impaired STAT5B phosphorylation upon interleukin-2 stimulation of the patients' lymphocytes. In conclusion, DOCK11 deficiency is a new X-linked immune-related actinopathy leading to impaired CDC42 activity and STAT5 activation, and is associated with abnormal actin cytoskeleton remodeling as well as Treg phenotype, culminating in immune dysregulation and severe early-onset autoimmunity.
The autoimmune lymphoproliferative syndrome (ALPS) is a non-infectious and non-malignant lymphoproliferative disease frequently associated with autoimmune cytopenia resulting from defective FAS ...signaling. We previously described germline mono-allelic FAS (TNFRSF6) haplo-insufficient mutations associated with somatic events, such as loss of heterozygosity (LOH) on the second allele of FAS, as a cause of ALPS-FAS. These somatic events were identified by sequencing FAS in DNA from double negative T cells (DN T), the pathognomonic T cell subset in ALPS, in which the somatic events accumulated.
In four unrelated ALPS patients carrying a germline mono-allelic mutation of FADD (FAS associated death domain protein) inherited from a healthy parent, we sought to identify whether a somatic event affecting the FADD gene could be related to the disease onset.
We sequenced FADD and performed array-based comparative genomic hybridization using DNA from sorted CD4+ or DN T cells.
We found homozygous FADD mutations in the DN T cells from all 4 patients which resulted from uniparental disomy. FADD deficiency caused by germline heterozygous FADD mutations associated with a somatic loss of heterozygosity (LOH) was a phenocopy of ALPS-FAS without the more complex symptoms reported in patients with germline bi-allelic FADD mutations.
The association of germline and somatic events affecting the FADD gene is a new genetic cause of ALPS.
Two out of four patients received sirolimus and were in remission. ALPS-FADD/sLOH patients can thus benefit from this targeted treatment which is standard of care in ALPS-FAS patients.
We identified the association of germline and somatic events affecting FADD as new genetic cause of autoimmune lymphoproliferative syndrome. Affected patients could benefit from MTOR pathway inhibitor treatment.
Early-onset inflammatory bowel diseases can result from a wide spectrum of rare mendelian disorders. Early molecular diagnosis is crucial in defining treatment and in improving life expectancy. ...Herein we aimed at defining the mechanism of an immunodeficiency-polyendrocrinopathy and enteropathy-X-linked (IPEX)-like disease combined with a severe immunodeficiency in 2 siblings born from distantly related parents.
Whole exome sequencing was performed on blood-extracted genomic DNA from the 2 affected children and their parents on the genomic platform of Institut IMAGINE. Candidate gene mutation was identified using the in-house software PolyWeb and confirmed by Sanger sequencing. Protein expression was determined by western blot. Flow cytometry was used to assess consequences of the mutation on lymphocyte phenotype and nuclear factor-kappa B (NF-κB) activation at diagnosis and after treatment by hematopoietic stem cell transplantation.
We identified a homozygous missense mutation in mucosa-associated lymphoid tissue lymphoma translocation 1 gene (MALT1), which precluded protein expression. In keeping with the known function of MALT1, NF-κB-dependent lymphocyte activation was severely impaired. Moreover, there was a drastic reduction in Forkhead box P3 (FOXP3) regulatory T cells accounting for the IPEX-like phenotype. Following identification of the mutation, both children received hematopoietic stem cell transplantation, which permitted full clinical recovery. Immunological workup at 6 and 12 months after transplantation showed normal NF-κB activation and correction of regulatory T cells frequency.
Along with FOXP3, interleukin 2 receptor alpha chain (IL2RA), and cytotoxic T-lymphocyte protein 4 precursor (CTLA-4) mutations, MALT1 deficiency should now be considered as a possible cause of IPEX-like syndrome associated with immunodeficiency that can be cured by hematopoietic stem cell transplantation.
Evans syndrome (ES) is a rare severe autoimmune disorder characterized by the combination of autoimmune hemolytic anemia and immune thrombocytopenia. In most cases, the underlying cause is unknown. ...We sought to identify genetic defects in pediatric ES (pES), based on a hypothesis of strong genetic determinism. In a national, prospective cohort of 203 patients with early-onset ES (median range age at last follow-up: 16.3 years (1.2-41.0 years) initiated in 2004, 80 nonselected consecutive individuals underwent genetic testing. The clinical data were analyzed as a function of the genetic findings. Fifty-two patients (65%) received a genetic diagnosis (the M+ group): 49 carried germline mutations and 3 carried somatic variants. Thirty-two (40%) had pathogenic mutations in 1 of 9 genes known to be involved in primary immunodeficiencies (TNFRSF6, CTLA4, STAT3, PIK3CD, CBL, ADAR1, LRBA, RAG1, and KRAS), whereas 20 patients (25%) carried probable pathogenic variants in 16 genes that had not previously been reported in the context of autoimmune disease. Lastly, no genetic abnormalities were found in the remaining 28 patients (35%, the M− group). The M+ group displayed more severe disease than the M− group, with a greater frequency of additional immunopathologic manifestations and a greater median number of lines of treatment. Six patients (all from the M+ group) died during the study. In conclusion, pES was potentially genetically determined in at least 65% of cases. Systematic, wide-ranging genetic screening should be offered in pES; the genetic findings have prognostic significance and may guide the choice of a targeted treatment.
•At least 65% of cases of pES may be genetically determined.•Genetic findings have prognostic significance and may guide the physician's choice of a targeted treatment.
The emergence of strains of SARS-CoV-2 exhibiting increase viral fitness and immune escape potential, such as the Delta variant (B.1.617.2), raises concerns in immunocompromised patients. We aimed to ...evaluate seroconversion, cross-neutralisation and T-cell responses induced by BNT162b2 in immunocompromised patients with systemic inflammatory diseases.
Prospective monocentric study including patients with systemic inflammatory diseases and healthcare immunocompetent workers as controls. Primary endpoints were anti-spike antibodies levels and cross-neutralisation of Alpha and Delta variants after BNT162b2 vaccine. Secondary endpoints were T-cell responses, breakthrough infections and safety.
Sixty-four cases and 21 controls not previously infected with SARS-CoV-2 were analysed. Kinetics of anti-spike IgG after BNT162b2 vaccine showed lower and delayed induction in cases, more pronounced with rituximab. Administration of two doses of BNT162b2 generated a neutralising response against Alpha and Delta in 100% of controls, while sera from only one of rituximab-treated patients neutralised Alpha (5%) and none Delta. Other therapeutic regimens induced a partial neutralising activity against Alpha, even lower against Delta. All controls and cases except those treated with methotrexate mounted a SARS-CoV-2 specific T-cell response. Methotrexate abrogated T-cell responses after one dose and dramatically impaired T-cell responses after two doses of BNT162b2. Third dose of vaccine improved immunogenicity in patients with low responses.
Rituximab and methotrexate differentially impact the immunogenicity of BNT162b2, by impairing B-cell and T-cell responses, respectively. Delta fully escapes the humoral response of individuals treated with rituximab. These findings support efforts to improve BNT162b2 immunogenicity in immunocompromised individuals (ClinicalTrials.gov number, NCT04870411).
Loss of NBEAL2 function leads to grey platelet syndrome (GPS), a bleeding disorder characterized by macro-thrombocytopenia and α-granule-deficient platelets. A proportion of patients with GPS develop ...autoimmunity through an unknown mechanism, which might be related to the proteins NBEAL2 interacts with, specifically in immune cells. Here we show a comprehensive interactome of NBEAL2 in primary T cells, based on mass spectrometry identification of altogether 74 protein association partners. These include LRBA, a member of the same BEACH domain family as NBEAL2, recessive mutations of which cause autoimmunity and lymphocytic infiltration through defective CTLA-4 trafficking. Investigating the potential association between NBEAL2 and CTLA-4 signalling suggested by the mass spectrometry results, we confirm by co-immunoprecipitation that CTLA-4 and NBEAL2 interact with each other. Interestingly, NBEAL2 deficiency leads to low CTLA-4 expression in patient-derived effector T cells, while their regulatory T cells appear unaffected. Knocking-down NBEAL2 in healthy primary T cells recapitulates the low CTLA-4 expression observed in the T cells of GPS patients. Our results thus show that NBEAL2 is involved in the regulation of CTLA-4 expression in conventional T cells and provide a rationale for considering CTLA-4-immunoglobulin therapy in patients with GPS and autoimmune disease.
Author Affiliation: (1) Pediatric Immunohematology and Rheumatology Department, Hopital Necker-Enfants Malades, Assistance Publique-Hopitaux de Paris (AP-HP), 149 rue de Sevres, F-75015, Paris, ...France (2) University of Paris, Paris, France (3) Laboratory of immunogenetics of pediatric autoimmune disease, Institut Imagine, INSERM UMR1163, Paris, France (4) Study Center for Primary Immunodeficiencies, Necker-Enfants Malades, AP-HP centre, Paris, France (5) Pediatric Intensive Care Unit, Necker-Enfants-Malades University Hospital, AP-HP centre, Paris, France (6) Pediatric Radiology Unit, Hopital Necker-Enfants Malades, AP-HP Centre, Paris, France (7) Pediatric Pneumology Unit, Hopital Necker-Enfants Malades, AP-HP Centre, Paris, France (8) Pediatric Endocrinology Unit, Hopital Necker-Enfants Malades, AP-HP Centre, Paris, France (9) Laboratory of Neurogenetics and Neuroinflammation, Institut Imagine, INSERM UMR1163, Paris, France (10) Department of Pathology, Hopital Necker-Enfants Malades, AP-HP Centre, Paris, France (11) Department of Pharmacology, Hopital Henri Mondor, AP-HP, Paris, France (12) College de France, Paris, France (u) benedicte.neven@aphp.fr Article History: Registration Date: 11/06/2020 Received Date: 08/10/2020 Accepted Date: 11/05/2020 Online Date: 01/11/2021 Byline:
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