Multisystem autoimmune disease caused by increased STAT3 phosphorylation, and dysregulated gene expression

Signal transducer and activator of transcription (STAT) 3 is a member of the STAT family, and plays a major role in various immunological mechanisms.1 Mutations in STAT3 are associated with a broad spectrum of manifestations, including immunodeficiency, autoimmunity, and malignancy.2 In particular, heterozygous germline loss-of-function (LOF) mutations cause Hyper-IgE syndrome (HIES),3–5 while heterozygous germline gain-of-function (GOF) mutations have recently been associated to multi-organ autoimmune manifestations (i.e. type 1 diabetes, enteropathy, cytopenia, interstitial lung disease, hypothyroidism), lymphoproliferation, short stature, and recurrent infections (OMIM #615952).6–8 We report a 7-year-old boy who presented with early-onset severe enteropathy, and diffuse eczematous dermatitis since birth. During the first weeks of life, Hirschsprung disease was also suspected and surgically treated. Gastrointestinal and cutaneous manifestations were first ascribed to food allergy with quite a good response to amino acid-based formula. In the following months, the patient failed to thrive, and developed respiratory tract infections. At two years, the patient presented with progressive interstitial lung disease characterized by lymphocytic interstitial infiltration leading to pulmonary hypertension, tricuspid insufficiency, and right ventricular heart failure with hepatomegaly. Because of the increased risk of infections, he received intravenous (IV) immunoglobulin infusions (400 mg/kg), prophylaxis with cotrimoxazole and fluconazole. Methylprednisolone at 0.3 mg/kg/day was also given to treat autoimmune manifestations

Inflammatory Bowel Diseases: genetic and functional approaches in the NGS era

Inflammatory Bowel Diseases (IBDs) are a group of pathologies characterized by chronic inflammation of the gastrointestinal tract. The two main types of IBDs are Crohn\u2019s disease and ulcerative colitis, which differ for the localization and intestinal wall layers interested by the inflammation. During the last decades, IBDs incidence is increased, especially in the case of pathologies with an onset before 6 years of age, namely Very Early Onset IBDs (VEO-IBDs). Various factors have been investigated for their role in IBD etiology, thus it is still unclear; environmental factors like breastfeeding, diet, smoke have been related to IBDs, but also genetic predisposition has been pointed out as an important element. In this work we wanted to evaluate genetic variants in patients with IBDs, using clinical exome sequencing (CES) for non-VEO patients and whole exome sequencing (WES) for VEO patients. We found different variants reported in literature to be risk factors for IBD. Moreover, we focused on a VEO patient with a novel mutation on IL-10RA gene, assessing the functional defect through phosphorylation assay, and evaluating Th17 and Treg population. We also evaluated Lag3+CD49b+ Tr1 cells, which produce large amounts of IL-10, and a subset expressing both Foxp3 and Ror\u3b3t, reported to be important for intestinal inflammation

Genetic Variants Assessing Crohn’s Disease Pattern in Pediatric Inflammatory Bowel Disease Patients by a Clinical Exome Survey

12Background: Inflammatory bowel diseases (IBDs) are complex, multifactorial disorders that comprise Crohn’s disease (CD) and ulcerative colitis (UC). Recent discoveries have brought much attention to the genetic predisposition of patients with IBD. Here we evaluate the interaction between IBD genetic risk factors susceptibility and CD occurrence in an IBD pediatric patient population, performing a clinical exome survey. Methods: From February 2018 to April 2019, we collected blood samples from 7 pediatric patients with IBD concerns from several collaborating health centers and/or hospitals. Blood samples were processed by extracting and sequencing DNA for a clinical exome survey. Shophia-DDM-v3-4 platform allowed sequenced reads alignment on hg19 genome as well as genetic variant calling. Both IBD risk and pathogenic genetic variants covered by at least 20 reads were selected for subjacent analysis. Results: Normality and Bartlett tests of both risk and pathogenic genetic variants suggested random and heterogeneous distribution of these variants in this group of IBD pediatric patients. P value clustering analysis by processing 157 IBD risk factors revealed genetic heterogeneity in IBD population and suggested two pathways influencing IBD development. In particular, (1) genetic variants associated with autoimmune and (2) metabolic diseases and CD risk factors (rs2066844 and rs2241880 single nucleotide polymorphism variants, respectively, of genes NOD2 and ATG16L) were identified in distinct clusters of IBD patients (P <.05). Moreover, the heterogeneous distribution of the following variants rs10065172 (IRGM), rs1805010 (IL4R), rs5030737 (MBL2), and rs33995883 (LRRK2) in this group of IBD patients was consistent with their random distribution in that population. Conclusion: Our study revealed specific genetic variants linked to CD susceptibility, autoimmune and/or innate immunodeficiency as well as to metabolic defects, as favoring factors of IBD, suggesting the valuable role of next generation sequencing (NGS) approaches in IBD molecular diagnostic procedures.openopenDago Dougba Noel, Pinelli Marinella, Giacomelli Mauro, Serena Ilaria Tripodi, Alessia Pin, Arrigo Serena, Bramuzzo Matteo, Fuoti Maurizio Giuseppe, Alvisi Patrizia, Calza Stefano, Alberto Tommasini, Badolato RaffaeleDago Dougba Noel, ; Pinelli, Marinella; Giacomelli, Mauro; Serena Ilaria Tripodi, ; Pin, Alessia; Arrigo, Serena; Bramuzzo, Matteo; Fuoti Maurizio Giuseppe, ; Alvisi, Patrizia; Calza, Stefano; Tommasini, Alberto; Badolato, Raffael

Peroxisome deficiency underlies failures in hepatic immune cell development and antigen presentation in a severe Zellweger disease model

Summary: Peroxisome biogenesis disorders (PBDs) represent a group of metabolic conditions that cause severe developmental defects. Peroxisomes are essential metabolic organelles, present in virtually every eukaryotic cell and mediating key processes in immunometabolism. To date, the full spectrum of PBDs remains to be identified, and the impact PBDs have on immune function is unexplored. This study presents a characterization of the hepatic immune compartment of a neonatal PBD mouse model at single-cell resolution to establish the importance and function of peroxisomes in developmental hematopoiesis. We report that hematopoietic defects are a feature in a severe PBD murine model. Finally, we identify a role for peroxisomes in the regulation of the major histocompatibility class II expression and antigen presentation to CD4+ T cells in dendritic cells. This study adds to our understanding of the mechanisms of PBDs and expands our knowledge of the role of peroxisomes in immunometabolism

Dataset related to article "Reduced G protein signaling despite impaired internalization and β-arrestin recruitment in patients carrying a novel CXCR4Leu317fsX3 mutation causing WHIM syndrome"

&lt;p&gt;This record contains raw data related to article &nbsp;"IReduced G protein signaling despite impaired internalization and β-arrestin recruitment in patients carrying a novel CXCR4Leu317fsX3 mutation causing WHIM syndrome"&lt;/p&gt;&lt;p&gt;WHIM syndrome is an inherited immune disorder caused by an autosomal dominant heterozygous mutation in CXCR4.&lt;i&gt;&nbsp;&lt;/i&gt;The disease is characterized by neutropenia/leukopenia (secondary to retention of mature neutrophils in bone marrow), recurrent bacterial infections, treatment-refractory warts, and hypogammaglobulinemia. All mutations reported in WHIM patients lead to the truncations in the C-terminal domain of CXCR4, R334X being the most frequent. This defect prevents receptor internalization, and enhances both calcium mobilization and ERK phosphorylation, resulting in increased chemotaxis in response to the unique ligand CXCL12. Here, we describe three patients presenting neutropenia and myelokathexis, but normal lymphocyte count and immunoglobulin levels, carrying a novel Leu317fsX3 mutation in CXCR4, leading to a complete truncation of its intracellular tail. The analysis of the L317fsX3 mutation in cells derived from patients and &lt;i&gt;in vitro&lt;/i&gt; cellular models reveals unique signaling features when compared to R334X mutation. L317fsX3 mutation impairs CXCR4 downregulation and&nbsp;β-arrestin recruitment&nbsp;in response to CXCL12 and reduces other signaling events including&nbsp;ERK1/2 phosphorylation, calcium mobilization and chemotaxis, all processes, which are typically enhanced in cells carrying the R334X mutation. Our findings suggest that overall, the L317fsX3 mutation may be causative of a form of WHIM syndrome not associated with an augmented CXCR4 response to CXCL12.&lt;/p&gt

Case Report: Hypomorphic Function and Somatic Reversion in DOCK8 Deficiency in One Patient With Two Novel Variants and Sclerosing Cholangitis

DOCK8 deficiency is a combined immunodeficiency due to biallelic variants in dedicator of cytokinesis 8 (DOCK8) gene. The disease has a wide clinical spectrum encompassing recurrent infections (candidiasis, viral and bacterial infections), virally driven malignancies and immune dysregulatory features, including autoimmune (cytopenia and vasculitis) as well as allergic disorders (eczema, asthma, and food allergy). Hypomorphic function and somatic reversion of DOCK8 has been reported to result in incomplete phenotype without IgE overproduction. Here we describe a case of DOCK8 deficiency in a 8-year-old Caucasian girl. The patient's disease was initially classified as autoimmune thrombocytopenia, which then evolved toward a combined immunodeficiency phenotype with recurrent infections, persistent EBV infection and lymphoproliferation. Two novel variants (one deletion and one premature stop codon) were characterized, resulting in markedly reduced, but not absent, DOCK8 expression. Somatic reversion of the DOCK8 deletion was identified in T cells. Hypomorphic function and somatic reversion were associated with restricted T cell repertoire, decreased STAT5 phosphorylation and impaired immune synapse functioning in T cells. Although the patient presented with incomplete phenotype (absence of markedly increase IgE and eosinophil count), sclerosing cholangitis was incidentally detected, thus indicating that hypomorphic function and somatic reversion of DOCK8 may delay disease progression but do not necessarily prevent from severe complications