Impaired T(H)17 cell differentiation in subjects with autosomal dominant hyper-IgE syndrome.
ABSTRACT: The autosomal dominant hyper-IgE syndrome (HIES, 'Job's syndrome') is characterized by recurrent and often severe pulmonary infections, pneumatoceles, eczema, staphylococcal abscesses, mucocutaneous candidiasis, and abnormalities of bone and connective tissue. Mutations presumed to underlie HIES have recently been identified in stat3, the gene encoding STAT3 (signal transducer and activator of transcription 3) (refs 3, 4). Although impaired production of interferon-gamma and tumour-necrosis factor by T cells, diminished memory T-cell populations, decreased delayed-type-hypersensitivity responses and decreased in vitro lymphoproliferation in response to specific antigens have variably been described, specific immunological abnormalities that can explain the unique susceptibility to particular infections seen in HIES have not yet been defined. Here we show that interleukin (IL)-17 production by T cells is absent in HIES individuals. We observed that ex vivo T cells from subjects with HIES failed to produce IL-17, but not IL-2, tumour-necrosis factor or interferon-gamma, on mitogenic stimulation with staphylococcal enterotoxin B or on antigenic stimulation with Candida albicans or streptokinase. Purified naive T cells were unable to differentiate into IL-17-producing (T(H)17) T helper cells in vitro and had lower expression of retinoid-related orphan receptor (ROR)-gammat, which is consistent with a crucial role for STAT3 signalling in the generation of T(H)17 cells. T(H)17 cells have emerged as an important subset of helper T cells that are believed to be critical in the clearance of fungal and extracellular bacterial infections. Thus, our data suggest that the inability to produce T(H)17 cells is a mechanism underlying the susceptibility to the recurrent infections commonly seen in HIES.
Project description:Chronic mucocutaneous candidiasis (CMC) is characterized by recurrent or persistent symptomatic infection of the nails, skin and mucosae mostly by Candida albicans. CMC is common in patients with profound primary T-cell immunodeficiency, who often display multiple infectious and autoimmune diseases. Patients with syndromic CMC, including autosomal dominant hyper IgE syndrome (AD-HIES) and autosomal recessive autoimmune polyendocrinopathy syndrome type I (APS-I), display fewer other infections. Patients with isolated CMC (CMCD) rarely display any other severe disease. We review here recent progress in the genetic dissection of these three types of inherited CMC.Low IL-17 T-cell proportions were reported in patients with AD-HIES bearing heterozygous STAT3 mutations, prone to CMC and staphylococcal diseases, and in a kindred with autosomal recessive CARD9 deficiency, prone to CMC and other fungal infections. High levels of neutralizing autoantibodies against IL-17 cytokines were documented in patients with APS-I presenting with CMC as their only infectious disease. The first three genetic causes of CMCD were then reported: autosomal recessive IL-17RA and autosomal dominant IL-17F deficiencies and autosomal dominant STAT1 gain-of-function, impairing IL-17-producing T-cell development.Inborn errors of human IL-17 immunity underlie CMC. Impaired IL-17 immunity may therefore account for CMC in other settings, including patients with acquired immunodeficiency.
Project description:Hyper-immunoglobulin E syndrome (HIES) is a primary immune deficiency characterized by abnormal and devastating susceptibility to a narrow spectrum of infections, most commonly Staphylococcus aureus and Candida albicans. Recent investigations have identified mutations in STAT3 in the majority of HIES patients studied. Despite the identification of the genetic cause of HIES, the mechanisms underlying the pathological features of this disease remain to be elucidated. Here, we demonstrate a failure of CD4+ T cells harboring heterozygous STAT3 mutations to generate interleukin 17-secreting (i.e., T helper [Th]17) cells in vivo and in vitro due to a failure to express sufficient levels of the Th17-specific transcriptional regulator retinoid-related orphan receptor t. Because Th17 cells are enriched for cells with specificities against fungal antigens, our results may explain the pattern of infection susceptibility characteristic of patients with HIES. Furthermore, they underscore the importance of Th17 responses in normal host defense against the common pathogens S. aureus and C. albicans.
Project description:The hyper IgE syndrome (HIES) is characterized by abscesses, eczema, recurrent infections, skeletal and connective tissue abnormalities, elevated serum IgE, and diminished inflammatory responses. It exists as autosomal-dominant and autosomal-recessive forms that manifest common and distinguishing clinical features. A majority of those with autosomal-dominant HIES have heterozygous mutations in signal transducer and activator of transcription (STAT)-3 and impaired T(H)17 differentiation.To elucidate mechanisms underlying different forms of HIES.A cohort of 25 Turkish children diagnosed with HIES were examined for STAT3 mutations by DNA sequencing. Activation of STAT3 by IL-6 and IL-21 and STAT1 by IFN-alpha was assessed by intracellular staining with anti-phospho (p)STAT3 and -pSTAT1 antibodies. T(H)17 and T(H)1 cell differentiation was assessed by measuring the production of IL-17 and IFN-gamma, respectively.Six subjects had STAT3 mutations affecting the DNA binding, Src homology 2, and transactivation domains, including 3 novel ones. Mutation-positive but not mutation-negative subjects with HIES exhibited reduced phosphorylation of STAT3 in response to cytokine stimulation, whereas pSTAT1 activation was unaffected. Both patient groups exhibited impaired T(H)17 responses, but whereas STAT3 mutations abrogated early steps in T(H)17 differentiation, the defects in patients with HIES with normal STAT3 affected more distal steps.In this cohort of Turkish children with HIES, a majority had normal STAT3, implicating other targets in disease pathogenesis. Impaired T(H)17 responses were evident irrespective of the STAT3 mutation status, indicating that different genetic forms of HIES share a common functional outcome.
Project description:The autosomal-dominant hyper-IgE syndrome (HIES), caused by mutations in STAT3, is a rare primary immunodeficiency that predisposes to mucocutaneous candidiasis and staphylococcal skin and lung infections. This infection phenotype is suggestive of defects in neutrophils, but data on neutrophil functions in HIES are inconsistent. This study was undertaken to functionally characterize neutrophils in STAT3-deficient HIES patients and to analyze whether the patients` eosinophilia affects the neutrophil phenotype in S. aureus infection. Neutrophil functions and cell death kinetics were studied in eight STAT3-deficient patients. Moreover, the response of STAT3-deficient neutrophils to S. aureus and the impact of autologous eosinophils on pathogen-induced cell death were analyzed. No specific aberrations in neutrophil functions were detected within this cohort. However, the half-life of STAT3-deficient neutrophils ex vivo was reduced, which was partially attributable to the presence of eosinophils. Increased S. aureus-induced cell lysis, dependent on the staphylococcal virulence controlling accessory gene regulator (agr)-locus, was observed in STAT3-deficient neutrophils and upon addition of eosinophils. Accelerated neutrophil cell death kinetics may underlie the reported variability in neutrophil function testing in HIES. Increased S. aureus-induced lysis of STAT3-deficient neutrophils might affect pathogen control and contribute to tissue destruction during staphylococcal infections in HIES.
Project description:The key role of interleukin (IL)-23 in the pathogenesis of autoimmune and chronic inflammatory disorders is supported by the identification of IL-23 receptor (IL-23R) susceptibility alleles associated with inflammatory bowel disease, psoriasis and ankylosing spondylitis. IL-23-driven inflammation has primarily been linked to the actions of T-helper type 17 (TH17) cells. Somewhat overlooked, IL-23 also has inflammatory effects on innate immune cells and can drive T-cell-independent colitis. However, the downstream cellular and molecular pathways involved in this innate intestinal inflammatory response are poorly characterized. Here we show that bacteria-driven innate colitis is associated with an increased production of IL-17 and interferon-gamma in the colon. Stimulation of colonic leukocytes with IL-23 induced the production of IL-17 and interferon-gamma exclusively by innate lymphoid cells expressing Thy1, stem cell antigen 1 (SCA-1), retinoic-acid-related orphan receptor (ROR)-gammat and IL-23R, and these cells markedly accumulated in the inflamed colon. IL-23-responsive innate intestinal cells are also a feature of T-cell-dependent models of colitis. The transcription factor ROR-gammat, which controls IL-23R expression, has a functional role, because Rag-/-Rorc-/- mice failed to develop innate colitis. Last, depletion of Thy1+ innate lymphoid cells completely abrogated acute and chronic innate colitis. These results identify a previously unrecognized IL-23-responsive innate lymphoid population that mediates intestinal immune pathology and may therefore represent a target in inflammatory bowel disease.
Project description:T helper 17 (Th17) cells play major roles in autoimmunity and bacterial infections, yet how T cell receptor (TCR) signaling affects Th17 cell differentiation is relatively unknown. We demonstrate that CD4(+) T cells lacking Itk, a tyrosine kinase required for full TCR-induced phospholipase C-gamma (PLC-gamma1) activation, exhibit decreased interleukin-17A (IL-17A) expression in vitro and in vivo, despite relatively normal expression of retinoic acid receptor-related orphan receptor-gammaT (ROR-gammaT) and IL-17F. IL-17A expression was rescued by pharmacologically induced Ca(2+) influx or constitutively activated nuclear factor of activated T cells (NFAT). Conversely, decreased TCR stimulation or calcineurin inhibition preferentially reduced IL-17A expression. We further found that the promoter of Il17a but not Il17f has a conserved NFAT binding site that bound NFATc1 in wild-type but not Itk-deficient cells, even though both exhibited open chromatin conformations. Finally, Itk(-/-) mice also showed differential regulation of IL-17A and IL-17F in vivo. Our results suggest that Itk specifically couples TCR signaling to Il17a expression and the differential regulation of Th17 cell cytokines through NFATc1.
Project description:Autosomal recessive, complete TYK2 deficiency was previously described in a patient (P1) with intracellular bacterial and viral infections and features of hyper-IgE syndrome (HIES), including atopic dermatitis, high serum IgE levels, and staphylococcal abscesses. We identified seven other TYK2-deficient patients from five families and four different ethnic groups. These patients were homozygous for one of five null mutations, different from that seen in P1. They displayed mycobacterial and/or viral infections, but no HIES. All eight TYK2-deficient patients displayed impaired but not abolished cellular responses to (a) IL-12 and IFN-?/?, accounting for mycobacterial and viral infections, respectively; (b) IL-23, with normal proportions of circulating IL-17(+) T cells, accounting for their apparent lack of mucocutaneous candidiasis; and (c) IL-10, with no overt clinical consequences, including a lack of inflammatory bowel disease. Cellular responses to IL-21, IL-27, IFN-?, IL-28/29 (IFN-?), and leukemia inhibitory factor (LIF) were normal. The leukocytes and fibroblasts of all seven newly identified TYK2-deficient patients, unlike those of P1, responded normally to IL-6, possibly accounting for the lack of HIES in these patients. The expression of exogenous wild-type TYK2 or the silencing of endogenous TYK2 did not rescue IL-6 hyporesponsiveness, suggesting that this phenotype was not a consequence of the TYK2 genotype. The core clinical phenotype of TYK2 deficiency is mycobacterial and/or viral infections, caused by impaired responses to IL-12 and IFN-?/?. Moreover, impaired IL-6 responses and HIES do not appear to be intrinsic features of TYK2 deficiency in humans.
Project description:STAT3 transcription factor signaling in specific T helper cell differentiation has been well described, although the broader roles for STAT3 in lymphocyte memory are less clear. Patients with autosomal-dominant hyper-IgE syndrome (AD-HIES) carry dominant-negative STAT3 mutations and are susceptible to a variety of bacterial and fungal infections. We found that AD-HIES patients have a cell-intrinsic defect in the number of central memory CD4(+) and CD8(+) T cells compared to healthy controls. Naive T cells from AD-HIES patients had lower expression of memory-related transcription factors BCL6 and SOCS3, a primary proliferation defect, and they failed to acquire central memory-like surface phenotypes in vitro. AD-HIES patients showed a decreased ability to control varicella zoster virus (VZV) and Epstein-Barr virus (EBV) latency, and T cell memory to both of these viruses was compromised. These data point to a specific role for STAT3 in human central memory T cell formation and in control of certain chronic viruses.
Project description:Signal transducer and activator of transcription 3 (STAT3) is a central regulator of immune homeostasis. STAT3 levels are strictly controlled, and STAT3 impairment contributes to several diseases including the monogenic autosomal-dominant hyper-immunoglobulin E (IgE) syndrome (AD-HIES). We investigated patients of four consanguineous families with an autosomal-recessive disorder resembling the phenotype of AD-HIES, with symptoms of immunodeficiency, recurrent infections, skeletal abnormalities, and elevated IgE. Patients presented with reduced STAT3 expression and diminished T helper 17 cell numbers, in absence of STAT3 mutations. We identified two distinct homozygous nonsense mutations in ZNF341, which encodes a zinc finger transcription factor. Wild-type ZNF341 bound to and activated the STAT3 promoter, whereas the mutant variants showed impaired transcriptional activation, partly due to nuclear translocation failure. In summary, nonsense mutations in ZNF341 account for the STAT3-like phenotype in four autosomal-recessive kindreds. Thus, ZNF341 is a previously unrecognized regulator of immune homeostasis.
Project description:<b>Introduction:</b> Hyper-IgE Syndrome (HIES) is a rare inborn error of immunity (IEI) characterized by a constellation of symptoms related to susceptibility to <i>Staphylococcal</i> skin and pulmonary infections, eczema, raised serum IgE (>2,000 IU/ml), craniofacial anomalies, and recurrent bone fractures. Data on HIES from the Indian subcontinent is scarce and restricted to small case series and case reports. This is the first compilation of national data on HIES. <b>Materials and Methods:</b> A total 103 cases clinically diagnosed and treated as HIES were analyzed from nine centers. Cases with clinical and/or molecular diagnosis of DOCK8 deficiency were not included. Patients were divided into two groups: group I for whom a heterozygous rare variant of STAT3 was identified, and group II, with clinical features similar to those of AD STAT3 deficiency, but without any genetic diagnosis. <b>Results:</b> Genetic diagnosis was available in 27 patients (26.2%) and all harbored rare variants in the STAT3 gene. Majority of these STAT3 HIES patients presented with recurrent skin abscesses (77.7%) or pneumonia (62.9%) or both (59.2%). Other features included eczema (37%), candidiasis (55.5%), facial dysmorphism (55.5%), recurrent fractures (11.1%), and retained primary teeth (7.4%). <i>Mycobacterial</i> infections were seen in a significant 18.5%. Mortality was seen in three subjects (11.1%). A similar trend in the clinical presentation was observed when all the 103 patients were analyzed together. Twenty percent of patients without a rare variant in the STAT3 gene had an NIH score of ?40, whereas, 51.9% of STAT3 HIES subjects had scores below the cut off of ?40. TH17 cell numbers were low in 10/11 (90.9%) STAT3 HIES tested. Rare variants observed were 8 in exon 21; 8 in exon 13; 3 in exon 10; 2 in exon 15, and one each in exon 6, 16, 17, 19, 22, and splice site downstream of exon 12. Seven variants were novel and included F174S, N567D, L404Sfs<sup>*</sup>8, G419 =, M329K, T714I, R518X, and a splice site variant downstream of exon 12. <b>Conclusions:</b> The report includes seven novel STAT3 variants, including a rare linker domain nonsense variant and a CC domain variant. <i>Mycobacterial</i> diseases were more frequent, compared to western literature.