Dedicator Of Cytokinesis 8 Deficiency Research Articles

P27 Successful treatment of severe eczema and plane warts with Dupilumab in a child with Dedicator of Cytokinesis 8 (DOCK8) deficiency (Autosomal recessive form of hyper-IgE syndrome)

Abstract A six-year-old girl first presented with severe eczema at the age of 6 months, which was difficult to control with topical treatments. She was found to have severely elevated total IgE and multiple food allergies. Due to recurrent ear and chest infections, and persistent varicella zoster, she was screened for a primary immunodeficiency and found to have a homozygous exon 29-46 deletion in the DOCK8 gene. Her eczema remained challenging, with coalescing warts on her limbs. She started Methotrexate with an initial good response; however, the frequency of infections and hospitalizations increased. After the diagnosis of DOCK8 deficiency was confirmed, she started Dupilumab, resulting in the complete resolution of her eczema and warts. She is awaiting haematopoietic stem cell transplant (HSCT) . DOCK8 deficiency is an autosomal recessive hyper-IgE syndrome that presents early in life with severe eczema, skin abscesses, multiple food allergies, recurrent respiratory tract infections, and severe viral (including skin) infections. Older patients invariably develop bronchiectasis and are at high risk of malignancy. Patients have a combined immunodeficiency, with T-cell lymphopenia, reduced thymic output and T-cell skewing to a Th2 response. Children with this condition often present to dermatologists because of severe eczema, which is usually difficult to treat with standard topical treatments. The decision to treat with systemic immunosuppression is often challenging due to recurrent infections. Although HSCT is the curative treatment for DOCK8 deficiency, Dupilumab can be used to reduce inflammation and infections, and improve quality of life in patients awaiting HSCT.

Hematopoietic stem cell transplantation in patient with DOCK8 deficiency: Ukrainian experience

Dedicator of Cytokinesis 8 (DOCK8) deficiency is a combined immunodeficiency that exemplifies the broad clinical features of primary immunodeficiencies (PIDs), extending beyond recurrent infections including atopy, autoimmunity, and cancer. Purpose - to describe the natural course of hyper-IgE syndrome (HIES) disease in an 8-year-old boy and his path to diagnosis, as well as our first local history of conservative treatment for 6 months. In particular, we describe the effectiveness of omalizumab, and the application of allogeneic hematopoietic stem cell transplantation with follow-up. Clinical case. The 8-year-old boy presented with severe eczema and an involvement of the whole surface of the body. Infectious syndrome manifested from the age of 4 months in a form of recurrent respiratory infections. Over the next few years, the child suffered from life-threatening infections with high serum IgE (>3000 IU/ml). The examination revealed a cushingoid constitution, flat-valgus feet, and dysmorphic features. Therefore, HIES was suspected. Genetic studies have confirmed the diagnosis by detecting a pathogenic homozygous mutation in the DOCK8 gene (Deletion Exons 2-46). We decided to use a humanized monoclonal anti-IgE antibody (off-label) to control the skin syndrome rather than systemic steroids. A significant improvement in skin condition, a decrease in eosinophils, and IgE were observed. Allogeneic stem cell transplantation of hematopoietic cells (HSCT) derived from peripheral blood of an human leukocyte antigen (HLA) - identical sibling donor was performed. The donor had a pathogenic mutation identical to the recipient in the DOCK8 gene but in a heterozygous state. Our data and treatment approach may be clinically useful as a diagnostic and treatment approach to HIES. The research was carried out in accordance with the principles of the Helsinki Declaration. The informed consent of the patient was obtained for conducting the studies No conflict of interests was declared by the authors.

Reduced toxicity conditioning and a high CD34+ cell dose can achieve full donor chimerism in DOCK8 deficiency.

Biallelic mutations in the dedicator of cytokinesis 8 (DOCK8) gene were identified as the cause of combined immunodeficiency in 2009. Survival rates without hematopoietic stem cell transplant in patients with DOCK8 deficiency decline from 87% at 10 years to 33% at 30 years. Hematopoietic stem cell transplant is therefore the recommended treatment for cure of DOCK8 deficiency. However, patients with DOCK8 deficiency have multiple infectious comorbidities; hence, they cannot tolerate myeloablative conditioning. Reduced intensity conditioning reduces the risk of transplant-related mortality but increases the possibility of mixed chimerism. Mixed chimerism in children with immunodeficiency increases the risk of autoimmunity and the need for long-term immunoglobulin infusion. Here we have sought to devise a strategy for reducing the possibility of mixed chimerism without increasing the risk of transplant-related mortality. To balance the risk of transplant-related mortality and mixed chimerism, we used treosulfan-based reduced toxicity conditioning with a high CD34+ cell dose and differential T-cell capping for HLA-matched and haploidentical transplants. We are able to report that by using the aforementioned novel strategy, we achieved excellent transplant outcomes in the first cohort of high-risk patients with DOCK8 deficiency from India. High CD34+ cell dose and reduced toxicity conditioning can achieve full donor chimerism in DOCK8 deficiency.

Successful treatment of DOCK8 deficiency by allogeneic hematopoietic cell transplantation from alternative donors.

Dedicator of cytokinesis 8 (DOCK8) deficiency is a rare autosomal recessive inborn error of immunity (IEI) characterized by eczematous dermatitis, elevated serum IgE, and recurrent infections, comprising a seemingly hyper-IgE syndrome (HIES). DOCK8 deficiency is only curable with allogeneic hematopoietic cell transplantation (HCT), but the outcome of HCT from alternative donors is not fully understood. Here, we describe the cases of two Japanese patients with DOCK8 deficiency who were successfully treated by allogeneic HCT from alternative donors. Patient 1 underwent cord blood transplantation at the age of 16years, and Patient 2 underwent haploidentical peripheral blood stem cell transplantation with post-transplant cyclophosphamide at the age of 22years. Each patient received a fludarabine-based conditioning regimen. Their clinical manifestations, including refractory molluscum contagiosum, promptly improved post-HCT. They achieved successful engraftment and immune reconstitution without serious complications. Alternative donor sources such as cord blood and haploidentical donors can be options for allogeneic HCT for DOCK8 deficiency.

Dedicator of cytokinesis 8 (DOCK8) is a negative regulator of skin mast cell function

Abstract Dysregulated expansion and/or activation of mast cells have detrimental consequences in allergic disease. In humans, homozygous or compound heterozygous deletions of DOCK8 cause a combined immunodeficiency characterized by allergic disorders. Based on this evidence, we hypothesized that DOCK8 may be a negative regulator of mast cell function. To address this hypothesis, we used mice with a loss-of-function mutation in Dock8 (primuris, Dock8 pri/primice) and conditional mice in which DOCK8 is ablated in connective tissue mast cells (Mcpt5-Cre +; Dock8 fl/flmice). Dock8 pri/primice exhibited increased plasma levels of mast cell protease-1 (MCPT1) in homeostatic conditions. Furthermore, Dock8 pri/primice and Mcpt5-Cre +; Dock8 fl/flmice experienced a more severe IgE-dependent passive cutaneous anaphylactic reaction (PCA) than control mice. This data suggests that DOCK8 deficiency is linked to increased mast cell activation in homeostatic conditions and upon stimulation by IgE-dependent mechanisms. Fetal skin derived cultured mast cells (FSMCs) generated from Dock8 pri/primice released increased amounts of β-hexosaminidase upon IgE-dependent activation. Consistent with this finding, naïve DOCK8-deficient FSMCs exhibited alterations in cytoskeletal dynamics that may facilitate mast cell degranulation. Finally, we observed an increased number of tryptase positive cells in skin biopsies obtained from three pediatric patients diagnosed with hyper IgE syndrome (HIES) due to DOCK8 mutations, suggesting that DOCK8 immunodeficiency may contribute to skin mast cell expansion in humans. Our findings provide strong evidence that DOCK8 can contribute to negative regulation of skin mast cell activation and expansion. R01 AI140626-05

DOCK8 interference alleviates Aβ‑induced damage of BV2 cells by inhibiting STAT3/NLRP3/NF‑κB signaling.

Dementia is defined as memory loss and other cognitive decline and it severely influences daily life. Alzheimer's disease (AD) is the most common cause of dementia. Dedicator of cytokinesis 8 (DOCK8) is reported to be involved in neurological diseases. The present study focused on investigating the role that DOCK8 serves in AD and addressing its hidden regulatory mechanism. Initially, Aβ1-42 (Aβ) was applied for the administration of BV2 cells. Subsequently, the mRNA and protein expression levels of DOCK8 were evaluated utilizing reverse transcription-quantitative PCR (RT-qPCR) and western blotting. After the DOCK8 silencing, immunofluorescence staining (IF), ELISA, wound healing and Transwell assays were applied to assess ionized calcium binding adapter molecule-1 (IBA-1) expression, release of inflammatory factors, migration and invasion in Aβ-induced BV2 cells. IF was used to evaluate cluster of differentiation (CD)11b expression. RT-qPCR and western blotting were to analyze the levels of M1 cell markers inducible nitric oxide synthase (iNOS) and CD86. The expression of STAT3/NLR family pyrin domain containing 3 (NLRP3)/NF-κB signaling-related proteins were determined by western blotting. Finally, the viability and apoptosis in hippocampal HT22 cells with DOCK8 depletion were estimated. Results revealed that Aβ induction greatly stimulated the expression levels of IBA-1 and DOCK8. DOCK8 silencing suppressed Aβ-induced inflammation, migration and invasion of BV2 cells. Additionally, DOCK8 deficiency conspicuously decreased the expression levels of CD11b, iNOS and CD86. The expression of phosphorylated (p-)STAT3, NLRP3, ASC, caspase1 and p-p65 was downregulated in Aβ-induced BV2 cells after DOCK8 depletion. STAT3 activator Colivelin reversed the effects of DOCK8 knockdown on IBA-1 expression, inflammation, migration, invasion and M1 cell polarization. In addition, the viability and apoptosis in hippocampal HT22 cells stimulated by neuroinflammatory release of BV2 cells were repressed following DOCK8 deletion. Collectively, DOCK8 interference alleviated Aβ-induced damage of BV2 cells by inhibiting STAT3/NLRP3/NF-κB signaling.

Insights into the pathogenesis of allergic disease from dedicator of cytokinesis 8 deficiency.

Clinical observations and mechanistic studies in dedicator of cytokinesis 8 (DOCK8)-deficient patients and mice have revealed multiple mechanisms that could contribute to their unusually prevalent and severe allergic disease manifestations. Physical interactions of DOCK8 with STAT3 in B cells and T cells may contribute to increased IgE isotype switching or defective immune synapse formation that decreases T-cell receptor signal strength. A newly discovered TFH13 cell type promotes the development of life-threatening allergy via production of IL-13 and is increased in DOCK8 deficiency. Cytoskeletal derangements and cytothripsis, which were previously shown to account for the increased susceptibility to viral skin infection in DOCK8 deficiency, can lead to interplay between myeloid cells and T cells to ultimately increase production of IL-4, IL-5, and IL-13. Finally, theeffects on type-2 innate lymphoid cells may also contribute to allergic disease.

Diagnostic challenge in a series of eleven patients with hyper IgE syndromes.

Hyper IgE syndromes (HIES) is a heterogeneous group of Inborn Errors of Immunity characterized by eczema, recurrent skin and lung infections associated with eosinophilia and elevated IgE levels. Autosomal dominant HIES caused by loss of function mutations in Signal transducer and activator of transcription 3 (STAT3) gene is the prototype of these disorders. Over the past two decades, advent in genetic testing allowed the identification of ten other etiologies of HIES. Although Dedicator of Cytokinesis 8 (DOCK8) deficiency is no more classified among HIES etiologies but as a combined immunodeficiency, this disease, characterized by severe viral infections, food allergies, autoimmunity, and increased risk of malignancies, shares some clinical features with STAT3 deficiency. The present study highlights the diagnostic challenge in eleven patients with the clinical phenotype of HIES in a resource-limited region. Candidate gene strategy supported by clinical features, laboratory findings and functional investigations allowed the identification of two heterozygous STAT3 mutations in five patients, and a bi-allelic DOCK8 mutation in one patient. Whole Exome Sequencing allowed to unmask atypical presentations of DOCK8 deficiency in two patients presenting with clinical features reminiscent of STAT3 deficiency. Our study underlies the importance of the differential diagnosis between STAT3 and DOCK8 deficiencies in order to improve diagnostic criteria and to propose appropriate therapeutic approaches. In addition, our findings emphasize the role of NGS in detecting mutations that induce overlapping phenotypes.

Deciphering the role of DOCK8 in tumorigenesis by regulating immunity and the application of nanotechnology in DOCK8 deficiency therapy.

The dedicator of cytokinesis 8 (DOCK8) immunodeficiency syndrome is a severe immune disorder and characterized by serum IgE levels elevation, fungal and viral infections, dermatitis and food allergies. It was well known that DOCK8 is crucial for the survival and function of multiple immune related cells. However, the critical role of DOCK8 on tumorigenesis through regulating immunity is poorly investigated. Accumulating evidences indicated that DOCK8 could affect tumorigenesis by regulating the immunity through immune cells, including NK cells, T cells, B cells and dendritic cells. Here, we summarized and discussed the critical role of DOCK8 in cytoskeleton reconstruction, CD4+ T cell differentiation, immune synaptic formation, tumor immune infiltration, tumor immune surveillance and tumorigenesis. Furthermore, the potential roles of nanotechnology in improving the hematopoietic stem cell transplantation-based therapy for DOCK8 deficiency diseases are also highlighted and discussed.

LB980 Skin microbiome restoration after transplantation for DOCK8 deficiency

Patients with the rare primary immunodeficiency due to dedicator of cytokinesis 8 (DOCK8) mutations commonly suffer from atopic disorders, recalcitrant viral infections, potential malignancy, and early mortality. Even in the absence of viral skin lesions, DOCK8-deficient skin has been previously shown to have an abundant virome. Hematopoietic stem cell transplantation (HSCT) is potentially curative for this disease and provides a unique opportunity to investigate the influence of host immunity on skin microbial communities.

Lack of DOCK8 impairs the primary biologic functions of human NK cells and abrogates CCR7 surface expression in a WASP-independent manner

Dedicator of Cytokinesis 8 (DOCK8) deficiency is a rare form of autosomal recessive combined immunodeficiency. The effect of DOCK8 deficiency on Natural Killer cell biology has not been fully elucidated yet. Thus, we undertook a detailed phenotypic and functional evaluation of NK cells from seven patients with DOCK8 deficiency.Patients' immature CD56bright NK cells were defective in IFN-γ secretion, while their mature CD56dim NK cells showed impaired cytotoxicity, partially rescued upon rIL-2 addition. Cross-linking of NK cell receptors revealed a specific defect in the CD3 zeta chain-dependent activation pathway in DOCK8 deficiency. Lack of DOCK8, but not of WASP, impaired CCR7 expression on human CD56bright NK cells, a critical receptor for their migration to secondary lymph nodes. Evaluation of a patient's lymph node showed a severe reduction in NK cells that showed increased intracellular expression of CCR7.Our data suggest that DOCK8 deficiency variably affects NK cell homeostasis in humans.

Proteomics Profiling to Distinguish DOCK8 Deficiency From Atopic Dermatitis.

Dedicator of cytokinesis 8 deficiency is an autosomal recessive primary immune deficiency disease belonging to the group of hyperimmunoglobulinemia E syndrome (HIES). The clinical phenotype of dedicator of cytokinesis 8 (DOCK8) deficiency, characterized by allergic manifestations, increased infections, and increased IgE levels, overlaps with the clinical presentation of atopic dermatitis (AD). Despite the identification of metabolomics and cytokine biomarkers, distinguishing between the two conditions remains clinically challenging. The present study used a label-free untargeted proteomics approach using liquid-chromatography mass spectrometry with network pathway analysis to identify the differentially regulated serum proteins and the associated metabolic pathways altered between the groups. Serum samples from DOCK8 (n = 10), AD (n = 9) patients and healthy control (Ctrl) groups (n = 5) were analyzed. Based on the proteomics profile, the PLS-DA score plot between the three groups showed a clear group separation and sample clustering (R2 = 0.957, Q2 = 0.732). Significantly differentially abundant proteins (p < 0.05, FC cut off 2) were identified between DOCK8-deficient and AD groups relative to Ctrl (n = 105, and n = 109) and between DOCK8-deficient and AD groups (n = 85). Venn diagram analysis revealed a differential regulation of 24 distinct proteins from among the 85 between DOCK8-deficient and AD groups, including claspin, haptoglobin-related protein, immunoglobulins, complement proteins, fibulin, and others. Receiver-operating characteristic curve (ROC) analysis identified claspin and haptoglobin-related protein, as potential biomarkers with the highest sensitivity and specificity (AUC = 1), capable of distinguishing between patients with DOCK8 deficiency and AD. Network pathway analysis between DOCK8-deficiency and AD groups revealed that the identified proteins centered around the dysregulation of ERK1/2 signaling pathway. Herein, proteomic profiling of DOCK8-deficiency and AD groups was carried out to determine alterations in the proteomic profiles and identify a panel of the potential proteomics biomarker with possible diagnostic applications. Distinguishing between DOCK8-deficiency and AD will help in the early initiation of treatment and preventing complications.

Lineage-Specific Chimerism and Outcome After Hematopoietic Stem Cell Transplantation for DOCK8 Deficiency

Bi-allelic variants in the dedicator of cytokinesis 8 (DOCK8) gene cause a combined immunodeficiency, characterized by recurrent sinopulmonary and skin infections, food allergies, eczema, eosinophilia, and elevated IgE. Long-term outcome is poor given susceptibility to infections, malignancy, and vascular complications. Allogeneic hematopoietic stem cell transplantation is currently the only curative treatment option and has shown promising outcome. The impact of mixed chimerism on long-term outcome is unclear. We reasoned that reversal of disease phenotype would depend on cell lineage-specific chimerism. DOCK8 variants were confirmed by Sanger and/or exome sequencing and immunoblot and/or intracellular flow cytometry. Donor chimerism was analyzed by XY-fluorescence in situ hybridization or quantitative short tandem repeat PCR. Outcome was assessed by laboratory tests, lymphocyte subsets, intracellular DOCK8 protein flow cytometry, T-cell proliferation analysis, and multiparameter immunoblot allergy screening. We report on nine patients, four of whom with mixed chimerism, with a median follow-up of 78 months after transplantation. Overall, we report successful transplantation with improvement of susceptibility to infections and allergies, and resolution of eczema in all patients. Immunological outcome in patients with mixed chimerism suggests a selective advantage for wild-type donor T-cells but lower donor B-cell chimerism possibly results in a tendency to hypogammaglobulinemia. No increased infectious and allergic complications were associated with mixed chimerism. Aware of the relatively small cohort size, we could not demonstrate a consistent detrimental effect of mixed chimerism on clinical outcomes. We nevertheless advocate aiming for complete donor chimerism in treating DOCK8 deficiency, but recommend reduced toxicity conditioning.

DOCK8 deficiency causes a skewing to type 2 immunity in the gut with expansion of group 2 innate lymphoid cells

Dedicator of cytokinesis 8 (DOCK8) is a guanine nucleotide exchange factor (GEF) for Cdc42. In humans, homozygous or compound heterozygous deletions in DOCK8 cause a combined immunodeficiency characterized by various allergic diseases including food allergies. Although group 2 innate lymphoid cells (ILC2s) contribute to the development of allergic inflammation by producing interleukin (IL)-5 and IL-13, the role of ILC2s in DOCK8 deficiency has not been fully explored. With the use of cytometry by time-of-flight (CyTOF), we performed high-dimensional phenotyping of intestinal immune cells and found that DOCK8-deficient (Dock8−/−) mice exhibited expansion of ILC2s and other leukocytes associated with type 2 immunity in the small intestine. Moreover, IL-5– and IL-13–producing cells markedly increased in Dock8−/− mice, and the majority of them were lineage-negative cells, most likely ILC2s. Intestinal ILC2s expanded when DOCK8 expression was selectively deleted in hematopoietic cells. Importantly, intestinal ILC2 expansion was also observed in Dock8VAGR mice having mutations in the catalytic center of DOCK8, thereby failing to activate Cdc42. Our findings indicate that DOCK8 is a negative regulator of intestinal ILC2s to inhibit their expansion via Cdc42 activation, and that deletion of DOCK8 causes a skewing to type 2 immunity in the gut.

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.

Thoracic Multidetector Computed Tomography Findings of Dedicator of Cytokinesis 8 Deficiency in Children.

To investigate the characteristic thoracic multidetector computed tomography (MDCT) findings of dedicator of cytokinesis 8 (DOCK8) deficiency, a rare autosomal recessive form of hyperimmunoglobulin E syndrome, in children. All pediatric patients (age 18 y and below) with a known diagnosis of DOCK8 deficiency based on genetic testing who underwent thoracic MDCT studies from November 2004 to November 2020 were included. Two pediatric radiologists independently evaluated MDCT studies for the presence of thoracic abnormalities in the lung [ground-glass opacity (GGO), consolidation, pulmonary nodule, mass, cyst, and bronchiectasis], pleura (pleural effusion and pneumothorax), and mediastinum (lymphadenopathy). When a lung abnormality was present, laterality, distribution (upper, middle, and lower lung zone), and extent were also evaluated. When a pleural abnormality was identified, laterality and size of the abnormality were also assessed. When mediastinal lymphadenopathy was present, its location and size were also evaluated. Interobserver agreement between two independent reviewers was evaluated with κ statistics. In all, 17 thoracic MDCT studies from 17 individual pediatric patients [5 males (29%) and 12 females (71%); mean age: 7.4 y; SD: 3.7; range: 1 to 13 y] comprised the final study population. Among 17 thoracic MDCT studies, 11 studies (65%) were performed with intravenous contrast (IV) and the remaining 6 MDCT studies (35%) were obtained without IV contrast. Bilateral bronchiectasis (11/17; 65%) with a middle lung zone predominance (8/11; 73%) was the most frequently detected lung abnormality, followed by GGO in 9/17 patients (53%). Among 11 contrast-enhanced MDCT studies, the majority (9 patients, 82%) had mediastinal lymphadenopathy. There was excellent interobserver κ agreement between 2 independent reviewers for detecting abnormalities on thoracic MDCT studies (κ>0.90). Children with DOCK8 deficiency have characteristic thoracic MDCT findings, including bilateral bronchiectasis with a middle lung zone predominance, GGO, and mediastinal lymphadenopathy. When these characteristic thoracic MDCT findings are detected, although rare, DOCK8 deficiency should be considered as a possible underlying diagnosis in the pediatric population.

DOCK8 Expression in Regulatory T Cells Maintains their Stability and Limits Contact Hypersensitivity

Chronic dermatitis is a hallmark of Dedicator of cytokinesis 8 (DOCK8) deficiency. The migration of DOCK8-deficient T cells to the skin and their survival there have been reported to be defective. Surprisingly, we found that Dock8-/- mice demonstrated an exaggerated contact hypersensitivity (CHS) response to oxazolone with increased ear swelling, T-cell infiltration, and expression of Ifng. To understand the mechanisms of persistent skin inflammation in DOCK8 deficiency, we examined mice with selective deficiency of DOCK8 in T cells or T regulatory cells (Tregs) and found that both have exaggerated CHS. Moreover, oral tolerance to oxazolone, mediated by Tregs, was impaired in Dock8-/- mice. Transfer of Tregs from oxazolone-sensitized wild-type mice, but not Dock8-/- mice, reduced the CHS response of Dock8-/- recipients. Lack of DOCK8 in Tregs resulted in their acquisition of a pathogenic FOXP3+T-bet+IFNγ+ phenotype at CHS sites and promoted their conversion into ex-Tregs. The transfer of Tregs from Dock8-/- mice increased the CHS response of wild-type recipients to oxazolone. Thus, DOCK8 expression in Tregs limits CHS by promoting Treg stability and fitness in inflamed skin. Interventions aimed at ameliorating Treg function may be useful in treating skin inflammation in DOCK8 deficiency.

Fertility preservation before hematopoetic stem cell transplantation: a case series of women with GATA binding protein 2 deficiency, dedicator of cytokinesis 8 deficiency, and sickle cell disease

ObjectiveTo describe fertility characteristics, outcomes of oocyte cryopreservation cycles, and safety of ovarian stimulation in patients with GATA binding protein 2 (GATA2) deficiency, dedicator of cytokinesis 8 (DOCK8) deficiency, and sickle cell disease (SCD) preparing for hematopoetic stem cell transplantation (HSCT).DesignRetrospective case series.SettingThe National Institutes of Health.Patient(s)Female patients with GATA2 deficiency, DOCK8 deficiency, and SCD aged between 13 and 38 years.Intervention(s)None.Main Outcome Measure(s)Demographic and ovarian reserve parameters, stimulation outcomes, and adverse event occurrences were collected through chart review. Descriptive statistics were used to identify trends within disease subcategories.Result(s)Twenty-one women with GATA2 deficiency, DOCK8 deficiency, and SCD underwent fertility preservation prior to HSCT. Patients with DOCK8 deficiency had the lowest mean age (16.5 years old) and antimüllerian hormone (0.85 ng/mL). Patients with GATA2 deficiency had the highest antral follicle count and antimüllerian hormone (25.77 and 5.07 ng/mL, respectively). Baseline follicle-stimulating hormone, luteinizing hormone, and estradiol were comparable between the cohorts. The duration of stimulation was similar (10.43 to 11.25 days) across all groups. Comparable peak estradiol levels were achieved across the cohorts. Patients with SCD had the highest mature (MII) oocyte yield (10.71). Three patients experienced complications related to stimulation: pain crisis in a patient with SCD, pulmonary embolism, and zero oocytes cryopreserved in a patient with GATA2 deficiency.Conclusion(s)This study offers insight into controlled ovarian stimulation in patients with these conditions prior to HSCT. Oocyte cryopreservation can be performed successfully, although adverse events must be considered. Following the outcomes of gamete use in this cohort will serve to further our knowledge of the true reproductive potential of this population.

DOCK8 controls survival of group 3 innate lymphoid cells in the gut through Cdc42 activation.

Innate lymphoid cells (ILCs) are a family of developmentally related leukocytes that rapidly secrete polarized sets of cytokines to combat infection and promote tissue repair at mucosal barriers. Among them, group 3 ILCs (ILC3s) play an important role in maintenance of the gut homeostasis by producing IL-22, and their development and function critically depend on the transcription factor RORγt. Although recent evidence indicates that RORγt+ ILC3s are reduced in the gut in the absence of the Cdc42 activator DOCK8 (dedicator of cytokinesis 8), the underlying mechanism remains unclear. We found that genetic deletion of Dock8 in RORγt+-lineage cells markedly reduced ILC3s in the lamina propria of the small intestine. By analyzing BrdU incorporation, it was revealed that DOCK8 deficiency did not affect the cell proliferation. Furthermore, when lineage marker-negative (Lin-) α4β7+ CD127+ RORγt- fetal liver cells were cultured with OP9 stromal cells in the presence of stem cell factor (SCF) and IL-7 in vitro, RORγt+ ILC3s normally developed irrespective of DOCK8 expression. However, DOCK8-deficient ILC3s exhibited a severe defect in survival of ILC3s under the condition with or without IL-7. Similar defects were observed when we analyzed Dock8VAGR mice having mutations in the catalytic center of DOCK8, thereby failing to activate Cdc42. Thus, DOCK8 acts in cell-autonomous manner to control survival of ILC3s in the gut through Cdc42 activation.

Clinical, immunological features and follow up of 20 patients with dedicator of cytokinesis 8 (DOCK8) deficiency.

Biallelic mutations in the dedicator of cytokinesis 8 gene (DOCK8) cause a progressive combined immunodeficiency (CID) characterized by susceptibility to severe viral skin infections, atopic diseases, recurrent respiratory infections, and malignancy. Hematopoietic stem cell transplantation (HSCT) is only curative treatment for the disease. However, there is limited information about long‐term outcome of HSCT and its effect to protect against cancer development in DOCK8‐deficient patients. In this study, we retrospectively evaluated clinical and immunologic characteristics of 20 DOCK8‐deficient patients and outcome of 11 patients who underwent HSCT. We aimed to report the experience of our center and the result of the largest transplantation series of DOCK8 deficiency in our country. Median follow‐up time is 71 months (min‐max: 16‐172) in all patients and 48 months (min‐max: 5‐84) in transplanted patients. Atopic dermatitis (18/20), recurrent respiratory tract infections (17/20), and food allergy (14/20) were the most frequent clinical manifestations. Failure to thrive (13/20), liver problems (12/20), bronchiectasis (11/20), chronic diarrhea (10/21), and autism spectrum disorders (3/20) were remarkable findings in our series. Elevated IgE level (20/20) and eosinophilia (17/20), low IgM level (15/20), and decreased CD3+ T (10/20) and CD4+ T (11/20) cell count were prominent laboratory findings. HSCT was performed in 11 patients. All patients achieved adequate engraftment and showed improvement in their clinical and immunologic findings. Atopic dermatitis and food allergies improved in all patients, and their dietary restriction was stopped except one patient who was transplanted recently. The frequency of infections was decreased. The overall survival is 91% in HSCT‐received patients and 80% in all. HSCT at the earliest possible period with most suitable donor‐ and patient‐specific appropriate conditioning regimen and GvHD prophylaxis is lifesaving for DOCK8 deficiency cases.