Pregnenolone sulfate induces transcriptional and immunoregulatory effects on T cells.

Pregnenolone sulfate is a steroid metabolite of the steroidogenesis precursor, pregnenolone, with similar functional properties, including immunosuppression. We recently reported an elevation in serum levels of pregnenolone sulfate in children with malaria, contributing to an immunosuppressed state. Yet, the molecular mechanisms in which this steroid exerts its immunoregulatory functions are lacking. In this study, we examined the effects of pregnenolone sulfate on T cell viability, proliferation and transcriptome. We observed a pregnenolone sulfate dose-dependent induction of T cell death and reduction in proliferation. RNA sequencing analysis of pregnenolone sulfate-treated T cells for 2 and 24 h revealed the downregulation of pro-inflammatory genes and the upregulation of the steroid nuclear receptor superfamily, NR4A, as early-response genes. We also report a strong activation of the integrated stress response mediated by the upregulation of EIF2AK3. These results contribute to the knowledge on transcriptional regulation driving the immunoregulatory effects of pregnenolone sulfate on T cells.

Biallelic NFATC1 mutations cause an inborn error of immunity with impaired CD8+ T-cell function and perturbed glycolysis.

The nuclear factor of activated T cells (NFAT) family of transcription factors plays central roles in adaptive immunity in murine models; however, their contribution to human immune homeostasis remains poorly defined. In a multigenerational pedigree, we identified 3 patients who carry germ line biallelic missense variants in NFATC1, presenting with recurrent infections, hypogammaglobulinemia, and decreased antibody responses. The compound heterozygous NFATC1 variants identified in these patients caused decreased stability and reduced the binding of DNA and interacting proteins. We observed defects in early activation and proliferation of T and B cells from these patients, amenable to rescue upon genetic reconstitution. Stimulation induced early T-cell activation and proliferation responses were delayed but not lost, reaching that of healthy controls at day 7, indicative of an adaptive capacity of the cells. Assessment of the metabolic capacity of patient T cells revealed that NFATc1 dysfunction rendered T cells unable to engage in glycolysis after stimulation, although oxidative metabolic processes were intact. We hypothesized that NFATc1-mutant T cells could compensate for the energy deficit due to defective glycolysis by using enhanced lipid metabolism as an adaptation, leading to a delayed, but not lost, activation responses. Indeed, we observed increased 13C-labeled palmitate incorporation into citrate, indicating higher fatty acid oxidation, and we demonstrated that metformin and rosiglitazone improved patient T-cell effector functions. Collectively, enabled by our molecular dissection of the consequences of loss-of-function NFATC1 mutations and extending the role of NFATc1 in human immunity beyond receptor signaling, we provide evidence of metabolic plasticity in the context of impaired glycolysis observed in patient T cells, alleviating delayed effector responses.

Treatment Strategies for Chronic Pruritus and Eczema/Dermatitis in Older Adults Under the Category of Chronic Eczematous Eruptions of Aging (CEEA).

Chronic eczematous eruptions of aging (CEEA) refers to a heterogenous group of longstanding, pruritic eczematous dermatoses with an unidentified etiology, or those which do not meet strict disease criteria. The literature has not yet established a single ubiquitous disease or term for these eruptions in adults over the age of 65 years. Instead, CEEA is attributed various names, including immunologic eruption of aging, and eruption of immunosenescence. Atopic dermatitis in the elderly, eczema in the elderly, and late- or adult-onset atopic dermatitis or eczema likely also fall under the umbrella of CEEA, given that older patients often do not meet strict criteria for atopic dermatitis. As a reflection of such terminological heterogeneity, CEEA does not have a standardized workup algorithm. This lack of uniformity can obscure the ability to study and understand appropriate treatments for this condition. Yet, as providers become increasingly aware of CEEA and more comfortable in making this diagnosis in older adults, it is necessary that dermatologists understand the safety and efficacy of common CEEA treatments in this population. Here, we discuss special considerations, challenges, and recommendations for treating older adults with CEEA with topical and systemic therapeutics. We provide an overview of therapeutic strategies and potential barriers to treatment and discuss the essential role of shared decision making when caring for this patient population.

Identification of germline monoallelic mutations in IKZF2 in patients with immune dysregulation.

Helios, encoded by IKZF2, is a member of the Ikaros family of transcription factors with pivotal roles in T-follicular helper, NK- and T-regulatory cell physiology. Somatic IKZF2 mutations are frequently found in lymphoid malignancies. Although germline mutations in IKZF1 and IKZF3 encoding Ikaros and Aiolos have recently been identified in patients with phenotypically similar immunodeficiency syndromes, the effect of germline mutations in IKZF2 on human hematopoiesis and immunity remains enigmatic. We identified germline IKZF2 mutations (one nonsense (p.R291X)- and 4 distinct missense variants) in six patients with systemic lupus erythematosus, immune thrombocytopenia or EBV-associated hemophagocytic lymphohistiocytosis. Patients exhibited hypogammaglobulinemia, decreased number of T-follicular helper and NK cells. Single-cell RNA sequencing of PBMCs from the patient carrying the R291X variant revealed upregulation of proinflammatory genes associated with T-cell receptor activation and T-cell exhaustion. Functional assays revealed the inability of HeliosR291X to homodimerize and bind target DNA as dimers. Moreover, proteomic analysis by proximity-dependent Biotin Identification revealed aberrant interaction of 3/5 Helios mutants with core components of the NuRD complex conveying HELIOS-mediated epigenetic and transcriptional dysregulation.

Germline biallelic mutation affecting the transcription factor Helios causes pleiotropic defects of immunity.

Helios, a member of the Ikaros family of transcription factors, is predominantly expressed in developing thymocytes, activated T cells, and regulatory T cells (Tregs). Studies in mice have emphasized its role in maintenance of Treg immunosuppressive functions by stabilizing Foxp3 expression and silencing the Il2 locus. However, its contribution to human immune homeostasis and the precise mechanisms by which Helios regulates other T cell subsets remain unresolved. Here, we investigated a patient with recurrent respiratory infections and hypogammaglobulinemia and identified a germline homozygous missense mutation in IKZF2 encoding Helios (p.Ile325Val). We found that HeliosI325V retains DNA binding and dimerization properties but loses interaction with several partners, including epigenetic remodelers. Whereas patient Tregs showed increased IL-2 production, patient conventional T cells had decreased accessibility of the IL2 locus and consequently reduced IL-2 production. Reduced chromatin accessibility was not exclusive to the IL2 locus but involved a variety of genes associated with T cell activation. Single-cell RNA sequencing of peripheral blood mononuclear cells revealed gene expression signatures indicative of a shift toward a proinflammatory, effector-like status in patient CD8+ T cells. Moreover, patient CD4+ T cells exhibited a pronounced defect in proliferation with delayed expression of surface checkpoint inhibitors, suggesting an impaired onset of the T cell activation program. Collectively, we identified a previously uncharacterized, germline-encoded inborn error of immunity and uncovered a cell-specific defect in Helios-dependent epigenetic regulation. Binding of Helios with specific partners mediates this regulation, which is ultimately necessary for the transcriptional programs that enable T cell homeostasis in health and disease.

Germline IKAROS dimerization haploinsufficiency causes hematologic cytopenias and malignancies.

IKAROS is a transcription factor forming homo- and heterodimers and regulating lymphocyte development and function. Germline mutations affecting the IKAROS N-terminal DNA binding domain, acting in a haploinsufficient or dominant-negative manner, cause immunodeficiency. Herein, we describe 4 germline heterozygous IKAROS variants affecting its C-terminal dimerization domain, via haploinsufficiency, in 4 unrelated families. Index patients presented with hematologic disease consisting of cytopenias (thrombocytopenia, anemia, neutropenia)/Evans syndrome and malignancies (T-cell acute lymphoblastic leukemia, Burkitt lymphoma). These dimerization defective mutants disrupt homo- and heterodimerization in a complete or partial manner, but they do not affect the wild-type allele function. Moreover, they alter key mechanisms of IKAROS gene regulation, including sumoylation, protein stability, and the recruitment of the nucleosome remodeling and deacetylase complex; none affected in N-terminal DNA binding defects. These C-terminal dimerization mutations are largely associated with hematologic disorders, display dimerization haploinsufficiency and incomplete clinical penetrance, and differ from previously reported allelic variants in their mechanism of action. Dimerization mutants contribute to the growing spectrum of IKAROS-associated diseases displaying a genotype-phenotype correlation.

CD137 deficiency causes immune dysregulation with predisposition to lymphomagenesis.

Dysregulated immune responses are essential underlying causes of a plethora of pathologies including cancer, autoimmunity, and immunodeficiency. We here investigated 4 patients from unrelated families presenting with immunodeficiency, autoimmunity, and malignancy. We identified 4 distinct homozygous mutations in TNFRSF9 encoding the tumor necrosis factor receptor superfamily member CD137/4-1BB, leading to reduced, or loss of, protein expression. Lymphocytic responses crucial for immune surveillance, including activation, proliferation, and differentiation, were impaired. Genetic reconstitution of CD137 reversed these defects. CD137 deficiency is a novel inborn error of human immunity characterized by lymphocytic defects with early-onset Epstein-Barr virus (EBV)-associated lymphoma. Our findings elucidate a functional role and relevance of CD137 in human immune homeostasis and antitumor responses.

Loss of the interleukin-6 receptor causes immunodeficiency, atopy, and abnormal inflammatory responses.

IL-6 excess is central to the pathogenesis of multiple inflammatory conditions and is targeted in clinical practice by immunotherapy that blocks the IL-6 receptor encoded by IL6R We describe two patients with homozygous mutations in IL6R who presented with recurrent infections, abnormal acute-phase responses, elevated IgE, eczema, and eosinophilia. This study identifies a novel primary immunodeficiency, clarifying the contribution of IL-6 to the phenotype of patients with mutations in IL6ST, STAT3, and ZNF341, genes encoding different components of the IL-6 signaling pathway, and alerts us to the potential toxicity of drugs targeting the IL-6R.

The Connected Intensive Care Unit Patient: Exploratory Analyses and Cohort Discovery From a Critical Care Telemedicine Database.

BACKGROUND: Many intensive care units (ICUs) utilize telemedicine in response to an expanding critical care patient population, off-hours coverage, and intensivist shortages, particularly in rural facilities. Advances in digital health technologies, among other reasons, have led to the integration of active, well-networked critical care telemedicine (tele-ICU) systems across the United States, which in turn, provide the ability to generate large-scale remote monitoring data from critically ill patients. OBJECTIVE: The objective of this study was to explore opportunities and challenges of utilizing multisite, multimodal data acquired through critical care telemedicine. Using a publicly available tele-ICU, or electronic ICU (eICU), database, we illustrated the quality and potential uses of remote monitoring data, including cohort discovery for secondary research. METHODS: Exploratory analyses were performed on the eICU Collaborative Research Database that includes deidentified clinical data collected from adult patients admitted to ICUs between 2014 and 2015. Patient and ICU characteristics, top admission diagnoses, and predictions from clinical scoring systems were extracted and analyzed. Additionally, a case study on respiratory failure patients was conducted to demonstrate research prospects using tele-ICU data. RESULTS: The eICU database spans more than 200 hospitals and over 139,000 ICU patients across the United States with wide-ranging clinical data and diagnoses. Although mixed medical-surgical ICU was the most common critical care setting, patients with cardiovascular conditions accounted for more than 20% of ICU stays, and those with neurological or respiratory illness accounted for nearly 15% of ICU unit stays. The case study on respiratory failure patients showed that cohort discovery using the eICU database can be highly specific, albeit potentially limiting in terms of data provenance and sparsity for certain types of clinical questions. CONCLUSIONS: Large-scale remote monitoring data sources, such as the eICU database, have a strong potential to advance the role of critical care telemedicine by serving as a testbed for secondary research as well as for developing and testing tools, including predictive and prescriptive analytical solutions and decision support systems. The resulting tools will also inform coordination of care for critically ill patients, intensivist coverage, and the overall process of critical care telemedicine.

Selective loss of function variants in IL6ST cause Hyper-IgE syndrome with distinct impairments of T-cell phenotype and function.

Hyper-IgE syndromes comprise a group of inborn errors of immunity. STAT3-deficient hyper-IgE syndrome is characterized by elevated serum IgE levels, recurrent infections and eczema, and characteristic skeletal anomalies. A loss-of-function biallelic mutation in IL6ST encoding the GP130 receptor subunit (p.N404Y) has very recently been identified in a singleton patient (herein referred to as PN404Y) as a novel etiology of hyper-IgE syndrome. Here, we studied a patient with hyper-IgE syndrome caused by a novel homozygous mutation in IL6ST (p.P498L; patient herein referred to as PP498L) leading to abrogated GP130 signaling after stimulation with IL-6 and IL-27 in peripheral blood mononuclear cells as well as IL-6 and IL-11 in fibroblasts. Extending the initial identification of selective GP130 deficiency, we aimed to dissect the effects of aberrant cytokine signaling on T-helper cell differentiation in both patients. Our results reveal the importance of IL-6 signaling for the development of CCR6-expressing memory CD4+ T cells (including T-helper 17-enriched subsets) and non-conventional CD8+T cells which were reduced in both patients. Downstream functional analysis of the GP130 mutants (p.N404Y and p.P498L) have shown differences in response to IL-27, with the p.P498L mutation having a more severe effect that is reflected by reduced T-helper 1 cells in this patient (PP498L) only. Collectively, our data suggest that characteristic features of GP130-deficient hyper-IgE syndrome phenotype are IL-6 and IL-11 dominated, and indicate selective roles of aberrant IL-6 and IL-27 signaling on the differentiation of T-cell subsets.

Tissue Augmentation with Allograft Adipose Matrix For the Diabetic Foot in Remission.

BACKGROUND: Repetitive stress on the neuropathic plantar foot is the primary cause of diabetic foot ulcers. After healing, recurrence is common. Modulating plantar pressure has been associated with extension of ulcer free days. Therefore, the goal of this study was to determine the effects of an injectable allograft adipose matrix in providing a protective padding and reducing the pressure in the plantar foot. METHODS: After healing his recurrent ulcer using total contact casting, a 71-year-old man with a 9-year history of recurrent diabetic foot ulcers was treated with injection of allograft adipose matrix, procured from donated human tissue. This was delivered under postulcerative callus on the weight-bearing surface of the distal end of the first ray resection. As is standard in our clinic for tissue augmentation procedures, our patient underwent serial plantar pressure mapping using an in-shoe pressure monitoring system. RESULTS: There was a 76.8% decrease in the mean peak pressure due to the fat matrix injected into the second metatarsal region and a 70.1% decrease in mean peak pressure for the first ray resection at the site of the postulcerative callus. By 2 months postoperatively, there was no evidence of residual callus. This extended out to the end of clinical follow-up at 4 months. CONCLUSION: The results from this preliminary experience suggest that allograft adipose matrix delivered to the high risk diabetic foot may have promise in reducing tissue stress over pre- and postulcerative lesions. This may ultimately assist the clinician in extending ulcer-free days for patients in diabetic foot remission.