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1.
Immunology ; 2024 May 22.
Article in English | MEDLINE | ID: mdl-38778445

ABSTRACT

Cytokines of the common-γ receptor chain (γc) family are crucial for T-cell differentiation and dysregulation of γc cytokine pathways is involved in the pathogenesis of autoimmune diseases. There is increasing evidence that the availability of the γc receptor (CD132) for the associated receptor chains has implications for T-cell functions. Here we studied the influence of differential γc expression on the expression of the IL-2Rα (CD25), the IL-7Rα (CD127) and the differentiation of activated naïve T cells. We fine-tuned the regulation of γc expression in human primary naïve T cells by lentiviral transduction using small hairpin (sh)RNAs and γc cDNA. Differential γc levels were then analysed for effects on T-cell phenotype and function after activation. Differential γc expression markedly affected IL-2Rα and IL-7Rα expression on activated naïve T cells. High γc expression (γc-high) induced significantly higher expression of IL-2Rα and re-expression of IL-7Rα after activation. Inhibition of γc caused lower IL-2Rα/IL-7Rα expression and impaired proliferation of activated naïve T cells. In contrast, γc-high T cells secreted significantly higher concentrations of effector cytokines (i.e., IFN-γ, IL-6) and showed higher cytokine-receptor induced STAT5 phosphorylation during initial stages as well as persistently higher pSTAT1 and pSTAT3 levels after activation. Finally, accelerated transition towards a CD45RO expressing effector/memory phenotype was seen especially for CD4+ γc-high naïve T cells. These results suggested that high expression of γc promotes expression of IL-2Rα and IL-7Rα on activated naïve T cells with significant effects on differentiation and effector cytokine expression.

2.
Horm Metab Res ; 56(3): 223-234, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38168730

ABSTRACT

For treatment of type 1 diabetes mellitus, a combination of immune-based interventions and medication to promote beta-cell survival and proliferation has been proposed. Dextromethorphan (DXM) is an N-methyl-D-aspartate receptor antagonist with a good safety profile, and to date, preclinical and clinical evidence for blood glucose-lowering and islet-cell-protective effects of DXM have only been provided for animals and individuals with type 2 diabetes mellitus. Here, we assessed the potential anti-diabetic effects of DXM in the non-obese diabetic mouse model of type 1 diabetes. More specifically, we showed that DXM treatment led to five-fold higher numbers of pancreatic islets and more than two-fold larger alpha- and beta-cell areas compared to untreated mice. Further, DXM treatment improved glucose homeostasis and reduced diabetes incidence by 50%. Our data highlight DXM as a novel candidate for adjunct treatment of preclinical or recent-onset type 1 diabetes.


Subject(s)
Diabetes Mellitus, Type 1 , Diabetes Mellitus, Type 2 , Islets of Langerhans , Mice , Animals , Mice, Inbred NOD , Dextromethorphan/pharmacology , Dextromethorphan/therapeutic use , Receptors, N-Methyl-D-Aspartate/therapeutic use , Diabetes Mellitus, Type 1/drug therapy , Insulin , Blood Glucose , Homeostasis
3.
Eur J Clin Microbiol Infect Dis ; 43(3): 611-616, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38167987

ABSTRACT

Impaired T-cell responses to mitogens and high T-cell activation marker (TAM) expression on Mycobacterium tuberculosis-specific T-cells characterize immunopathology in patients with tuberculosis (TB). In a study of patients with TB (n = 60) and asymptomatic contacts (controls, n = 37), we found that TB patients had higher CD38+ T-cell proportions specific for M. tuberculosis protein (PPDMtb), yet total proportions of PPDMtb-specific T-cells were comparable. Notably, both activated (CD38+) and total IFN-γ+ T-cells from TB patients had lower mitogen (phytohemagglutinin, PHA)-induced responses. This impaired mitogen response improved the classification efficacy of the TAM-TB assay, especially employing the PPD/PHA-induced T-cell ratio.


Subject(s)
Mycobacterium tuberculosis , Tuberculosis , Humans , Mitogens/pharmacology , Tuberculin , T-Lymphocytes , Antigens, Bacterial
4.
Int J Mol Sci ; 25(2)2024 01 20.
Article in English | MEDLINE | ID: mdl-38279270

ABSTRACT

The BiP co-chaperone DNAJC3 protects cells during ER stress. In mice, the deficiency of DNAJC3 leads to beta-cell apoptosis and the gradual onset of hyperglycemia. In humans, biallelic DNAJC3 variants cause a multisystem disease, including early-onset diabetes mellitus. Recently, hyperinsulinemic hypoglycemia (HH) has been recognized as part of this syndrome. This report presents a case study of an individual with HH caused by DNAJC3 variants and provides an overview of the metabolic phenotype of individuals with HH and DNAJC3 variants. The study demonstrates that HH may be a primary symptom of DNAJC3 deficiency and can persist until adolescence. Additionally, glycemia and insulin release were analyzed in young DNACJ3 knockout (K.O.) mice, which are equivalent to human infants. In the youngest experimentally accessible age group of 4-week-old mice, the in vivo glycemic phenotype was already dominated by a reduced total insulin secretion capacity. However, on a cellular level, the degree of insulin release of DNAJC3 K.O. islets was higher during periods of increased synthetic activity (high-glucose stimulation). We propose that calcium leakage from the ER into the cytosol, due to disrupted DNAJC3-controlled gating of the Sec61 channel, is the most likely mechanism for HH. This is the first genetic mechanism explaining HH solely by the disruption of intracellular calcium homeostasis. Clinicians should screen for HH in DNAJC3 deficiency and consider DNAJC3 variants in the differential diagnosis of congenital hyperinsulinism.


Subject(s)
Congenital Hyperinsulinism , HSP40 Heat-Shock Proteins , Adolescent , Animals , Humans , Mice , Calcium/metabolism , Congenital Hyperinsulinism/genetics , HSP40 Heat-Shock Proteins/genetics , HSP40 Heat-Shock Proteins/metabolism , Insulin/metabolism , Insulin Secretion , Molecular Chaperones/genetics , Molecular Chaperones/metabolism
5.
Clin Infect Dis ; 76(3): e1399-e1407, 2023 02 08.
Article in English | MEDLINE | ID: mdl-35657028

ABSTRACT

BACKGROUND: Doxycycline is used for treatment of Mansonella perstans infection. Immune modulatory effects of both M. perstans and doxycycline have been described but long-term implications on host immune response are not defined. Here we determined multiple immune parameters of M. perstans-infected individuals before and after doxycycline treatment to characterize doxycycline effects on host T-cell immunity. METHODS: Immune characterization of doxycycline-treated M. perstans-infected individuals was performed as part of an open-label randomized clinical trial. Immune cell population phenotyping by flow cytometry and functional in vitro T-cell assays were performed at baseline, 6 months, and "long term" (18-24 months) after treatment start. Treatment efficacy, based on peripheral blood microfilaria (mf) burden, was correlated with immune parameters and effects on immune response against concomitant Mycobacterium tuberculosis infection were determined. RESULTS: Immune population phenotyping indicated changes in functional T-cell responses after doxycycline treatment. Constitutive and superantigen-induced T-cell activation and polarization towards T-helper type (TH) 1 phenotype at baseline declined after doxycycline treatment, whereas low proportions of TH17 and TH1* cells at baseline increased significantly at follow-up. In accordance, long-term decline in antigen-specific TH1 responses against concomitant M. tuberculosis infection was seen. Notably, only TH17 and TH1* changes after 6 months and TH17 at baseline were negatively correlated with M. perstans microfilaria burden or reduction, whereas long-term changes were not associated with treatment efficacy. CONCLUSIONS: We found long-term immune modulatory effects of doxycycline treatment leading to decreased constitutive T-cell activation, polarization towards TH17/TH1*, and impaired immune response against concomitant M. tuberculosis infection.


Subject(s)
Mansonella , Mansonelliasis , T-Lymphocytes , Animals , Doxycycline/therapeutic use , Mansonelliasis/epidemiology , Treatment Outcome
6.
Immunology ; 170(1): 154-166, 2023 09.
Article in English | MEDLINE | ID: mdl-37219921

ABSTRACT

Monocyte-derived macrophages contribute centrally to immune protection in Mycobacterium tuberculosis infection and changes in monocyte phenotype characterize immunopathology in tuberculosis patients. Recent studies highlighted an important role of the plasma milieu in tuberculosis immunopathology. Here, we investigated monocyte pathology in patients with acute tuberculosis and determined tuberculosis plasma milieu effects on phenotype as well as cytokine signalling of reference monocytes. Patients with tuberculosis (n = 37) and asymptomatic contacts (controls n = 35) were recruited as part of a hospital-based study in the Ashanti region of Ghana. Multiplex flow cytometry phenotyping of monocyte immunopathology was performed and effects of individual blood plasma samples on reference monocytes prior to and during treatment were characterized. Concomitantly, cell signalling pathways were analysed to elucidate underlying mechanisms of plasma effects on monocytes. Multiplex flow cytometry visualization characterized changes in monocyte subpopulations and detected higher expression of CD40, CD64 and PD-L1 in monocytes from tuberculosis patients as compared to controls. Aberrant expression normalized during anti-mycobacterial treatment and also CD33 expression decreased markedly. Notably, higher CD33, CD40 and CD64 expression was induced in reference monocytes when cultured in the presence of plasma samples from tuberculosis patients as compared to controls. STAT signalling pathways were affected by the aberrant plasma milieu and higher levels of STAT3 and STAT5 phosphorylation was found in tuberculosis plasma-treated reference monocytes. Importantly, high pSTAT3 levels were associated with high CD33 expression and pSTAT5 correlated with CD40 as well as CD64 expression. These results suggested plasma milieu effects with potential implications on monocyte phenotype and function in acute tuberculosis.


Subject(s)
Monocytes , Tuberculosis , Humans , Macrophages , CD40 Antigens , Plasma
7.
Am J Hum Genet ; 106(2): 246-255, 2020 02 06.
Article in English | MEDLINE | ID: mdl-32004447

ABSTRACT

Ral (Ras-like) GTPases play an important role in the control of cell migration and have been implicated in Ras-mediated tumorigenicity. Recently, variants in RALA were also described as a cause of intellectual disability and developmental delay, indicating the relevance of this pathway to neuropediatric diseases. Here, we report the identification of bi-allelic variants in RALGAPA1 (encoding Ral GTPase activating protein catalytic alpha subunit 1) in four unrelated individuals with profound neurodevelopmental disability, muscular hypotonia, feeding abnormalities, recurrent fever episodes, and infantile spasms . Dysplasia of corpus callosum with focal thinning of the posterior part and characteristic facial features appeared to be unifying findings. RalGAPA1 was absent in the fibroblasts derived from two affected individuals suggesting a loss-of-function effect of the RALGAPA1 variants. Consequently, RalA activity was increased in these cell lines, which is in keeping with the idea that RalGAPA1 deficiency causes a constitutive activation of RalA. Additionally, levels of RalGAPB, a scaffolding subunit of the RalGAP complex, were dramatically reduced, indicating a dysfunctional RalGAP complex. Moreover, RalGAPA1 deficiency clearly increased cell-surface levels of lipid raft components in detached fibroblasts, which might indicate that anchorage-dependence of cell growth signaling is disturbed. Our findings indicate that the dysregulation of the RalA pathway has an important impact on neuronal function and brain development. In light of the partially overlapping phenotype between RALA- and RALGAPA1-associated diseases, it appears likely that dysregulation of the RalA signaling pathway leads to a distinct group of genetic syndromes that we suggest could be named RALopathies.


Subject(s)
Feeding and Eating Disorders/etiology , GTPase-Activating Proteins/genetics , Muscle Hypotonia/etiology , Mutation , Nerve Tissue Proteins/genetics , Neurodevelopmental Disorders/etiology , Spasms, Infantile/etiology , Alleles , Cell Movement , Cell Proliferation , Child, Preschool , Family , Feeding and Eating Disorders/pathology , Female , Humans , Infant , Male , Muscle Hypotonia/pathology , Neurodevelopmental Disorders/pathology , Phenotype , Spasms, Infantile/pathology
8.
Eur J Immunol ; 52(6): 958-969, 2022 06.
Article in English | MEDLINE | ID: mdl-35279828

ABSTRACT

Bacterial components and cytokines induce IL-7 receptor (IL-7Rα) expression in monocytes. Aberrant low IL-7Rα expression of monocytes has been identified as a feature of tuberculosis immunopathology. Here, we investigated the mechanisms underlying IL-7Rα regulation of monocytes and tuberculosis serum effects on IL-7Rα expression. Serum samples from tuberculosis patients and healthy controls, cytokine candidates, and mycobacterial components were analyzed for in vitro effects on IL-7Rα expression of primary monocytes, monocyte-derived macrophages (MDM), and monocyte cell lines. IL-7Rα regulation during culture and the role of FoxO1 were characterized. In vitro activation-induced IL-7Rα expression in human monocytes and serum samples from tuberculosis patients boosted IL-7Rα expression. Although pathognomonic tuberculosis cytokines were not associated with serum effects, we identified cytokines (i.e., GM-CSF, IL-1ß, TNF-α, IFN-γ) that induced IL-7Rα expression in monocytes and/or MDM comparable to mycobacterial components. Blocking of cytokine subsets (i.e., IL-1ß/TNF-α in monocytes, GM-CSF in MDM) largely diminished IL-7Rα expression induced by mycobacterial components. Finally, we showed that in vitro-induced IL-7Rα expression was transient and dependent on constitutive FoxO1 expression in primary monocytes and monocyte cell lines. This study demonstrated the crucial roles of cytokines and constitutive FoxO1 expression for transient IL-7Rα expression in monocytes.


Subject(s)
Interleukin-7 Receptor alpha Subunit/metabolism , Monocytes , Tuberculosis , Cells, Cultured , Cytokines/metabolism , Granulocyte-Macrophage Colony-Stimulating Factor/metabolism , Humans , Monocytes/metabolism , Tuberculosis/microbiology , Tumor Necrosis Factor-alpha/metabolism
9.
Genet Med ; 25(7): 100836, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37013901

ABSTRACT

PURPOSE: Rothmund-Thomson syndrome (RTS) is characterized by poikiloderma, sparse hair, small stature, skeletal defects, cancer, and cataracts, resembling features of premature aging. RECQL4 and ANAPC1 are the 2 known disease genes associated with RTS in >70% of cases. We describe RTS-like features in 5 individuals with biallelic variants in CRIPT (OMIM 615789). METHODS: Two newly identified and 4 published individuals with CRIPT variants were systematically compared with those with RTS using clinical data, computational analysis of photographs, histologic analysis of skin, and cellular studies on fibroblasts. RESULTS: All CRIPT individuals fulfilled the diagnostic criteria for RTS and additionally had neurodevelopmental delay and seizures. Using computational gestalt analysis, CRIPT individuals showed greatest facial similarity with individuals with RTS. Skin biopsies revealed a high expression of senescence markers (p53/p16/p21) and the senescence-associated ß-galactosidase activity was elevated in CRIPT-deficient fibroblasts. RECQL4- and CRIPT-deficient fibroblasts showed an unremarkable mitotic progression and unremarkable number of mitotic errors and no or only mild sensitivity to genotoxic stress by ionizing radiation, mitomycin C, hydroxyurea, etoposide, and potassium bromate. CONCLUSION: CRIPT causes an RTS-like syndrome associated with neurodevelopmental delay and epilepsy. At the cellular level, RECQL4- and CRIPT-deficient cells display increased senescence, suggesting shared molecular mechanisms leading to the clinical phenotypes.


Subject(s)
Rothmund-Thomson Syndrome , Humans , Rothmund-Thomson Syndrome/genetics , Rothmund-Thomson Syndrome/diagnosis , Rothmund-Thomson Syndrome/pathology , Cellular Senescence/genetics , DNA Damage , Hydroxyurea/metabolism , Fibroblasts , Mutation , Adaptor Proteins, Signal Transducing/metabolism
10.
Genet Med ; 25(7): 100838, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37057673

ABSTRACT

PURPOSE: Mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) regulates cell growth in response to nutritional status. Central to the mTORC1 function is the Rag-GTPase heterodimer. One component of the Rag heterodimer is RagC (Ras-related GTP-binding protein C), which is encoded by the RRAGC gene. METHODS: Genetic testing via trio exome sequencing was applied to identify the underlying disease cause in 3 infants with dilated cardiomyopathy, hepatopathy, and brain abnormalities, including pachygyria, polymicrogyria, and septo-optic dysplasia. Studies in patient-derived skin fibroblasts and in a HEK293 cell model were performed to investigate the cellular consequences. RESULTS: We identified 3 de novo missense variants in RRAGC (NM_022157.4: c.269C>A, p.(Thr90Asn), c.353C>T, p.(Pro118Leu), and c.343T>C, p.(Trp115Arg)), which were previously reported as occurring somatically in follicular lymphoma. Studies of patient-derived fibroblasts carrying the p.(Thr90Asn) variant revealed increased cell size, as well as dysregulation of mTOR-related p70S6K (ribosomal protein S6 kinase 1) and transcription factor EB signaling. Moreover, subcellular localization of mTOR was decoupled from metabolic state. We confirmed the key findings for all RRAGC variants described in this study in a HEK293 cell model. CONCLUSION: The above results are in line with a constitutive overactivation of the mTORC1 pathway. Our study establishes de novo missense variants in RRAGC as cause of an early-onset mTORopathy with unfavorable prognosis.


Subject(s)
Mechanistic Target of Rapamycin Complex 1 , Monomeric GTP-Binding Proteins , TOR Serine-Threonine Kinases , Humans , Infant , Fibroblasts/metabolism , Genetic Diseases, Inborn/genetics , HEK293 Cells , Mechanistic Target of Rapamycin Complex 1/genetics , Monomeric GTP-Binding Proteins/genetics , Monomeric GTP-Binding Proteins/metabolism , Multiprotein Complexes/genetics , Mutation, Missense , TOR Serine-Threonine Kinases/genetics , TOR Serine-Threonine Kinases/metabolism
11.
J Pediatr ; 258: 113399, 2023 07.
Article in English | MEDLINE | ID: mdl-37019330

ABSTRACT

We describe 16 infants born preterm with birth weights <1500 g and transient hyperinsulinism. The onset of hyperinsulinism was delayed and often coincident with clinical stabilization. We hypothesize that postnatal stress caused by prematurity and associated problems may contribute to development of delayed-onset transient hyperinsulinism.


Subject(s)
Hyperinsulinism , Hypoglycemia , Pancreatic Diseases , Infant, Newborn , Humans , Infant , Hypoglycemia/complications , Hypoglycemia/diagnosis , Cohort Studies , Infant, Extremely Low Birth Weight , Hyperinsulinism/complications , Infant, Premature , Pancreatic Diseases/complications
12.
Infection ; 51(1): 169-179, 2023 Feb.
Article in English | MEDLINE | ID: mdl-35759173

ABSTRACT

BACKGROUND: Mycobacterium (M.) tuberculosis-caused immunopathology is characterized by aberrant expression of plasma cytokines in human tuberculosis. Disease severity and long-term anti-mycobacterial treatment are potentially influenced by immunopathology and normalization of plasma cytokine levels during therapy may indicate treatment efficacy and recovery. STUDY DESIGN AND METHODS: In this study, we analyzed the concentrations of selected plasma cytokines (i.e., IL-6, IP-10, IL-10, IL-22, IFNγ, GM-CSF, IL-8) and M. tuberculosis sputum burden in patients with tuberculosis (n = 76). Cytokine levels were compared to healthy contacts (n = 40) and changes under treatment were monitored (i.e., 6 and 16 weeks after treatment start). According to differences in M. tuberculosis sputum burden and conversion, tuberculosis patients were classified as paucibacillary as well as 'rapid' or 'slow' treatment responders. A subgroup of tuberculosis patients had fatal disease courses. RESULTS: Six of seven cytokines were significantly higher in tuberculosis patients as compared to contacts and four of these (i.e., IL-6, IP-10, IL-10, and IL-22) were detectable in the majority of tuberculosis patients. IL-6 showed the strongest discriminating capacity for tuberculosis disease and in combination with IL-10 concentrations efficiently classified paucibacillary tuberculosis cases as well as those with fatal disease outcome. In addition, IL-6 and IP-10 levels decreased significantly after 6 weeks of treatment and analyses of subgroups with differential treatment response showed delayed decline of IL-6 levels in slow treatment responders. CONCLUSIONS: Combinations of different plasma cytokine (namely, IL-6, IL-10, and IP-10) efficiently classified tuberculosis patients with differential mycobacterial burden and especially IL-6 qualified as a biomarker candidate for early treatment response.


Subject(s)
Mycobacterium tuberculosis , Tuberculosis , Humans , Cytokines , Interleukin-10 , Chemokine CXCL10 , Interleukin-6 , Tuberculosis/drug therapy , Tuberculosis/microbiology
13.
Infection ; 51(4): 1013-1023, 2023 Aug.
Article in English | MEDLINE | ID: mdl-36650358

ABSTRACT

PURPOSE: Human tuberculosis is characterized by immunopathology that affects T-cell phenotype and functions. Previous studies found impaired T-cell response to phytohemagglutinin (PHA) in patients with acute tuberculosis. However, the influence of disease severity, affected T-cell subsets, and underlying mechanisms remain elusive. METHODS: Here we investigated PHA-induced and antigen-specific T-cell effector cytokines in tuberculosis patients (n = 55) as well as in healthy asymptomatic contacts (n = 32) from Ghana. Effects of Mycobacterium (M.) tuberculosis sputum burden and treatment response were analyzed and compared during follow-up. Finally, cytokine characteristics of the aberrant plasma milieu in tuberculosis were analyzed as a potential cause for impaired PHA response. RESULTS: PHA-induced IFN-γ expression was significantly lower in sputum-positive tuberculosis patients as compared to both, contacts and paucibacillary cases, and efficiently discriminated the study groups. T-cell responses to PHA increased significantly early during treatment and this was more pronounced in tuberculosis patients with rapid treatment response. Analysis of alternative cytokines revealed distinct patterns and IL-22, as well as IL-10, showed comparable expression to IFN-γ in response to PHA. Finally, we found that high IL-6 plasma levels were strongly associated with impaired IFN-γ and IL-22 response to PHA. CONCLUSION: We conclude that impaired T-cell response to PHA stimulation in acute tuberculosis patients (i) was potentially caused by the aberrant plasma milieu, (ii) affected differentially polarized T-cell subsets, (iii) normalized early during treatment. This study shed light on the mechanisms of impaired T-cell functions in tuberculosis and yielded promising biomarker candidates for diagnosis and monitoring of treatment response.


Subject(s)
Interleukin-6 , T-Lymphocytes , Tuberculosis , Humans , Cytokines/metabolism , Interleukin-6/blood , Mycobacterium tuberculosis , Phytohemagglutinins/pharmacology , T-Lymphocytes/immunology , Tuberculosis/drug therapy , Interferon-gamma , Interleukin-22
14.
BMC Infect Dis ; 23(1): 393, 2023 Jun 12.
Article in English | MEDLINE | ID: mdl-37308884

ABSTRACT

BACKGROUND: Buruli ulcer disease (BUD) caused by Mycobacterium (M.) ulcerans is characterized by necrotic skin lesions. As for other mycobacterial infections, e.g., tuberculosis, the immune response is important for host protection. B-cells may play a role in antimycobacterial immunity but studies characterizing the B-cell repertoire and memory generation in BUD and during the course of treatment are scarce. METHODS: We investigated the adaptive immune cell repertoire in children with BUD and healthy matched controls by flow cytometry. Analyses prior to treatment, also in a study group of patients with tuberculosis, as well as three time points during BUD treatment (i.e., week 8, 16, and 32) were performed. In addition, BUD disease severity as well as treatment response were analysed for association with B-cell repertoire differences. RESULTS: Children with BUD had comparable total B- and T-cell proportions but differed largely in B-cell subsets. Memory B-cell (B mem) proportions were higher in children with BUD whereas regulatory B-cell (B reg) proportions were lower as compared to healthy controls and tuberculosis patients. Lower naïve (B naïve) and higher transitional B-cell (B trans) proportions characterized children with BUD in comparison with tuberculosis patients. Under treatment, B mem proportions decreased significantly whereas proportions of B reg and B naive increased concomitantly in children with BUD. Also, we found significant correlation between lesion size and B mem as well as B reg. However, we did not detect associations between treatment efficacy and B-cell proportions. CONCLUSIONS: These results suggest a role of B-cell subsets in the immune response against M. ulcerans. Furthermore, changes in B-cell subset proportions may be used as markers for treatment monitoring in BUD.


Subject(s)
Buruli Ulcer , Mycobacterium Infections , Child , Humans , Memory B Cells , B-Lymphocytes , Flow Cytometry
15.
J Immunol ; 206(10): 2430-2440, 2021 05 15.
Article in English | MEDLINE | ID: mdl-33911006

ABSTRACT

Altered monocyte differentiation and effector functions characterize immune pathogenesis of tuberculosis. IL-7 is an important factor for proliferation of T cells and impaired IL-7 sensitivity due to decreased IL-7 receptor α-chain (IL-7Rα) expression was found in patients with acute tuberculosis. Peripheral blood monocytes have moderate IL-7Rα expression and increased IL-7Rα levels were described for inflammatory diseases. In this study, we investigated a potential role of IL-7 and IL-7Rα expression for monocyte functions in tuberculosis. We analyzed the phenotype of monocytes in the blood from tuberculosis patients (n = 33), asymptomatic contacts of tuberculosis patients (contacts; n = 30), and healthy controls (n = 20) from Ghana by multicolor flow cytometry. Mycobacterial components were analyzed for their capacity to induce IL-7Rα expression in monocytes. Functional effects of monocyte to IL-7 were measured during signaling and by using an antimycobacterial in vitro kill assay. Monocytes were more frequent in peripheral blood from patients with tuberculosis and especially higher proportions of CD14+/CD16+ (M1/2) monocytes with increased PD-L1 expression characterized acute tuberculosis. IL-7Rα expression was decreased particularly on M1/2 monocytes from patients with tuberculosis and aberrant low expression IL-7Rα correlated with high PD-L1 levels. Constitutive low pSTAT5 levels of monocytes ex vivo and impaired IL-7 response confirmed functionally decreased monocyte IL-7 sensitivity of patients with tuberculosis. Mycobacteria and mycobacterial cell wall components induced IL-7 receptor expression in monocytes and IL-7 boosted mycobacterial killing by monocyte-derived macrophages in vitro. We demonstrated impaired monocyte IL-7 receptor expression as well as IL-7 sensitivity in tuberculosis with potential effects on antimycobacterial effector functions.


Subject(s)
Asymptomatic Diseases , Monocytes/immunology , Mycobacterium tuberculosis/immunology , Receptors, Interleukin-7/metabolism , Tuberculosis/immunology , Acute Disease , Adolescent , Adult , Aged , Aged, 80 and over , Case-Control Studies , Child , Cohort Studies , Female , Humans , Interleukin-7/metabolism , Macrophages/immunology , Male , Middle Aged , Signal Transduction/immunology , Tuberculosis/blood , Tuberculosis/microbiology , Young Adult
16.
J Med Genet ; 59(9): 878-887, 2022 Sep.
Article in English | MEDLINE | ID: mdl-34656997

ABSTRACT

BACKGROUND: Human coenzyme Q4 (COQ4) is essential for coenzyme Q10 (CoQ10) biosynthesis. Pathogenic variants in COQ4 cause childhood-onset neurodegeneration. We aimed to delineate the clinical spectrum and the cellular consequences of COQ4 deficiency. METHODS: Clinical course and neuroradiological findings in a large cohort of paediatric patients with COQ4 deficiency were analysed. Functional studies in patient-derived cell lines were performed. RESULTS: We characterised 44 individuals from 36 families with COQ4 deficiency (16 newly described). A total of 23 different variants were identified, including four novel variants in COQ4. Correlation analyses of clinical and neuroimaging findings revealed three disease patterns: type 1: early-onset phenotype with neonatal brain anomalies and epileptic encephalopathy; type 2: intermediate phenotype with distinct stroke-like lesions; and type 3: moderate phenotype with non-specific brain pathology and a stable disease course. The functional relevance of COQ4 variants was supported by in vitro studies using patient-derived fibroblast lines. Experiments revealed significantly decreased COQ4 protein levels, reduced levels of cellular CoQ10 and elevated levels of the metabolic intermediate 6-demethoxyubiquinone. CONCLUSION: Our study describes the heterogeneous clinical presentation of COQ4 deficiency and identifies phenotypic subtypes. Cell-based studies support the pathogenic characteristics of COQ4 variants. Due to the insufficient clinical response to oral CoQ10 supplementation, alternative treatment strategies are warranted.


Subject(s)
Mitochondrial Proteins , Ubiquinone , Cell Line , Child , Humans , Infant, Newborn , Mitochondrial Proteins/genetics , Neuroimaging , Phenotype , Ubiquinone/genetics , Ubiquinone/metabolism
17.
Klin Padiatr ; 235(1): 13-22, 2023 Jan.
Article in English | MEDLINE | ID: mdl-35948048

ABSTRACT

BACKGROUND: The COVID-19 pandemic dramatically affects children's and adolescents' mental health. The accumulation of stress factors and a lack of social support complicate a healthy development. Since the beginning of the pandemic, there has been almost a doubling of mental health problems in children and adolescents. Promoting resilience is a possible approach to reduce the incidence of mental health problems despite these adverse circumstances. OBJECTIVES: This literature search aims at identifying and evaluating interventions to promote resilience mechanisms, with a special focus on feasibility in a crisis situation. MATERIALS AND METHODS: This scoping review is based on a systematic literature search including the databases Cochrane Library, PubMed, Psyc-Info, Psyndex and Google Scholar (2006-2020). Of 1733 identified articles 75 were included. RESULTS: Out of 72 identified intervention studies 28% were feasible under pandemic conditions. The most effective resilience trainings seem to be individualized interventions using cognitive behavioral therapy elements. However, many approaches primarily show short-term success. DISCUSSION: Few evidence-based programs are feasible online or under pandemic restrictions. Most of them show short-term effects and focus on parents and individuals. Multiple programs are ready for use, but still lack proof of efficacy. The development and improvement of (digital) resilience interventions should be an essential part of preventive health care, especially for risk groups. HINTERGRUND: Die COVID-19-Pandemie beeinflusst die mentale Gesundheit von Kindern und Jugendlichen auf dramatische Weise. Durch eine Akkumulation von Belastungsfaktoren und das Wegfallen sozialer Unterstützung ist eine regelrechte Entwicklung erschwert. Seit Beginn der Pandemie kam es nahezu zu einer Verdopplung der psychischen Auffälligkeiten. Die Förderung der Resilienz kann ein Ansatz sein, das Auftreten von psychischen Auffälligkeiten trotz dieser widrigen Umstände zu vermindern. ZIEL DER ARBEIT: Ziel dieser Literaturrecherche ist die Identifikation und Bewertung von Interventionen zur Förderung von Resilienzmechanismen, mit Fokus auf die Durchführbarkeit unter Krisenbedingungen. MATERIAL UND METHODEN: Dieses Scoping Review basiert auf einer systematischen Literaturrecherche der Datenbanken Cochrane Library, PubMed, Psyc-Info, Psyndex sowie Google Scholar (2006-2021). Von der insgesamt 1733 Artikel umfassenden Suche wurden 75 Artikel eingeschlossen. ERGEBNISSE: Von 72 identifizierten Interventionsstudien sind 28% unter Pandemiebedingungen durchführbar. Die wirksamsten Resilienztrainings scheinen individualisierte Interventionen mit Elementen der kognitiven Verhaltenstherapie zu sein. Viele Ansätze zeigen jedoch in erster Linie kurzfristige Erfolge. DISKUSSION: Nur wenige evidenzbasierte Programme sind online oder unter Pandemiebedingungen verfügbar. Die meisten von ihnen zeigen kurzfristige Effekte und konzentrieren sich auf Eltern und Einzelpersonen. Zahlreiche Programme sind nutzbar, allerdings fehlt häufig ein Evidenznachweis. Die Entwicklung und Verbesserung von (digitalen) Resilienzmaßnahmen sollte ein wesentlicher Bestandteil der präventiven Gesundheitsversorgung sein, insbesondere für Risikogruppen.


Subject(s)
COVID-19 , Pandemics , Humans , Adolescent , Child , Pandemics/prevention & control
18.
Clin Immunol ; 235: 108928, 2022 02.
Article in English | MEDLINE | ID: mdl-35063672

ABSTRACT

High soluble IL-7 receptor (sIL-7R) serum levels and associated single nucleotide polymorphisms in the IL7RA gene were found in autoimmune diseases including type 1 diabetes. Further determinants on sIL-7R and IL-7 availability as well as changes during type 1 diabetes disease course remain elusive. Here we performed multiparameter analysis to identify influential genetic and disease-associated factors on sIL-7R and IL-7 serum levels during type 1 diabetes disease course (239 children) and in healthy controls (101 children). We found higher sIL-7R serum concentrations at type 1 diabetes onset and decreasing levels during therapy whereas IL-7 was only higher in long term patients as compared to controls. Multiple linear regression analyses revealed several factors, including IL7RA SNP rs6897932 and HLA risk haplotypes, influencing sIL-7R levels but not IL-7, which was solely associated with the sIL-7R. This study revealed unexpected complexity in the regulation of the sIL-7R but not for IL-7.


Subject(s)
Diabetes Mellitus, Type 1/genetics , Histocompatibility Antigens Class I/genetics , Interleukin-7/metabolism , Polymorphism, Genetic , Receptors, Interleukin-7/metabolism , Adolescent , Child , Genetic Predisposition to Disease , Haplotypes , Humans , Interleukin-7/genetics , Receptors, Interleukin-7/genetics
19.
Eur J Immunol ; 51(12): 3214-3227, 2021 12.
Article in English | MEDLINE | ID: mdl-34625948

ABSTRACT

The important role of IL-7 in the generation of self-reactive T-cells in autoimmune diseases is well established. Recent studies on autoimmunity-associated genetic polymorphisms indicated that differential IL-7 receptor (IL-7R) expression of monocytes may play a role in the underlying pathogenesis. The relevance of IL-7-mediated monocyte functions in type 1 diabetes remains elusive. In the present study, we characterized monocyte phenotype and IL-7-mediated effects in children with type 1 diabetes and healthy controls with multicolor flow cytometry and t-distributed Stochastic Neighbor-Embedded (t-SNE)-analyses. IL-7R expression of monocytes rapidly increased in vitro and was boosted through LPS. In the presence of IL-7, we detected lower monocyte IL-7R expression in type 1 diabetes patients as compared to healthy controls. This difference was most evident for the subset of nonclassical monocytes, which increased after IL-7 stimulation. t-SNE analyses revealed IL-7-dependent differences in monocyte subset distribution and expression of activation and maturation markers (i.e., HLA-DR, CD80, CD86, CD40). Notably, monocyte CD40 expression increased considerably by IL-7 and CD40/IL-7R co-expression differed between patients and controls. This study shows the unique effects of IL-7 on monocyte phenotype and functions. Lower IL-7R expression on IL-7-induced CD40high monocytes and impaired IL-7 response characterize monocytes from patients with type 1 diabetes.


Subject(s)
CD40 Antigens/immunology , Diabetes Mellitus, Type 1/immunology , Gene Expression Regulation/immunology , Interleukin-7/immunology , Monocytes/immunology , Adolescent , Child , Female , Humans , Interleukin-7 Receptor alpha Subunit/immunology , Male
20.
J Pediatr ; 245: 22-29.e2, 2022 06.
Article in English | MEDLINE | ID: mdl-35240137

ABSTRACT

OBJECTIVES: To evaluate, using video documentation, the sensitivity, specificity, and interobserver reliability of visualizable signs of neonatal hypoglycemia at different glucose concentrations in neonates. STUDY DESIGN: In a prospective cohort study of 145 neonates with and without risk factors for hypoglycemia, 430 videos were recorded before blood glucose measurements and analyzed by 10 blinded investigators of different professions. The primary outcome measures were sensitivity and specificity for clinical detection of hypoglycemia. RESULTS: The overall sensitivity to detect low blood glucose (<55 mg/dL [<3.1 mmol/L]) based on signs was 30%, and the specificity was 82%. Significantly more investigators suspected hypoglycemia while viewing videos of infants with blood glucose levels of 46-54 mg/dL (2.6-3.0 mmol/L) and 30-45 mg/dL (1.7-2.5 mmol/L) compared with ≥55 mg/dL (≥3.1 mmol/L) (29 ± 3% and 31 ± 4% vs 18 ± 1%; P = .001; P = .007). After 48 hours of life, significantly more investigators suspected hypoglycemia in videos of infants with blood glucose levels of ≤45 mg/dL (≤2.5 mmol/L) compared with blood glucose levels of >45 mg/dL (>2.5 mmol/L) (28.9 ± 8.1% vs 10.9 ± 1.8%; P = .007). For blood glucose levels 30-45 mg/dL (1.7-2.5 mmol/L), sensitivity varied widely between investigators, ranging from 5% to 62%. Three hypoglycemic episodes <30 mg/dL (<1.7 mmol/L) were only partially recognized. CONCLUSIONS: Clinical observation of signs is neither sensitive nor specific to detect neonatal hypoglycemia, and there are large interobserver differences. Thus, guidelines on neonatal hypoglycemia should reconsider whether distinguishing between asymptomatic and symptomatic hypoglycemia provides useful information for the management of neonatal hypoglycemia, because it may pose a risk for systematic under-recognition and undertreatment, leading to an increased risk for neurodevelopmental impairment. TRIAL REGISTRATION: German Clinical Trials Register: DRKS00021500 www.drks.de/drks_web/setLocale_EN.do.


Subject(s)
Hypoglycemia , Infant, Newborn, Diseases , Blood Glucose , Humans , Hypoglycemia/diagnosis , Hypoglycemia/etiology , Infant , Infant, Newborn , Infant, Newborn, Diseases/diagnosis , Prospective Studies , Reproducibility of Results
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