Therapeutic management of osteosarcoma and chondrosarcoma is limited by cisplatin (CP)-associated systemic toxicity and acquired chemoresistance. Strategies enabling effective dose reduction while maintaining antitumor activity are urgently required. This study investigated whether melatonin (MEL) and cannabinoids (CBD, THC) enhance CP efficacy through synergistic, multi-target mechanisms in osteosarcoma (MG63, Saos2) and chondrosarcoma (SW1353) cells, with normal fibroblast (FL) and osteoblast (HC) cells as controls. Cytotoxicity and antiproliferative effects were evaluated using MTT and LDH assays. Drug interactions were quantified via combination index (CI) and dose-reduction index (DRI) analyses. Apoptotic mechanisms were assessed by Casp3, Casp8, Casp9, and Bax gene expression, DNA fragmentation, DAPI nuclear staining, and Rhodamine-123-based mitochondrial membrane potential analysis. Anti-migratory and anti-invasive effects were examined using wound-healing and invasion assays. Molecular docking was performed to predict interactions with COX-2, MMPs, ADAMTS-5, and MAPK pathway proteins. Combination regimens, particularly THC + CP + MEL, and CP + MEL, demonstrated strong synergism (CI < 1) in SW1353 and Saos2 cells, enabling up to a 2.77 - 4.38-fold reduction in CP dose. Synergistic treatments significantly upregulated apoptotic markers and induced selective DNA fragmentation, chromatin condensation, and mitochondrial depolarization in cancer cells, while normal cells showed minimal alterations. Cannabinoids markedly suppressed migration and invasion, effects further enhanced in combination treatments. Docking analyses supported high-affinity multi-target interactions consistent with the observed biological responses. Collectively, melatonin enhances cannabinoid-mediated chemosensitization to cisplatin through selective, pro-apoptotic and anti-invasive mechanisms, supporting a low-dose, multi-target combinatorial strategy for bone sarcoma therapy.

TBK1 is a serine-tyrosine kinase protein that transmits signals from pattern recognition receptors to the NF-κB pathway leading to production of Type 1 Interferons. Mutations in this protein have been associated with arthritis, vasculitis, herpes simplex encephalitis and amyotrophic lateral sclerosis. In the current study, we characterized the functional consequences of a TBK1-variant bearing a truncation in exon 4 and 5 in a patient with poly arthritis resembling juvenile idiopathic arthritis and necrotizing encephalitis. The truncation was associated with reduced TBK1 protein abundance and altered phosphorylation. The variant was associated with increased basal/and or Poly-I: C induced IL-6, TNFα, IL-1β and IL-18 and type 1 Interferon ex vivo. Our findings expand the phenotypic spectrum of TBK1 loss-of-function variants and may provide insight into the management of immune dysregulation in affected patients.

Isocitrate dehydrogenase 1 (IDH1) mutations confer distinct biological properties to gliomas, including the reshaping of the tumor immune microenvironment. While T cell dysfunction in glioblastoma has been extensively characterized, the role of innate lymphoid cells (ILCs)-critical regulators of tissue homeostasis and early immune responses- remains poorly understood. We investigated how IDH1 mutations and their oncometabolite D-2-hydroxyglutarate (D-2HG) influence ILC subset distribution, immune checkpoint expression, and cytokine production in glioma patients, glioma-conditioned medium (GCM) models, and in vivo mouse experiments. Tumor and peripheral blood samples from 32 glioma patients (WHO 2021 classification, grades II–IV) were analyzed by flow cytometry to assess ILC subsets and immunecheckpoint molecules (PD-1, CTLA-4, KLRG1). Tonsil-derived human ILCs were co-cultured with IDH1-mutant or wild-type glioma cells and their GCM. In vitro, ILCs were exposed to graded concentrations of D-2HG, whereas in vivo studies involved intraperitoneal administration of D-2HG or L-2HG in mice to evaluate ILC distribution across lymphoid and mucosal tissues. IDH1-mutant gliomas exhibited increased ILC3 and decreased ILC1 frequencies in both tumor tissue and peripheral blood. ILC3s in IDH1-mutant tumors expressed higher PD-1, whereas ILC2s showed reduced PD-1 levels. In co-culture assays, IDH1-mutant glioma cells and their GCM suppressed PD-1 and CTLA-4 expression on ILCs while promoting proliferation. Exposure to D-2HG recapitulated these effects in a dose-dependent manner, reducing checkpoint expression and enhancing IFN-γ and TNF-α secretion. In vivo, D-2HG and L-2HG differentially altered ILC subset distribution across mucosal and lymphoid compartments. IDH1 mutations and their associated oncometabolite D-2HG remodel the innate lymphoid cell landscape in gliomas, driving an ILC3-biased phenotype with reduced checkpoint receptor expression. These findings identify ILCs as key modulators of glioma immunity and suggest that targeting innate immune pathways could complement existing immunotherapeutic approaches.

Juvenile myelomonocytic leukemia (JMML) is a childhood hematological cancer that often results from mutations in the PTPN11 gene. This study aims to report an original proband with JMML, COVID-19, HLH, and mucormycosis phenotypes. In JMML patients, secondary HLH associated with SARS-CoV-2 and mucor infection has not been reported in the literature. We identified a missense variant c.226G>C (p. Glu76Gln) (NM_001330437) in PTPN11. The patient suffered from SARS-CoV-2-related secondary Hemophagocytic lymphohistiocytosis (HLH) and mucormycosis in the right eye and the synoidal ethmoidal sinuses, which eventually led to the patient’s death due to cardiopulmonary arrest. We report a child with JMML complicated with COVID-19-related secondary HLH and mucormycosis, which underlines the need for effective and urgent treatment to reduce further mortalities.

This study aimed to determine the effects of the Mediterranean diet (MD) and lycopene on the development of EAE and on inflammatory markers. In the 43-day study, 72 female C57BL/6 mice were randomly divided into eight groups according to whether they were EAE or naive (control) mice, fed a Western diet or a MD, and whether they received lycopene. During the study, mice were fed ad libitum, and lycopene groups were given 10 mg/kg/day lycopene per mouse every other day for 28 days in oral gavage. The mice were scored for EAE, sacrificed and their spleen, lymph nodes, and spinal cords were removed. We observed slightly delayed EAE onset in the MD-Lyc group compared to the others, and the EAE clinical scores were also lower than in the other groups. T-cell counts in the spleen and lymph nodes of the MD-Lyc group were significantly lower than in other groups. The production of IFN-γ and IL-22 was higher than in the other groups. IL-17 A cytokine produced in the spleen was lower in the MD-Lyc group than in the other groups. In addition, the highest myelination score was seen in the MD-Lyc group. MD-Lyc group also had a unique microbiome profile compared with the remaining groups. In summary, MD and lycopene administration positively impacted EAE scores and myelination. However, more comprehensive studies at the in vitro and in vivo levels are needed to reveal the effect of this intervention on cell numbers in the CNS. Graphical Abstract

The anti-inflammatory and immunosuppressive drugs which are used in the treatment of Graft-versus-Host Disease (GVHD) have limited effects in controlling the severity of the disease. In this study, we aimed to investigate the prophylactic effect of Alantolactone (ALT) in a murine model of experimental GVHD. The study included 4 BALB/c groups as hosts: Naive (n = 7), Control GVHD (n = 16), ALT-GVHD (n = 16), and Syngeneic transplantation (n = 10). Busulfan (20 mg/kg/day) for 4 days followed by cyclophosphamide (100 mg/kg/day) were administered for conditioning. Allogeneic transplantation was performed with cells collected from mismatched female C57BL/6, and GVHD development was monitored by histological and flow cytometric assays. Additionally, liver biopsies were taken from GVHD patient volunteers between ages 2-18 (n = 4) and non-GVHD patients between ages 2-50 (n = 5) and cultured ex vivo with ALT, and the supernatants were used for ELISA. ALT significantly ameliorated histopathological scores of the GVHD and improved GVHD clinical scores. CD8+ T cells were shown to be reduced after ALT treatment. More importantly, ALT treatment skewed T cells to a more naive phenotype (CD62L+ CD44-). ALT did not alter Treg cell number or frequency. ALT treatment appears to suppress myeloid cell lineage (CD11c+). Consistent with reduced myeloid lineage, liver and small intestine levels of GM-CSF were reduced in ALT-treated mice. IL-6 gene expression was significantly reduced in the intestinal tissue. Ex vivo ALT-treated liver biopsy samples from GVHD patients showed a trend of decrease in proinflammatory cytokines but there was no statistical significance. Collectively, the data indicated that ALT may have immunomodulatory actions in a preclinical murine GVHD model.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease, with a high mortality if left untreated. In addition, the disease has unique diagnostic challenges. Therefore, despite the existing guidelines on management, current clinical practice data is informative on the course and outcome. Herein, a retrospective chart review study was conducted through the collaboration of six centers, located in central and southeastern Turkiye. The demographical data, laboratory results, and treatment outcomes were evaluated. Eighty-three patients were enrolled in the study. The mean age was 2 years, whereas the median age was 8 months with a range of a minimum of 1 week and a maximum of 12.6 years. Consanguineous marriage, history of sibling death, and familial history of similar disease were determined in 72.2% (n:60), 34.9% (n:29), and 39.8% (n:33) of the patients, respectively. The most common presentation was fever, followed by hepatosplenomegaly on admission. Disease-causing familial HLH variants were identified in 60.2% (n:50) of the patients. Hematopoietic stem cell transplantation (HSCT) was performed in 39.7% (n:33) of the cohort. The 2-year overall survival (OS) rate was 62.4% for the whole group. Comparing the patients who received HSCT and those who did not; the HSCT group had a 2-year OS of 84.7%, which was significantly better than patients who did not receive HSCT had a 2-year OS of 47.1% (p:0.001). Despite the improvement in HLH diagnostics and treatment options over the last decade, early death remains a leading problem for the survival of these patients. Therefore, appropriate assessment of the patients in experienced centers and HSCT are pivotal for better outcomes.

Loss of function mutations in Diaphanous related formin 1 (DIAPH1) are associated with seizures, cortical blindness, and microcephaly syndrome (SCBMS) and are recently linked to combined immunodeficiency. However, the extent of defects in T and innate lymphoid cells (ILCs) remain unexplored. Herein, we characterized the primary T, natural killer (NK) and helper ILCs of six patients carrying two novel loss of function mutation in DIAPH1 and Jurkat cells after DIAPH1 knockdown. Mutations were identified by whole exome sequencing. T-cell immunophenotyping, proliferation, migration, cytokine signaling, survival, and NK cell cytotoxicity were studied via flow cytometry-based assays, confocal microscopy, and real-time qPCR. CD4+ T cell proteome was analyzed by mass spectrometry. p.R351* and p.R322*variants led to a significant reduction in the DIAPH1 mRNA and protein levels. DIAPH1-deficient T cells showed proliferation, activation, as well as TCR-mediated signaling defects. DIAPH1-deficient PBMCs also displayed impaired transwell migration, defective STAT5 phosphorylation in response to IL-2, IL-7 and IL-15. In vitro generation/expansion of Treg cells from naïve T cells was significantly reduced. shRNA-mediated silencing of DIAPH1 in Jurkat cells reduced DIAPH1 protein level and inhibited T cell proliferation and IL-2/STAT5 axis. Additionally, NK cells from patients had diminished cytotoxic activity, function and IL-2/STAT5 axis. Lastly, DIAPH1-deficient patients’ peripheral blood contained dramatically reduced numbers of all helper ILC subsets. DIAPH1 deficiency results in major functional defects in T, NK cells and helper ILCs underlining the critical role of formin DIAPH1 in the biology of those cell subsets.

BACKGROUND AND AIMS:The inconsistent data on thiamine status in obese subjects necessitates an examination of genes associated with intestinal absorption of thiamine. We aimed to reveal thiamine status in obese subjects and examine the expression of SLC19A2/3 genes encoding thiamine transporters and Sp1 transcription factor. METHODS AND RESULTS:Thirty-five adult obese subjects and 11 healthy controls were included in this cross-sectional study. Small intestine epithelial cells were used for quantitative RT-PCR analysis of the gene expression. The daily thiamine and energy intake were assessed with a food frequency questionnaire. Thiamine phosphate esters were hydrolyzed to free thiamine, and liquid chromatography with a tandem mass spectrometry-based method was used to measure total thiamine in whole blood. Daily energy intake according to body weight and daily carbohydrate intake were not significantly different between groups after adjustment for sex. Although daily thiamine intake was significantly lower in the obesity group (p = 0.015), obese subjects had significantly higher whole blood thiamine levels than controls (44.96 ± 14.6 ng/mL and 33.05 ± 8.6 ng/mL, p = 0.002). There was a significant positive correlation between whole blood thiamine and BMI (r = 0.342, p = 0.020). SLC19A2 gene expression was lower in those with BMI ≥35 kg/m2 (p = 0.036). A significant positive correlation was found between SLC19A2 expression and whole blood thiamine level (r = 0.310, p = 0.038). CONCLUSION:A possible association between intestinal thiamine intake and total thiamine in whole blood was determined. The transcriptional changes of genes encoding the high-affinity membrane thiamine transporters, especially SLC19A2, probably play a role in this relationship.

In 15 Turkish LAD-1 patients and controls, we assessed the impact of pathogenic ITGB2 mutations on Th17/Treg differentiation and functions, and innate lymphoid cell (ILC) subsets. The percentage of peripheral blood Treg cells, in vitro-generated induced Tregs differentiated from naive CD4+ T cells were decreased despite the elevated absolute counts of CD4+ cells in LAD-1 patients. Serum IL-23 levels were elevated in LAD-1 patients. Post-curdlan stimulation, LAD-1 patient-derived PBMCs produced more IL-17A. Additionally, the percentages of CD18-deficient Th17 cells expanded from total or naïve CD4+ T cells were higher. The blood ILC3 subset was significantly elevated in LAD-1. Finally, LAD-1 PBMCs showed defects in trans-well migration and proliferation and were more resistant to apoptosis. Defects in de novo generation of Tregs from CD18-deficient naïve T cells and elevated Th17s, and ILC3s in LAD-1 patients' peripheral blood suggest a type 3-skewed immunity and may contribute to LAD-1-associated autoimmune symptoms.

Although pregnant women with gestational diabetes (GD), morbidly adherent placenta (MAP), and pregnancy hypertension (pHT) diseases lead to intrauterine growth restriction (IUGR), little is known about their effect on mucosal‐associated invariant T (MAIT) and innate lymphoid cells (ILC) in the umbilical cord. This study aimed to quantify and characterize MAIT cells and ILCs in the cord blood of pregnant women with GD, MAP, and pHT diseases.

Activation of the hypothalamic–pituitary–adrenal (HPA) axis using an insulin tolerance test (ITT) is a medical diagnostic procedure that is frequently used in humans to assess the HPA and growth-hormone (GH) axes. Whether sex differences exist in the response to ITT stress is unknown. Thus, investigations into the analysis of transcripts during activation of the HPA axis in response to hypoglycemia have revealed the underlying influences of sex in signaling pathways that stimulate the HPA axis. We assessed four time points of ITT application in Balb/c mice. After insulin injection, expression levels of 192 microRNAs and 41 mRNAs associated with the HPA, GH and hypothalamic-pituitary-gonadal (HPG) axes were determined by real-time RT-PCR in the hypothalamus, pituitary and adrenal tissues, as well as blood samples (Raw data accession: https://drive.google.com/drive/folders/10qI00NAtjxOepcNKxSJnQbJeBFa6zgHK?usp=sharing ). Although the ITT is commonly used as a gold standard for evaluating the HPA axis, we found completely different responses between males and females with respect to activation of the HPA axis. While activation of several transcripts in the hypothalamus and pituitary was observed after performing the ITT in males within 10 min, females responded via the pituitary and adrenal immediately and durably over 40 min. Additionally, we found that microRNA alterations precede mRNA responses in the HPA axis. Furthermore, robust changes in the levels of several transcripts including Avpr1b and Avpr2 observed at all time points strongly suggest that transcriptional control of these genes occurs mostly via differential signaling in pituitary and blood between males and females. Male and female HPA axis responses to ITT involve a number of sophisticated regulatory signaling pathways of miRNAs and mRNAs. Our results highlight the first robust markers in several layers of HPA, HPG and GH axis involved in ITT/hypoglycemia stress-induced dynamics.

Insufficient dietary folate intake, hereditary malabsorption, or defects in folate transport may lead to combined immunodeficiency (CID). Although loss of function mutations in the major intestinal folate transporter PCFT/SLC46A1 was shown to be associated with CID, the evidence for pathogenic variants of RFC/SLC19A1 resulting in immunodeficiency was lacking. We report two cousins carrying a homozygous pathogenic variant c.1042 G > A, resulting in p.G348R substitution who showed symptoms of immunodeficiency associated with defects of folate transport. SLC19A1 expression by peripheral blood mononuclear cells (PBMC) was quantified by real-time qPCR and immunostaining. T cell proliferation, methotrexate resistance, NK cell cytotoxicity, Treg cells and cytokine production by T cells were examined by flow cytometric assays. Patients were treated with and benefited from folinic acid. Studies revealed normal NK cell cytotoxicity, Treg cell counts, and naive-memory T cell percentages. Although SLC19A1 mRNA and protein expression were unaltered, remarkably, mitogen induced-T cell proliferation was significantly reduced at suboptimal folic acid and supraoptimal folinic acid concentrations. In addition, patients’ PBMCs were resistant to methotrexate-induced apoptosis supporting a functionally defective SLC19A1. This study presents the second pathogenic SLC19A1 variant in the literature, providing the first experimental evidence that functionally defective variants of SLC19A1 may present with symptoms of immunodeficiency.

Clinical & Experimental AllergyVolume 52, Issue 7 p. 907-910 RESEARCH LETTER A novel gain-of-function mutation in STAT5B is associated with treatment-resistant severe atopic dermatitis Nurhan Kasap, Corresponding Author Nurhan Kasap [email protected] orcid.org/0000-0001-5432-4076 Department of Pediatric Allergy-Immunology, Istanbul Medeniyet University Faculty of Medicine, Istanbul, Turkey Correspondence Nurhan Kasap, Division of Pediatric Allergy/Immunology, Medeniyet University, Istanbul, Turkey. Email: [email protected] Ahmet Eken, Department of Medical Biology, Erciyes University Faculty of Medicine, Kayseri 38030, Turkey. Email: [email protected]Search for more papers by this authorKubra Aslan, Kubra Aslan orcid.org/0000-0002-5952-906X Department of Medical Biology, Genome and Stem Cell Center (GENKOK), Erciyes University Faculty of Medicine, Kayseri, TurkeySearch for more papers by this authorLeman Tuba Karakurt, Leman Tuba Karakurt orcid.org/0000-0003-0818-8063 Department of Pediatric Allergy-Immunology, Istanbul Medeniyet University Faculty of Medicine, Istanbul, TurkeySearch for more papers by this authorHayrunnisa Bozkurt, Hayrunnisa Bozkurt orcid.org/0000-0001-8642-4872 Department of Pediatric Allergy-Immunology, Istanbul Medeniyet University Faculty of Medicine, Istanbul, TurkeySearch for more papers by this authorHalit Canatan, Halit Canatan orcid.org/0000-0002-0978-8311 Department of Medical Biology, Genome and Stem Cell Center (GENKOK), Erciyes University Faculty of Medicine, Kayseri, TurkeySearch for more papers by this authorOzlem Cavkaytar, Ozlem Cavkaytar orcid.org/0000-0002-5747-7032 Department of Pediatric Allergy-Immunology, Istanbul Medeniyet University Faculty of Medicine, Istanbul, TurkeySearch for more papers by this authorAhmet Eken, Corresponding Author Ahmet Eken [email protected] orcid.org/0000-0002-5816-0686 Department of Medical Biology, Genome and Stem Cell Center (GENKOK), Erciyes University Faculty of Medicine, Kayseri, Turkey Correspondence Nurhan Kasap, Division of Pediatric Allergy/Immunology, Medeniyet University, Istanbul, Turkey. Email: [email protected] Ahmet Eken, Department of Medical Biology, Erciyes University Faculty of Medicine, Kayseri 38030, Turkey. Email: [email protected]Search for more papers by this authorMustafa Arga, Mustafa Arga orcid.org/0000-0002-0940-7398 Department of Pediatric Allergy-Immunology, Istanbul Medeniyet University Faculty of Medicine, Istanbul, TurkeySearch for more papers by this author Nurhan Kasap, Corresponding Author Nurhan Kasap [email protected] orcid.org/0000-0001-5432-4076 Department of Pediatric Allergy-Immunology, Istanbul Medeniyet University Faculty of Medicine, Istanbul, Turkey Correspondence Nurhan Kasap, Division of Pediatric Allergy/Immunology, Medeniyet University, Istanbul, Turkey. Email: [email protected] Ahmet Eken, Department of Medical Biology, Erciyes University Faculty of Medicine, Kayseri 38030, Turkey. Email: [email protected]Search for more papers by this authorKubra Aslan, Kubra Aslan orcid.org/0000-0002-5952-906X Department of Medical Biology, Genome and Stem Cell Center (GENKOK), Erciyes University Faculty of Medicine, Kayseri, TurkeySearch for more papers by this authorLeman Tuba Karakurt, Leman Tuba Karakurt orcid.org/0000-0003-0818-8063 Department of Pediatric Allergy-Immunology, Istanbul Medeniyet University Faculty of Medicine, Istanbul, TurkeySearch for more papers by this authorHayrunnisa Bozkurt, Hayrunnisa Bozkurt orcid.org/0000-0001-8642-4872 Department of Pediatric Allergy-Immunology, Istanbul Medeniyet University Faculty of Medicine, Istanbul, TurkeySearch for more papers by this authorHalit Canatan, Halit Canatan orcid.org/0000-0002-0978-8311 Department of Medical Biology, Genome and Stem Cell Center (GENKOK), Erciyes University Faculty of Medicine, Kayseri, TurkeySearch for more papers by this authorOzlem Cavkaytar, Ozlem Cavkaytar orcid.org/0000-0002-5747-7032 Department of Pediatric Allergy-Immunology, Istanbul Medeniyet University Faculty of Medicine, Istanbul, TurkeySearch for more papers by this authorAhmet Eken, Corresponding Author Ahmet Eken [email protected] orcid.org/0000-0002-5816-0686 Department of Medical Biology, Genome and Stem Cell Center (GENKOK), Erciyes University Faculty of Medicine, Kayseri, Turkey Correspondence Nurhan Kasap, Division of Pediatric Allergy/Immunology, Medeniyet University, Istanbul, Turkey. Email: [email protected] Ahmet Eken, Department of Medical Biology, Erciyes University Faculty of Medicine, Kayseri 38030, Turkey. Email: [email protected]Search for more papers by this authorMustafa Arga, Mustafa Arga orcid.org/0000-0002-0940-7398 Department of Pediatric Allergy-Immunology, Istanbul Medeniyet University Faculty of Medicine, Istanbul, TurkeySearch for more papers by this author First published: 15 April 2022 https://doi.org/10.1111/cea.14148Citations: 3Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat CONFLICT OF INTEREST The authors declare no competing interests. Open Research DATA AVAILABILITY STATEMENT Additional information about study methods is available in the following repository 10.5281/zenodo.5809618, 10.5281/zenodo.5812231. REFERENCES 1Hwa V. STAT5B deficiency: impacts on human growth and immunity. Growth Horm IGF Res. 2016; 28: 16-20. doi:10.1016/j.ghir.2015.12.006 2Bandapalli OR, Schuessele S, Kunz JB, et al. The activating STAT5B N642H mutation is a common abnormality in pediatric T-cell acute lymphoblastic leukemia and confers a higher risk of relapse. Haematologica. 2014; 99(10): e188-e192. doi:10.3324/haematol.2014.104992 3Kucuk C, Jiang B, Hu X, et al. Activating mutations of STAT5B and STAT3 in lymphomas derived from gammadelta-T or NK cells. Nat Commun. 2015; 6: 6025. doi:10.1038/ncomms7025 4Cross NCP, Hoade Y, Tapper WJ, et al. Recurrent activating STAT5B N642H mutation in myeloid neoplasms with eosinophilia. Leukemia. 2019; 33(2): 415-425. doi:10.1038/s41375-018-0342-3 5Kawakami T, Ando T, Kawakami Y. Hypothetical atopic dermatitis-myeloproliferative neoplasm syndrome. Front Immunol. 2015; 6: 434. doi:10.3389/fimmu.2015.00434 6Ando T, Xiao W, Gao P, et al. Critical role for mast cell Stat5 activity in skin inflammation. Cell Rep. 2014; 6(2): 366-376. doi:10.1016/j.celrep.2013.12.029 7Ma CA, Xi L, Cauff B, et al. Somatic STAT5b gain-of-function mutations in early onset nonclonal eosinophilia, urticaria, dermatitis, and diarrhea. Blood. 2017; 129(5): 650-653. doi:10.1182/blood-2016-09-737817 8Klammt J, Neumann D, Gevers EF, et al. Dominant-negative STAT5B mutations cause growth hormone insensitivity with short stature and mild immune dysregulation. Nat Commun. 2018; 9(1): 2105. doi:10.1038/s41467-018-04521-0 9Brunner PM, Israel A, Zhang N, et al. Early-onset pediatric atopic dermatitis is characterized by TH2/TH17/TH22-centered inflammation and lipid alterations. J Allergy Clin Immunol. 2018; 141(6): 2094-2106. doi:10.1016/j.jaci.2018.02.040 10Eisenberg R, Gans MD, Leahy TR, et al. JAK inhibition in early-onset somatic, nonclonal STAT5B gain-of-function disease. J Allergy Clin Immunol Pract. 2021; 9(2): 1008-1010.e2. doi:10.1016/j.jaip.2020.11.050 Citing Literature Volume52, Issue7July 2022Pages 907-910 ReferencesRelatedInformation

BACKGROUND:Sitosterolemia, also known as phytosterolemia, results from increased intestinal absorption of plant sterols and decreased intestinal and biliary excretion of sterols, resulting in increased levels of plant sterols in the plasma. The most common symptoms include xanthomas, premature atherosclerosis, hemolytic anemia and macrothrombocytopenia, however delayed diagnosis or misdiagnosis also occur. PATIENT AND METHODS:Clinical exome sequencing was performed on a 10-year-old boy whom we followed up with signs of pancytopenia accompanied by macrothrombocytopenia and stomatocytosis. In addition, the blood sterol levels of the patient and his family were studied. RESULTS:A novel homozygous c.904 + 5G > C intronic variant was detected in ABCG5 gene in index case. The mother and father were identified as carriers. The blood plant sterol levels of the patient and his family were studied, and the levels in the patient confirmed Sitosterolemia. Sitosterol levels decreased dramatically with restricted diet and ezetimibe treatment. CONCLUSION:In children, signs of Sitosterolemia may be subtle and the only symptom may be hematological. Therefore, Sitosterolemia should be kept in mind in children with stomatocytosis and macrothrombocytopenia.

Multiple Sclerosis is an immune-mediated neurodegenerative disease. IL-23-mediated signaling and Th17 cells play critical roles in disease pathogenesis in murine models of disease and humans. Sphingosine 1 phosphate (S1P) regulates migration of several types of immune cells including Th17 cells. S1P analogues (fingolimod (FTY720) and Siponimod (BAF312)) have been approved and currently used for MS treatment. Immunomodulatory roles for FTY720 have been defined, however, how different S1P analogues impact human Th17 and Treg cell generation and cytokine production, and IL-23-mediated signaling have not yet been explored in detail. In the current study, we investigated the effects of S1P receptor 1 (S1P1) specific S1P analogue SEW2871, S1P1 and S1P5 specific BAF312, and non-selective FTY720 on human Th17 and Treg differentiation and IL-23-mediated signaling. All three S1P analogues directly inhibited Th17 cell differentiation ex vivo while increasing Treg differentiation from naive CD4 + T cells. All three S1P analogues suppressed IL-23-mediated STAT4, NF-kappa B and AKT activation. Lastly, all three S1P analogues also inhibited Dectin-1 expression by both mature and immature monocyte-derived dendritic cells (moDCs) and in turn curdlan-mediated production of IL-23p19, p40, IL-6 and IL-113 cytokines. Our results provide novel insight into the immunomodulatory roles of different S1P analogues on human Th17 and Treg cell biology.

IL-22 is an alpha-helical cytokine which belongs to the IL-10 family of cytokines. IL-22 is produced by RORγt+ innate and adaptive lymphocytes, including ILC3, γδ T, iNKT, Th17 and Th22 cells and some granulocytes. IL-22 receptor is expressed primarily by non-haematopoietic cells. IL-22 is critical for barrier immunity at the mucosal surfaces in the steady state and during infection. Although IL-22 knockout mice were previously shown to develop experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis (MS), how temporal IL-22 manipulation in adult mice would affect EAE course has not been studied previously. In this study, we overexpressed IL-22 via hydrodynamic gene delivery or blocked it via neutralizing antibodies in C57BL/6 mice to explore the therapeutic impact of IL-22 modulation on the EAE course. IL-22 overexpression significantly decreased EAE scores and demyelination, and reduced infiltration of IFN-γ+IL-17A+Th17 cells into the central nervous system (CNS). The neutralization of IL-22 did not alter the EAE pathology significantly. We show that IL-22-mediated protection is independent of Reg3γ, an epithelial cell-derived antimicrobial peptide induced by IL-22. Thus, overexpression of Reg3γ significantly exacerbated EAE scores, demyelination and infiltration of IFN-γ+IL-17A+ and IL-17A+GM-CSF+Th17 cells to CNS. We also show that Reg3γ may inhibit IL-2-mediated STAT5 signalling and impair expansion of Treg cells in vivo and in vitro. Finally, Reg3γ overexpression dramatically impacted intestinal microbiota during EAE. Our results provide novel insight into the role of IL-22 and IL-22-induced antimicrobial peptide Reg3γ in the pathogenesis of CNS inflammation in a murine model of MS.