Search

BackgroundDedicator of cytokinesis 8 (DOCK8) deficiency is the main cause of the autosomal recessive hyper-IgE syndrome (HIES). We previously reported the selective loss of group 3 innate lymphoid cell (ILC) number and function in a Dock8-deficient mouse model. In this study, we sought to test whether DOCK8 is required for the function and maintenance of ILC subsets in humans.MethodsPeripheral blood ILC1-3 subsets of 16 DOCK8-deficient patients recruited at the pretransplant stage, and seven patients with autosomal dominant (AD) HIES due to STAT3 mutations, were compared with those of healthy controls or post-transplant DOCK8-deficient patients (n = 12) by flow cytometry and real-time qPCR. Sorted total ILCs from DOCK8- or STAT3-mutant patients and healthy controls were assayed for survival, apoptosis, proliferation, and activation by IL-7, IL-23, and IL-12 by cell culture, flow cytometry, and phospho-flow assays.ResultsDOCK8-deficient but not STAT3-mutant patients exhibited a profound depletion of ILC3s, and to a lesser extent ILC2s, in their peripheral blood. DOCK8-deficient ILC1-3 subsets had defective proliferation, expressed lower levels of IL-7R, responded less to IL-7, IL-12, or IL-23 cytokines, and were more prone to apoptosis compared with those of healthy controls.ConclusionDOCK8 regulates human ILC3 expansion and survival, and more globally ILC cytokine signaling and proliferation. DOCK8 deficiency leads to loss of ILC3 from peripheral blood. ILC3 deficiency may contribute to the susceptibility of DOCK8-deficient patients to infections.

Problem: 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. Method of study: Cord blood mononuclear cells (CBMCs) were isolated by Ficoll‐Paque gradient. CD3+TCRVα7.2+CD161high cells and ILC subsets were quantified by flow cytometry. CBMCs were stimulated with PMA/Ionomycin and Golgi Plug for 4 h and stained for IFN‐γ, TNF‐α, and granzyme B. The stained cells were analyzed on FACS ARIA III. Results: Compared with healthy pregnancies, in the cord blood of the pHT group, elevated number of lymphocytes was observed. Moreover, the absolute number of IFN‐γ producing CD4+ or CD4− subsets of CD3+TCRVα7.2+CD161high cells as well as those producing granzyme B were significantly elevated in the pHT group compared to healthy controls suggesting increased MAIT cell activity in the pHT cord blood. Similarly, in the MAP group, the absolute number of total CD3+TCRVα7.2+CD161high cells, but not individual CD4+ or negative subsets, were significantly increased compared with healthy controls' cord blood. Absolute numbers of total CD3+TCRVα7.2+CD161high cells and their subsets were comparable in the cord blood of the GD group compared with healthy controls. Finally, the absolute number of total ILCs and ILC3 subset were significantly elevated in only pHT cord blood compared with healthy controls. Our data also reveal that IFN‐γ+ or granzyme B+ cell numbers negatively correlated with fetal birth weight. Conclusions: CD3+TCRVα7.2+CD161high cells and ILCs show unique expansion and activity in the cord blood of pregnant women with distinct diseases causing IUGR and may play roles in fetal growth restriction. [ABSTRACT FROM AUTHOR]

Inherited bone-marrow failure syndromes (IBMFS) are heterogeneous disorders with multiple reported gene mutations and a range of pleiotropic phenotypes impacting normal haematopoiesis.1,2 The most common cause of IBMFS is Fanconi anaemia, characterized by increased chromosomal breakage, skeletal abnormalities, and multiorgan malformations.3 Shwachman-Diamond Syndrome (SDS) is an autosomal-recessive bone-marrow failure disorder associated with ribosomopathy, which presents with haematologic abnormalities with single or multilineage cytopenias, a hypoplastic marrow, skeletal malformations and pancreatic exocrine dysfunction.4,5 Approximately 90% of patients have bi-allelic mutations in the Shwachman-Bodian-Diamond Syndrome ( I SBDS i ) gene while the remaining patients are negative for I SBDS i mutations.4 Several cases with SDS-like syndrome have been reported to harbour mutations in the DNAJ domain of I DNAJC21 i . While the chromosomal changes are found in the bone marrow of patients with SDS,6 peripheral-blood samples from SDS patients have not been tested for such anomalies. (1) Mononucleated cell; (2) binucleated cell; (3) binucleated cell with one micronucleus (arrow); (4) binucleated cell with multi-micronucleus (13 MN) gl In summary, we report a distinct presentation of an IBMFS due to bi-allelic I DNAJC21 i mutations. A novel missense mutation outside the DNAJ domain of DNAJC21 is associated with Shwachman-Diamond syndrome. [Extracted from the article]

OBJECTIVE: In this study, we aimed to assess the effects of long- and short-term IL-15 cytokine exposure of human monocyte- derived curdlan-matured dendritic cells (DCs) on the production of Th17 cell-polarizing cytokine IL-23 and subsequent Th17 cell activation. METHODS: Peripheral blood mononuclear cells (PBMCs) were purified using Ficoll-Paque from healthy donors. Monocytes were magnetically selected using CD14 Miltenyi beads and differentiated into DCs with granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-4 for five days in the presence or absence of IL-15 (100ng/ml) for long-term exposure experiments. Then, DCs were matured with peptidoglycan (PGN), or curdlan for 24 hours. For short-term exposure experiments, IL-15 was added only during maturation of DCs. Then, DCs were characterized concerning the expression of MHC II and costimulatory molecules, production of cytokine subunits IL-23p19, IL-12p40, IL-12p35 and cytokine IL-23 via flow cytometry or real-time qPCR or ELISA. Finally, the phosphorylation of signaling molecules after curdlan stimulation was assessed using phospho-flow assays. RESULTS: IL-15 exposure suppressed IL-23 production by DCs. As a result, IL-15-exposed DCs suppressed IL-17 production by allogeneic T cells. Importantly, we observed a reduction in the surface Dectin-1 receptor levels by IL-15-exposed DCs. In line with these observations, curdlan stimulation resulted in reduced phosphorylation of ERK1/2, NF-kB p65 and AKT by human DCs exposed to IL-15 compared with controls. These results may explain why IL-15-exposed DCs produce less IL-23 after maturation with curdlan, which is a ligand of Dectin-1. CONCLUSION: Short- or long-term exposure to IL-15 of human DCs during their differentiation or maturation programs DCs against Th17 cell polarization, which suggests that IL-15 availability may affect CD4+ T cell-mediated protective immunity to fungal infections. [ABSTRACT FROM AUTHOR]