100 research outputs found
Endothelin-Dependent Vasoconstriction in Human Uterine Artery: Application to Preeclampsia
BACKGROUND: Reduced uteroplacental perfusion, the initiating event in preeclampsia, is associated with enhanced endothelin-1 (ET-1) production which feeds the vasoconstriction of uterine artery. Whether the treatments of preeclampsia were effective on ET-1 induced contraction and could reverse placental ischemia is the question addressed in this study. We investigated the effect of antihypertensive drugs used in preeclampsia and of ET receptor antagonists on the contractile response to ET-1 on human uterine arteries. METHODOLOGY/PRINCIPAL FINDINGS: Experiments were performed, ex vivo, on human uterine artery samples obtained after hysterectomy. We studied variations in isometric tension of arterial rings in response to the vasoconstrictor ET-1 and evaluated the effects of various vasodilators and ET-receptor antagonists on this response. Among antihypertensive drugs, only dihydropyridines were effective in blocking and reversing the ET-1 contractile response. Their efficiency, independent of the concentration of ET-1, was only partial. Hydralazine, alpha-methyldopa and labetalol had no effect on ET-1 induced contraction which is mediated by both ET(A) and ET(B) receptors in uterine artery. ET receptors antagonists, BQ-123 and BQ-788, slightly reduced the amplitude of the response to ET-1. Combination of both antagonists was more efficient, but it was not possible to reverse the maximal ET-1-induced contraction with antagonists used alone or in combination. CONCLUSION: Pharmacological drugs currently used in the context of preeclampsia, do not reverse ET-1 induced contraction. Only dihydropyridines, which partially relax uterine artery previously contracted with ET-1, might offer interesting perspectives to improve placental perfusion
Peripheral blood T-cell signatures from high-resolution immune phenotyping of γΎ and αÎČ T-cells in younger and older subjects in the Berlin Aging Study II
Background Aging and latent infection with Cytomegalovirus (CMV) are thought
to be major factors driving the immune system towards immunosenescence,
primarily characterized by reduced amounts of naĂŻve T-cells and increased
memory T-cells, potentially associated with higher morbidity and mortality.
The composition of both major compartments, γΎ as well as αÎČ T-cells, is
altered by age and CMV, but detailed knowledge of changes to the γΎ subset is
currently limited. Results Here, we have surveyed a population of 73 younger
(23â35 years) and 144 older (62â85 years) individuals drawn from the Berlin
Aging Study II, investigating the distribution of detailed differentiation
phenotypes of both γΎ and αÎČ T-cells. Correlation of frequencies and absolute
counts of the identified phenotypes with age and the presence of CMV revealed
a lower abundance of VÎŽ2-positive and a higher amount of VÎŽ1-positive cells.
We found higher frequencies of late-differentiated and lower frequencies of
early-differentiated cells in the VÎŽ1+ and VÎŽ1-VÎŽ2-, but not in the VÎŽ2+
populations in elderly CMV-seropositive individuals confirming the association
of these VÎŽ2-negative cells with CMV-immunosurveillance. We identified the
highest VÎŽ1:VÎŽ2 ratios in the CMV-seropositive elderly. The observed increased
CD4:CD8 ratios in the elderly were significantly lower in CMV-seropositive
individuals, who also possessed a lower naĂŻve and a larger late-differentiated
compartment of CD8+ αÎČ T-cells, reflecting the consensus in the literature.
Conclusions Our findings illustrate in detail the strong influence of CMV on
the abundance and differentiation pattern of γΎ T-cells as well as αÎČ T-cells
in older and younger people. Mechanisms responsible for the phenotypic
alterations in the γΎ T-cell compartment, associated both with the presence of
CMV and with age require further clarification
The effect of cigarette smoking, alcohol consumption and fruit and vegetable consumption on IVF outcomes: A review and presentation of original data
Background - Lifestyle factors including cigarette smoking, alcohol consumption and nutritional habits impact on health, wellness, and the risk of chronic diseases. In the areas of in-vitro fertilization (IVF) and pregnancy, lifestyle factors influence oocyte production, fertilization rates, pregnancy and pregnancy loss, while chronic, low-grade oxidative stress may underlie poor outcomes for some IVF cases. Methods - Here, we review the current literature and present some original, previously unpublished data, obtained from couples attending the PIVET Medical Centre in Western Australia. Results - During the study, 80 % of females and 70 % of male partners completed a 1-week diary documenting their smoking, alcohol and fruit and vegetable intake. The subsequent clinical outcomes of their IVF treatment such as quantity of oocytes collected, fertilization rates, pregnancy and pregnancy loss were submitted to multiple regression analysis, in order to investigate the relationship between patients, treatment and the recorded lifestyle factors. Of significance, it was found that male smoking caused an increased risk of pregnancy loss (pâ=â0.029), while female smoking caused an adverse effect on ovarian reserve. Both alcohol consumption (ÎČâ=â0.074, pâ<â0.001) and fruit and vegetable consumption (ÎČâ=â0.034, pâ<â0.001) had positive effects on fertilization. Conclusion - Based on our results and the current literature, there is an important impact of lifestyle factors on IVF clinical outcomes. Currently, there are conflicting results regarding other lifestyle factors such as nutritional habits and alcohol consumption, but it is apparent that chronic oxidative stress induced by lifestyle factors and poor nutritional habits associate with a lower rate of IVF success
Clonal selection in the human VΎ1 T cell repertoire indicates γΎ TCR-dependent adaptive immune surveillance
γΎ T cells are considered to be innate-like lymphocytes that respond rapidly to stress without clonal selection and differentiation. Here we use next-generation sequencing to probe how this paradigm relates to human VΎ2neg T cells, implicated in responses to viral infection and cancer. The prevalent VΎ1 T cell receptor (TCR) repertoire is private and initially unfocused in cord blood, typically becoming strongly focused on a few high-frequency clonotypes by adulthood. Clonal expansions have differentiated from a naive to effector phenotype associated with CD27 downregulation, retaining proliferative capacity and TCR sensitivity, displaying increased cytotoxic markers and altered homing capabilities, and remaining relatively stable over time. Contrastingly, VΎ2+ T cells express semi-invariant TCRs, which are present at birth and shared between individuals. Human VΎ1+ T cells have therefore evolved a distinct biology from the VΎ2+ subset, involving a central, personalized role for the γΎ TCR in directing a highly adaptive yet unconventional form of immune surveillance
Elevated serum levels of soluble CD154 in children with juvenile idiopathic arthritis
<p>Abstract</p> <p>Objective</p> <p>Cytokines play important roles in mediating inflammation in autoimmunity. Several cytokines are elevated in serum and synovial fluid samples from children with Juvenile Idiopathic Arthritis (JIA). Soluble CD154 (sCD154) is elevated in other autoimmune disorders, but has not been characterized in JIA. Our objectives were to determine if sCD154 is elevated in JIA, and to examine correlations between sCD154 and other inflammatory cytokines.</p> <p>Methods</p> <p>Serum from 77 children with JIA and 81 pediatric controls was analyzed for interleukin (IL)1ÎČ, IL2, IL4, IL5, IL6, IL8, IL10, IL12, IL13, sCD154, interferon-Îł (IFNÎł), soluble IL2 receptor (sIL2R), and tumor necrosis factor-α (TNFα), using the Luminex Multi-Analyte Profiling system. Differences in levels of cytokines between cases and controls were analyzed. Logistic regression was also performed.</p> <p>Results</p> <p>sCD154 was significantly elevated in cases compared to controls (p < 0.0001). IL1ÎČ, IL5, IL6, IL8, IL13, IFNÎł, sIL2R, and TNFα were also significantly elevated in JIA. Levels of sCD154 were highly correlated with IL1ÎČ, IL6, IL8, and TNFα (p < 0.0001). Logistic regression analysis suggested that IL6 (odds ratio (OR): 1.4, p < 0.0001), sCD154 (OR: 1.1, p < 0.0001), and TNFα (OR: 1.1, p < 0.005) were positively associated with JIA, while IL10 (OR: 0.5, p < 0.002) was protective. sCD154 was elevated in all JIA subtypes, with highest levels among more severe subtypes. IL1ÎČ, IL6, IL8, sIL2R and TNFα were also elevated in several JIA subtypes.</p> <p>Conclusion</p> <p>Serum levels of sCD154, IL1ÎČ, IL6, IL8, sIL2R and TNFα are elevated in most JIA subtypes, suggesting a major role for sCD154, and these cytokines and cytokine receptors in the pathogenesis of JIA.</p
Inborn errors of OAS-RNase L in SARS-CoV-2-related multisystem inflammatory syndrome in children
Multisystem inflammatory syndrome in children (MIS-C) is a rare and severe condition that follows benign COVID-19. We report autosomal recessive deficiencies of OAS1, OAS2, or RNASEL in five unrelated children with MIS-C. The cytosolic double-stranded RNA (dsRNA)-sensing OAS1 and OAS2 generate 2'-5'-linked oligoadenylates (2-5A) that activate the single-stranded RNA-degrading ribonuclease L (RNase L). Monocytic cell lines and primary myeloid cells with OAS1, OAS2, or RNase L deficiencies produce excessive amounts of inflammatory cytokines upon dsRNA or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) stimulation. Exogenous 2-5A suppresses cytokine production in OAS1-deficient but not RNase L-deficient cells. Cytokine production in RNase L-deficient cells is impaired by MDA5 or RIG-I deficiency and abolished by mitochondrial antiviral-signaling protein (MAVS) deficiency. Recessive OAS-RNase L deficiencies in these patients unleash the production of SARS-CoV-2-triggered, MAVS-mediated inflammatory cytokines by mononuclear phagocytes, thereby underlying MIS-C
Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19
Background: We previously reported that impaired type I IFN activity, due to inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity or to autoantibodies against type I IFN, account for 15â20% of cases of life-threatening COVID-19 in unvaccinated patients. Therefore, the determinants of life-threatening COVID-19 remain to be identified in ~ 80% of cases. Methods: We report here a genome-wide rare variant burden association analysis in 3269 unvaccinated patients with life-threatening COVID-19, and 1373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. Among the 928 patients tested for autoantibodies against type I IFN, a quarter (234) were positive and were excluded. Results: No gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7, with an OR of 27.68 (95%CI 1.5â528.7, P = 1.1 Ă 10â4) for biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR = 3.70[95%CI 1.3â8.2], P = 2.1 Ă 10â4). This enrichment was further strengthened by (1) adding the recently reported TYK2 and TLR7 COVID-19 loci, particularly under a recessive model (OR = 19.65[95%CI 2.1â2635.4], P = 3.4 Ă 10â3), and (2) considering as pLOF branchpoint variants with potentially strong impacts on splicing among the 15 loci (OR = 4.40[9%CI 2.3â8.4], P = 7.7 Ă 10â8). Finally, the patients with pLOF/bLOF variants at these 15 loci were significantly younger (mean age [SD] = 43.3 [20.3] years) than the other patients (56.0 [17.3] years; P = 1.68 Ă 10â5). Conclusions: Rare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie life-threatening COVID-19, particularly with recessive inheritance, in patients under 60 years old
Autoantibodies against type I IFNs in patients with life-threatening COVID-19
Interindividual clinical variability in the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is vast. We report that at least 101 of 987 patients with life-threatening coronavirus disease 2019 (COVID-19) pneumonia had neutralizing immunoglobulin G (IgG) autoantibodies (auto-Abs) against interferon-w (IFN-w) (13 patients), against the 13 types of IFN-a (36), or against both (52) at the onset of critical disease; a few also had auto-Abs against the other three type I IFNs. The auto-Abs neutralize the ability of the corresponding type I IFNs to block SARS-CoV-2 infection in vitro. These auto-Abs were not found in 663 individuals with asymptomatic or mild SARS-CoV-2 infection and were present in only 4 of 1227 healthy individuals. Patients with auto-Abs were aged 25 to 87 years and 95 of the 101 were men. A B cell autoimmune phenocopy of inborn errors of type I IFN immunity accounts for life-threatening COVID-19 pneumonia in at least 2.6% of women and 12.5% of men
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