Clinical and experimental immunology最新文献

Introduction: Multiple Sclerosis (MS) is a complex auto-inflammatory disease affecting the brain and spinal cord, which results in axonal de-myelination and symptoms including fatigue, pain, and difficulties with vision and mobility. The involvement of the immune system in the pathology of MS is well established, particularly the adaptive T cell response, and there has been a particular focus on the IL-17-producing subset of Th17 cells and their role in driving disease. However, the importance of innate immune cells has not been so well characterised.

Method: Here we focused on neutrophils, which are innate immune cells and rapid responders to inflammation, and which have recently been linked to other chronic autoimmune conditions. Multiple strands of evidence in patients with MS and in mice with the experimental autoimmune encephalomyelitis MS model suggest neutrophils may play a role in driving MS inflammation. Here, we performed proteomic analysis on neutrophils from patients with MS and healthy donors, revealing striking differences.

Results: In particular, granule proteins were significantly more abundant in the MS neutrophils compared to the healthy controls, with a particular over-abundance of proteins in primary and secondary granules. In addition, members of the MAVS signalling pathway were differently regulated compared to healthy donor cells.

Conclusion: Finally, we find that MS neutrophils do not suppress T cell activation equivalently to healthy neutrophils, and in particular are unable to suppress expression of CD161 on the T cells, indicative of a suppression of Th17 differentiation. We propose that neutrophil dysregulation in MS may contribute to dysfunctional T cell responses.

Introduction: The ability of SARS-CoV-2 to evade antiviral immune signaling in the airway contributes to the severity of COVID-19 disease. Additionally, COVID-19 is influenced by age and has more severe presentations in older individuals. This raises questions about innate immune signaling as a function of lung development and age.

Method: Therefore, we investigated the transcriptome of different cell populations of the airway epithelium using pediatric and adult lung tissue samples from the LungMAP Human Tissue Core Biorepository. Specifically, lung lobes were digested and cultured into a biomimetic model of the airway epithelium on an air-liquid interface. Cells were then infected with SARS-CoV-2 and subjected to single-cell RNA sequencing. Transcriptional profiling and differential expression analysis were carried out using Seurat.

Results: The clustering analysis identified several cell populations: club cells, proliferating epithelial cells, multiciliated precursor cells, ionocytes, and two biologically distinct clusters of ciliated cells (FOXJ1high and FOXJ1low). Interestingly, the two ciliated cell clusters showed different infection rates and enrichment of processes involved in ciliary biogenesis and function; we observed a cell-type-specific suppression of innate immunity in infected cells from the FOXJ1low subset. We also identified a significant number of genes that were differentially expressed in lung cells derived from children as compared to adults, suggesting the differential pathogenesis of SARS-CoV-2 infection in children versus adults.

Conclusion: We discuss how this work can be used to identify drug targets to modulate molecular signaling cascades that mediate an innate immune response and begin to understand differences in COVID-19 outcomes for pediatric vs. adult populations.

Background: Acquired angioedema due to C1-inhibitor deficiency (AAE-C1-INH) is very rare compared to its prototype, hereditary angioedema. An updated characterisation of the AAE-C1-INH cohort in UK is required to inform management.

Objectives: To describe the disease burden of AAE-C1-INH, long-term prophylaxis (LTP) and the clinical, immunochemical and treatment profiles of AAE-associated diseases in UK.

Method: Retrospective data on 117 AAE-C1-INH patients were collected using a national survey proforma across 25/34 Adult Clinical Immunology and Allergy centres in UK. Other European cohorts were compared.

Results: Median age at AAE-C1-INH diagnosis was 65 years with 3.4% of patients diagnosed below 40 years. The median delay in diagnosis was one year. Antifibrinolytics and attenuated androgens showed comparable efficacy as LTP 88.9% and 89.5%, respectively. A haematological disorder was identified in 83.8% AAE-C1-INH patients compared to 3.4% autoimmune diseases. The predominant haematological disorders were splenic marginal zone lymphoma (SZL) 34% followed by MGUS 16%. The severity of angioedema did not depend on the associated disease. Anti-C1INH-autoantibodies testing was limited at 23.1%. Rituximab monotherapy was effective in treating 9/9 SZL and 1/2 MGUS-associated AAE-C1-INH. Rituximab efficacy was independent of anti-C1INH-autoantibodies detection with response in 3/3 seronegative and 4/4 seropositive patients.

Conclusion: The diagnosis of AAE-C1-INH should not be overlooked below the age of 40 years. The choice of oral LTP should be informed by propensity to side-effects. B-cell depletion could be considered in treating monoclonal B cell disorder-associated-AAE-C1-INH in the absence of haematological indications. Further studies are required to address the clinical utility of anti-C1INH-autoantibodies.

Adult-onset immunodeficiency with antibodies to interferon-γ (AOID with AIGA) is a rare, acquired immunodeficiency causing susceptibility to disseminated non-tuberculous mycobacteria and other intracellular opportunistic infections. The diagnosis depends on demonstrating the presence of endogenous anti-interferon-γ antibodies (AIGA) that suppress Th1 cell-mediated immunity. Bioluminescent immunoassays are a newly emerging immunoassay format which utilize the action of bioluminescent enzymes on a substrate for specific analyte detection. In short, detecting antibodies are conjugated with a bioluminescent enzyme. The detecting antibodies bind the analyte of interest and produce light (luminescence) after addition of a substrate. The purpose of this study was to evaluate two newly developed bioluminescent immunoassays using Lumit® (Promega) technology as a diagnostic test for AOID with AIGA. Specific aims included the clinical validation of a new inhibition bioluminescent immunoassay technique to detect AIGA which block detection of interferon-γ (IFN-γ) in vitro and correlation of inhibition bioluminescent immunoassay results with AOID with AIGA disease status. Two bioluminescent inhibition immunoassays were developed. One which adapted an existing kit from Promega (Lumit® Human IFN-γ Immunoassay) and the other which was developed in house. Eighty-seven healthy controls and 48 patients with previously diagnosed AOID with AIGA were recruited and tested using these two methods. Results showed both bioluminescent inhibition immunoassays were able to clearly discriminate between AOID with AIGA patients and healthy controls. The mean inhibition percentage between patient groups correlated with disease activity. Both assays appeared to be more sensitive when compared to the existing inhibition ELISA.

Acquired aplastic anemia (AA) often results from immune destruction of hematopoietic stem and progenitor cells. However, only 60%-70% of patients with AA respond to immunosuppressive therapy (IST). There is a lack of strong predictive markers for response to IST which can help therapy. Our study sought to pinpoint unique immune markers in AA patients and validate established predictors for response to IST. We enrolled 51 severe AA patients and analyzed 57 immunological parameters via flow cytometry. Additionally, we measured paroxysmal nocturnal hemoglobinuria (PNH) clone, telomere length, and thrombopoietin (TPO) levels prior to IST. After a 6-month follow-up, a response was observed. Patients with AA had a distinct immunological signature characterized by absolute lymphopenia, skewed CD4/CD8 ratio with expansion of CD8 T cells with activated and senescent phenotype. Treg counts were reduced, while the proportion of Treg A and B was comparable to controls. Treatment response was correlated with elevated absolute neutrophil count (ANC), absolute reticulocyte count (ARC), and reduced CD57+ CD8+ naive cells and B cell % before therapy. However, predictors like TPO, telomere length, and PNH did not emerge as indicators of treatment response. Identifying predictors for treatment response in AA is challenging due to abnormal hematopoiesis, genetic mutations, and treatment variables.

Cellular phenotype and function are altered in different microenvironments. For targeted therapies it is important to understand site-specific cellular adaptations. Juvenile idiopathic arthritis (JIA) is characterized by autoimmune joint inflammation, with frequent inadequate treatment responses. To comprehensively assess the inflammatory immune landscape, we designed a 37-parameter spectral flow cytometry panel delineating mononuclear cells from JIA synovial fluid (SF) of autoimmune inflamed joints, compared to JIA and healthy control blood. Synovial monocytes and NK cells (CD56bright) lack Fc-receptor CD16, suggesting antibody-mediated targeting may be ineffective. B cells and DCs, both in small frequencies in SF, undergo maturation with high 4-1BB, CD71, CD39 expression, supporting T-cell activation. SF effector and regulatory T cells were highly active with newly described co-receptor combinations that may alter function, and suggestion of metabolic reprogramming via CD71, TNFR2, and PD-1. Most SF effector phenotypes, as well as an identified CD4-Foxp3+ T-cell population, were restricted to the inflamed joint, yet specific SF-predominant CD4+ Foxp3+ Treg subpopulations were increased in blood of active but not inactive JIA, suggesting possible recirculation and loss of immunoregulation at distal sites. This first comprehensive dataset of the site-specific inflammatory landscape at protein level will inform functional studies and the development of targeted therapeutics to restore immunoregulatory balance and achieve remission in JIA.

Psoriasis is a chronic, inflammatory skin disease characterized by a dysregulated immune response and systemic inflammation. Up to one-third of patients with psoriasis have psoriatic arthritis (PsA). Targeted treatment with antibodies neutralizing tumor necrosis factor can ameliorate both diseases. We here explored the impact of long-term infliximab treatment on the composition and activity status of circulating immune cells involved in chronic skin and joint inflammation. Immune cells were analyzed by multicolor flow cytometry. We measured markers of immune activation in peripheral blood mononuclear cell populations in 24 infliximab-treated patients with psoriasis/PsA compared to 32 healthy controls. We observed a significant decrease in the frequency of both peripheral natural killer (NK) cells and their subset CD56dimCD16+ NK cells in PsA compared to healthy controls and patients with psoriasis. The latter had a strong-positive correlation with psoriasis area severity index (PASI) in these patients, while CD56brightCD16- NK cells were negatively correlated with PASI. In addition, we observed an upregulation of CD69+ intermediate CD14+CD16+ and CD69+ classical CD14+CD16- monocytes in PsA and increased activity of CD38+ intermediate CD14+CD16+ monocytes in patients with psoriasis. Compared to healthy controls, psoriasis patients demonstrated shifts of the three B-cell subsets with a decrease in transitional CD27-CD38high B cells. Our exploratory study indicates a preserved pathophysiological process including continuous systemic inflammation despite clinical stability of the patients treated with infliximab.

The recent pandemic was caused by the emergence of a new human pathogen, SARS-CoV-2. While the rapid development of many vaccines provided an end to the immediate crisis, there remains an urgent need to understand more about this new virus and what constitutes a beneficial immune response in terms of successful resolution of infection. Indeed, this is key for development of vaccines that provide long lasting protective immunity. The interferon lambda (IFNL) family of cytokines are produced early in response to infection and are generally considered anti-viral and beneficial. However, data regarding production of IFNL cytokines in coronavirus disease 2019 (COVID-19) patients is highly variable, and generally from underpowered studies. In this study, we measured all three IFNL1, IFNL2, and IFNL3 cytokines in plasma from a well characterized, large COVID-19 cohort (n = 399) that included good representation from patients with a more indolent disease progression, and hence a beneficial immune response. While all three cytokines were produced, they differed in both the frequency of expression in patients, and the levels produced. IFNL3 was produced in almost all patients but neither protein level nor IFNL3/IFNL4 single nucleotide polymorphisms were associated with clinical outcome. In contrast, both IFNL1 and IFNL2 levels were significantly lower, or absent, in plasma of patients that had a more severe disease outcome. These data are consistent with the concept that early IFNL1 and IFNL2 cytokine production is protective against SARS-CoV-2 infection.

Clinical manifestations, as distinct from thrombotic and obstetric morbidity, were recently included in the update of classification criteria of the antiphospholipid syndrome (APS). However, the existence of several patients with clinical manifestations suggestive of APS, but negative for criteria antiphospholipid antibodies (aPLs) [anti-cardiolipin antibodies (aCL), anti-β2-glycoprotein I antibodies (aβ2-GPI), and lupus anticoagulant] may suggest an update of diagnostic criteria. In this study, we analysed the prevalence of six non-criteria aPLs in a large monocentric cohort of patients with seronegative APS (SN-APS), to investigate their possible diagnostic role. aCL IgA, aβ2-GPI IgA, and aβ2-GPI Domain 1 antibodies were detected by chemiluminescence, anti-phosphatidylserine/prothrombin (aPS/PT) IgG, anti-vimentin/cardiolipin (aVim/CL) IgG, and anti-carbamylated-β2-glycoprotein I (aCarb-β2-GPI) IgG by ELISA in sera from 144 SN-APS patients. In SN-APS patients, aCL IgA was detected in 4/144 (2.77%), aβ2-GPI IgA in 2/144 (1.39%), aβ2-GPI-Domain 1 in 1/144 (0.69%), aPS/PT in 16/144 (11.11%), aVim/CL in 37/144 (25.69%), and aCarb-β2-GPI in 43/144 patients (29.86%). Patients negative for all non-criteria aPL assays were 77/144 (53.47%). Notably, the Venn diagram showed that aCarb-β2-GPI together with aVim/CL represented the prevalent combination of positive antibodies. In SN-APS patients, aCL IgA were associated with recurrent thrombosis (OR 11.48; P = 0.03); in obstetric SN-APS patients, aPS/PT were significantly associated with foetal deaths (OR 4.84; P = 0.01), aVim/CL with spontaneous abortions (OR 2.71; P = 0.016). This study indicates that aPS/PT, aVim/CL and aCarb-β2-GPI antibodies may represent useful tools to identify 'seronegative' APS patients, who are negative for criteria aPLs, supporting the need to make testing for non-criteria aPLs more accessible in patients with SN-APS.