Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 18 de 18
Filter
Add more filters










Publication year range
1.
Immunity ; 2024 May 06.
Article in English | MEDLINE | ID: mdl-38723638

ABSTRACT

Induction of commensal-specific immunity contributes to tissue homeostasis, yet the mechanisms underlying induction of commensal-specific B cells remain poorly understood in part due to a lack of tools to identify these cells. Using phage display, we identified segmented filamentous bacteria (SFB) antigens targeted by serum and intestinal antibodies and generated B cell tetramers to track SFB-specific B cells in gut-associated lymphoid tissues. We revealed a compartmentalized response in SFB-specific B cell activation, with a gradient of immunoglobulin A (IgA), IgG1, and IgG2b isotype production along Peyer's patches contrasted by selective production of IgG2b within mesenteric lymph nodes. V(D)J sequencing and monoclonal antibody generation identified somatic hypermutation driven affinity maturation to SFB antigens under homeostatic conditions. Combining phage display and B cell tetramers will enable investigation of the ontogeny and function of commensal-specific B cell responses in tissue immunity, inflammation, and repair.

2.
J Exp Med ; 221(6)2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38634869

ABSTRACT

We previously reported two siblings with inherited PD-1 deficiency who died from autoimmune pneumonitis at 3 and 11 years of age after developing other autoimmune manifestations, including type 1 diabetes (T1D). We report here two siblings, aged 10 and 11 years, with neonatal-onset T1D (diagnosed at the ages of 1 day and 7 wk), who are homozygous for a splice-site variant of CD274 (encoding PD-L1). This variant results in the exclusive expression of an alternative, loss-of-function PD-L1 protein isoform in overexpression experiments and in the patients' primary leukocytes. Surprisingly, cytometric immunophenotyping and single-cell RNA sequencing analysis on blood leukocytes showed largely normal development and transcriptional profiles across lymphoid and myeloid subsets in the PD-L1-deficient siblings, contrasting with the extensive dysregulation of both lymphoid and myeloid leukocyte compartments in PD-1 deficiency. Our findings suggest that PD-1 and PD-L1 are essential for preventing early-onset T1D but that, unlike PD-1 deficiency, PD-L1 deficiency does not lead to fatal autoimmunity with extensive leukocytic dysregulation.


Subject(s)
B7-H1 Antigen , Diabetes Mellitus, Type 1 , Child , Child, Preschool , Humans , Infant, Newborn , Autoimmunity , B7-H1 Antigen/deficiency , B7-H1 Antigen/genetics , B7-H1 Antigen/immunology , Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 1/immunology , Homozygote , Programmed Cell Death 1 Receptor/deficiency , Programmed Cell Death 1 Receptor/genetics , Programmed Cell Death 1 Receptor/immunology
3.
bioRxiv ; 2024 Apr 04.
Article in English | MEDLINE | ID: mdl-37745328

ABSTRACT

Autoantibodies to nuclear antigens are hallmarks of the autoimmune disease systemic lupus erythematosus (SLE) where they contribute to pathogenesis. However, there remains a gap in our knowledge regarding how different isotypes of autoantibodies contribute to disease, including the production of the critical type I interferon (IFN) cytokines by plasmacytoid dendritic cells (pDCs) in response to immune complexes (ICs). We focused on IgA, which is the second most prevalent isotype in serum, and along with IgG is deposited in glomeruli in lupus nephritis. Here, we show that individuals with SLE have IgA autoantibodies against most nuclear antigens, correlating with IgG against the same antigen. We investigated whether IgA autoantibodies against a major SLE autoantigen, Smith ribonucleoproteins (Sm/RNPs), play a role in IC activation of pDCs. We found that pDCs express the IgA-specific Fc receptor, FcαR, and there was a striking ability of IgA1 autoantibodies to synergize with IgG in RNA-containing ICs to generate robust pDC IFNα responses. pDC responses to these ICs required both FcαR and FcγRIIa, showing a potent synergy between these Fc receptors. Sm/RNP IC binding to and internalization by pDCs were greater when ICs contained both IgA1 and IgG. pDCs from individuals with SLE had higher binding of IgA1-containing ICs and higher expression of FcαR than pDCs from healthy control individuals. Whereas pDC FcαR expression correlated with blood ISG signature in SLE, TLR7 agonists, but not IFNα, upregulated pDC FcαR expression in vitro. Together, we show a new mechanism by which IgA1 autoantibodies contribute to SLE pathogenesis.

4.
J Allergy Clin Immunol ; 152(1): 56-67, 2023 07.
Article in English | MEDLINE | ID: mdl-37001649

ABSTRACT

BACKGROUND: Despite well-known susceptibilities to other respiratory viral infections, individuals with allergic asthma have shown reduced susceptibility to severe coronavirus disease 2019 (COVID-19). OBJECTIVE: We sought to identify mechanisms whereby type 2 inflammation in the airway protects against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by using bronchial airway epithelial cells (AECs) from aeroallergen-sensitized children with asthma and healthy nonsensitized children. METHODS: We measured SARS-CoV-2 replication and ACE2 protein and performed bulk and single-cell RNA sequencing of ex vivo infected AEC samples with SARS-CoV-2 infection and with or without IL-13 treatment. RESULTS: We observed that viral replication was lower in AECs from children with allergic asthma than those from in healthy nonsensitized children and that IL-13 treatment reduced viral replication only in children with allergic asthma and not in healthy children. Lower viral transcript levels were associated with a downregulation of functional pathways of the ciliated epithelium related to differentiation as well as cilia and axoneme production and function, rather than lower ACE2 expression or increases in goblet cells or mucus secretion pathways. Moreover, single-cell RNA sequencing identified specific subsets of relatively undifferentiated ciliated epithelium (which are common in allergic asthma and highly responsive to IL-13) that directly accounted for impaired viral replication. CONCLUSION: Our results identify a novel mechanism of innate protection against SARS-CoV-2 in allergic asthma that provides important molecular and clinical insights during the ongoing COVID-19 pandemic.


Subject(s)
Asthma , COVID-19 , Child , Humans , SARS-CoV-2 , Interleukin-13 , Pandemics , Asthma/epidemiology , Inflammation , Epithelial Cells/metabolism , Epithelium/metabolism
5.
JCI Insight ; 7(22)2022 11 22.
Article in English | MEDLINE | ID: mdl-36282595

ABSTRACT

Therapeutics that inhibit IL-6 at different points in its signaling pathway are in clinical use, yet whether the immunological effects of these interventions differ based on their molecular target is unknown. We performed short-term interventions in individuals with type 1 diabetes using anti-IL-6 (siltuximab) or anti-IL-6 receptor (IL-6R; tocilizumab) therapies and investigated the impact of this in vivo blockade on T cell fate and function. Immune outcomes were influenced by the target of the therapeutic intervention (IL-6 versus IL-6R) and by peak drug concentration. Tocilizumab reduced ICOS expression on T follicular helper cell populations and T cell receptor-driven (TCR-driven) STAT3 phosphorylation. Siltuximab reversed resistance to Treg-mediated suppression and increased TCR-driven phosphorylated STAT3 and production of IL-10, IL-21, and IL-27 by T effectors. Together, these findings indicate that the context of IL-6 blockade in vivo drives distinct T cell-intrinsic changes that may influence therapeutic outcomes.


Subject(s)
Cytokines , Receptors, Antigen, T-Cell , Humans , Cytokines/pharmacology , Signal Transduction , Phosphorylation
6.
Diabetologia ; 63(8): 1576-1587, 2020 08.
Article in English | MEDLINE | ID: mdl-32500289

ABSTRACT

AIMS/HYPOTHESIS: Self-antigen-specific T cell responses drive type 1 diabetes pathogenesis, but alterations in innate immune responses are also critical and not as well understood. Innate immunity in human type 1 diabetes has primarily been assessed via gene-expression analysis of unstimulated peripheral blood mononuclear cells, without the immune activation that could amplify disease-associated signals. Increased responsiveness in each of the two main innate immune pathways, driven by either type 1 IFN (IFN-1) or IL-1, have been detected in type 1 diabetes, but the dominant innate pathway is still unclear. This study aimed to determine the key innate pathway in type 1 diabetes and assess the whole blood immune stimulation assay as a tool to investigate this. METHODS: The TruCulture whole blood ex vivo stimulation assay, paired with gene expression and cytokine measurements, was used to characterise changes in the stimulated innate immune response in type 1 diabetes. We applied specific cytokine-induced signatures to our data, pre-defined from the same assays measured in a separate cohort of healthy individuals. In addition, NOD mice were stimulated with CpG and monocyte gene expression was measured. RESULTS: Monocytes from NOD mice showed lower baseline vs diabetes-resistant B6.g7 mice, but higher induced IFN-1-associated gene expression. In human participants, ex vivo whole blood stimulation revealed higher induced IFN-1 responses in type 1 diabetes, as compared with healthy control participants. In contrast, neither the IL-1-induced gene signature nor response to the adaptive immune stimulant Staphylococcal enterotoxin B were significantly altered in type 1 diabetes samples vs healthy control participants. Targeted gene-expression analysis showed that this enhanced IFN response was specific to IFN-1, as IFN-γ-driven responses were not significantly different. CONCLUSIONS/INTERPRETATION: Our study identifies increased responsiveness to IFN-1 as a feature of both the NOD mouse model of autoimmune diabetes and human established type 1 diabetes. A stimulated IFN-1 gene signature may be a potential biomarker for type 1 diabetes and used to evaluate the effects of therapies targeting this pathway. DATA AVAILABILITY: Mouse gene expression data are found in the gene expression omnibus (GEO) repository, accession GSE146452 ( www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE146452 ). Nanostring count data from the human experiments were deposited in the GEO repository, accession GSE146338 ( www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE146338 ). Data files and R code for all analyses are available at https://github.com/rodriguesk/T1D_truculture_diabetologia . Graphical abstract.


Subject(s)
Diabetes Mellitus, Type 1/physiopathology , Immunity, Innate/physiology , Leukocytes, Mononuclear/metabolism , Monocytes/metabolism , Animals , Diabetes Mellitus, Type 1/immunology , Diabetes Mellitus, Type 1/metabolism , Enterotoxins/pharmacology , Female , Humans , Immunity, Innate/drug effects , Immunity, Innate/genetics , Interleukin-1/pharmacology , Leukocytes, Mononuclear/drug effects , Mice , Mice, Inbred NOD , Monocytes/drug effects
7.
J Clin Invest ; 130(1): 480-490, 2020 01 02.
Article in English | MEDLINE | ID: mdl-31815738

ABSTRACT

Although most patients with type 1 diabetes (T1D) retain some functional insulin-producing islet ß cells at the time of diagnosis, the rate of further ß cell loss varies across individuals. It is not clear what drives this differential progression rate. CD8+ T cells have been implicated in the autoimmune destruction of ß cells. Here, we addressed whether the phenotype and function of autoreactive CD8+ T cells influence disease progression. We identified islet-specific CD8+ T cells using high-content, single-cell mass cytometry in combination with peptide-loaded MHC tetramer staining. We applied a new analytical method, DISCOV-R, to characterize these rare subsets. Autoreactive T cells were phenotypically heterogeneous, and their phenotype differed by rate of disease progression. Activated islet-specific CD8+ memory T cells were prevalent in subjects with T1D who experienced rapid loss of C-peptide; in contrast, slow disease progression was associated with an exhaustion-like profile, with expression of multiple inhibitory receptors, limited cytokine production, and reduced proliferative capacity. This relationship between properties of autoreactive CD8+ T cells and the rate of T1D disease progression after onset make these phenotypes attractive putative biomarkers of disease trajectory and treatment response and reveal potential targets for therapeutic intervention.


Subject(s)
Autoimmunity , CD8-Positive T-Lymphocytes/immunology , Diabetes Mellitus, Type 1/immunology , Immunologic Memory , Islets of Langerhans/immunology , Lymphocyte Activation , Adolescent , Adult , CD8-Positive T-Lymphocytes/pathology , Child , Child, Preschool , Diabetes Mellitus, Type 1/pathology , Female , Humans , Infant , Islets of Langerhans/pathology , Male , Middle Aged
8.
Sci Transl Med ; 11(521)2019 12 04.
Article in English | MEDLINE | ID: mdl-31801887

ABSTRACT

CCR5 is thought to play a central role in orchestrating migration of cells in response to inflammation. CCR5 antagonists can reduce inflammatory disease processes, which has led to an increased interest in using CCR5 antagonists in a wide range of inflammation-driven diseases. Paradoxically, these antagonists appear to function without negatively affecting host immunity at barrier sites. We reasoned that the resolution to this paradox may lie in the CCR5+ T cell populations that permanently reside in tissues. We used a single-cell analysis approach to examine the human CCR5+ T cell compartment in the blood, healthy, and inflamed mucosal tissues to resolve these seemingly contradictory observations. We found that 65% of the CD4 tissue-resident memory T (TRM) cell compartment expressed CCR5. These CCR5+ TRM cells were enriched in and near the epithelial layer and not only limited to TH1-type cells but also contained a large TH17-producing and a stable regulatory T cell population. The CCR5+ TRM compartment was stably maintained even in inflamed tissues including the preservation of TH17 and regulatory T cell populations. Further, using tissues from the CHARM-03 clinical trial, we found that CCR5+ TRM are preserved in human mucosal tissue during treatment with the CCR5 antagonist Maraviroc. Our data suggest that the human CCR5+ TRM compartment is functionally and spatially equipped to maintain barrier immunity even in the absence of CCR5-mediated, de novo T cell recruitment from the periphery.


Subject(s)
Cell Compartmentation , Inflammation/immunology , Receptors, CCR5/metabolism , T-Lymphocytes/cytology , T-Lymphocytes/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Antigens, CD/metabolism , Antigens, Differentiation, T-Lymphocyte/metabolism , CD8-Positive T-Lymphocytes/drug effects , CD8-Positive T-Lymphocytes/immunology , Cell Compartmentation/drug effects , Cytokines/biosynthesis , Female , Humans , Lectins, C-Type/metabolism , Lymphocyte Subsets/drug effects , Lymphocyte Subsets/immunology , Male , Maraviroc/pharmacology , Middle Aged , Mouth Mucosa/drug effects , Mouth Mucosa/immunology , Mouth Mucosa/pathology , Receptors, Antigen, T-Cell/metabolism , T-Lymphocytes/drug effects , Th17 Cells/drug effects , Th17 Cells/immunology , Transcriptome/genetics , Young Adult
9.
JCI Insight ; 4(23)2019 12 05.
Article in English | MEDLINE | ID: mdl-31671072

ABSTRACT

At diagnosis, most people with type 1 diabetes (T1D) produce measurable levels of endogenous insulin, but the rate at which insulin secretion declines is heterogeneous. To explain this heterogeneity, we sought to identify a composite signature predictive of insulin secretion, using a collaborative assay evaluation and analysis pipeline that incorporated multiple cellular and serum measures reflecting ß cell health and immune system activity. The ability to predict decline in insulin secretion would be useful for patient stratification for clinical trial enrollment or therapeutic selection. Analytes from 12 qualified assays were measured in shared samples from subjects newly diagnosed with T1D. We developed a computational tool (DIFAcTO, Data Integration Flexible to Account for different Types of data and Outcomes) to identify a composite panel associated with decline in insulin secretion over 2 years following diagnosis. DIFAcTO uses multiple filtering steps to reduce data dimensionality, incorporates error estimation techniques including cross-validation and sensitivity analysis, and is flexible to assay type, clinical outcome, and disease setting. Using this novel analytical tool, we identified a panel of immune markers that, in combination, are highly associated with loss of insulin secretion. The methods used here represent a potentially novel process for identifying combined immune signatures that predict outcomes relevant for complex and heterogeneous diseases like T1D.


Subject(s)
Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 1/immunology , Disease Progression , Insulin Secretion/physiology , Adolescent , Adult , Child , Computational Biology , Female , Humans , Hypoglycemic Agents/pharmacology , Immunotherapy/methods , Insulin-Secreting Cells/metabolism , Male , Young Adult
10.
N Engl J Med ; 381(7): 603-613, 2019 08 15.
Article in English | MEDLINE | ID: mdl-31180194

ABSTRACT

BACKGROUND: Type 1 diabetes is a chronic autoimmune disease that leads to destruction of insulin-producing beta cells and dependence on exogenous insulin for survival. Some interventions have delayed the loss of insulin production in patients with type 1 diabetes, but interventions that might affect clinical progression before diagnosis are needed. METHODS: We conducted a phase 2, randomized, placebo-controlled, double-blind trial of teplizumab (an Fc receptor-nonbinding anti-CD3 monoclonal antibody) involving relatives of patients with type 1 diabetes who did not have diabetes but were at high risk for development of clinical disease. Patients were randomly assigned to a single 14-day course of teplizumab or placebo, and follow-up for progression to clinical type 1 diabetes was performed with the use of oral glucose-tolerance tests at 6-month intervals. RESULTS: A total of 76 participants (55 [72%] of whom were ≤18 years of age) underwent randomization - 44 to the teplizumab group and 32 to the placebo group. The median time to the diagnosis of type 1 diabetes was 48.4 months in the teplizumab group and 24.4 months in the placebo group; the disease was diagnosed in 19 (43%) of the participants who received teplizumab and in 23 (72%) of those who received placebo. The hazard ratio for the diagnosis of type 1 diabetes (teplizumab vs. placebo) was 0.41 (95% confidence interval, 0.22 to 0.78; P = 0.006 by adjusted Cox proportional-hazards model). The annualized rates of diagnosis of diabetes were 14.9% per year in the teplizumab group and 35.9% per year in the placebo group. There were expected adverse events of rash and transient lymphopenia. KLRG1+TIGIT+CD8+ T cells were more common in the teplizumab group than in the placebo group. Among the participants who were HLA-DR3-negative, HLA-DR4-positive, or anti-zinc transporter 8 antibody-negative, fewer participants in the teplizumab group than in the placebo group had diabetes diagnosed. CONCLUSIONS: Teplizumab delayed progression to clinical type 1 diabetes in high-risk participants. (Funded by the National Institutes of Health and others; ClinicalTrials.gov number, NCT01030861.).


Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , CD3 Complex/antagonists & inhibitors , Diabetes Mellitus, Type 1/prevention & control , Adolescent , Adult , Antibodies, Monoclonal, Humanized/adverse effects , Child , Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 1/immunology , Disease Progression , Double-Blind Method , Exanthema/chemically induced , Female , Glucose Tolerance Test , HLA-DR3 Antigen , HLA-DR4 Antigen , Humans , Lymphocyte Count , Lymphopenia/chemically induced , Male , Middle Aged , Proportional Hazards Models , T-Lymphocytes/immunology , Young Adult
11.
JCI Insight ; 4(4)2019 02 21.
Article in English | MEDLINE | ID: mdl-30830868

ABSTRACT

The rate of decline in insulin secretion after diagnosis with type 1 diabetes (T1D) varies substantially among individuals and with age at diagnosis, but the mechanism(s) behind this heterogeneity are not well understood. We investigated the loss of pancreatic ß cell function in new-onset T1D subjects using unbiased whole blood RNA-seq and verified key findings by targeted cell count measurements. We found that patients who lost insulin secretion more rapidly had immune phenotypes ("immunotypes") characterized by higher levels of B cells and lower levels of neutrophils, especially neutrophils expressing primary granule genes. The B cell and neutrophil immunotypes showed strong age dependence, with B cell levels in particular predicting rate of progression in young subjects only. This age relationship suggested that therapy targeting B cells in T1D would be most effective in young subjects with high pretreatment B cell levels, a prediction which was supported by data from a clinical trial of rituximab in new-onset subjects. These findings demonstrate a link between age-related immunotypes and disease outcome in new-onset T1D. Furthermore, our data suggest that greater success could be achieved by targeted use of immunomodulatory therapy in specific T1D populations defined by age and immune characteristics.


Subject(s)
Diabetes Mellitus, Type 1/immunology , Immunologic Factors/therapeutic use , Insulin Secretion/immunology , Insulin-Secreting Cells/metabolism , Leukocytes/immunology , Adolescent , Adult , Age Factors , Child , Controlled Clinical Trials as Topic , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/diagnosis , Diabetes Mellitus, Type 1/drug therapy , Disease Progression , Female , Humans , Immunologic Factors/pharmacology , Insulin/metabolism , Insulin Secretion/drug effects , Insulin-Secreting Cells/drug effects , Insulin-Secreting Cells/pathology , Leukocyte Count , Leukocytes/drug effects , Male , Middle Aged , Patient Selection , Prognosis , RNA-Seq , Treatment Outcome , Young Adult
12.
JCI Insight ; 4(4)2019 02 21.
Article in English | MEDLINE | ID: mdl-30830871

ABSTRACT

Costimulatory interactions control T cell activation at sites of activated antigen-presenting cells, including B cells. Blockade of the CD28/CD80/CD86 costimulatory axis with CTLA4Ig (abatacept) is widely used to treat certain autoimmune diseases. While transiently effective in subjects with new-onset type 1 diabetes (T1D), abatacept did not induce long-lasting immune tolerance. To elucidate mechanisms limiting immune tolerance in T1D, we performed unbiased analysis of whole blood transcriptomes and targeted measurements of cell subset levels in subjects from a clinical trial of abatacept in new-onset T1D. We showed that individual subjects displayed age-related immune phenotypes ("immunotypes") at baseline, characterized by elevated levels of B cells or neutrophils, that accompanied rapid or slow progression, respectively, in both abatacept- and placebo-treated groups. A more pronounced immunotype was exhibited by a subset of subjects showing poor response (resistance) to abatacept. This resistance immunotype was characterized by a transient increase in activated B cells (one of the cell types that binds abatacept), reprogrammed costimulatory ligand gene expression, and reduced inhibition of anti-insulin antibodies. Our findings identify immunotypes in T1D subjects that are linked to the rate of disease progression, both in placebo- and abatacept-treated subjects. Furthermore, our results suggest therapeutic approaches to restore immune tolerance in T1D.


Subject(s)
Abatacept/pharmacology , B-Lymphocytes/metabolism , Diabetes Mellitus, Type 1/drug therapy , Gene Expression Regulation/genetics , Immunosuppressive Agents/pharmacology , Abatacept/therapeutic use , Adolescent , Age Factors , B-Lymphocytes/drug effects , B-Lymphocytes/immunology , B7-1 Antigen/immunology , B7-1 Antigen/metabolism , B7-2 Antigen/immunology , B7-2 Antigen/metabolism , CD28 Antigens/immunology , CD28 Antigens/metabolism , CTLA-4 Antigen/antagonists & inhibitors , CTLA-4 Antigen/immunology , CTLA-4 Antigen/metabolism , Child , Clinical Trials, Phase II as Topic , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 1/immunology , Disease Progression , Drug Resistance/genetics , Drug Resistance/immunology , Female , Gene Expression Regulation/immunology , Humans , Immune Tolerance/drug effects , Immunosuppressive Agents/therapeutic use , Lymphocyte Activation/immunology , Male , RNA-Seq , Randomized Controlled Trials as Topic , Signal Transduction/drug effects , Signal Transduction/genetics , Signal Transduction/immunology , Treatment Outcome , Young Adult
13.
Genes Immun ; 20(4): 293-307, 2019 04.
Article in English | MEDLINE | ID: mdl-29925930

ABSTRACT

Biologic treatment of type 1 diabetes (T1D) with agents including anti-CD3 (otelixizumab and teplizumab), anti-CD20 (rituximab), LFA3Ig (alafacept), and CTLA4Ig (abatacept) results in transient stabilization of insulin C-peptide, a surrogate for endogenous insulin secretion. With the goal of inducing more robust immune tolerance, we used systems biology approaches to elucidate mechanisms associated with C-peptide stabilization in clinical trial blood samples from new-onset T1D subjects treated with the B cell-depleting drug, rituximab. RNA sequencing (RNA-seq) analysis of whole-blood samples from this trial revealed a transient increase in heterogeneous T cell populations, which were associated with decreased pharmacodynamic activity of rituximab, increased proliferative responses to islet antigens, and more rapid C-peptide loss. Our findings illustrate complexity in hematopoietic remodeling that accompanies B cell depletion by rituximab, which impacts and predicts therapeutic efficacy in T1D. Our data also suggest that a combination of rituximab with therapy targeting CD4 + T cells may be beneficial for T1D subjects.


Subject(s)
Diabetes Mellitus, Type 1/drug therapy , Immunologic Factors/therapeutic use , Rituximab/therapeutic use , T-Lymphocytes/cytology , Adolescent , Adult , Biomarkers/blood , Diabetes Mellitus, Type 1/blood , Female , Humans , Lymphocyte Count , Male , Treatment Outcome
14.
JCI Insight ; 3(18)2018 09 20.
Article in English | MEDLINE | ID: mdl-30232284

ABSTRACT

BACKGROUND: Neutrophils and their inflammatory mediators are key pathogenic components in multiple autoimmune diseases, while their role in human type 1 diabetes (T1D), a disease that progresses sequentially through identifiable stages prior to the clinical onset, is not well understood. We previously reported that the number of circulating neutrophils is reduced in patients with T1D and in presymptomatic at-risk subjects. The aim of the present work was to identify possible changes in circulating and pancreas-residing neutrophils throughout the disease course to better elucidate neutrophil involvement in human T1D. METHODS: Data collected from 389 subjects at risk of developing T1D, and enrolled in 4 distinct studies performed by TrialNet, were analyzed with comprehensive statistical approaches to determine whether the number of circulating neutrophils correlates with pancreas function. To obtain a broad analysis of pancreas-infiltrating neutrophils throughout all disease stages, pancreas sections collected worldwide from 4 different cohorts (i.e., nPOD, DiViD, Siena, and Exeter) were analyzed by immunohistochemistry and immunofluorescence. Finally, circulating neutrophils were purified from unrelated nondiabetic subjects and donors at various T1D stages and their transcriptomic signature was determined by RNA sequencing. RESULTS: Here, we show that the decline in ß cell function is greatest in individuals with the lowest peripheral neutrophil numbers. Neutrophils infiltrate the pancreas prior to the onset of symptoms and they continue to do so as the disease progresses. Of interest, a fraction of these pancreas-infiltrating neutrophils also extrudes neutrophil extracellular traps (NETs), suggesting a tissue-specific pathogenic role. Whole-transcriptome analysis of purified blood neutrophils revealed a unique molecular signature that is distinguished by an overabundance of IFN-associated genes; despite being healthy, said signature is already present in T1D-autoantibody-negative at-risk subjects. CONCLUSIONS: These results reveal an unexpected abnormality in neutrophil disposition both in the circulation and in the pancreas of presymptomatic and symptomatic T1D subjects, implying that targeting neutrophils might represent a previously unrecognized therapeutic modality. FUNDING: Juvenile Diabetes Research Foundation (JDRF), NIH, Diabetes UK.


Subject(s)
Diabetes Mellitus, Type 1/immunology , Neutrophils/immunology , Pancreas/immunology , Autoantibodies , Autoimmune Diseases , Extracellular Traps/immunology , Gene Expression , Gene Expression Profiling , Humans , Immunity, Innate , Insulin-Secreting Cells , Interferons/genetics , Interferons/metabolism , Neutrophils/pathology , Transcriptome
15.
J Immunol ; 199(1): 323-335, 2017 07 01.
Article in English | MEDLINE | ID: mdl-28566371

ABSTRACT

The significance of islet Ag-reactive T cells found in peripheral blood of type 1 diabetes (T1D) subjects is unclear, partly because similar cells are also found in healthy control (HC) subjects. We hypothesized that key disease-associated cells would show evidence of prior Ag exposure, inferred from expanded TCR clonotypes, and essential phenotypic properties in their transcriptomes. To test this, we developed single-cell RNA sequencing procedures for identifying TCR clonotypes and transcript phenotypes in individual T cells. We applied these procedures to analysis of islet Ag-reactive CD4+ memory T cells from the blood of T1D and HC individuals after activation with pooled immunodominant islet peptides. We found extensive TCR clonotype sharing in Ag-activated cells, especially from individual T1D subjects, consistent with in vivo T cell expansion during disease progression. The expanded clonotype from one T1D subject was detected at repeat visits spanning >15 mo, demonstrating clonotype stability. Notably, we found no clonotype sharing between subjects, indicating a predominance of "private" TCR specificities. Expanded clones from two T1D subjects recognized distinct IGRP peptides, implicating this molecule as a trigger for CD4+ T cell expansion. Although overall transcript profiles of cells from HC and T1D subjects were similar, profiles from the most expanded clones were distinctive. Our findings demonstrate that islet Ag-reactive CD4+ memory T cells with unique Ag specificities and phenotypes are expanded during disease progression and can be detected by single-cell analysis of peripheral blood.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , Diabetes Mellitus, Type 1/immunology , Islets of Langerhans/immunology , Lymphocyte Activation , Adult , Clone Cells , Diabetes Mellitus, Type 1/blood , Female , Gene Expression Profiling , Humans , Immunologic Memory , Male , Peptides/immunology , Phenotype , Receptors, Antigen, T-Cell, alpha-beta/immunology , Sequence Analysis, RNA , Single-Cell Analysis
16.
Mol Phylogenet Evol ; 94(Pt A): 313-26, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26416706

ABSTRACT

The accumulation of DNA sequence data in public repositories allows for phylogenetic inference on unprecedented taxonomic scales using supermatrix approaches. Careful analysis of available data allows strategic augmentation with new sequences in order to maximize taxonomic sampling and coverage of informative loci. I inferred relationships among 179 species (76%) in the avian family Picidae (woodpeckers, piculets, and wrynecks), using publicly available sequence data supplemented with targeted sequencing to increase species-level and locus-level sampling and maximize resolution. Results of these analyses generally corroborate previous molecular studies, with consensus on the membership of most genera and tribes. However, several newly placed taxa show surprising affinities, and several genera as currently delineated appear to be paraphyletic. Relationships among major clades of Picidae remain poorly resolved, particularly among the three lineages of piculets, the unusual woodpecker genus Hemicircus, and the remaining woodpeckers, and among the major groups of true woodpeckers (Picinae). If these deep relationships are to be resolved, phylogenomic approaches may be necessary.


Subject(s)
Birds/classification , Birds/genetics , Animals , Bayes Theorem , Genetic Speciation , Likelihood Functions , Pedigree , Phylogeny , Sequence Analysis, DNA/veterinary , Uncertainty
17.
Ecol Evol ; 3(15): 4910-24, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24455125

ABSTRACT

Geographic distributions of genetic and phenotypic characters can illuminate historical evolutionary processes. In particular, mosaic distributions of phenotypically similar populations can arise from parallel evolution or from irregular patterns of dispersal and colonization by divergent forms. Two phenotypically divergent forms of the red-winged blackbird (Agelaius phoeniceus) show a mosaic phenotypic distribution, with a "bicolored" form occurring disjunctly in California and Mexico. We analyzed the relationships among these bicolored populations and neighboring typical populations, using ∼600 bp of mitochondrial DNA sequence data and 10 nuclear short tandem repeat loci. We find that bicolored populations, although separated by ∼3000 km, are genetically more similar to one other than they are to typical populations separated by ∼400 km. We also find evidence of ongoing gene flow among populations, including some evidence of asymmetric gene flow. We conclude that the current distribution of bicolored forms represents incomplete speciation, where recent asymmetric hybridization with typical A. phoeniceus is dividing the range of a formerly widespread bicolored form. This hypothesis predicts that bicolored forms may suffer extinction by hybridization. Future work will use fine-scaled geographical sampling and nuclear sequence data to test for hybrid origins of currently typical populations and to more precisely quantify the directionality of gene flow.

18.
Mol Ecol Resour ; 11(6): 1124-6, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21951598

ABSTRACT

This article documents the addition of 112 microsatellite marker loci and 24 pairs of single nucleotide polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Agelaius phoeniceus, Austrolittorina cincta, Circus cyaneus, Circus macrourus, Circus pygargus, Cryptocoryne × purpurea Ridl. nothovar. purpurea, Mya arenaria, Patagioenas squamosa, Prochilodus mariae, Scylla serrata and Scytalopus speluncae. These loci were cross-tested on the following species: Cryptocoryne × purpurea nothovar. purpurea, Cryptocoryne affinis, Cryptocoryne ciliata, Cryptocoryne cordata var. cordata, Cryptocoryne elliptica, Cryptocoryne griffithii, Cryptocoryne minima, Cryptocoryne nurii and Cryptocoryne schulzei. This article also documents the addition of 24 sequencing primer pairs and 24 allele-specific primers or probes for Aphis glycines.


Subject(s)
Databases, Genetic , Ecology/methods , Microsatellite Repeats/genetics , Polymorphism, Single Nucleotide/genetics , DNA Primers/genetics , Species Specificity
SELECTION OF CITATIONS
SEARCH DETAIL
...