Project description:<p>Whole exome sequencing of a trio (parents and offspring) reveals PIK3CG mutations that result in loss of protein in the child with immunodeficiency and immunopathology.</p>
Project description:Background: Noninfectious complications are the greatest cause of morbidity and mortality in common variable immunodeficiency (CVID), but their pathogenesis remains poorly defined. Objective: Using high-throughput approaches, we aimed to identify, correlate, and determine the significance of immunologic features of CVID with noninfectious complications (CVIDc). Methods: We simultaneously applied proteomics, RNA sequencing, and mass cytometry to a large cohort with primary antibody deficiency. Results: CVIDc is differentiated from uncomplicated CVID, other forms of primary antibody deficiency, and healthy controls by a distinct plasma proteomic profile. In addition to confirming previously reported elevations of 4-1BB, IL-6, IL-18, and IFN-γ, we found elevations of colony-stimulating factor 1, IL-12p40, IL-18R, oncostatin M, TNF, and vascular endothelial growth factor A to differentiate CVIDc. This cytokine dysregulation correlated with deficiency of LPS-specific antibodies and increased soluble CD14, suggesting microbial translocation. Indicating potential significance of reduced LPS-specific antibodies and resultant microbial-induced inflammation, CVIDc had altered LPS-induced gene expression matching plasma proteomics and corresponding with increased CD14+CD16- monocytes, memory T cells, and tissue inflammation ameliorated by T-cell-targeted therapy. Unsupervised machine learning accurately differentiated subjects with CVIDc and supported cytokine dysregulation, antibody deficit, and T-cell activation as defining and convergent features. Conclusions: Our data expand understanding of CVIDc proteomics, establish its link with deficiency of IgA and LPS-specific antibodies, and implicate altered LPS-induced gene expression and elevated monocytes and T cells in this cytokine dysregulation. This work indicates that CVIDc results when insufficient antibody neutralization of pathogen-associated molecular patterns, like LPS, occurs in those with a heightened response to these inflammatory mediators, suggesting a 2-hit model of pathogenesis requiring further exploration.
Project description:In our study we aimed to analyze the gene expression profile of Treg cells in CVID and SIgAD patients, compared to age-matched healthy controls. Selective IgA deficiency (SIgAD) is the most common and common variable immunodeficiency (CVID) is the most symptomatic form of predominant antibody deficiency. Despite differences in the clinical picture, a similar genetic background is suggested. A common feature of both disorders is the occurrence of autoimmune conditions. Regulatory T cells (Tregs) are the major immune cell type that maintains autoimmune tolerance. As the different types of abnormalities of Treg cells were associated with autoimmune disorders in primary immunodeficiency (PID) patients, in our study we aimed to analyze the gene expression profile of Treg cells in CVID and SIgAD patients, compared to age-matched healthy controls. The transcriptome-wide gene profiling was performed using microarray technology. As a results, we analyzed and visualized global expression patterns of genes and pathways of isolated population of Treg cells. We showed the differences at gene-level between patients with and without autoimmunizations. Our finding suggest that gene signature of Treg cells isolated from SIgAD and CVID patients differ from age-matched healthy controls and form each other, while the occurrence of autoimmunity in both PID is associated with IFN signaling pathway. In sum, our findings improve our understanding of Treg dysfunctions in patients with common PIDs and associated autoimmunity.
Project description:Clinically, obesity is strongly associated with severe TH2 immunopathology, though the physiological, cellular, and molecular underpinnings of this association remain obscure. We demonstrate that obese mice are susceptible to severe atopic dermatitis (AD), a major manifestation of TH2 immunopathology and disease burden in humans. Mechanistically, we show that dysregulation of the nuclear hormone receptor peroxisome proliferator-activated receptor gamma (PPARg) in T cells is a causal link between obesity and the increased TH2 immunopathology. We find that PPARg directly controls a cellular metabolic transcriptional program that restrains nuclear gene expression of the chief TH2 effector cytokines interleukin-4 (IL-4) and interleukin-13 (IL-13). Accordingly, thiazolidinediones (TZDs), potent PPARg agonists, robustly protect obese mice from TH2 immunopathology. Collectively, these findings establish PPARg as a molecular link between obesity and TH2 immune homeostasis and identify TZDs as novel therapeutic candidates for TH2 immunopathology.