Widespread shortening of 3â untranslated regions and increased exon inclusion characterize the human macrophage response to infection [mRNA]
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ABSTRACT: Changes in gene regulation have long been known to play important roles in both innate and adaptive immune responses. However, post-transcriptional mechanisms involved in mRNA processing have been poorly studied despite emerging examples of their role as regulators of immune defenses. We sought to investigate the role of mRNA processing in the cellular responses of human macrophages to live bacterial infections. Transcriptomic profiles of 198 infected (Listeria and Salmonella) and non-infected samples at multiple time points.
Project description:Changes in gene regulation have long been known to play important roles in both innate and adaptive immune responses. However, post-transcriptional mechanisms involved in mRNA processing have been poorly studied despite emerging examples of their role as regulators of immune defenses. We sought to investigate the role of mRNA processing in the cellular responses of human macrophages to live bacterial infections. miRNAs profiles for infected and non-infected samples at multiple time points.
Project description:Individuals from different populations vary considerably in their susceptibility to immune-related diseases. To understand how genetic variation and natural selection contribute to these differences, we tested for the effects of African versus European ancestry on the transcriptional response of primary macrophages to live bacterial pathogens. 12% of macrophage-expressed genes show ancestry-associated differences in the gene regulatory response to infection, and African ancestry specifically predicts a stronger inflammatory response and reduced intracellular bacterial growth. A large proportion of these differences are under genetic control: for 569 genes, more than 75% of ancestry effects on the immune response can be explained by a single cis- or trans-acting eQTL. Finally, we show that genetic effects on the immune response are strongly enriched for recent, population-specific signatures of adaptation. Together, our results demonstrate how historical selective events continue to shape human phenotypic diversity today, including for traits that are central to coping with infection. Transcriptomic profiles of 503 infected (Listeria and Salmonella) and non-infected samples at 2hr time point.
Project description:CD8+ T cells contribute to protective immunity to Mycobacterium tuberculosis (Mtb), but the principles that govern presentation of Mtb peptides on MHC class I (MHC-I) on the surface of infected macrophages for CD8+ T cell recognition are incompletely understood. Here, we use internal standard parallel reaction monitoring (IS-PRM, also known as SureQuant) to rigorously validate identifications of Mtb-derived MHC-I peptides obtained in data-dependent MS analyses. We further use SureQuant to quantify presentation of Mtb peptides derived from the secreted effector proteins EsxA and EsxJ across multiple experimental conditions. We show that presentation of both EsxA- and EsxJ-derived peptides requires the activity of the mycobacterial ESX-1 type VII secretion system, possibly indicating that ESX-1-mediated phagosome membrane damage allows Mtb proteins to access MHC-I antigen processing pathways. We show that this requirement is independent of type I interferon signaling that occurs downstream of phagosome damage. Treatment with inhibitors of conventional proteolytic pathways involved in MHC-I antigen processing inhibits presentation of self peptides as expected, but does not inhibit presentation of Mtb peptides, implying an alternative or redundant mechanism of processing.
Project description:Monocytes can give rise to multiple highly specialized cell types to perform a wide array of functions, ranging from pathogen phagocytosis to bone resorption. This differentiation is induced by the binding of cytokines to dedicated receptors on the surface of monocytes, which results in the initiation of genetic programs that enable cells to perform their specialized functions. Given their common background, it is not surprising that monocyte-derived cells share abilities and cellular markers, yet their specialized functions require a dedicated set of proteins. In order to dissect the monocyte differentiation process and to define cell type-specific marker proteins, we differentiated circulating monocytes into dendritic cells, M1 and M2 macrophages, and osteoclasts, and assessed their proteomes by quantitative mass spectrometry throughout the differentiation process. Statistical analysis indicated that monocyte differentiation is a linear process characterized by a common core of proteins that is similarly affected among the distinct differentiation paths. Throughout the specialization process a cluster of RNA-binding and processing proteins was downregulated whereas proteins associated to metabolic processes were increased. Analysis of the specialized cells after 10 days of differentiation uncovered existing and putative novel dendritic cell markers. Combined, we here present a comprehensive proteomic analysis of monocyte differentiation uncovering shared and distinct proteomic features of differentiating monocytes and monocyte-derived cells.
Project description:New tuberculosis vaccines are highly desirable and urgently needed since the attenuated Mycobacterium bovis Bacillus Calmette-Guerin (BCG) provides only variable efficacy against the pulmonary form of the disease. The region of difference 1 (RD1), which is deleted in BCG and strongly impacts on Mycobacterium tuberculosis (Mtb) virulence and immunogenicity, represents a crucial locus to be engineered for either the improvement of the current BCG vaccine, or the attenuation of Mtb. Therefore, mutants secreting or not wild-type or mutated variants of the RD1-encoded 6 kDa early secreted antigenic target (ESAT-6) were generated. Comparative analysis of the transcriptome, phenotype, cytokine production profiles and the capacity to promote T cell responses were conducted in human primary dendritic cells (DCs), as they represent critical regulators of vaccine-induced immunity, unveiling a distinct immunogenic potential for BCG or Mtb mutants. In contrast to Mtb, BCG induced a poor DC maturation, and to our surprise, a BCG strain complemented with the RD1 region only partially restored DC maturation and expansion of interferon (IFN)-γ producing T cells. In contrast, infection with a recombinant attenuated Mtb strain, secreting a truncated version of ESAT-6 lacking 11 amino acids at the C-terminus portion, drove full maturation in infected DC and maintained their capacity to promote polarization of T helper (Th) 1 cells, as observed upon infection with the virulent Mtb. We performed a comparative microarray analysis of dendritic cells (DCs), infected with Mtb and BCG strains, expressing/complemented (MtbÎRD1::RD1 and BCG::RD1) or not (MtbÎRD1::B412 and BCG::B412) the/with the RD1 region. DCs were challenged with different BCG and Mtb recombinant strains for 8h.
Project description:Microarray analysis and quantitative real-time PCR revealed that TB40E infection of DCs led to changes of the gene expression pattern. A variety of pro-inflammatory cytokines and chemokines (CXCL10, CXCL11, CCL5), TLR3 and genes whose products function downstream of the TLR3 signalling pathway (e.g. IFN-alpha, IFN-beta) were significantly upregulated. Three mock transfected DC vs. three TB40 transfected DCs
Project description:In this project we conducted a comprehensive analysis of expression and global phosphorylation status of the host proteins following infection with virulent and avirulent mycobacteria. Our objective is to identify previously uncharacterized proteins of host macrophages that are specifically expressed and phosphorylated in response to Mtb and BCG, respectively and may play important role in regulating their intracellular survival
Project description:To study monocyte and macrophage activation in ANCA-associtated vasculitis (AAV), we performed bulk RNA sequencing of bead-selected monocytes and in vitro cultured monocyte-derived macrophages from AAV patients and healthy controls. Overview patients included for sequencing monocytes: - AAV active disease, n=4, MPO-AAV=4 - AAV remission, n=10, PR3-AAV=5, MPO-AAV=5 - Healthy controls, n=6 Overview patients included for sequencing monocyte-derived macrophages: - AAV active, n=1, PR3-AAV=1 - AAV remission, n=3, PR3-AAV=3 - Healthy controls, n=3
Project description:Comparison of gene expression from subjects who resolved or formed pustules to H.ducreyi. In human inoculation experiments, the cutaneous immune response to Haemophilus ducreyi consists of serum, PMN, macrophages, T cells and myeloid DC. In reinfection experiments, some subjects form pustules twice (PP group) or resolve infection twice (RR group). Although pustule formation is associated with serum resistance and phagocytic failure, there are no differences in the ability of isolated phagocytes or serum obtained from PP and RR subjects to ingest or kill H. ducreyi. To identify the basis for differential host susceptibility to H. ducreyi, we used microarrays to profile gene expression in infected and uninfected tissue and monocyte-derived DC obtained from PP and RR subjects. In infected tissue, both groups had a core response to H. ducreyi. Many additional transcripts that signify active immune function were upregulated exclusively in RR tissue, while PP tissue exclusively contained differentially regulated transcripts consistent with immune dysregulation. The core response of infected DC from both groups was typical of a DC1 response. RR DC exclusively expressed many additional transcripts indicative of DC1 function, while PP DC uniquely expressed differentially regulated transcripts characteristic of both DC1 and DCreg. The data suggest that DC from PP and RR subjects are prewired to respond differentially to H. ducreyi. Experiment Overall Design: Six healthy adult volunteers (5 females, 1 male, 36 ± 13 yrs, mean age ± SD) who had been infected with H. ducreyi twice were inoculated a third time. Each volunteer was inoculated at 3 sites on the upper arm with live H. ducreyi 35000HP (a human passaged isolate of strain 35000) and at 1 site with sterile PBS. Forty-eight hours after inoculation, lesion size was measured and RNA was isolated from the infected site that had the largest diameter. RNA was also obtained from the PBS control site (uninfected site). We obtained peripheral blood 6 to 12 months after inoculation of the 6th subject and derived myeloid DC in vitro. In brief, CD14+ peripheral blood monocytes were isolated from PBMC by positive selection magnetic beads (Miltenyi Biotec, Auburn, CA) and grown in the presence of recombinant human (rh) IL-4 (1 ng/ml) and rhGM-CSF (0.2 ng/ml) (R&D Systems, Minneapolis, MN). The cells were HLA-DR+, CD86+ CD40+, CD3-, CD14-, and CD19- by flow cytometry. The experiment was done in pairs so that DC from 1 RR subject were exposed to the same inoculum as DC from 1 PP subject. DC were incubated with nonopsonized H. ducreyi for 90 minutes at an MOI of 30:1. The DC were washed to remove non-associated bacteria, and incubated an additional 22.5 hours. Cells were collected and used for microarray analysis. Supernatants were collected and analyzed for cytokines using the Human Th1/Th2 II Cytometric Bead Array Kit per manufacturerâs instructions (BD Biosciences).