Project description:An IRF4 de novo mutation affecting the DNA binding domain of encoded IRF4 protein (mutDBD) was identified in a patient presenting with combined immunodeficiency. The patient exhibited profound susceptibility to opportunistic infections notably Pneumocystis jirovecii and humoral immunodeficiency caused by a failure of terminal B cell differentiation. A heterozygous IRF4 missense variant resulting in a phenylalanine-to-leucine replacement within the interferon activation domain of the encoded IRF4 protein (mutIAD) was identified in three patients from a multigenerational family suffering from a novel autosomal dominant disease predominantly presenting as a hypogammaglobulinemia with recurrent infections. In this experiment we aimed to investigate the effect of the two different mutations on IRF4 regulated transcription.
Project description:An IRF4 de novo mutation affecting the DNA binding domain of encoded IRF4 protein (mutDBD) was identified in a patient presenting with combined immunodeficiency. The patient exhibited profound susceptibility to opportunistic infections notably Pneumocystis jirovecii and humoral immunodeficiency caused by a failure of terminal B cell differentiation. A heterozygous IRF4 missense variant resulting in a phenylalanine-to-leucine replacement within the interferon activation domain of the encoded IRF4 protein (mutIAD) was identified in three patients from a multigenerational family suffering from a novel autosomal dominant disease predominantly presenting as a hypogammaglobulinemia with recurrent infections. In this experiment we aimed to investigate the effect of the two different mutations on IRF4 genomic binding.
Project description:An IRF4 de novo mutation affecting the DNA binding domain of encoded IRF4 protein (mutDBD) was identified in a patient presenting with combined immunodeficiency. The patient exhibited profound susceptibility to opportunistic infections notably Pneumocystis jirovecii and humoral immunodeficiency caused by a failure of terminal B cell differentiation. A heterozygous IRF4 missense variant resulting in a phenylalanine-to-leucine replacement within the interferon activation domain of the encoded IRF4 protein (mutIAD) was identified in three patients from a multigenerational family suffering from a novel autosomal dominant disease predominantly presenting as a hypogammaglobulinemia with recurrent infections. In these experiments we aimed to investigate the effect of the two different mutations on IRF4 genomic binding and regulated transcription. This SuperSeries is composed of the SubSeries listed below.
Project description:HIV-infected persons are at increased risk for developing pulmonary diseases including chronic obstructive pulmonary disease (COPD), and the fungal opportunistic pathogen, Pneumocystis jirovecii (Pc) has been implicated in the pathogenesis of HIV-related COPD. We previously developed a non-human primate model of HIV-related COPD using simian-human immunodeficiency virus (SHIV) and Pc co-infection in cynomolgus macaques. In the present study we examined gene expression profiles in lung tissue from SHIV/Pc co-infected monkeys with COPD and compared them to SHIV-infected monkeys infected with normal lung function. Microarray technology was used to develop gene profiles, and differential gene expression was determined by a comparative evaluation of competing normalization methods applied to our expression data set followed by validation using quantitative real-time polymerase chain reaction analysis for select genes. Of over 52,000 transcripts representing more than 20,000 genes analyzed, the SHIV/Pc infected macaques with COPD exhibited 243 differentially expressed (DE) genes compared to SHIV-infected monkeys with normal lung function. DE genes fell into a number of functional categories which may be important in COPD development including: inflammation (pulmonary surfactants A2, B, C, D, upregulated; alternative macrophage activation-associated CC chemokine, upregulated), protease/antiprotease balance (cathepsin H, upregulated; alpha-1-chymotrypsin and secretory leukocyte peptidase inhibitor, downregulated), redox balance (glutathione peroxidase 4 and mitochondrial aldehyde dehydrogenase 2, upregulated) and tissue homeostasis (connective tissue growth factor, downregulated; ornithine decarboxylase antizyme, upregulated). These results identify factors and pathways that may be involved in early development of Pneumocystis and SHIV-associated COPD and reveal several novel, potential therapeutic targets. There are totally 11 samples in the experiment. The sample breakdown is as follows: KN14(group 1) is a true control in that the monkey was not infected with simian-human immunodeficiency virus (SHIV) nor was it colonized with Pneumocystis. KN02, KN03, KN07 and KN08 (group 2) are also controls of a sort. They were infected with SHIV but they did not become colonized with Pneumocystis. The remainder (KN01, KN04, KN06, KN11, KN12, KN13) (group3) were both infected with SHIV and colonized with Pneumocystis. The primary interest is in comparing the two SHIV-infected groups (2 and 3)
Project description:Pneumocystis pneumonia is an opportunistic pneumonia that has been increasing in non-HIV patients in recent years. To obtain a better understanding of the cellular and molecular mechanisms involved in disease pathogenesis, we profile the transcriptomes of mouse lungs with Pneumocystis pneumonia and from uninfected control subjects using single-cell RNA sequencing, yielding multiple populations of myeloid cells, T cells and B cells. We uncover a PCP-associated TREM2+ subpopulation of interstitial macrophages, which expands in PCP, differentiates from Ly6C+ monocytes. We also define the subsets of effector CD4+ T cells that expand after the infection of Pneumocystis. Finally, intercellular crosstalk between interstitial macrophages and effector CD4+ T cells via multiple ligand and receptor interactions reveals several anti-pneumocystis pathways. Our work dissects unanticipated aspects of the cellular and molecular basis of Pneumocystis pneumonia at a single-cell level, and provides a conceptual framework for the discovery of rational therapeutic targets in Pneumocystis pneumonia.
Project description:β-glucans, which can activate innate immune responses, are a major component in the cell wall of the cyst form of Pneumocystis. In the current study we examined whether β-1,3 glucans are masked by surface proteins in Pneumocystis, and what role β-glucans play in Pneumocystis-associated inflammation. For 3 species, including P. jirovecii, which causes Pneumocystis pneumonia (PCP) in humans, P. carinii, and P. murina, β-1,3 glucans were masked in most organisms, as demonstrated by increased exposure following trypsin treatment. Using Q-PCR and microarray techniques, we demonstrated in a mouse model of PCP that treatment with caspofungin, an inhibitor of β-1,3 glucan synthesis, for 21 days, decreased expression of a broad panel of inflammatory markers, including IFN-γ, TNF-α, IL-1β, IL-6, and multiple chemokines/chemokine ligands. Thus, β-glucans in Pneumocystis cysts are largely masked, which likely decreases innate immune activation; this mechanism presumably was developed for interactions with immunocompetent hosts, in whom organism loads are substantially lower. In immunosuppressed hosts with a high organism burden, organism death and release of glucans appears to be an important contributor to deleterious host inflammatory responses.