Project description:Brucellosis is one of the most widespread bacterial zoonoses worldwide. Here, our aim was to identify the effector mechanisms controlling the early stages of intranasal infection with Brucella in C57BL/6 mice. During the first 48 hours of infection, alveolar macrophages (AMs) are the main cells infected in the lungs. Using RNA sequencing, we identified the aconitate decarboxylase 1 gene (Acod1; also known as Immune responsive gene 1), as one of the genes most upregulated in murine AMs in response to B. melitensis infection at 24 hours post-infection. Upregulation of Acod1 was confirmed by RT-qPCR in lungs infected with B. melitensis and B. abortus. We observed that Acod1-/- C57BL/6 mice display a higher bacterial load in their lungs than wild-type (wt) mice following B. melitensis or B. abortus infection, demonstrating that Acod1 participates in the control of pulmonary Brucella infection. The ACOD1 enzyme is mostly produced in mitochondria of macrophages, and converts cis-aconitate, a metabolite in the Krebs cycle, into itaconate. Dimethyl itaconate (DMI), a chemically-modified membrane permeable form of itaconate, has a dose-dependent inhibitory effect on Brucella growth in vitro. Interestingly, modelling studies suggest the binding of itaconate into the binding site of isocitrate lyase. DMI does not inhibit multiplication of the isocitrate lyase deletion mutant ∆aceA B. abortus in vitro. Finally, we observed that, unlike the wt strain, the ∆aceA B. abortus strain multiplies similarly in wt and Acod1-/- C57BL/6 mice. These data suggest that bacterial isocitrate lyase might be a target of itaconate in AMs.
Project description:The white-footed deermouse Peromyscus leucopus is a primary reservoir for the agents of Lyme disease and other zoonoses in North America. These and other species of Peromyscus are tolerant of the infection by the bacteria, protozoa, and viruses they host. This is mainly by mitigating the damaging effects of the innate immune response. In previous studies we demonstrated differences between P. leucopus and either inbred or outbred M. musculus in the degree of sickness and profiles of biomarkers after exposure to bacterial lipopolysaccharide, a TLR4 agonist. With the objective of developing a method for broadly assessing of innate immunity of capture-release mammals in nature, we evaluated using bulk and single cell RNA-seq primary dermal fibroblast cultures of P. leucopus and M. musculus in their short-term responses to a lipopeptide that is a TLR2 agonist. As we had observed for experimental animals, the fibroblast cultures of the two species displayed both similarities and differences in their responses to the agonist. The notable differences included the greater magnitude of an anti-viral profile of cytokines and other effectors in the deermouse fibroblasts and the occurrence of an interleukin-11 response in the mouse cultures but not deermouse. We also observed in both species' cultures an increased transcription of several types of endogenous retrovirus (ERV) elements after exposure of the cells to the agonist. The P. leucopus cells were distinguished from M. musculus cells in the generally shorter retroviral open reading frames among the differentially expressed sequences. This was consistent with previous findings about ERV transcription in P. leucopus and M. musculus and suggests a greater suppression of ERV activity in P. leuocopus. The results affirm the feasibility of this in vitro model for both laboratory- and field-based studies without need for euthanasia and that inherent differences between deermice and mice in innate immune responses can be demonstrated in primary fibroblasts as well as the animals themselves.
Project description:This study aims to investigate the DNA methylation patterns at transcription factor binding regions and their evolutionary conservation with respect to binding activity divergence. We combined newly generated bisulfite-sequencing experiments in livers of five mammals (human, macaque, mouse, rat and dog) and matched publicly available ChIP-sequencing data for five transcription factors (CEBPA, HNF4a, CTCF, ONECUT1 and FOXA1). To study the chromatin contexts of TF binding subjected to distinct evolutionary pressures, we integrated publicly available active promoter, active enhancer and primed enhancer calls determined by profiling genome wide patterns of H3K27ac, H3K4me3 and H3K4me1.
Project description:Whole genome sequencing of the Arabidopsis thaliana dot5-1 transposon insertion line described in Petricka et al 2008 The Plant Journal 56(2): 251-263.
Project description:The analysis identifies differentially occupied genomic regions of H2Bub1, H3K79me3, and H3K27ac by RNF40 silencing in HCC1806 cells
Project description:This study aims to investigate the interactions of mutagenic lesions from diethylnitrosamine (DEN) treatment of mouse livers with such processes as replication, transcription, and interaction of DNA with proteins. Liver samples of 15-day old (P15) untreated C3H/HeOuJ mice were isolated and flash-frozen. ChIP-seq was performed to identify CTCF binding sites in livers of ten pooled individuals. The experiment was done with five biological replicates with a matched input library.