Project description:APEC-OMV has complex proteomics. In order to screen the key virulence factors of APEC-OMV, comparative proteomics between APEC-OMV isolated from APEC and APEC-OMV isolated from APEC infection with cells was carried out, laying a good foundation for the study of the pathogenicity and pathogenic mechanism of APEC-OMV
Project description:Although A2AR is a key immunoregulatory receptor that suppresses CD8⁺ T-cell activation in response to elevated extracellular adenosine in inflamed or hypoxic microenvironments, its role in CD8⁺ T cell differentiation and cell-fate decisions during chronic viral infection and cancer remains poorly understood. Using A2AR-eGFP reporter mice, we show that A2AR expression is rapidly induced by TCR stimulation and persists under chronic antigen exposure and hypoxia, with sustained expression strongly associated with terminal exhaustion via the canonical Gαs–cAMP–PKA pathway. Paradoxically, A2AR loss does not alleviate exhaustion but instead accelerates differentiation toward the terminally exhausted state. Single-cell multiomics profiling revealed that A2AR deficiency activates CD122 (IL-2Rβ)–dependent signaling, driving T-cell exhaustion. Genetic deletion of CD122 in A2AR-deficient CD8⁺ T cells reduced terminal exhaustion, identifying CD122 signaling as a key mediator of A2AR loss–driven exhaustion. Intriguingly, both sustained A2AR expression and A2AR loss converge to promote T cell exhaustion differentiation through distinct mechanisms. These findings uncover a paradoxical role of A2AR in shaping CD8⁺ T cell fate choices during chronic infection and cancer.
Project description:The adenosine 2A receptor (A2AR) is expressed on regulatory T cells (Tregs), but the functional significance is currently unknown. We compared the gene expression between wild-type (WT) and A2AR knockout (KO) Tregs and between WT Tregs treated with vehicle or a selective A2AR agonist. FACS-sorted GFP positive Tregs from WT or A2AR KO FoxP3GFP mouse spleen and lymph nodes were incubated 18 hr with vehicle (DMSO), a separate set of WT Tregs were incubated with the selective A2AR agonist ATL1222 10 nM (Dogwood Pharmaceuticals, Inc.) for 18 hr prior to RNA isolation.
Project description:Understanding of the mechanism by which A2AR is regulated has been limited by difficulty in identifying the cell types that express A2AR due to a lack of robust antibodies for these receptors. To overcome this we developed an A2AR-eGFP reporter mouse and assessed the expression of A2AR during ongoing anti-tumor immune responses.
Project description:APEC most often infect chickens, turkeys, ducks, and other avian species, and therefore pose a significant economic burden on the poultry industry worldwide. Few studies have analyzed the genome-wide transcriptional profile of APEC during infection in vivo. In this study, we examined the genome-wide transcriptional response of APEC O2 strain E058 in an in vivo chicken infection model to better understand the factors necessary for APEC colonization, growth, and survival in vivo. An Affymetrix multigenome DNA microarray, which contains most of the genomic open reading frames of E. coli K-12 strain MG1655, uropathogenic E. coli strain CFT073, and E. coli O157:H7 strain EDL 933, was used to profile the gene expression in APEC E058.The genes highly expressed during infection were involved in metabolism, iron acquisition or transport, virulence, response to stress, and biological regulation. Many genes encoding putative or hypothetical proteins were also strongly upregulated, implying that some undiscovered mechanism may underlie APEC pathogenesis.
Project description:Colisepticemia caused by avian pathogenic Escherichia coli (APEC) results in annual multimillion dollar losses to the poultry industry. Recent research suggests that APEC may have an important role in public health as well. Generally, colisepticemia follows a respiratory tract infection in which APEC penetrate the respiratory epithelium to enter the bloodstream. From the bloodstream, bacteria may spread to various internal organs resulting in perihepatitis, pericarditis, and other conditions. The aim of this study was to identify molecular mechanisms enabling APEC to survive and grow in the bloodstream. To do so, we compared the transcriptome of APEC O1 during growth in Luria-Bertani broth and chicken serum. Selected genes that were significantly up-regulated in chicken serum were then subjected to mutational analysis to confirm their role in APEC pathogenesis. Several categories of genes, predicted to contribute to adaptation and growth in the avian host, were identified. These included several known virulence genes and genes involved in adaptive metabolism, protein transport, biosynthesis pathways, stress resistance, and virulence regulation. Several genes with unknown function, which were localized to pathogenicity islands or APEC O1’s large virulence plasmid, were also identified, suggesting that they too contribute to survival in chicken serum. This genome-wide analysis provides novel insight into processes that are essential to APEC O1’s survival and growth in chicken serum.
Project description:Avian Pathogenic Escherichia coli (APEC) are a group of extra-intestinal E. coli that infect poultry, and are able to cause a variety of diseases, systemic or localized, collectively designated as colibacillosis. Colibacillosis is the most common bacterial illness in poultry production, resulting in significant economic losses world-wide. Despite of its importance, pathogenicity mechanisms of APEC strains remain not completelly elucidated and available vaccines are not fully effectives. In order to better understand which genes could be related to pathogenicity in different APEC isolated, a microarray analyses of two APEC strains representing: Swollen Head Syndrome and Omphalitis was carried out.
Project description:The adenosine 2A receptor (A2AR) is expressed on regulatory T cells (Tregs), but the functional significance is currently unknown. We compared the gene expression between wild-type (WT) and A2AR knockout (KO) Tregs and between WT Tregs treated with vehicle or a selective A2AR agonist.
Project description:Avian Pathogenic Escherichia coli (APEC) poses a significant threat to the global poultry industry and has also zoonotic potential, meaning it could infect humans. One critical factor in APEC infection is its ability to adhere to host tissues, a process mediated by a protein called FdeC among others. This protein is present in pathogenic E. coli strains but is often nonfunctional in nonpathogenic ones. Our study focused on understanding the role of FdeC in APEC's ability to bind to chicken intestinal cells. Through an extensive screen of 2000 transposon mutants from the APEC IMT5155 strain, we discovered that a specific mutation in the fdeC gene led to enhanced adhesion. However, a direct deletion of the fdeC gene did not produce the same effect under standard conditions, which led us to investigate the environmental factors that might regulate FdeC expression. We found that FdeC's expression is highly dependent on the environmental conditions such as temperature and pH. Using optimized conditions for FdeC expression, we observed significantly higher adhesion and motility levels in the fdeC-deleted IMT5155 strain compared to the wild type. To understand the mechanisms behind this, we employed mass spectrometry and discovered that the absence of FdeC led to changes in ion transport and downregulated a protein called YbjN, which usually inhibits bacterial movement. Collectively, our findings suggest that FdeC has host-dependent expression and contributes to enhancement of bacterial fitness by modulating motility during colonization.
Project description:This dataset is related to our recent study "APEC: an accesson-based method for single-cell chromatin accessibility analysis". We adopted a fluorescent tagmentation-based single-cell ATAC-seq technique (ftATAC-seq) to investigated the per cell regulome dynamics of mouse thymocytes. Associated with ftATAC-seq, APEC revealed a detailed epigenomic heterogeneity of thymocytes, characterized the developmental trajectory and predicted the regulators that control the stages of maturation process.