Project description:Bacterial infection in the mammary gland parenchyma induces local inflammation that can lead to a multietiological complex disease called mastitis. Globally Staphylococcus aureus is the single largest mastitis pathogen and the infection can ultimately result in either subclinical or chronic and sometimes lifelong infection. In the present report we have addressed the differential inflammatory response in the mice mammary tissue during intramammary infection and the altered epigenetic context induced by two closely related strains of S. aureus. Immunohistochemical and immunoblot analysis showed strain specific hyperacetylation at histone H3K9 and H3K14 residues. Real-time PCR and genome-wide gene expression studied showed expression of a set of proinflammatory genes and cytokines in a temporal manner. Remarkably, over expression of the genes significantly correlated with the promoter specific acetylation in these residues. Furthermore, we have identified several differentially expressed known miRNAs and 4 novel miRNAs in the S. aureus infected mice mammary tissue by small RNA sequencing. By employing these gene expression data, an attempt has been made to delineate the gene regulatory networks in the strain specific inflammatory response. Apparently, one of the isolates of S. aureus activated the NFkB signaling leading to drastic inflammatory response and induction of immune surveillance, which could lead to rapid clearance of the pathogen. The other strain repressed most of the inflammatory response, which might help in its sustenance in the host tissue. Taken together, our studies shed substantial lights to understand the mechanisms of strain specific differential inflammatory response to S. aureus infection during mastitis. One control and two samples infected with two different strains of S. aureus
Project description:Bacterial infection in the mammary gland parenchyma induces local inflammation that can lead to a multietiological complex disease called mastitis. Globally Staphylococcus aureus is the single largest mastitis pathogen and the infection can ultimately result in either subclinical or chronic and sometimes lifelong infection. In the present report we have addressed the differential inflammatory response in the mice mammary tissue during intramammary infection and the altered epigenetic context induced by two closely related strains of S. aureus. Immunohistochemical and immunoblot analysis showed strain specific hyperacetylation at histone H3K9 and H3K14 residues. Real-time PCR and genome-wide gene expression studied showed expression of a set of proinflammatory genes and cytokines in a temporal manner. Remarkably, over expression of the genes significantly correlated with the promoter specific acetylation in these residues. Furthermore, we have identified several differentially expressed known miRNAs and 4 novel miRNAs in the S. aureus infected mice mammary tissue by small RNA sequencing. By employing these gene expression data, an attempt has been made to delineate the gene regulatory networks in the strain specific inflammatory response. Apparently, one of the isolates of S. aureus activated the NFkB signaling leading to drastic inflammatory response and induction of immune surveillance, which could lead to rapid clearance of the pathogen. The other strain repressed most of the inflammatory response, which might help in its sustenance in the host tissue. Taken together, our studies shed substantial lights to understand the mechanisms of strain specific differential inflammatory response to S. aureus infection during mastitis. 3 samples in two biological replicates. One control and two samples infected with two different strains of S. aureus
Project description:Bacterial infection in the mammary gland parenchyma induces local inflammation that can lead to a multietiological complex disease called mastitis. Globally Staphylococcus aureus is the single largest mastitis pathogen and the infection can ultimately result in either subclinical or chronic and sometimes lifelong infection. In the present report we have addressed the differential inflammatory response in the mice mammary tissue during intramammary infection and the altered epigenetic context induced by two closely related strains of S. aureus. Immunohistochemical and immunoblot analysis showed strain specific hyperacetylation at histone H3K9 and H3K14 residues. Real-time PCR and genome-wide gene expression studied showed expression of a set of proinflammatory genes and cytokines in a temporal manner. Remarkably, over expression of the genes significantly correlated with the promoter specific acetylation in these residues. Furthermore, we have identified several differentially expressed known miRNAs and 4 novel miRNAs in the S. aureus infected mice mammary tissue by small RNA sequencing. By employing these gene expression data, an attempt has been made to delineate the gene regulatory networks in the strain specific inflammatory response. Apparently, one of the isolates of S. aureus activated the NFkB signaling leading to drastic inflammatory response and induction of immune surveillance, which could lead to rapid clearance of the pathogen. The other strain repressed most of the inflammatory response, which might help in its sustenance in the host tissue. Taken together, our studies shed substantial lights to understand the mechanisms of strain specific differential inflammatory response to S. aureus infection during mastitis.
Project description:Bacterial infection in the mammary gland parenchyma induces local inflammation that can lead to a multietiological complex disease called mastitis. Globally Staphylococcus aureus is the single largest mastitis pathogen and the infection can ultimately result in either subclinical or chronic and sometimes lifelong infection. In the present report we have addressed the differential inflammatory response in the mice mammary tissue during intramammary infection and the altered epigenetic context induced by two closely related strains of S. aureus. Immunohistochemical and immunoblot analysis showed strain specific hyperacetylation at histone H3K9 and H3K14 residues. Real-time PCR and genome-wide gene expression studied showed expression of a set of proinflammatory genes and cytokines in a temporal manner. Remarkably, over expression of the genes significantly correlated with the promoter specific acetylation in these residues. Furthermore, we have identified several differentially expressed known miRNAs and 4 novel miRNAs in the S. aureus infected mice mammary tissue by small RNA sequencing. By employing these gene expression data, an attempt has been made to delineate the gene regulatory networks in the strain specific inflammatory response. Apparently, one of the isolates of S. aureus activated the NFkB signaling leading to drastic inflammatory response and induction of immune surveillance, which could lead to rapid clearance of the pathogen. The other strain repressed most of the inflammatory response, which might help in its sustenance in the host tissue. Taken together, our studies shed substantial lights to understand the mechanisms of strain specific differential inflammatory response to S. aureus infection during mastitis.
Project description:Background: Staphylococcus aureus is a major pathogen of humans and animals and rapidly emerging antibiotic-resistant strains have further increased the severity of this health issue. Host genetics influence susceptibility to S. aureus infections, and genes determining infection outcome should be identified to analyze immune-based therapies as an alternative to antibiotics. Here, we used outbred animals from a divergent selection on susceptibility towards Staphylococcus infection to explore host immunogenetics. Methodology/Principal Findings: We investigated how dendritic cells respond to heat-inactivated S. aureus and whether dendritic cells from animals with different degree of susceptibility have distinct gene expression profiles. We measured expression levels of 15K probes from in vitro S. aureus-stimulated bone marrow-derived dendritic cells at three different time points (0, 3 and 8 hours) by using Agilent microarrays. Furthermore, a selected number of genes were confirmed by RT-qPCR. Gene signatures of stimulated DCs were obtained and genes involved in inflammatory process and T helper cell polarization were highly up regulated upon stimulation. Moreover, a set of 204 genes were statistically different between susceptible and resistant animals, and grouped them according to their predisposition to staphylococcal infection. Interestingly, a role of classical pathway of Complement and early regulation of inflammation is observed in the resistant line through over expression of C1q and Ido1 genes respectively. On the opposite, over expression of genes in the IL1R pathway in the susceptible animals was noticed. Furthermore, leucocyte extravasation pathway was also found dominant in the susceptible line. Conclusion/Significance: we successfully obtained Staphylococcus aureus associated gene expression of ovine BM-DC in 8 hour kinetics experiment. Distinct transcriptional profiles of dendritic cells obtained from resistant and susceptible lines may explain susceptibility towards S. aureus infections in a broad context. Keywords: Staphylococcus aureus, dendritic cells, mammalian, transcriptome, immunity, mastitis 44 sample records; two-colour dye-swap experimental design
Project description:Escherichia coli and Staphylococcus aureus are two common pathogenic microorganisms that cause mastitis in dairy cows. They can cause clinical mastitis and subclinical mastitis. In recent studies, lncRNAs have been found to play an important role in the immune responses triggered by microbial inducers. However, the actions of lncRNAs in bovine mastitis remain unclear. The purpose of this study was to explore the lncRNA profile on mastitis.
Project description:In vitro challenge of bovine macrophages (derived from blood monocytes)with live bacteria of a Staphylococcus aureus strain isolated from a clinical mastitis case.
Project description:Mastitis is a common disease in dairy cows and brings massive losses to the dairy industry. m6A is a type of modification strongly associated with many diseases. However, the role of m6A in mastitis caused by Staphylococcus aureus and Escherichia coli has not been investigated.We used MeRIP-seq technology to sequence the bovine mammary epithelial cells (MAC-T) infected with inactivated S. aureus/E. coli for 24 h.