Project description:The transcriptional profile of the porcine lung pathogen, Actinobacillus pleuropneumoniae, was monitored during the acute phase of infection in its natural host. Bacterial expression profiles of A. pleuropneumoniae isolated from lung lesions of 25 infected pigs were compared in samples taken 6, 12, 24 and 48 hours post infection.
Project description:Mannose-specific interactions of Lactobacillus plantarum 299v with jejunal epithelium were investigated using an in situ pig small intestinal segment perfusion (SISP) model. L. plantarum 299v wildtype strain was compared to two isogenic mutant strains either lacking the gene encoding for the mannose-specific adhesin (msa) or sortase (srtA; responsible for anchoring of cell surface proteins like Msa to the cell wall). Salmonella typhimurium served as a positive control for gene expression analysis. Scrapings from jejunal segments were collected after perfusion with bacterial suspensions or PBS (control) for 4 or 8 hours, and host gene expression was assessed using a home-made cDNA porcine microarray. Keywords: host-microbe interaction, Lactobacillus plantarum, mannose-specific adhesion
Project description:In this study, the effects of Lactobacillus plantarum 299v wildtype strain on host responses are compared to those of an isogenic mutant strain lacking the gene encoding the mannose-specific adhesin (msa). Either of these bacterial strains - separately or as a 50-50% mixture - are orally administered to groups of eight pigs each, and host gene expression is assessed with pooled RNA samples isolated from jejunum, ileum and colon scrapings using Affymetrix Porcine microarrays
Project description:Digesta and mucosa samples from stomach, jejunum, ileum, cecum and colon of the porcine GIT from four animals were analysed by metaproteomics to obtain a deeper insight into the functions of bacterial groups with a concomitant analyses of host proteins.
Project description:Detection of immunogenic proteins remains an important task for life sciences as it nourishes the understanding of pathogenicity, illuminates new potential vaccine candidates and broadens the spectrum of biomarkers applicable in diagnostic tools. Traditionally, immunoscreenings of expression libraries via polyclonal sera on nitrocellulose membranes or screenings of whole proteome lysates in 2-D gel electrophoresis are performed. However, these methods feature some rather inconvenient disadvantages. Screening of expression libraries to expose novel antigens from bacteria often lead to an abundance of false positive signals owing to the high cross reactivity of polyclonal antibodies towards the proteins of the expression host. A method is presented that overcomes many disadvantages of the old procedures. We incorporated a fusion tag prior to our genes of interest and attached the expressed fusion proteins covalently on microarrays. This enhances the specific binding of the proteins compared to nitrocellulose. Thus, it helps to reduce the number of false positives significantly. It enables us to screen for immunogenic proteins in a shorter time, with more samples and statistical reliability. We validated our method by employing several known genes from Campylobacter jejuni NCTC 11168. Four of proteins that have previously been described as immunogenic have successfully been assessed immunogenic abilities with our method. One protein with no known immunogenic behaviour before suggested potential immunogenicity. The method presented offers a new approach for screening of bacterial expression libraries to illuminate novel proteins with immunogenic features. It could provide a powerful and attractive alternative to existing methods and help to detect and identify bacterial virulence factors, vaccine candidates and potential biomarkers.
Project description:Detection of immunogenic proteins remains an important task for life sciences as it nourishes the understanding of pathogenicity, illuminates new potential vaccine candidates and broadens the spectrum of biomarkers applicable in diagnostic tools. Traditionally, immunoscreenings of expression libraries via polyclonal sera on nitrocellulose membranes or screenings of whole proteome lysates in 2-D gel electrophoresis are performed. However, these methods feature some rather inconvenient disadvantages. Screening of expression libraries to expose novel antigens from bacteria often lead to an abundance of false positive signals owing to the high cross reactivity of polyclonal antibodies towards the proteins of the expression host. A method is presented that overcomes many disadvantages of the old procedures. We incorporated a fusion tag prior to our genes of interest and attached the expressed fusion proteins covalently on microarrays. This enhances the specific binding of the proteins compared to nitrocellulose. Thus, it helps to reduce the number of false positives significantly. It enables us to screen for immunogenic proteins in a shorter time, with more samples and statistical reliability. We validated our method by employing several known genes from Campylobacter jejuni NCTC 11168. Four of proteins that have previously been described as immunogenic have successfully been assessed immunogenic abilities with our method. One protein with no known immunogenic behaviour before suggested potential immunogenicity. The method presented offers a new approach for screening of bacterial expression libraries to illuminate novel proteins with immunogenic features. It could provide a powerful and attractive alternative to existing methods and help to detect and identify bacterial virulence factors, vaccine candidates and potential biomarkers. The overall study was done with five technical replicates. Ten proteins derived from Campylobacter jejuni were tested regarding their immunogenic potential. The ten proteins derived from Campylobacter jejuni were fusion proteins, i.e., N-terminal HaloTag fused to: Gene <--> Protein cjaA <--> putative amino-acid transporter periplasmic solute-binding protein hisJ <--> histidine-binding protein precursor pal <--> peptidoglycan associated lipoprotein flaC <--> flagellin flaA <--> flagellin peb1a <--> bifunctional adhesin/ABC transporter aspartate/glutamate-binding protein pyrC <--> dihydroorotase (EC:3.5.2.3) pseB <--> UDP-GlcNAc-specific C4,6 dehydratase/C5 epimerase gapA <--> glyceraldehyde 3-phosphate dehydrogenase (EC:1.2.1.12) argC <--> N-acetyl-gamma-glutamyl-phosphate reductase (EC:1.2.1.38)
Project description:To understand how the interaction between an intracellular bacterium and the host immune system contributes to outcome at the site of infection, we studied leprosy, a disease that forms a clinical spectrum, in which progressive infection by the intracellular bacterium Mycobacterium leprae is characterized by the production of type I IFNs and antibody production. We performed dual RNAseq on patient lesions, identifying a continuum of distinct bacterial states that are linked to the host immune response. The bacterial burden, represented by the fraction of bacterial transcripts, correlates with a host type I IFN gene signature, known to inhibit antimicrobial responses. Second, the bacterial transcriptional activity, defined by the bacterial mRNA/rRNA ratio, links bacterial heat shock proteins with the BAFF-BCMA host antibody response pathway. Our findings provide a platform for interrogation of host and pathogen transcriptomes at the site of infection, allowing insight into mechanisms of inflammation in human disease
Project description:Understanding the immune response to tuberculosis requires greater knowledge of humoral responses. To characterize antibody targets and the effect of disease parameters on target recognition, we developed a systems immunology approach that integrated detection of antibodies against the entire Mycobacterium tuberculosis proteome, bacterial metabolic and regulatory pathway information, and patient data. Probing ~4,000 M. tuberculosis proteins with sera from >500 suspected tuberculosis patients worldwide revealed that antibody responses recognized ~10% of the bacterial proteome. This result defines the immunoproteome of M. tuberculosis, which is rich in membrane-associated and extracellular proteins. Most serum reactivity during active tuberculosis focused onto ~0.5% of the proteome. Within this pool, which is selectively enriched for extracellular proteins (but not for membrane-associated proteins), relative target preference varied among patients. The shift in relative M. tuberculosis protein reactivity observed with active tuberculosis defines the evolution of the humoral immune response during M. tuberculosis infection and disease.
Project description:We use the a porcine genome-scale CRISPR/Cas9 knockout (PigGeCKO) library (Zhao et al., 2020) to identify key host factors facilitating TGEV infection in porcine cells.
Project description:A first generation Affymetrix GeneChip® Porcine genome array was used to profile the gene expression in porcine mesenteric lymph nodes over a time course of infection with S. Typhimurium, including the acute (8 hours post inoculation (hpi), 24 hpi, 48 hpi) and chronic (21 days post-inoculation (dpi)) stages of infection. Our objectives were to 1) identify and examine the stereotypical gene expression response within host MLN to S. Typhimurium infection, 2) characterize global host responses by revealing the specific features of the host’s innate immunity pathways, and 3) explore if and how S. Typhimurium may escape the host immune response and develop into a carrier state. Our study has attempted to investigate the features of host gene expression profiling during S. Typhimurium infection at the acute and chronic infection stages and to explore the mechanism by which S. Typhimurium can escape from the host immune response and develop a carrier state in the host. In conclusion, by using the Affymetrix porcine GeneChip, 848 differentially expressed genes were identified in porcine MLN during infection and several specific features of host response were revealed by gene cluster and pathway analysis. Our data are the first report to investigate global host responses to S. Typhimurium in porcine MLN, and this new study provides data applicable for studying enteric salmonellosis of pigs, as well as humans. Keywords: time course