Project description:Aims: To assess the virulence of multiple Aeromonas spp. using two models, a neonatal mouse assay and a mouse intestinal cell culture. Methods and Results: Transcriptional responses to both infection models were evaluated using microarrays. After artificial infection with a variety of Aeromonas spp., mRNA extracts from the two models were processed and hydridized to murine microarrays to determine host gene response. Definition of virulence was determined based on host mRNA production in murine neonatal intestinal tissue and mortality of infected animals. Infections of mouse intestinal cell cultures were then performed to determine whether this simpler model system's mRNA responses correlated to neonatal results and therefore be predictive of virulence of Aeromonas spp. Virulent aeromonads up-regulated transcripts in both models including multiple host defense gene products (chemokines, regulation of transcription and apoptosis, cell signaling). Avirulent species exhibited little or no host response in neonates. Mortality results correlated well with both bacterial dose and average fold change of up-regulated transcripts in the neonatal mice. Conclusions: Cell culture results were less discriminating but showed promise as potentially being able to be predictive of virulence. Jun oncogene up-regulation in murine cell culture is potentially predictive of Aeromonas virulence. Significance and Impact of the Study: Having the ability to determine virulence of waterborne pathogens quickly would potentially assist public health officials to rapidly assess exposure risks. Experiment Overall Design: Two infection models were assessed, live, whole animals (neonatal Swiss Webster mice) and a murine small intestinal cell culture. Biological replicates (n=5) were infected with different Aeromonas species/strains and compared to uninfected controls.
Project description:Aims: To assess the virulence of multiple Aeromonas spp. using two models, a neonatal mouse assay and a mouse intestinal cell culture. Methods and Results: Transcriptional responses to both infection models were evaluated using microarrays. After artificial infection with a variety of Aeromonas spp., mRNA extracts from the two models were processed and hydridized to murine microarrays to determine host gene response. Definition of virulence was determined based on host mRNA production in murine neonatal intestinal tissue and mortality of infected animals. Infections of mouse intestinal cell cultures were then performed to determine whether this simpler model system's mRNA responses correlated to neonatal results and therefore be predictive of virulence of Aeromonas spp. Virulent aeromonads up-regulated transcripts in both models including multiple host defense gene products (chemokines, regulation of transcription and apoptosis, cell signaling). Avirulent species exhibited little or no host response in neonates. Mortality results correlated well with both bacterial dose and average fold change of up-regulated transcripts in the neonatal mice. Conclusions: Cell culture results were less discriminating but showed promise as potentially being able to be predictive of virulence. Jun oncogene up-regulation in murine cell culture is potentially predictive of Aeromonas virulence. Significance and Impact of the Study: Having the ability to determine virulence of waterborne pathogens quickly would potentially assist public health officials to rapidly assess exposure risks. Keywords: Aeromonas; Virulence; Gene expression; Host response
Project description:Aeromonas caviae has been associated with human gastrointestinal disease. Strains of this species typically lack virulence factors (VFs) such as enterotoxins and hemolysins that are produced by other human pathogens of the Aeromonas genus. Microarray profiling of murine small intestinal extracts, 24 hours after oral infection with an A. caviae strain, provides evidence of a Th1 type immune response. A large number of gamma-interferon (γ-IFN) induced genes are up-regulated as well as several tumor necrosis factor-alpha (TNF-α) transcripts. A. caviae has always been considered an opportunistic pathogen because it lacks obvious virulence factors. This current effort suggests A. caviae colonizes murine intestinal tract and causes what has been described by others as a dysregulatory cytokine response leading to an irritable bowel-like syndrome. This response would explain why a number of diarrheal waterborne outbreaks have been attributed to A. caviae even though it lacks obvious enteropathogenic properties. Keywords: Aeromonas caviae, infection, disease mechanism, TH1 resposne
Project description:We found that BAP1 (BRCA1 Associated Protein-1) shows loss of heterozygosity in over 25% of pancreatic cancer patients and functions as tumor suppressor. Conditional deletion of Bap1 in murine pancreas led to genomic instability, accumulation of DNA damage, and an inflammatory response that evolved to pancreatitis with full penetrance. Concomitant expression of oncogenic KrasG12D led to malignant transformation and development of invasive and metastatic pancreatic cancer. At the molecular level, BAP1 maintains the integrity of the exocrine pancreas by regulating genomic stability and its loss confers sensitivity to radio- and platinum-based therapies.
Project description:The importance of unanchored Ub in innate immunity has been shown only for a limited number of unanchored Ub-interactors. We investigated what additional cellular factors interact with unanchored Ub and whether unanchored Ub plays a broader role in innate immunity. To identify unanchored Ub-interacting factors from murine lungs, we used His-tagged recombinant poly-Ub chains as bait. These chains were mixed with lung tissue lysates and protein complexes were isolated with Ni-NTA beads. Sample elutions were subjected to mass spectrometry (LC-MSMS) analysis.