Project description:Streptococcus pyogenes (Group A Streptococcus: GAS) is a major human pathogen that causes streptococcal pharyngitis, skin and soft-tissue infections, and life-threatening conditions such as streptococcal toxic shock syndrome (STSS). A large number of virulence-related genes are encoded on GAS genomes, which are involved in host-pathogen interaction, colonization, immune invasion, and long-term survival within hosts, causing the diverse symptoms. Here, we investigated the interaction between GAS-derived extracellular vesicles and host cells in order to reveal pathogenicity mechanisms induced by GAS infection.
Project description:We investigated the interaction of Salmonella Typhimurium with Embryonic stem cell derived Dendritic Cells (ESDCs) as a new model to study host-pathogen interaction.
Project description:Relatively little is understood about the dynamics of global host–pathogen transcriptome changes that occur during bacterial infection of mucosal surfaces. To test the hypothesis that group A Streptococcus (GAS) infection of the oropharynx provokes a host transcriptome response, we performed genome-wide transcriptome analysis using a nonhuman primate model of experimental pharyngitis. We also identified host and pathogen biological processes and individual host and pathogen gene pairs with correlated patterns of expression, suggesting interaction. For this study, 509 host genes and seven biological pathways were differentially expressed throughout the entire 32-day infection cycle. GAS infection produced an initial widespread significant decrease in expression of many host genes, including those involved in cytokine production, vesicle formation, metabolism, and signal transduction. This repression lasted until day 4, at which time a large increase in expression of host genes was observed, including those involved in protein translation, antigen presentation, and GTP-mediated signaling. The interactome analysis identified 73 host and pathogen gene pairs with correlated expression levels. We discovered significant correlations between transcripts of GAS genes involved in hyaluronic capsule production and host endocytic vesicle formation, GAS GTPases and host fibrinolytic genes, and GAS response to interaction with neutrophils. We also identified a strong signal, suggesting interaction between host γδ T cells and genes in the GAS mevalonic acid synthesis pathway responsible for production of isopentenyl-pyrophosphate, a short-chain phospholipid that stimulates these T cells. Taken together, our Q:2 results are unique in providing a comprehensive understanding of the host–pathogen interactome during mucosal infection by a bacterial pathogen.
Project description:The downy mildew oomycete Hyaloperonospora arabidopsidis, an obligate filamentous pathogen, infect Arabidopsis by forming feeding structures called haustoria inside the host cell. Previous transcriptome analysis revealed host genes specifically induced during infection. However, whole infected tissue-derived RNA profiling may fail to capture the key transcriptional events that may occur exclusively in haustoriated host cells where the pathogen injects virulence effectors to modulate host immunity for successful accommodation. To understand the interaction between Arabidopsis and H. arabidopsidis at the cellular level, we established a new translating ribosome affinity purification (TRAP) system applicable to pathogen-responsive promoters, enabling haustoriated cell-specific RNA profiling. Among the host genes specifically expressed in H. arabidopsidis-haustoriated cells, we found genes that promote either susceptibility or resistance to the pathogen, providing new insights into the Arabidopsis/downy mildew interaction. We also expect that our new TRAP system could be applicable to several stimulus-specific contexts as well as other plant–pathogen interactions.
Project description:To advance our understanding of cellular host-pathogen interactions, technologies that facilitate the co-capture of both host and pathogen spatial transcriptome information are needed. Here, we present an approach to simultaneously capture host and pathogen spatial gene expression information from the same formalin-fixed paraffin embedded (FFPE) tissue section using the spatial transcriptomics technology. We applied the method to COVID-19 patient lung samples and enabled the dual detection of human and SARS-CoV-2 transcriptomes at 55 µm resolution. We validated our spatial detection of SARS-CoV-2 and identified an average specificity of 94.92% in comparison to RNAScope and 82.20% in comparison to in situ sequencing (ISS). COVID-19 tissues showed an upregulation of host immune response, such as increased expression of inflammatory cytokines, lymphocyte and fibroblast markers. Our colocalization analysis revealed that SARS-CoV-2+ spots presented shifts in host RNA metabolism, autophagy, NFκB, and interferon response pathways. Future applications of our approach will enable new insights into host response to pathogen infection through the simultaneous, unbiased detection of two transcriptomes.
Project description:An accessible, simple, reliable, next-gen in-vitro platform to further the screening for Mtb drugs and understand TB host-pathogen interaction.
Project description:The factors that determine the outcome of clinical tuberculosis lie within both the host and the pathogen, Mycobacterium tuberculosis (Mtb). The advent of recombinant inbred mouse panels and next-generation transposon mutagenesis and sequencing approaches has enabled dissection of the host-pathogen interface for mammalian and pathogen genetic determinants of disease outcome. To identify host and pathogen genetic drivers of Mtb infection, we infected 19 genotypes from the BXD panel, bred from Mtb-resistant C57BL/6J (B6) and Mtb-susceptible DBA/2J (D2), with a comprehensive library of transposon mutants (TnSeq). The survival of each of the ~4000 bacterial mutants within each distinct host was quantified and leveraged as refined “endophenotypes”, directly reporting on the infection microenvironment. We leveraged QTL mapping to associate each varying bacterial fitness endophenotype to the host genome and identified 140 significant host-pathogen quantitative trait loci (hpQTL). This host-pathogen interaction screen reinforces the utility of bacterial mutant libraries as precise reporters of host immunological microenvironment during infection and highlights host gene candidates for further investigation.