Project description:The microbial cell surface is a critical site of microbe-host interactions that often control infection outcomes. Defining the set of host proteins present at this interface has been challenging. Here, we used a surface biotinylation approach coupled to quantitative mass spectrometry to identify and quantify both bacterial and host proteins present on the surface of diarrheal fluid-derived V. cholerae in an infant rabbit model of cholera. Our data showed that V. cholerae surfaces were coated with numerous host proteins, whose abundance were driven by the presence of cholera toxin, including the C type lectin SP-D. Mice lacking SP-D had enhanced V. cholerae intestinal colonization. Additional host proteins (AnxA1, LPO and ZAG) capable of binding V. cholerae were also found to recognize distinct taxa of the murine intestinal microbiota, suggesting that these host factors may play roles in intestinal homeostasis in addition to host defense. Proteomic analysis of microbial surfaces is valuable for identifying host interactions that regulate infection and homeostasis with both pathogens and endogenous microbiota alike.
Project description:The microbial cell surface is a critical site of microbe-host interactions that often control infection outcomes. Defining the set of host proteins present at this interface has been challenging. Here, we used a surface biotinylation approach coupled to quantitative mass spectrometry to identify and quantify both bacterial and host proteins present on the surface of diarrheal fluid-derived V. cholerae in an infant rabbit model of cholera. Our data showed that V. cholerae surfaces were coated with numerous host proteins, whose abundance were driven by the presence of cholera toxin, including the C type lectin SP-D. Mice lacking SP-D had enhanced V. cholerae intestinal colonization. Additional host proteins (AnxA1, LPO and ZAG) capable of binding V. cholerae were also found to recognize distinct taxa of the murine intestinal microbiota, suggesting that these host factors may play roles in intestinal homeostasis in addition to host defense. Proteomic analysis of microbial surfaces is valuable for identifying host interactions that regulate infection and homeostasis with both pathogens and endogenous microbiota alike.
Project description:Numerous host factors of SARS-CoV-2 have been identified by screening approaches, but delineating their molecular roles during infection and whether they can be targeted for antiviral intervention remains a challenge. Here we use Perturb-seq, a single-cell CRISPR screening approach, to investigate how CRISPR interference of host factors changes the course of SARS-CoV-2 infection and the host response in human lung epithelial cells. Our data reveal two classes of host factors with pronounced phenotypes: factors required for the response to interferon, and factors required for entry or early infection, respectively. Among the latter, we have characterized the NF-κB inhibitor IκBα (NFKBIA), as well as the translation factors EIF4E2 and EIF4H as strong host dependency factors acting early in infection. Overall, our study provides high-throughput functional validation of host factors of SARS-CoV-2 and their roles during viral infection in both infected and uninfected bystander cells.
Project description:To identify novel host factors as putative targets to reverse HIV-1 latency, we performed an insertional mutagenesis genetic screen in a latently HIV-1-infected pseudohaploid KBM7 cell line (Hap-Lat). Following mutagenesis, insertions were mapped to the genome, and bioinformatic analysis resulted in the identification of 69 candidate host genes involved in maintaining HIV-1 latency.
Project description:Study purpose: to explore the entire spectrum of proteomic and genomic changes (amongst others) involved in diseases and in healthy/control populations. The Study is designed to discover biomarkers, develop and validate diagnostic assays, instruments and therapeutics as well as other medical research. Specifically, researchers may analyze proteins, RNA, DNA copy number changes, including large and small (1,000-100,000 kb) scale rearrangements, transcription profiles, epigenetic modifications, sequence variation, and sequence in both diseased tissue and case-matched germline DNA from Subjects.
Project description:Kaposi's sarcoma-associated herpesvirus (KSHV) encodes multiple short and long noncoding RNAs which contribute to viral latency, persistence, host gene regulation, and immune evasion. The Antisense-to-Latency Transcript (ALT) is a ~10 kb long noncoding RNA (lncRNA) located on the opposite strand of the major latency-associated region encoding the latency associated nuclear antigen, vCyclin, vFLIP, the Kaposin's and 12 microRNA genes. ALT is a nuclear lncRNA that is lowly expressed during latency, but strongly upregulated during lytic replication. Using RNA antisense purification and quantitative mass spectrometry (RAP-MS) in lytically induced primary effusion lymphoma cells, we identified 51 human and 3 viral proteins that directly interact with ALT. Of these enriched proteins, 48 are splicing factors, including core and alternative splicing proteins, such as U2AF2, PTBP1/2, SRSF1/3 and MBNL1. Interaction and co-localization of ALT was confirmed with various splicing factors in ribonucleoprotein complexes suggesting that ALT sequesters splicing factors in nuclear condensates. We further identified that induction of lytic replication in lymphoid and epithelial cells leads to thousands of host gene splicing changes, which are partially restored upon perturbation of ALT expression. Finally, transient knockdown of ALT strongly inhibits viral reactivation and virion production. Hence, sequestering of splicing factors by ALT, interferes with host gene expression. Our results uncover a novel mechanism that shifts gene expression from the host to the virus late during the viral replication cycle to efficiently produce progeny virus and potentially antagonize host immune defenses.