Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Intraepithelial lymphocytes (IEL) of the gut represent a primary immune barrier against infection by orally acquired pathogens. Naturally acquired infection with Toxoplasma gondii induces the proliferation of CD8+ T cells in both the gut and spleen. Gut-derived CD8alpha/beta+ IEL exhibit MHC-restricted cytotoxicity against parasite-infected enterocytes and macrophages. In a murine model, we demonstrate that the adoptive transfer of IEL obtained from inbred mice at day 11 postinfection is able to protect against a virulent challenge in syngenic recipients. In CBA mice, the parasite cyst load within the brain of the recipients receiving primed IEL was reduced by 90%. In BALB/c and C57BL/6 mice, a 50% decrease in mortality was observed following adoptive transfer of primed IEL. To determine the T cell subset responsible for protective immunity, a purified CD8alpha/beta+ IEL population was isolated from infected mice at day 11 postinfection. These cells were able to protect naive mice by adoptive transfer against a lethal parasite challenge. RNA analysis by reverse-transcriptase PCR revealed that primed CD8alpha/beta+ IEL produce significant message for IFN-gamma, an essential cytokine for host protection against toxoplasmosis. Administration of anti-IFN-gamma at the time of adoptive transfer of primed IEL abrogated protection. The adoptive transfer of these protective IEL was not restricted to the Ld class I locus. These data demonstrate that IFN-gamma-producing IEL may be an important primary barrier against acute and perhaps recurrent infection with T. gondii.
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PMID:Adoptive transfer of gut intraepithelial lymphocytes protects against murine infection with Toxoplasma gondii. 919 Sep 41

Toxoplasmosis is characterized by fast lytic replication cycles leading to severe tissue lesions. Successful host cell invasion is essential for pathogenesis. The division cycle of Toxoplasma gondii is characterized by an unusual cell cycle progression and a distinct internal budding mechanism. To identify essential genes involved in the lytic cycle we devised an insertional gene trapping strategy using the Tet-transactivator system. In essence, a random, active promoter is displaced with a tetracycline regulatable promoter, which if in an essential gene, will result in a conditionally lethal phenotype upon tetracycline addition. We isolated eight mutants with growth defects, two of which displayed modest invasion defects, one of which had an additional cell cycle defect. The trapped loci were identified using expression microarrays, exploiting the tetracycline dependent expression of the trapped genes. In mutant 3.3H6 we identified TCP-1, a component of the chaperonin protein folding machinery under the control of the Tet promoter. However, this gene was not critical for growth of mutant 3.3H6. Subsequently, we identified a suppressor gene encoding a protein with a hypothetical function by guided cosmid complementation. In mutant 4.3B13, we identified TAF250, an RNA polymerase II complex component, as the trapped, essential gene. Furthermore, by mapping the plasmid insertion boundaries we identified multiple genomic rearrangements, which hint at a potential replication dependent DNA repair mechanism. Furthermore, these rearrangements provide an explanation for inconsistent locus rescue results observed by molecular biological approaches. Taken together, we have added an approach to identify and study essential genes in Toxoplasma.
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PMID:An insertional trap for conditional gene expression in Toxoplasma gondii: identification of TAF250 as an essential gene. 2103 8

Differentially methylated genes (DMGs) play a crucial role in the etiology and pathogenesis of esophageal squamous cell carcinoma (ESCC). This study aimed to ascertain aberrant DMGs and pathways by comprehensive bioinformatics analysis. We downloaded the gene expression microarray of GSE51287 from the Gene Expression Omnibus (GEO). Aberrant DMGs were obtained using the GEO2R tool. Gene ontology (GO) analysis and Kyoto Encyclopedia of Gene and Genome pathway enrichment analyses were performed on selected genes by using the Database for Annotation Visualization and Integrated Discovery. A protein-protein interaction (PPI) network was constructed with the Retrieval of Interacting Genes (STRING) and visualized in Cytoscape. Then, the modules in the PPI networks were analyzed with Molecular Complex Detection, and the hub genes derived from the PPI networks were verified by using the Cancer Genome Atlas. A total of 271 DMGs, including 173 hypermethylated genes, were enriched in the biological processes of peptidyl-tyrosine phosphorylation, positive regulation of transcription from RNA polymerase II promoters, and autophosphorylation. Pathway analysis enrichment revealed cancer, PI3K-Akt, and Ras signaling pathways, and 98 hypomethylated genes were enriched in the biological processes of the immune response, extracellular matrix disassembly, and macrophage differentiation. Pathway enrichment showed rheumatoid arthritis, cytokine-cytokine receptor interaction, and toxoplasmosis. Furthermore, bioinformatics analysis indicated feasible aberrant DMGs and pathways in ESCC. The results provided valuable information on the pathogenesis of ESCC. The significant DMGs may provide novel insights into their potential predictive and prognostic value as methylation-based biomarkers for the precise diagnosis and treatment of ESCC.
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PMID:Comprehensive bioinformation analysis of methylated and differentially expressed genes in esophageal squamous cell carcinoma. 3070 27