Microbiology Commons^™

Subtype-Associated Differences In Hiv-1 Reverse Transcription Affect The Viral Replication, Sergey Iordanskiy, Mackenzie Waltke, Yanjun Feng, Charles Wood

Nebraska Center for Virology: Faculty Publications

Background: The impact of the products of the pol gene, specifically, reverse transcriptase (RT) on HIV-1 replication, evolution, and acquisition of drug resistance has been thoroughly characterized for subtype B. For subtype C, which accounts of almost 60% of HIV cases worldwide, much less is known. It has been reported that subtype C HIV-1 isolates have a lower replication capacity than B; however, the basis of these differences remains unclear.

Results: We analyzed the impact of the pol gene products from HIV-1 B and C subtypes on the maturation of HIV virions, accumulation of reverse transcription products, integration …

Topological Layers In The Hiv-1 Gp120 Inner Domain Regulate Gp41 Interaction And Cd4-Triggered Conformational Transitions, Andrés Finzi, Shi-Hua Xiang, Beatriz Pacheco, Dana-Farber Cancer Institute Wang, Jessica Haight, Aemro Kassa, Brenda Danek, Marie Pancera, Peter D. Kwong, Joseph Sodroski

Nebraska Center for Virology: Faculty Publications

The entry of human immunodeficiency virus (HIV-1) into cells is initiated by binding of the gp120 exterior envelope glycoprotein to the receptor, CD4. How does CD4 binding trigger conformational changes in gp120 that allow the gp41 transmembrane envelope glycoprotein to mediate viral-cell membrane fusion? The transition from the unliganded to the CD4-bound state is regulated by two potentially flexible topological layers (layers 1 and 2) in the gp120 inner domain. Both layers apparently contribute to the noncovalent association of unliganded gp120 with gp41. After CD4 makes initial contact with the gp120 outer domain, layer 1-layer 2 interactions strengthen gp120-CD4 binding …

Yersinia Pestis Virulence Factor Yopm Undermines The Function Of Distinct Ccr2+Gr1+ Cells In Spleen And Liver During Systemic Plague, Zhan Ye

University of Kentucky Doctoral Dissertations

Yersinia pestis, the infective agent of bubonic and pneumonic plague, is classified as a category A agent of bioterrorism. YopM, a protein toxin of Y. pestis, is necessary for full virulence in a systemic plague mouse model with ambient-temperature grown bacteria. We used this model to identify the cells undermined by YopM. Natural killer (NK) cells were previously reported to be lost in spleen and blood in a YopM-associated way; however, NK cell depletion was found not to occur in liver, and ablation of NK cells had no effect on bacterial growth, indicating that NK cells are redundant …

Thermocrinis Minervae Sp. Nov., A Hydrogen And Sulfur-Oxidizing, Thermophilic Member Of The Aquificales From A Costa Rican Terrestrial Hot Spring, Sara L. Caldwell, Yitai Liu, Isabel Ferrera, Terry Beveridge, Anna-Louise Reysenbach

Biology Faculty Publications and Presentations

A thermophilic bacterium, designated strain CR11T , was isolated from a filamentous sample collected from a terrestrial hot spring on the south-western foothills of the Rincón volcano in Costa Rica. The Gram-negative cells are approximately 2.4–3.9 mm long and 0.5–0.6 mm wide and are motile rods with polar flagella. Strain CR11T grows between 65 and 85 6C (optimum 75 6C, doubling time 4.5 h) and between pH 4.8 and 7.8 (optimum pH 5.9–6.5). The isolate grows chemolithotrophically with S0 , S2O2{ 3 or H2 as the electron donor and with O2 (up to 16 %, v/v) as the sole electron …

Hypervirulent Clostridium Difficile Strains: Adherence, Toxin Production And Sporulation, Michelle Marie Merrigan

Dissertations

Clostridium difficile is a leading cause of nosocomial infections, and recently emerged "hypervirulent" C. difficile strains have caused epidemics worldwide. We hypothesized that multiple factors were responsible for this phenotype, particularly the interaction of C. difficile with the epithelial cell, as well as toxin production and sporulation.

To test if host interaction varied in HV strains, we developed a quantitative host-cell adherence assay, and found that while C. difficile strains varied in adherence to human intestinal epithelial cells, hypervirulent strains were not significantly more adherent than other strains. The bacterial surface protein SlpA varied in both size and amount between …