Microbiology Commons^™

Primary Gamma-Herpesviral Infection In Zambian Children, Veenu Minhas, Brad P. Brayfield, Kay L. Crabtree, Chipepo Kankasa, Charles D. Mitchell, Charles Wood

Nebraska Center for Virology: Faculty Publications

Background: HHV-8 is closely related to Epstein-Barr virus (EBV), but the clinical presentations of these two infections in early childhood are not well understood. Also, it is not known whether infection by one virus correlates with another. Here, we compare the natural history of infection by these two viruses along with the clinical manifestations and risk factors that are associated with early childhood infection in Zambia, which is an endemic area for HHV-8.

Methods: This study was conducted in a cohort of 12 month old Zambian children (N = 677). Data on socio-economic status and a wide range …

Restricted Genetic Diversity Of Hiv-1 Subtype C Envelope Glycoprotein From Perinatally Infected Zambian Infants, Hong Zhang, Damien C. Tully, Federico G. Hoffmann, Jun He, Chipepo Kankasa, Charles Wood

Nebraska Center for Virology: Faculty Publications

Background: Mother-to-child transmission of HIV-1 remains a significant problem in the resource-constrained settings where anti-retroviral therapy is still not widely available. Understanding the earliest events during HIV-1 transmission and characterizing the newly transmitted or founder virus is central to intervention efforts. In this study, we analyzed the viral env quasispecies of six mother-infant transmission pairs (MIPs) and characterized the genetic features of envelope glycoprotein that could influence HIV-1 subtype C perinatal transmission.

Methodology and Findings: The V1-V5 region of env was amplified from 6 MIPs baseline samples and 334 DNA sequences in total were analyzed. A comparison of …

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 …

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 …