Microbiology Commons^™

Inhibition Of The Host Translation Shutoff Response By Herpes Simplex Virus 1 Triggers Nuclear Envelope-Derived Autophagy, Kerstin Radtke, Luc English, Christiane Rondeau, David Leib

Dartmouth Scholarship

Macroautophagy is a cellular pathway that degrades intracellular pathogens and contributes to antigen presentation. Herpes simplex virus 1 (HSV-1) infection triggers both macroautophagy and an additional form of autophagy that uses the nuclear envelope as a source of membrane. The present study constitutes the first in-depth analysis of nuclear envelope-derived autophagy (NEDA). We established LC3a as a marker that allowed us to distinguish between NEDA and macroautophagy in both immunofluorescence and flow cytometry. NEDA was observed in many different cell types, indicating that it is a general response to HSV-1 infection. This autophagic pathway is known to depend on the …

Mitochondrial Dna Instability In Cells Lacking Aconitase Correlates With Iron Citrate Toxicity, Zhengchang Liu, Fei Xiao, Zhejun Dong, Tammy Pracheil, Muhammad Farooq

Biological Sciences Faculty Publications

Aconitase, the second enzyme of the tricarboxylic acid cycle encoded by ACO1 in the budding yeast Saccharomyces cerevisiae, catalyzes the conversion of citrate to isocitrate. aco1Δ results in mitochondrial DNA (mtDNA) instability. It has been proposed that Aco1 binds to mtDNA and mediates its maintenance. Here we propose an alternative mechanism to account for mtDNA loss in aco1Δ mutant cells. We found that aco1Δ activated the RTG pathway, resulting in increased expression of genes encoding citrate synthase. By deleting RTG1, RTG3, or genes encoding citrate synthase, mtDNA instability was prevented in aco1Δ mutant cells. Increased activity of citrate synthase leads …

Human Cytomegalovirus Us17 Locus Fine-Tunes Innate And Intrinsic Immune Responses, Stephen James Gurczynski

Wayne State University Dissertations

HCMV employs numerous strategies to combat, subvert, or co-opt host immunity. One evolutionary strategy for this involves "capture" of a host gene and then its successive duplication and divergence, forming a gene family, many of which have immunomodulatory activities. The HCMV US12 family consists of ten tandemly arranged sequence-related genes in the unique short region of the HCMV genome (US12-US21). Each gene encodes a protein possessing seven predicted transmembrane domains, and patches of sequence similarity with cellular GPCRs and the bax inhibitor-1 family of anti-apoptotic proteins. We show that one member, US17, plays an important role during virion maturation. Microarray …

Critical Events In Human Metapneumovirus Infection: From Entry To Egress, Brent A. Hackett

Theses and Dissertations--Molecular and Cellular Biochemistry

Human metapneumovirus (HMPV) is a respiratory pathogen in Paramyxovirus family that demonstrates extremely high morbidity in the population, with most individuals having been infected by the age of five. Despite the prevalence of this negative-sense RNA virus in the population for decades, it was only identified in 2001. As such, there is currently no specific treatment for HMPV and the potentially severe consequences of infection for elderly and immunocompromised individuals and particularly infants make development of antivirals targeting HMPV of high significance. HMPV constitutes a quarter of all respiratory hospitalizations among infants, placing it second only to RSV, in addition …

Amp-Activated Protein Kinase Knockdown In Labyrinthine Trophoblast Cells Results In Altered Morphology And Function, Erica Ashton Kayleigh Carey

Browse all Theses and Dissertations

The placenta is a transient organ that develops upon initiation of pregnancy and is essential for fetal development and survival. The rodent placenta consists of three layers with predominantly analogous cell types in the human placenta. The labyrinth layer, which lies closest to the fetus, facilitates nutrient and waste exchange between mother and baby. Abnormalities of the placenta may occur as a result of cellular stress and have been associated with the pregnancy-associated disorders, intrauterine growth restriction and placental insufficiency. AMP-activated protein kinase (AMPK) is a master sensor of cellular stress and changes in AMPK expression or activation could be …

The Effect Of Hsv-1 Infection On Differentiated And Polarized U937 Cells, Allolo Dreiwish Aldreiwish

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Herpes simplex virus type 1 (HSV-1) challenges the host immune system through several mechanisms (Frey, et al., 2009). In vitro, U937 cells (human macrophage-like precursor cell line) are not susceptible to HSV-1 infection when they are not differentiating (Lopez-Guerrero and Alonso, 1997). Differentiation of these cells resistance can abrogates their resistance to HSV-1 (Tenney and Morahan, 1991). In this study, we examined the effect of HSV-1 infection on differentiated and polarized U937 cells. U937 cells are differentiated to M0 cells.

Then, M0 cells are polarized to distinct phenotypes, M1 or M2. M1 are proinflammatory macrophages while M2 are anti-inflammatory cells. …

Establishment Of A Quiscence Herpes Simplex Type 1 Infection In L929 Fibroblasts And Neuro-2a Cells By A Nucleoside Analogue Acyclovir, Noura Shaklawoon

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Herpes simplex type 1 (HSV-1) quiescent infection was established in L929 cells, murine fibroblasts, and in Neuro-2A (N2A) cells, mouse neuroblastoma, by treating them with the nucleoside analogue acyclovir (ACV) 24 hours before infection. Subsequent release of virus from the non-productive state was accomplished by treating the cells with the histone deacetylase inhibitor trichostatin A (TSA). Treatment of both L929 and N2A cell lines with ACV 24 hours before infection induced protection from HSV-1 cytopathic effect. A quiescent state was confirmed by absence of virus plaques when supernatant fluids from ACV-treated HSV-1 infected cultures were titered on Vero cell monolayers. …

N-Glycosylation, Localization And Trafficking Of Endogenous Nkcc1 In Cos7 Cells, Richa Singh

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The Na+K+2Cl^- co-transporter-1 (NKCC1) effects the electroneutral movement of Na+, K+ and 2Cl^- ions across plasma membranes. NKCC1 is considered a widely distributed, highly N-glycosylated ion transporter involved in the regulation of the intracellular chloride concentration ([Cl^-]i), cell volume and salt secretion. NKCC1 locates in the plasma membrane of all cells studied so far, particularly on the basolateral side of most polarized cells. However, the majority of immunoreactive NKCC1 distributes in intracellular compartments of unknown nature whereas a small proportion of the transporter appears to be located in the plasma membrane. Here, we identified and characterized …

Novel Approaches For The Eradication Of Hiv Latently Infected Cells, Sally Al Ali

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The development of a suitable experimental cell model to study HIV latency in primary cells could have a massive effect on the current approaches to eradicate virus in latently infected cells. The main proposal of this paper is to develop an in vitro HIV cell model that represents HIV latency in vivo, then to create a more effective viral vector in order to target HIV reservoirs. For this goal, a directed evolution method is suggested to be used in order to mutate the AAV cap gene to generate a recombinant AAV vector that is capable of infecting primary resting CD4+ …

Conversion Of The U937 Monocyte Into "Macrophage-Like" Populations Exhibiting M1 Or M2 Characteristics, Bradley M. Sharp

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The U937 cell line is an oncogenic human monocyte cell line. These monocytes have the potential of differentiating into either macrophages or dendritic cells (Lawrence et al., 2011). This differentiation pattern depends on the characteristics of the tissue microenvironment (Kigerl et al., 2009). PMA (Phorbol 12-Myristate 13-Acetate) is a phorbol ester capable of transforming monocytic cells toward the macrophage pathway. Upon treatment with PMA, U937 cells under-go a series of morphological and functional changes. Traditionally monocytic cell lines are used as a model of macrophage function, because current human macrophage cell lines require a T-cell conditioned growth medium and contact …

Hpai H5n1: A Global Pandemic Concern, With Implications For Pandemic Preperation And Public Health Policy, Lauren M. Koontz

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Research on highly pathogenic avian influenza A (HPAI) H5N1 has gained much attention in recent years due to its devastating impact within the bird population. While transmission to humans is rare, infections are fatal in more than half of the cases. One of the main concerns among the scientific community is the ability for this virus to mutate in a way much like seasonal influeanza that would allow it to be transmitted efficiently among the human population. Two researchers were able to separately create mutant isolates of H5N1 influenza A virus that could be transmitted via the respiratory route between …

Clinicopathological Spectrum Of Ovarian Sex Cord-Stromal Tumors; 20years' Retrospective Study In A Developing Country, Saroona Haroon, Aleena Zia, Romana Idrees, Aisha Memon, Saira Fatima, Naila Kayani

Department of Pathology and Laboratory Medicine

Background:
Ovarian sex cord stromal tumors are rare neoplasms as compared to epithelial tumors. No large study has been done in Pakistan to find out the frequencies of various sex cord stromal tumors and their clinicopathological behavior in our region. The purpose of our study was to determine the various histological patterns and clinical features of ovarian sex cord stromal tumors along with follow-up in our set-up.
Methods:
It is a retrospective observational study. The study was conducted in section of Histopathology, Aga Khan University Hospital, Karachi, Pakistan. All reported cases of sex cord stromal tumors of ovary during 1992 …

Frequency And Outcome Of Graft Versus Host Disease After Stem Cell Transplantation: A Six-Year Experience From A Tertiary Care Center In Pakistan, Natasha Ali, Salman Naseem Adil, Mohammad Usman Shaikh, Nehal Masood

Department of Pathology and Laboratory Medicine

Objective: The objective of this study was to evaluate the frequency and outcome of graft versus host disease after stem cell transplantation for various haematological disorders in Pakistan.
Materials and Methods: Pretransplant workup of the patient and donor was performed. Mobilization was done with G-CSF 300 mu g twice daily for five day. Standard GvHD prophylaxis was done with methotrexate 15mg/m(2) on day +1 followed by 10mg/m(2) on days +3 and +6 and cyclosporine. Grading was done according to the Glucksberg classification.
Results: A total of 153 transplants were done from April 2004 to December 2011. Out of these were …

Identification Of Non-Tuberculous Mycobacteria Isolated From Clinical Specimens At A Tertiary Care Hospital: A Cross-Sectional Study, Imran Ahmed, Kauser Jabeen, Rumina Hasan

Department of Pathology and Laboratory Medicine

Background:
Non-tuberculous mycobacteria (NTM) are opportunistic pathogens in immuno-compromised patients. They are also increasingly recognized as pathogens in immuno-competent individuals. Globally, an increase in NTM isolation is being reported with a varied geographic prevalence of different species around the world. There is lack of data on species distribution of these organisms from Pakistan. Treatment options differ according to the species isolated and its susceptibility profile. Knowledge of local species variation would help targeted therapy. This study was performed to determine frequencies of different NTM species isolated from various clinical specimens submitted at a tertiary care hospital laboratory.
Methods:
NTM isolated …

Overview Of Benign And Malignant Prostatic Disease In Pakistani Patients: A Clinical And Histopathological Perspective, Huma Arshad, Zubair Ahmad

Department of Pathology and Laboratory Medicine

Background: To present the overall clinical and histological perspective of benign and malignant prostatic disease as seen in our practice in the Section of Histopathology, Department of Pathology and Microbiology, Aga Khan University Hospital, Karachi, Pakistan.
Materials and Methods: All consecutive prostate specimens (transurethral resection or TUR, enucleation, needle biopsies) received between July 1, 2012 and December 31, 2012 were included in the study.
Results: Of the total of 785 cases, 621 (79.1%) were TUR specimens, 80 (10.2%) enucleation specimens, and 84 (10.7%) needle biopsies. Some 595 (75.8%) were benign, while 190 (24.2%) were malignant. Mean weight of BPH specimens …

Peripheral T-Cell Lymphoma Presenting As Testicular Mass; A Diagnostic Challenge, Saroona Haroon, Arsalan Ahmed

Department of Pathology and Laboratory Medicine

Background: T-cell lymphomas involve the testis infrequently, which deserve special attention because of the poor prognosis and the need to make an appropriate diagnosis, which could lead to a better therapeutic strategy.
Case Presentation: A 40-year-old man presented with right testicular swelling for past three months. The swelling was painless, hard and rubbery. Testicular ultrasound showed diffuse increase in size of the testicle, with alteration in its echogenicity. The patient underwent orchidectomy, and based on histopathological and immunohistochemical tests, a peripheral T-cell lymphoma, not otherwise specified was diagnosed.
Conclusion: Testicular peripheral T-cell lymphomas are rare and aggressive cancers, with clinical …

Prevalence Of Drug Resistance Associated Mutations In Plasmodium Vivax Against Sulphadoxine-Pyrimethamine In Southern Pakistan, Afsheen Raza, Najia K. Ghanchi, Muhammad Shahzeb Khan, Mohammad Asim Beg

Department of Pathology and Laboratory Medicine

Background: In Pakistan, Plasmodium vivax and Plasmodium falciparum co-exist and usage of sulphadoxine-pyrimethamine (SP) against P. falciparum exposes P. vivax to the drug leading to generation of resistant alleles. The main aim of this study was to investigate frequency distribution of drug resistance associated mutations in pvdhfr, pvdhps genes and provide baseline molecular epidemiological data on SP-associated resistance in P. vivax from southern Pakistan.
Methods: From January 2008 to May 2009, a total of 150 samples were collected from patients tested slide-positive for P. vivax, at the Aga Khan University Hospital, Karachi, or its collection units located in Baluchistan and …

Malnutrition In Sickle Cell Anemia: Implications For Infection, Growth And Maturation, Hyacinth I. Hyacinth, Oluwatoyosi A. Adekeye, Christopher S. Yilgwan

Journal of Social, Behavioral, and Health Sciences

Sickle cell anemia (SCA) is a genetic disease that affects mostly individuals of African and/or Hispanic descent, with the majority of cases in sub-Saharan Africa. Individuals with this disease show slowed growth, delayed sexual maturity, and poor immunologic function. These complications could partly be explained by the state of undernutrition associated with the disease. Proposed mechanism of undernutrition include protein hypermetabolism, decreased dietary intake possibly from interleukin-6-related appetite suppression, increased cardiac energy demand/expenditure, and increased red cell turnover. All the above mechanisms manifest as increased resting energy expenditure. Nutritional intervention utilizing single or multiple nutrient supplementation has led to improved …

Neisseria Oralis Sp. Nov., Isolated From Healthy Gingival Plaque And Clinical Samples, William J. Wolfgang, Teresa V. Passaretti, Reashma Jose, Jocelyn Cole, An Coorevits, Andrea N. Carpenter, Sherly Jose, Anita Van Landschoot, Jacques Izard, Donna J. Kohlerschmidt, Peter Vandamme, Floyd E. Dewhirst, Mark A. Fisher, Kimberlee A. Musser

Department of Food Science and Technology: Faculty Publications

A polyphasic analysis was undertaken of seven independent isolates of gram-negative cocci collected from pathological clinical samples from New York, Louisiana, Florida, and Illinois and healthy subgingival plaque from a patient in Virginia, USA. The 16S rRNA gene sequence similarity among these isolates was 99.7–100 %, and the closest species with a validly published name was Neisseria lactamica (96.9 % similarity to the type strain). DNA–DNA hybridization confirmed that these isolates are of the same species and are distinct from their nearest phylogenetic neighbor, N. lactamica. Phylogenetic analysis of 16S and 23S rRNA gene sequences indicated that the …

Towards Defining The Chloroviruses: A Genomic Journey Through A Genus Of Large Dna Viruses, Adrien Jeanniard, David D. Dunigan, James Gurnon, Irina V. Agarkova, Ming Kang, Jason Vitek, Garry Duncan, O William Mcclung, Megan Larsen, Jean-Michel Claverie, James L. Van Etten, Guillaume Blanc

Nebraska Center for Virology: Faculty Publications

Background: Giant viruses in the genus Chlorovirus (family Phycodnaviridae) infect eukaryotic green microalgae. The prototype member of the genus, Paramecium bursaria chlorella virus 1, was sequenced more than 15 years ago, and to date there are only 6 fully sequenced chloroviruses in public databases. Presented here are the draft genome sequences of 35 additional chloroviruses (287 – 348 Kb/319 – 381 predicted protein encoding genes) collected across the globe; they infect one of three different green algal species. These new data allowed us to analyze the genomic landscape of 41 chloroviruses, which revealed some remarkable features about these viruses. …