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Tissue Compartmentalization And Tropism Of Hiv-1: A Dissertation, Robin L. Brese Aug 2016

Tissue Compartmentalization And Tropism Of Hiv-1: A Dissertation, Robin L. Brese

GSBS Dissertations and Theses

Despite the development of effective antiretroviral treatments, there is still no cure for HIV-1. Major barriers to HIV-1 eradication include the diversity of intrapatient viral quasispecies and the establishment of reservoirs in tissue sanctuary sites. A better understanding of these populations is required for targeted treatments. While previous studies have examined the relationship between brain and blood or immune tissues, few have looked at and compared the properties of viruses from other tissue compartments. In this study, 75 full length HIV-1 envelopes were isolated from the frontal lobe, occipital lobe, parietal lobe, colon, lung, and lymph node of an HIV-1 ...


Amphiphilic Degradable Polymer/Hydroxyapatite Composites As Smart Bone Tissue Engineering Scaffolds: A Dissertation, Artem B. Kutikov Nov 2014

Amphiphilic Degradable Polymer/Hydroxyapatite Composites As Smart Bone Tissue Engineering Scaffolds: A Dissertation, Artem B. Kutikov

GSBS Dissertations and Theses

Over 600,000 bone-grafting operations are performed each year in the United States. The majority of the bone used for these surgeries comes from autografts that are limited in quantity or allografts with high failure rates. Current synthetic bone grafting materials have poor mechanical properties, handling characteristics, and bioactivity. The goal of this dissertation was to develop a clinically translatable bone tissue engineering scaffold with improved handling characteristics, bioactivity, and smart delivery modalities. We hypothesized that this could be achieved through the rational selection of Food and Drug Administration (FDA) approved materials that blend favorably with hydroxyapatite (HA), the principle ...


Runx Expression In Normal And Osteoarthritic Cartilage: Possible Functions Of Runx Proteins In Chondrocytes: A Dissertation, Kimberly T. Leblanc Feb 2013

Runx Expression In Normal And Osteoarthritic Cartilage: Possible Functions Of Runx Proteins In Chondrocytes: A Dissertation, Kimberly T. Leblanc

GSBS Dissertations and Theses

The Runx family of transcription factors supports cell fate determination, cell cycle regulation, global protein synthesis control, and genetic as well as epigenetic regulation of target genes. Runx1, which is essential for hematopoiesis; Runx2, which is required for osteoblast differentiation; and Runx3, which is involved in neurologic and gut development; are expressed in the growth plate during chondrocyte maturation, and in the chondrocytes of permanent cartilage structures. While Runx2 is known to control genes that contribute to chondrocyte hypertrophy, the functions of Runx1 and Runx3 during chondrogenesis and in cartilage tissue have been less well studied.

The goals of this ...


An Extra-Embryonic Wnt Signaling Event Controls Gastrulation In Mice: A Dissertation, Giovane G. Tortelote Nov 2012

An Extra-Embryonic Wnt Signaling Event Controls Gastrulation In Mice: A Dissertation, Giovane G. Tortelote

GSBS Dissertations and Theses

The formation of the anterior-posterior axis requires a symmetry-breaking event that starts gastrulation. Ultimately, the morphogenetic movements of gastrulation reshape the embryo to its final tri-dimensional form. In mouse embryos, the identity of the molecule that breaks the bilateral symmetry and sets in motion gastrulation remains elusive. The Wnt signaling pathway plays a pivotal role during axial specification and gastrulation in metazoans. Loss-of-function experiments have demonstrated a requirement of Wnt3 for gastrulation in mice. But because Wnt3 is expressed sequentially in two tissues, the visceral endoderm and the epiblast, its tissue specific requirements remain uncertain. Here, we report that embryos ...


Investigating The Roles Of Nedd4.2s And Nef In The Release And Replication Of Hiv-1: A Dissertation, Eric R. Weiss Sep 2012

Investigating The Roles Of Nedd4.2s And Nef In The Release And Replication Of Hiv-1: A Dissertation, Eric R. Weiss

GSBS Dissertations and Theses

Replication of HIV-1 requires the assembly and release of mature and infectious viral particles. In order to accomplish this goal, HIV-1 has evolved multiple methods to interact with the host cell. HIV-1 recruits the host cell ESCRT machinery to facilitate the release of nascent viral particles from the host cell membrane. Recruitment of these cellular factors is dependent on the presence of short motifs in Gag referred to as Late-domains. Deletion or mutation of these domains results in substantial decrease in the release of infectious virions. However, previously published work has indicated that over-expression of the E3 ubiquitin ligase, NEDD4 ...


Glial Control Of Synapse Assembly At The Drosophila Neuromuscular Junction: A Dissertation, Kimberly S. Kerr Sep 2012

Glial Control Of Synapse Assembly At The Drosophila Neuromuscular Junction: A Dissertation, Kimberly S. Kerr

GSBS Dissertations and Theses

Emerging evidence in both vertebrates and invertebrates is redefining glia as active and mobile players in synapse formation, maturation and function. However, the molecular mechanisms through which neurons and glia interact with each other to regulate these processes is not well known. My thesis work begins to understand how glia use secreted factors to modulate synaptic function. We use Drosophila melanogaster, a simple and genetically tractable model system, to understand the molecular mechanisms by which glia communicate with neurons at glutamatergic neuromuscular junctions (NMJs). We previously showed that a specific subtype of glia, subperineurial peripheral glia cells (SPGs), establish dynamic ...


Serotonin-Expressing Cells In The Corpus Of The Stomach Originate From Bone Marrow: A Master’S Thesis, Brian T. Johnston Aug 2012

Serotonin-Expressing Cells In The Corpus Of The Stomach Originate From Bone Marrow: A Master’S Thesis, Brian T. Johnston

GSBS Dissertations and Theses

Neurogenin 3 and its downstream target NeuroD are basic helix-loop-helix transcription factors which promote endocrine differentiation in the gastrointestinal tract. However, mice lacking Ngn3 still produce several hormones in the stomach. Lineage tracing mouse models demonstrated that a majority of hormone cells in the corpus region of the stomach did not express Ngn3 or NeuroD during differentiation. Serotonin and histamine cells were entirely NeuroD-independently derived, and serotonin cells were additionally entirely Ngn3-independently derived. In this study, we isolated serotonin and histamine cells from the gastric corpus of transgenic mice expressing the fluorescent marker CFP. Serotonin cells expressed multiple mast cell ...


A Novel Communication Mechanism Between The Presynapse And Postsynapse Through Exosomes: A Dissertation, Ceren Korkut Aug 2012

A Novel Communication Mechanism Between The Presynapse And Postsynapse Through Exosomes: A Dissertation, Ceren Korkut

GSBS Dissertations and Theses

The minimal element of the nervous system, the synapse, is a plastic structure that has the ability to change in response to various internal and external factors. This property of the synapse underlies complex behaviors such as learning and memory. However, the exact molecular and cellular mechanisms involved in this process are not fully understood. To understand the mechanisms that regulate synapse development and plasticity I took advantage of a powerful model system, the Drosophila larval neuromuscular junction (NMJ). In this system, both anterograde and retrograde signaling pathways critical for coordinated synapse development and plasticity have been documented.

An anterograde ...


Sequence And Target Specificity Of The C. Elegans Cell Fate Specification Factor Pos-1: A Dissertation, Brian M. Farley Aug 2012

Sequence And Target Specificity Of The C. Elegans Cell Fate Specification Factor Pos-1: A Dissertation, Brian M. Farley

GSBS Dissertations and Theses

In most metazoans, early embryogenesis is controlled by the translational regulation of maternally supplied mRNA. Sequence-specific RNA-binding proteins play an important role in regulating early embryogenesis, yet their specificities and regulatory targets are largely unknown. To understand how these RNA-binding proteins select their targets, my research focused on the C. elegans CCCH-type tandem zinc finger protein POS-1. Embryos lacking maternally supplied POS-1 die prior to gastrulation, and exhibit defects in the specification of pharyngeal, intestinal, and germline precursor cells. To identify the regulatory targets that contribute to the POS-1 mutant phenotype, we set out to determine the sequence specificity of ...


The Role Of Itk In The Development Of Gamma Delta Nkt Cells: A Dissertation, Catherine C. Yin Aug 2012

The Role Of Itk In The Development Of Gamma Delta Nkt Cells: A Dissertation, Catherine C. Yin

GSBS Dissertations and Theses

The immune system is a complex network of interacting cells and tissues that is designed to protect the body from pathogens and other foreign substances. T cells are a major component of the immune system and consist of two distinct lineages distinguished by the expression of αβ or γδ T cell receptors (TCR). The Tec family kinase, Itk is an important mediator of signaling downstream of the TCR. Past studies on Itk has focused on how Itk regulates development, activation and differentiation of conventional αβ T cells and more recently how Itk regulates the development of innate-like αβ T cells ...


Maintaining The Balance: Coordinating Excitation And Inhibition In A Simple Motor Circuit: A Dissertation, Hilary A. Petrash Aug 2012

Maintaining The Balance: Coordinating Excitation And Inhibition In A Simple Motor Circuit: A Dissertation, Hilary A. Petrash

GSBS Dissertations and Theses

The generation of complex behaviors often requires the coordinated activity of diverse sets of neural circuits in the brain. Activation of neuronal circuits drives behavior. Inappropriate signaling can contribute to cognitive disorders such as epilepsy, Parkinson’s, and addiction (Nordberg et al., 1992; Quik and McIntosh, 2006; Steinlein et al., 2012). The molecular mechanisms by which the activity of neural circuits is coordinated remain unclear. What are the molecules that regulate the timing of neural circuit activation and how is signaling between various neural circuits achieved? While much work has attempted to address these points, answers to these questions have ...


Mechanical Activation Of Valvular Interstitial Cell Phenotype: A Dissertation, Angela M. Throm Quinlan Aug 2012

Mechanical Activation Of Valvular Interstitial Cell Phenotype: A Dissertation, Angela M. Throm Quinlan

GSBS Dissertations and Theses

During heart valve remodeling, and in many disease states, valvular interstitial cells (VICs) shift to an activated myofibroblast phenotype which is characterized by enhanced synthetic and contractile activity. Pronounced alpha smooth muscle actin (αSMA)-containing stress fibers, the hallmark of activated myofibroblasts, are also observed when VICs are placed under tension due to altered mechanical loading in vivo or during in vitro culture on stiff substrates or under high mechanical loads and in the presence of transforming growth factor-beta1 (TGF-β1). The work presented herein describes three distinct model systems for application of controlled mechanical environment to VICs cultured in vitro ...


Role Of Perivascular And Visceral Adipose Tissues In Murine Models Of Obesity And Atherosclerosis: A Dissertation, Timothy P. Fitzgibbons Jul 2012

Role Of Perivascular And Visceral Adipose Tissues In Murine Models Of Obesity And Atherosclerosis: A Dissertation, Timothy P. Fitzgibbons

GSBS Dissertations and Theses

Expansion of visceral adipose tissue correlates with the metabolic syndrome and increased cardiovascular risk. Hypertrophied visceral fat becomes inflamed, causing increased lipolysis, decreased triglyceride storage, and lipotoxicity in skeletal muscle and liver resulting in insulin resistance. Perivascular adipose tissue is a normal component of the adventitia of arteries in humans and animals. Whether or not perivascular adipose also becomes inflamed in obesity is an important question, as this may be an additional, direct mechanism by which obesity causes vascular inflammation and disease.

Thus, for the first part of my thesis, we asked the question: does perivascular adipose in mice become ...


Molecular Studies Of T Cell Recognition And Cross-Reactivity: A Dissertation, Zu T. Shen Jul 2012

Molecular Studies Of T Cell Recognition And Cross-Reactivity: A Dissertation, Zu T. Shen

GSBS Dissertations and Theses

Intracellular pathogens are recognized by a specialized subset of lymphocytes known as CD8+ T cells. Pathogen recognition by CD8+ T cells occurs through binding of T cell receptors (TCR) to processed antigens in complex with major histocompatibility complex (MHC) class I proteins. TCR engagement of antigens in complex with MHC class I typically lead to cytotoxic CD8+ T cell responses, which result in pathogen clearance. Due to the large number of foreign antigens that might be encountered by any given host a diverse repertoire of TCRs must be available for immune recognition. The main source of TCR diversity is generated ...


Microrna Markers Of Acetaminophen Toxicity: A Master's Thesis, Jeanine Ward Jul 2012

Microrna Markers Of Acetaminophen Toxicity: A Master's Thesis, Jeanine Ward

GSBS Dissertations and Theses

Background
To investigate plasma microRNA (miRNA) profiles indicative of hepatotoxicity in the setting of lethal acetaminophen (APAP) toxicity in mice.

Methods
Using plasma from APAP poisoned mice, either lethally (500 mg/kg) or sublethally (150 mg/kg) dosed, we screened commercially available murine microRNA libraries (SABiosciences, Qiagen Sciences, MD) to evaluate for unique miRNA profiles between these two dosing parameters.

Results
We distinguished numerous, unique plasma miRNAs both up- and down-regulated in lethally compared to sublethally dosed mice. Of note, many of the greatest up- and down-regulated miRNAs, included, but were not limited to, 574-5p, 466g, 466f-3p, 375, 29c, and ...


Gene Expression And Profiling Of Human Islet Cell Subtypes: A Master’S Thesis, David M. Blodgett Jul 2012

Gene Expression And Profiling Of Human Islet Cell Subtypes: A Master’S Thesis, David M. Blodgett

GSBS Dissertations and Theses

Background: The endocrine pancreas contains multiple cell types co-localized into clusters called the Islets of Langerhans. The predominant cell types include alpha and beta cells, which produce glucagon and insulin, respectively. The regulated release of these hormones maintains whole body glucose homeostasis, essential for normal metabolism and to prevent diabetes and complications from the disease. Given the heterogeneous nature of islet composition and absence of unique surface markers, many previous studies have focused on the whole islet. Sorting islet cells by intracellular hormone expression overcomes this limitation and provides pure populations of individual islet cell subsets, specifically alpha and beta ...


Rna-Sensing Pattern Recognition Receptors And Their Effects On T-Cell Immune Responses: A Dissertation, Rachel F. Madera Jul 2012

Rna-Sensing Pattern Recognition Receptors And Their Effects On T-Cell Immune Responses: A Dissertation, Rachel F. Madera

GSBS Dissertations and Theses

Virus infection is sensed by the innate immune system through germline encoded pattern recognition receptors (PRRs). Toll-like receptors (TLRs), retinoic acid-inducible gene-I-like receptors (RLRs) and nucleotide-binding oligomerization domain-like receptors (NLRs) serve as PRRs that recognize different viral components. Microbial nucleic acids such as Ribonucleic acid (RNA) are important virus-derived pathogen-associated molecular patterns (PAMPs) to be recognized by PRRs. Virus recognition may occur at multiple stages of the viral life cycle. Replication intermediates such as single-stranded RNA (ssRNA) and double-stranded RNA (dsRNA) are detected by the RNA-sensing PRRs that initiate innate and adaptive immune responses. Triggering of the innate immune system ...


Mdm2-P53 Signaling In Tissue Homeostasis And The Dna Damage Response: A Dissertation, Hugh S. Gannon Jun 2012

Mdm2-P53 Signaling In Tissue Homeostasis And The Dna Damage Response: A Dissertation, Hugh S. Gannon

GSBS Dissertations and Theses

The p53 transcription factor responds to various cellular stressors by regulating the expression of numerous target genes involved in cellular processes such as cell cycle arrest, apoptosis, and senescence. As these downstream pathways are harmful to the growth and development of normal cells when prolonged or deregulated, p53 activity needs to be under tight regulatory control. The Mdm2 oncoprotein is the chief negative regulator of p53, and many mouse models have demonstrated that absence of Mdm2 expression leads to constitutive p53 activation in a variety of cell types. While unregulated p53 can be deleterious to cells, functional p53 is essential ...


Slow-Cycling Cancer Cells: A Dissertation, Nathan F. Moore Jun 2012

Slow-Cycling Cancer Cells: A Dissertation, Nathan F. Moore

GSBS Dissertations and Theses

Tumor recurrence after chemotherapy is a major cause of patient morbidity and mortality. Recurrences are thought to be due to small subsets of stem-like cancer cells that are able to survive chemotherapy and drive tumor re-growth. A more complete understanding of stem-like cancer cell regulation is required to develop therapies to better target and eliminate these cells.

Slow-cycling stem cells are integral components of adult epithelial tissues and may give rise to cancer stem cell populations that share similar characteristics. These slow-cycling adult stem cells are inherently resistant to traditional forms of chemotherapy and transference of this characteristic may help ...


Innate Signaling Pathways In The Maintenance Of Serological Memory: A Dissertation, Forum M. Raval Jun 2012

Innate Signaling Pathways In The Maintenance Of Serological Memory: A Dissertation, Forum M. Raval

GSBS Dissertations and Theses

Long-term antiviral antibody responses provide protection from re-infection and recurrence of persistent viruses. Using a polyomavirus (PyV) mouse model, our lab has shown that MyD88-deficient mice generate low levels of virus-specific IgG after the acute phase of infection and that these IgG responses have a skewed isotype distribution with low levels of IgG2a/c. Moreover MyD88-deficient mice have reduced numbers of long-lived plasma cells in the bone marrow. These studies suggest an important role of MyD88-mediated signaling in long-term antiviral responses. Our lab has shown that T cell-deficient mice can also maintain long-term virus-specific IgG responses following PyV infection. The ...


Eaters Of The Dead: How Glial Cells Respond To And Engulf Degenerating Axons In The Cns: A Dissertation, Jennifer S. Ziegenfuss Jun 2012

Eaters Of The Dead: How Glial Cells Respond To And Engulf Degenerating Axons In The Cns: A Dissertation, Jennifer S. Ziegenfuss

GSBS Dissertations and Theses

Glia, whose name derives from the original Greek word, meaning “glue,” have long been understood to be cells that play an important functional role in the nutritive and structural support of the central nervous system, yet their full involvement has been historically undervalued. Despite the strong evidence that glial reactions to cellular debris govern the health of the nervous system, the specific properties of damaged axonal debris and the mechanisms by which glia sense them, morphologically adapt to their presence, and initiate phagocytosis for clearance, have remained poorly understood. The work presented in this thesis was aimed at addressing this ...


A Role For C-Jun Kinase (Jnk) Signaling In Glial Engulfment Of Degenerating Axons: A Dissertation, Jennifer M. Macdonald Jun 2012

A Role For C-Jun Kinase (Jnk) Signaling In Glial Engulfment Of Degenerating Axons: A Dissertation, Jennifer M. Macdonald

GSBS Dissertations and Theses

The central nervous system (CNS) is composed of two types of cells: neurons that send electrical signals to transmit information throughout the animal and glial cells. Glial cells were long thought to be merely support cells for the neurons; however, recent work has identified many critical roles for these cells during development and in the mature animal. In the CNS, glial cells act as the resident immune cell and they are responsible for the clearance of dead or dying material. After neuronal injury or death, glial cells become reactive, exhibiting dramatic changes in morphology and patterns of gene expression and ...


Transposition Driven Genomic Heterogeneity In The Drosophila Brain: A Dissertation, Paola N. Perrat Jun 2012

Transposition Driven Genomic Heterogeneity In The Drosophila Brain: A Dissertation, Paola N. Perrat

GSBS Dissertations and Theses

In the Drosophila brain, memories are processed and stored in two mirrorsymmetrical structures composed of approximately 5,000 neurons called Mushroom Bodies (MB). Depending on their axonal extensions, neurons in the MB can be further classified into three different subgroups: αβ, α’β’ and γ. In addition to the morphological differences between these groups of neurons, there is evidence of functional differences too. For example, it has been previously shown that while neurotransmission from α’β’ neurons is required for consolidation of olfactory memory, output from αβ neurons is required for its later retrieval. To gain insight into the functional ...


Antagonistic Pleiotropy: The Role Of Smurf2 In Cancer And Aging: A Dissertation, Charusheila Ramkumar Jun 2012

Antagonistic Pleiotropy: The Role Of Smurf2 In Cancer And Aging: A Dissertation, Charusheila Ramkumar

GSBS Dissertations and Theses

In response to telomere shortening, oxidative stress, DNA damage or aberrant activation of oncogenes, normal somatic cells exit the cell cycle and enter an irreversible growth arrest termed senescence. The limited proliferative capacity imposed by senescence on cells impedes the accumulation of mutations necessary for tumorigenesis and prevents proliferation of cells at risk of neoplastic transformation. Opposite to the tumor suppressor function, accumulation of senescent cells in adult organisms is thought to contribute to aging by depleting the renewal capacity of tissues and stem/progenitor cells, and by interfering with tissue homeostasis and functions. The Antagonistic Pleiotropy Theory of senescence ...


Transcriptional Regulation Of The Interleukin-8 Promoter By Multiple Dengue Viral Proteins: A Dissertation, Jacob M. Collins May 2012

Transcriptional Regulation Of The Interleukin-8 Promoter By Multiple Dengue Viral Proteins: A Dissertation, Jacob M. Collins

GSBS Dissertations and Theses

Dengue virus (DENV) causes over 500,000 infections annually with a spectrum of clinical diseases ranging from subclinical infection to dengue, a mild febrile illness, to life-threatening severe dengue. Vascular leakage without endothelial cell damage is the hallmark symptom of severe dengue illness and is proposed to be directly mediated by soluble inflammatory mediators IL-8 and TNFα. IL-8 production occurs in response to DENV infection, is elevated during severe dengue, is proposed to inhibit interferon, and could potentially recruit target cells to sites of infection. We previously showed that expression of DENV NS5 activates the IL-8 promoter, induces IL-8 transcription ...


Runx1 C-Terminal Domains During Hematopoietic Development And Leukemogenesis: A Dissertation, Christopher R. Dowdy May 2012

Runx1 C-Terminal Domains During Hematopoietic Development And Leukemogenesis: A Dissertation, Christopher R. Dowdy

GSBS Dissertations and Theses

Runx1 is a master regulator of hematopoiesis, required for the initiation of definitive hematopoiesis in the embryo and essential for appropriate differentiation of many hematopoietic lineages in the adult. The roles of Runx1 in normal hematopoiesis are juxtaposed with the high frequency of Runx1 mutations and translocations in leukemia. Leukemia associated Runx1 mutations that retain DNA-binding ability have truncations or frame shifts that lose C-terminal domains. These domains are important for subnuclear localization of Runx1 and protein interactions with co-factors. The majority of leukemia associated Runx1 translocations also replace the C-terminus of Runx1 with chimeric fusion proteins. The common loss ...


Chromatin Dynamics In Pluripotency And Differentiation: A Dissertation, Ozlem Yildirim May 2012

Chromatin Dynamics In Pluripotency And Differentiation: A Dissertation, Ozlem Yildirim

GSBS Dissertations and Theses

Different cell types in multi-cellular organisms heritably maintain different gene expression patterns despite carrying the same genome; a phenomenon termed epigenetics. It is widely believed that the packaging state of the genome, known as chromatin structure, carries epigenetic information. How chromatin states are inherited and how chromatin structure changes during development, moreover how different epigenomes, such as chromatin and DNA modifications communicate with each other during these processes are important questions. Accordingly, understanding the mechanisms that govern pluripotency and differentiation requires details of chromatin dynamics. The major goal of my doctoral thesis was to understand the genome wide view of ...


The Role Of Adaptor Protein Complex-3 Delta-Mediated Hiv-1 Gag Trafficking In Hiv-1 Replication: A Dissertation, Adonia Lee Kim May 2012

The Role Of Adaptor Protein Complex-3 Delta-Mediated Hiv-1 Gag Trafficking In Hiv-1 Replication: A Dissertation, Adonia Lee Kim

GSBS Dissertations and Theses

The process of HIV-1 particle production is a multi-step process directed by the viral structural protein Gag. As Gag is the only viral protein required to form virus-like particles, it presents a viable target for anti-viral therapeutics of which there are currently none. Although the functions of Gag during the particle assembly process have been well characterized, one of the least known parts of the assembly process is how Gag is targeted to the site of virus assembly.

Two main virus assembly sites have been identified in cells that support HIV-1 replication: the plasma membrane or multivesicular bodies (MVBs). However ...


Inflammation Inhibits Osteoblast-Mediated Bone Formation In Rheumatoid Arthritis And Regulates The Wnt And Bmp Signaling Pathways: A Dissertation, Melissa M. Matzelle May 2012

Inflammation Inhibits Osteoblast-Mediated Bone Formation In Rheumatoid Arthritis And Regulates The Wnt And Bmp Signaling Pathways: A Dissertation, Melissa M. Matzelle

GSBS Dissertations and Theses

Osteoclast-mediated focal articular bone erosion is a hallmark of rheumatoid arthritis, a disease of inflammation-induced bone loss. Inflammation in the bone microenvironment enhances osteoclast differentiation leading to bone erosion. Simultaneously, inflammation also inhibits osteoblast-mediated bone formation, further contributing to the net loss of bone. Previous studies have shown a paucity of mature osteoblasts at eroded bone surfaces correlating with suppression of bone formation and upregulation of antagonists of the Wnt pathway, a signaling cascade essential for osteoblast lineage commitment. Despite these observations, the exact pathogenesis of impaired bone formation in the setting of inflammation is not clearly understood.

This dissertation ...


Hiv-1 R5 Tropism: Determinants, Macrophages, And Dendritic Cells: A Dissertation, Thomas A. Musich May 2012

Hiv-1 R5 Tropism: Determinants, Macrophages, And Dendritic Cells: A Dissertation, Thomas A. Musich

GSBS Dissertations and Theses

Around thirty years ago HIV-1 was identified, and from that point the known epidemic has grown to over 30 million infected individuals. Early on in the course of HIV-1 research, viruses were classified as either syncytia inducing, CXCR4-using, T-cell tropic or non-syncytia inducing, CCR5-using, macrophage tropic. Since that time, several groups have shown that this is an oversimplification. There is a great deal of diversity amongst CCR5-using HIV-1 variants. There remains a great deal to be discovered regarding HIV-1 CCR5-tropism and how this affects other aspects of HIV-1 infection.

The CD4 binding site (CD4bs) on the HIV-1 envelope plays a ...