Open Access. Powered by Scholars. Published by Universities.®

Molecular Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 16 of 16

Full-Text Articles in Molecular Biology

Wnt5a Signaling Induced Phosphorylation Increases Acyl Protein Thioesterase Activity And Promotes Melanoma Metastatic Behavior, Rochelle Shirin Sadeghi Jan 2018

Wnt5a Signaling Induced Phosphorylation Increases Acyl Protein Thioesterase Activity And Promotes Melanoma Metastatic Behavior, Rochelle Shirin Sadeghi

Publicly Accessible Penn Dissertations

Wnt5a has been implicated in melanoma progression and metastasis, although the exact downstream signaling events that contribute to melanoma metastasis are poorly understood. Wnt5a signaling results in acyl protein thioesterase 1 (APT1) mediated depalmitoylation of pro-metastatic cell adhesion molecules CD44 and MCAM, resulting in increased melanoma invasion. The mechanistic details that underlie Wnt5a-mediated regulation of APT1 activity and cellular function remains unknown. Here, we show Wnt5a signaling regulates APT1 activity through induction of APT1 phosphorylation and we further investigate the functional role of APT1 phosphorylation on its depalmitoylating activity. We found phosphorylation increased APT1 depalmitoylating activity and reduced APT1 dimerization ...


Gene Therapy Approaches To Immune Tolerance Induction In Canine Hemophilia, Robert French Jan 2018

Gene Therapy Approaches To Immune Tolerance Induction In Canine Hemophilia, Robert French

Publicly Accessible Penn Dissertations

A key issue in gene therapy is the immune response to the therapeutic transgene. This is especially important in applications where current treatments often elicit an antibody response, like hemophilia, where protein replacement therapy results in neutralizing

antibodies (“inhibitors”) in ~25% of severe hemophilia A and 1-3% of severe hemophilia B patients. To test the ability of skeletal muscle-directed gene therapy to prevent an immune response, we used an inhibitor-prone dog model of severe hemophilia B to express a hyperactive factor IX (FIX) variant from skeletal muscle via adeno-associated viral (AAV) vector and observed curative levels of expression that lasted ...


Impact Of Host Factors On The Adaptive Immune Response To Aav Gene Therapy, Scott N. Ashley Jan 2017

Impact Of Host Factors On The Adaptive Immune Response To Aav Gene Therapy, Scott N. Ashley

Publicly Accessible Penn Dissertations

Impact of host factor on the adaptive immune response to AAV gene therapy

Scott Ashley

James Wilson

Adaptive immune responses to the transgene product remain an active area of concern for the gene therapy field. How host factors can influence the activation of the immune system is an important consideration in the development of gene therapy for different genetic disorders. One factor considered by many to shape the adaptive immune response is an individual’s genotype. Nonsense mutations were thought to result in an absence of tolerance to a replacement protein provided by gene therapy, due to a lack of ...


Intrathecal Aav9.Trastuzumab Tumor Prophylaxis And Treatment In A Murine Xenograft Model Of Her2+ Breast Cancer Brain Metastases, William Thomas Rothwell Jan 2017

Intrathecal Aav9.Trastuzumab Tumor Prophylaxis And Treatment In A Murine Xenograft Model Of Her2+ Breast Cancer Brain Metastases, William Thomas Rothwell

Publicly Accessible Penn Dissertations

Breast cancer brain metastases (BCBM) are a deadly sequela of breast tumors that overexpress human epidermal growth factor receptor 2 (HER2). HER2+ BCBM affects approximately 17,000 women in the US every year. Median survival is 10-13 months from the time of diagnosis of central nervous system (CNS) disease. Current therapeutic interventions are invasive, toxic, and largely ineffective, leaving a clear, unmet need for targeted HER2+ BCBM treatments. Trastuzumab(Herceptin®) is a monoclonal antibody used to treat HER2+ breast cancer successfully, but systemic trastuzumab cannot bypass the blood-brain barrier (BBB). To solve this problem, we have developed an adeno-associated virus ...


Dna Double Strand Breaks Suppress Expression Of The Rag Recombinase: Mechanisms And Consequences, Megan Rose Fisher Jan 2017

Dna Double Strand Breaks Suppress Expression Of The Rag Recombinase: Mechanisms And Consequences, Megan Rose Fisher

Publicly Accessible Penn Dissertations

Developing B and T lymphocytes must rearrange the genomic sequence of antigen receptor genes by V(D)J recombination. The lymphocyte-specific endonuclease RAG, composed of Rag1 and Rag2, initiates this process by cleaving specific sites within antigen receptor loci. RAG expression must be carefully regulated to ensure that V(D)J recombination occurs only under appropriate circumstances. The Bassing laboratory has previously demonstrated that Igκ locus cleavage by RAG in pre-B cells initiates a feedback-inhibition signal suppressing RAG expression. Here, we show that DNA double strand breaks (DSBs) induced by a variety of genotoxic agents have a similar effect in ...


Modulation Of Antitumor Immunity By The Mek Inhibitor Trametinib: Implications For Targeted Therapy Of Cancer, Michael J. Allegrezza Jan 2016

Modulation Of Antitumor Immunity By The Mek Inhibitor Trametinib: Implications For Targeted Therapy Of Cancer, Michael J. Allegrezza

Publicly Accessible Penn Dissertations

Through rational drug design, much progress has been made to develop small molecules that specifically inhibit the oncogenic signaling pathways driving malignant growth. However, the normal function of immune cells depends upon many of the same pathways inhibited by such targeted cancer therapies. Because the immune system can influence the growth of many cancers, I hypothesized that most small molecule inhibitors would have activity on leukocytes relevant in cancer, and this activity would contribute to their antitumor mechanisms. In order to test this hypothesis, I first screened a panel of over 40 small molecule inhibitors for their activity on proliferating ...


Car Drivers And Fuel Sources: How Distinct Signaling Domains In Chimeric Antigen Receptors Reprogram T Cells, Omkar Uday Kawalekar Jan 2016

Car Drivers And Fuel Sources: How Distinct Signaling Domains In Chimeric Antigen Receptors Reprogram T Cells, Omkar Uday Kawalekar

Publicly Accessible Penn Dissertations

With breakthroughs in synthetic biology, improved cell culture techniques and advanced genetic engineering, it has now become possible to generate bi-specific primary human T cells with desired specificities. One mode of redirecting specificity is the modification of T cells to express chimeric antigen receptors (CARs). Recent studies indicate that natural T cells have distinct biochemical and metabolic features that endow them with short lived effector or long lived memory fates. The central objective of this thesis was to investigate whether the signaling endodomain of CARs could reprogram T cells with pre-specified effector and memory fates. This thesis describes a novel ...


Coming Full Circle: Epithelial Plasticity And The Natural History Of Metastasis, Nicole Aiello Jan 2016

Coming Full Circle: Epithelial Plasticity And The Natural History Of Metastasis, Nicole Aiello

Publicly Accessible Penn Dissertations

The primary cause of cancer-related deaths is metastasis— the spread of cancer cells to distant organs— and yet the mechanisms underlying this process remain elusive due to the difficulty in detecting early metastatic events, which are rare, stochastic and microscopic. To investigate the cellular and molecular mechanisms of metastasis, I utilized an autochthonous mouse model of pancreatic cancer (KPCY) in which all tumor cells are genetically labeled with yellow fluorescent protein (YFP). The YFP lineage label allows for the detection and isolation of disseminated tumor cells as they delaminate from epithelial structures within the primary tumor, invade into the stroma ...


Defining Mechanisms Of Autoimmunity In Pemphigus Vulgaris, Michael Jeffrey Tejada Cho Jan 2016

Defining Mechanisms Of Autoimmunity In Pemphigus Vulgaris, Michael Jeffrey Tejada Cho

Publicly Accessible Penn Dissertations

A prominent question in the field of autoimmunity is how these diseases arise. Currently, the etiologies of many autoimmune diseases remain unclear. The work described here provides insight into this question in the context of pemphigus vulgaris (PV), a prototypic autoimmune disease characterized by serum autoantibodies to desmoglein (Dsg) 3. We utilize a combination of both antibody phage display and heterohybridoma to probe the anti-Dsg3 antibody repertoires of patients with PV. We first address whether a cohort of four patients with active disease demonstrate any shared characteristics in their anti-Dsg3 antibody repertoires (Chapter 2), and if so, why. We find ...


Alarming Immunity: A Wake Up Call For Cd8 T Cells Using Genetic Adjuvants (Il-33 And Isg15), Daniel Villarreal Jan 2015

Alarming Immunity: A Wake Up Call For Cd8 T Cells Using Genetic Adjuvants (Il-33 And Isg15), Daniel Villarreal

Publicly Accessible Penn Dissertations

There exists a paramount need for effective vaccines against cancer, TB, malaria, HIV, HCV, and other chronic infections. The hope for long-term control of these important diseases ultimately may depend upon development of potent T cell-based therapeutic vaccines. However, current, licensed vaccines or capable vaccine platforms have not made a substantial impact on treatment of these conditions, likely due in part to poor CD8 T cell immune induction. Thus, identification of novel adjuvants to be deployed to induce effective T responses is an important area of research in T cell based vaccines. While multiple adjuvants have been readily identified which ...


Context- Dependent Gene Expression Programs Promote Lymphocyte Development And Function And Suppress Transformation, Amy Demicco Jan 2015

Context- Dependent Gene Expression Programs Promote Lymphocyte Development And Function And Suppress Transformation, Amy Demicco

Publicly Accessible Penn Dissertations

Coordinated orchestration of gene expression programs at the transcriptional, post-transcriptional, and post-translational levels is essential for development and function of all cells, including lymphocytes. Normal tissue function also demands that the genome be faithfully passed from mother to daughter cell during the many rounds of cell division required to generate a mammalian organism. Genome integrity is maintained in part by integration of DNA damage signaling with cell cycle control. These mechanisms are especially critical for lymphocytes following V(D)J recombination, since V(D)J recombination involves genetic cutting and pasting of germline gene segments to form antigen receptors (AgRs ...


Adeno-Associated Viral Vector-Driven Expression Of Coagulation Proteins For Treatment Of Hemophilias And Cancer, Julie Marie Crudele Jan 2015

Adeno-Associated Viral Vector-Driven Expression Of Coagulation Proteins For Treatment Of Hemophilias And Cancer, Julie Marie Crudele

Publicly Accessible Penn Dissertations

Treatment of hemophilia, which involves infusion of the missing clotting factor, is often hindered by the development of neutralizing antibodies to the replaced clotting factor. We utilized liver-directed AAV gene therapy to tolerize outbred hemophiliac dogs with pre-existing anti-factor VIII and IX antibodies and to treat their underlying hemophilia. Additionally, we sought to shed light on the immunologic mechanisms responsible for this tolerization. Staining for CD4+CD25+FoxP3+ T cells and cytokine profiles of treated dogs suggest that induced Tregs are at least partially responsible for inducing and maintaining tolerance.

The second part of the dissertation attempts to determine the ...


Role Of Cytoskeletal Remodeling In T Cell Receptor Signaling And Integrin Activation At The Immunological Synapse, Alexander Babich Jan 2014

Role Of Cytoskeletal Remodeling In T Cell Receptor Signaling And Integrin Activation At The Immunological Synapse, Alexander Babich

Publicly Accessible Penn Dissertations

The efficiency of an immune response critically depends on the ability of T cells to respond to antigens. Upon encountering cognate antigenic peptides on the surface of antigen-presenting cells, T cells form a specialized interface, termed the immunological synapse (IS), which serves as the site of information transfer between the cells. This contact zone is characterized by the enrichment of signaling receptors, kinases and adaptor proteins, and is the site of extensive cytoskeletal remodeling. The versatile nature and spatio-temporal regulation of signaling cascades at the IS has long been recognized but the exact mechanisms that coordinate these processes remain poorly ...


Tegument Protein Bnrf1 Regulation Of Epstein-Barr Virus Genome Chromatinization During Early Infection, Kevin Tsai Jan 2014

Tegument Protein Bnrf1 Regulation Of Epstein-Barr Virus Genome Chromatinization During Early Infection, Kevin Tsai

Publicly Accessible Penn Dissertations

Epstein-Barr virus (EBV) is a ubiquitously prevalent human herpesvirus whose persistent latent infection is associated with many lymphomas. The prevalence of this virus can be attributed to its ability to establish a persistent latent infection in host cells, during which only a small number of viral genes are expressed from a highly regulated viral genome. However, it is not completely understood how EBV evades cellular antiviral defenses and regulates chromatin assembly to establish latent infections. The EBV major tegument protein BNRF1 was found to be required for the establishment of latent infections, and contains sequence homology to cellular purine biosynthesis ...


Mechanisms Of Non-Canonical Nf-Kappab Regulation, Carolyn Margaret Gray Jan 2014

Mechanisms Of Non-Canonical Nf-Kappab Regulation, Carolyn Margaret Gray

Publicly Accessible Penn Dissertations

NF-kappaB is activated through two signaling cascades: the classical and non-canonical pathways, which are distinguished based on the Inhibitor of kappaB Kinase (IKK) components required to activate each pathway. Whereas classical NF-kappaB requires NF-kappaB Essential Modulator (NEMO) and IKKbeta, non-canonical NF-kappaB requires IKKalpha and upstream stabilization of NF-kappaB Inducing Kinase (NIK), but not NEMO. However, we have previously shown that IKKalpha contains a functional NEMO binding domain and associates with NEMO and IKKbeta as part of the heterotrimeric IKK complex. The overarching goal of the work described in this thesis was to determine whether the interaction between NEMO and IKKalpha ...


Development And Regulation Of Natural T Helper 17 Cells, Ji-Yeon Kim Jan 2012

Development And Regulation Of Natural T Helper 17 Cells, Ji-Yeon Kim

Publicly Accessible Penn Dissertations

CD4+ T helper (Th) cells are essential components of the adaptive immune system that orchestrate the immune response by producing a distinct array of cytokines specific to each subset. Th17 cells, the IL-17 producing subset of the CD4+ Th cell family, are critical for host defense again extracellular pathogens, especially at barrier and mucosal sites. Dysregulation of Th17 cells, meanwhile, leads to the pathogenesis of a number of autoimmune and inflammatory diseases, and modulating the development and/or function of these cells for therapeutic purposes are of great interest. The conventional paradigm dictated that all Th17 cells differentiate from naà ...