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Full-Text Articles in Medicine and Health Sciences
Herpes Simplex Virus And Interferon Signaling Induce Novel Autophagic Clusters In Sensory Neurons, Sarah Katzenell, David A. Leib
Herpes Simplex Virus And Interferon Signaling Induce Novel Autophagic Clusters In Sensory Neurons, Sarah Katzenell, David A. Leib
Dartmouth Scholarship
Herpes simplex virus 1 (HSV-1) establishes lifelong infection in the neurons of trigeminal ganglia (TG), cycling between productive infection and latency. Neuronal antiviral responses are driven by type I interferon (IFN) and are crucial to controlling HSV-1 virulence. Autophagy also plays a role in this neuronal antiviral response, but the mechanism remains obscure. In this study, HSV-1 infection of murine TG neurons triggered unusual clusters of autophagosomes, predominantly in neurons lacking detectable HSV-1 antigen. Treatment of neurons with IFN-β induced a similar response, and cluster formation by infection or IFN treatment was dependent upon an intact IFN-signaling pathway. The autophagic …
Cyclin-Dependent Kinase Inhibitor P1446a Induces Apoptosis In A Jnk/P38 Mapk-Dependent Manner In Chronic Lymphocytic Leukemia B-Cells, Cody Paiva, J. Claire Godbersen, Ryan S. Soderquist, Taylor Rowland, Sumner Kilmarx
Cyclin-Dependent Kinase Inhibitor P1446a Induces Apoptosis In A Jnk/P38 Mapk-Dependent Manner In Chronic Lymphocytic Leukemia B-Cells, Cody Paiva, J. Claire Godbersen, Ryan S. Soderquist, Taylor Rowland, Sumner Kilmarx
Dartmouth Scholarship
CDK (cyclin-dependent kinase) inhibitors have shown remarkable activity in CLL, where its efficacy has been linked to inhibition of the transcriptional CDKs (7 and 9) and deregulation of RNA polymerase and short-lived pro-survival proteins such as MCL1. Furthermore, ER (endoplasmic reticulum) stress has been implicated in CDK inhibition in CLL. Here we conducted a pre-clinical study of a novel orally active kinase inhibitor P1446A in CLL B-cells. P1446A inhibited CDKs at nanomolar concentrations and induced rapid apoptosis of CLL cells in vitro, irrespective of chromosomal abnormalities or IGHV mutational status. Apoptosis preceded inactivation of RNA polymerase, and was accompanied by …
Numerical Chromosomal Instability Mediates Susceptibility To Radiation Treatment, Samuel F. Bakhoum, Lilian Kabeche, Matthew D. Wood, Christopher D. Laucius
Numerical Chromosomal Instability Mediates Susceptibility To Radiation Treatment, Samuel F. Bakhoum, Lilian Kabeche, Matthew D. Wood, Christopher D. Laucius
Dartmouth Scholarship
The exquisite sensitivity of mitotic cancer cells to ionizing radiation (IR) underlies an important rationale for the widely used fractionated radiation therapy. However, the mechanism for this cell cycle-dependent vulnerability is unknown. Here we show that treatment with IR leads to mitotic chromosome segregation errors in vivo and long-lasting aneuploidy in tumour-derived cell lines. These mitotic errors generate an abundance of micronuclei that predispose chromosomes to subsequent catastrophic pulverization thereby independently amplifying radiation-induced genome damage. Experimentally suppressing whole-chromosome missegregation reduces downstream chromosomal defects and significantly increases the viability of irradiated mitotic cells. Further, orthotopically transplanted human glioblastoma tumours in which …
A Cysteine Zipper Stabilizes A Pre-Fusion F Glycoprotein Vaccine For Respiratory Syncytial Virus, Guillaume B. E. Stewart-Jones, Paul V. Thomas, Man Chen, Aliaksandr Druz, Gordon M. Joyce, Wing-Pui Kong, Mallika Sastry, Conque Soto, Yongping Yang, Baoshan Zhang, Lei Chen, Gwo-Yu Chuang, Ivelin S. Georgiev, Jason S. Mclellan
A Cysteine Zipper Stabilizes A Pre-Fusion F Glycoprotein Vaccine For Respiratory Syncytial Virus, Guillaume B. E. Stewart-Jones, Paul V. Thomas, Man Chen, Aliaksandr Druz, Gordon M. Joyce, Wing-Pui Kong, Mallika Sastry, Conque Soto, Yongping Yang, Baoshan Zhang, Lei Chen, Gwo-Yu Chuang, Ivelin S. Georgiev, Jason S. Mclellan
Dartmouth Scholarship
Recombinant subunit vaccines should contain minimal non-pathogen motifs to reduce potential off-target reactivity. We recently developed a vaccine antigen against respiratory syncytial virus (RSV), which comprised the fusion (F) glycoprotein stabilized in its pre-fusion trimeric conformation by “DS-Cav1” mutations and by an appended C-terminal trimerization motif or “foldon” from T4-bacteriophage fibritin. Here we investigate the creation of a cyste- ine zipper to allow for the removal of the phage foldon, while maintaining the immunogenic- ity of the parent DS-Cav1+foldon antigen. Constructs without foldon yielded RSV F monomers, and enzymatic removal of the phage foldon from pre-fusion F trimers resulted in …
Syndecan 4 Is Required For Endothelial Alignment In Flow And Atheroprotective Signaling, Nicolas Baeyens, Mary Jo Mulligan-Kehoe, Federico Corti, David D. Simon, Tyler D. Ross, John M. Rhodes, Thomas Z. Wang
Syndecan 4 Is Required For Endothelial Alignment In Flow And Atheroprotective Signaling, Nicolas Baeyens, Mary Jo Mulligan-Kehoe, Federico Corti, David D. Simon, Tyler D. Ross, John M. Rhodes, Thomas Z. Wang
Dartmouth Scholarship
Atherosclerotic plaque localization correlates with regions of disturbed flow in which endothelial cells (ECs) align poorly, whereas sustained laminar flow correlates with cell alignment in the direction of flow and resistance to atherosclerosis. We now report that in hypercholesterolemic mice, deletion of syndecan 4 (S4−/−) drastically increased atherosclerotic plaque burden with the appearance of plaque in normally resistant locations. Strikingly, ECs from the thoracic aortas of S4−/− mice were poorly aligned in the direction of the flow. Depletion of S4 in human umbilical vein endothelial cells (HUVECs) using shRNA also inhibited flow-induced alignment in vitro, which was rescued by re-expression …
Host Species Restriction Of Middle East Respiratory Syndrome Coronavirus Through Its Receptor, Dipeptidyl Peptidase 4, Neeltje Van Doremalen, Kerri L. Miazgowicz, Shauna Milne-Price, Trenton Bushmaker, Shelly Robertson, Dana Scott, Joerg Kinne, Jason S. Mclellan
Host Species Restriction Of Middle East Respiratory Syndrome Coronavirus Through Its Receptor, Dipeptidyl Peptidase 4, Neeltje Van Doremalen, Kerri L. Miazgowicz, Shauna Milne-Price, Trenton Bushmaker, Shelly Robertson, Dana Scott, Joerg Kinne, Jason S. Mclellan
Dartmouth Scholarship
Middle East respiratory syndrome coronavirus (MERS-CoV) emerged in 2012. Recently, the MERS-CoV receptor dipeptidyl peptidase 4 (DPP4) was identified and the specific interaction of the receptor-binding domain (RBD) of MERS-CoV spike protein and DPP4 was determined by crystallography. Animal studies identified rhesus macaques but not hamsters, ferrets, or mice to be susceptible for MERS-CoV. Here, we investigated the role of DPP4 in this observed species tropism. Cell lines of human and nonhuman primate origin were permissive of MERS-CoV, whereas hamster, ferret, or mouse cell lines were not, despite the presence of DPP4. Expression of human DPP4 in nonsusceptible BHK and …
Avirulent Strains Of Toxoplasma Gondii Infect Macrophages By Active Invasion From The Phagosome, Yanlin Zhao, Andrew H. Marple, David J. P. Ferguson, David J. Bzik, George S. Yap
Avirulent Strains Of Toxoplasma Gondii Infect Macrophages By Active Invasion From The Phagosome, Yanlin Zhao, Andrew H. Marple, David J. P. Ferguson, David J. Bzik, George S. Yap
Dartmouth Scholarship
Unlike most intracellular pathogens that gain access into host cells through endocytic pathways, Toxoplasma gondii initiates infection at the cell surface by active penetration through a moving junction and subsequent formation of a parasitophorous vacuole. Here, we describe a noncanonical pathway for T. gondii infection of macrophages, in which parasites are initially internalized through phagocytosis, and then actively invade from within a phagosomal compartment to form a parasitophorous vacuole. This phagosome to vacuole invasion (PTVI) pathway may represent an intermediary link between the endocytic and the penetrative routes for host cell entry by intracellular pathogens. The PTVI pathway is preferentially …
Integrated Assessment Of Predicted Mhc Binding And Cross-Conservation With Self Reveals Patterns Of Viral Camouflage, Lu He, Anne S. De Groot, Andres H. Gutierrez, William D. Martin, Lenny Moise, Chris Bailey-Kellogg
Integrated Assessment Of Predicted Mhc Binding And Cross-Conservation With Self Reveals Patterns Of Viral Camouflage, Lu He, Anne S. De Groot, Andres H. Gutierrez, William D. Martin, Lenny Moise, Chris Bailey-Kellogg
Dartmouth Scholarship
Immune recognition of foreign proteins by T cells hinges on the formation of a ternary complex sandwiching a constituent peptide of the protein between a major histocompatibility complex (MHC) molecule and a T cell receptor (TCR). Viruses have evolved means of "camouflaging" themselves, avoiding immune recognition by reducing the MHC and/or TCR binding of their constituent peptides. Computer-driven T cell epitope mapping tools have been used to evaluate the degree to which articular viruses have used this means of avoiding immune response, but most such analyses focus on MHC-facing ‘agretopes'. Here we set out a new means of evaluating the …
Attention Deficit Associated With Early Life Interictal Spikes In A Rat Model Is Improved With Acth, Amanda E. Hernan, Abigail Alexander, Pierre-Pascal Lenck-Santini, Rod C. Scott
Attention Deficit Associated With Early Life Interictal Spikes In A Rat Model Is Improved With Acth, Amanda E. Hernan, Abigail Alexander, Pierre-Pascal Lenck-Santini, Rod C. Scott
Dartmouth Scholarship
Children with epilepsy often present with pervasive cognitive and behavioral comorbidities including working memory impairments, attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder. These non-seizure characteristics are severely detrimental to overall quality of life. Some of these children, particularly those with epilepsies classified as Landau-Kleffner Syndrome or continuous spike and wave during sleep, have infrequent seizure activity but frequent focal epileptiform activity. This frequent epileptiform activity is thought to be detrimental to cognitive development; however, it is also possible that these IIS events initiate pathophysiological pathways in the developing brain that may be independently associated with cognitive deficits. These …
The Differential Interferon Responses Of Two Strains Of Stat1-Deficient Mice Do Not Alter Susceptibility To Hsv-1 And Vsv In Vivo, Sarah Katzenell, Yufei Chen, Zachary M. Parker, David A. Leib
The Differential Interferon Responses Of Two Strains Of Stat1-Deficient Mice Do Not Alter Susceptibility To Hsv-1 And Vsv In Vivo, Sarah Katzenell, Yufei Chen, Zachary M. Parker, David A. Leib
Dartmouth Scholarship
Stat1 is a pivotal transcription factor for generation of the interferon (IFN)-dependent antiviral response. Two Stat1 knockout mouse lines have been previously generated, one deleted the N-terminal domain (ΔNTD) and one in the DNA-binding domain (ΔDBD). These widely-used strains are assumed interchangeable, and both are highly susceptible to various pathogens. In this study, primary cells derived from ΔNTD mice were shown to be significantly more responsive to IFN, and established an antiviral state with greater efficiency than cells derived from ΔDBD mice, following infection with vesicular stomatitis virus and herpes simplex virus type-1. Also, while mice from both strains succumbed …
Sensitization Of Human Cancer Cells To Gemcitabine By The Chk1 Inhibitor Mk-8776: Cell Cycle Perturbation And Impact Of Administration Schedule In Vitro And In Vivo, Ryan Montano, Ruth Thompson, Injae Chung, Huagang Hou, Nadeem Khan, Alan Eastman
Sensitization Of Human Cancer Cells To Gemcitabine By The Chk1 Inhibitor Mk-8776: Cell Cycle Perturbation And Impact Of Administration Schedule In Vitro And In Vivo, Ryan Montano, Ruth Thompson, Injae Chung, Huagang Hou, Nadeem Khan, Alan Eastman
Dartmouth Scholarship
Chk1 inhibitors have emerged as promising anticancer therapeutic agents particularly when combined with antimetabolites such as gemcitabine, cytarabine or hydroxyurea. Here, we address the importance of appropriate drug scheduling when gemcitabine is combined with the Chk1 inhibitor MK-8776, and the mechanisms involved in the schedule dependence.
In Vivo Bioluminescence Imaging To Evaluate Systemic And Topical Antibiotics Against Community-Acquired Methicillin-Resistant Staphylococcus Aureus-Infected Skin Wounds In Mice, Yi Guo, Romela Irene Ramos, John S. Cho, Niles P. Donegan, Ambrose L. Cheung, Lloyd S. Miller
In Vivo Bioluminescence Imaging To Evaluate Systemic And Topical Antibiotics Against Community-Acquired Methicillin-Resistant Staphylococcus Aureus-Infected Skin Wounds In Mice, Yi Guo, Romela Irene Ramos, John S. Cho, Niles P. Donegan, Ambrose L. Cheung, Lloyd S. Miller
Dartmouth Scholarship
Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) frequently causes skin and soft tissue infections, including impetigo, cellulitis, folliculitis, and infected wounds and ulcers. Uncomplicated CA-MRSA skin infections are typically managed in an outpatient setting with oral and topical antibiotics and/or incision and drainage, whereas complicated skin infections often require hospitalization, intravenous antibiotics, and sometimes surgery. The aim of this study was to devel
Multi-Criteria Decision Analysis As An Innovative Approach To Managing Zoonoses: Results From A Study On Lyme Disease In Canada, Cécile Aenishaenslin, Valérie Hongoh, Hassane D. Cissé, Anne Gatewood Hoen
Multi-Criteria Decision Analysis As An Innovative Approach To Managing Zoonoses: Results From A Study On Lyme Disease In Canada, Cécile Aenishaenslin, Valérie Hongoh, Hassane D. Cissé, Anne Gatewood Hoen
Dartmouth Scholarship
ackground: Zoonoses are a growing international threat interacting at the human-animal-environment interface and call for transdisciplinary and multi-sectoral approaches in order to achieve effective disease management. The recent emergence of Lyme disease in Quebec, Canada is a good example of a complex health issue for which the public health sector must find protective interventions. Traditional preventive and control interventions can have important environmental, social and economic impacts and as a result, decision-making requires a systems approach capable of integrating these multiple aspects of interventions. This paper presents the results from a study of a multi-criteria decision analysis (MCDA) approach for …
Bioengineered Lysozyme Reduces Bacterial Burden And Inflammation In A Murine Model Of Mucoid Pseudomonas Aeruginosa Lung Infection, Charlotte C. Teneback, Thomas C. Scanlon, Matthew J. Wargo, Jenna L. Bement, Karl E. Griswold, Laurie W. Leclair
Bioengineered Lysozyme Reduces Bacterial Burden And Inflammation In A Murine Model Of Mucoid Pseudomonas Aeruginosa Lung Infection, Charlotte C. Teneback, Thomas C. Scanlon, Matthew J. Wargo, Jenna L. Bement, Karl E. Griswold, Laurie W. Leclair
Dartmouth Scholarship
The spread of drug-resistant bacterial pathogens is a growing global concern and has prompted an effort to explore potential adjuvant and alternative therapies derived from nature's repertoire of bactericidal proteins and peptides. In humans, the airway surface liquid layer is a rich source of antibiotics, and lysozyme represents one of the most abundant and effective antimicrobial components of airway secretions. Human lysozyme is active against both Gram-positive and Gram-negative bacteria, ac
Id4 Deficiency Attenuates Prostate Development And Promotes Pin-Like Lesions By Regulating Androgen Receptor Activity And Expression Of Nkx3.1 And Pten, Pankaj Sharma, Ashley Knowell, Swathi Chinaranagari, Shravan Komaragiri, Peri Nagappan, Divya Patel, Mathew C. Havrda, Jaideep Chaudhary
Id4 Deficiency Attenuates Prostate Development And Promotes Pin-Like Lesions By Regulating Androgen Receptor Activity And Expression Of Nkx3.1 And Pten, Pankaj Sharma, Ashley Knowell, Swathi Chinaranagari, Shravan Komaragiri, Peri Nagappan, Divya Patel, Mathew C. Havrda, Jaideep Chaudhary
Dartmouth Scholarship
Background: Inhibitor of differentiation 4 (Id4), a member of the helix-loop-helix family of transcriptional regulators has emerged as a tumor suppressor in prostate cancer. Id4 is expressed in the normal prostate where its expression is also regulated by androgens. In this study we investigated the effect of loss of Id4 (Id4-/-) on adult prostate morphology. Methods: Histological analysis was performed on prostates from 6-8 weeks old Id4-/-, Id4+/- and Id4+/+ mice. Expression of Id1, Sox9, Myc, androgen receptor, Akt, p-Akt, Pten and Nkx3.1 was investigated by immunohistochemistry. Androgen receptor binding on NKX3.1 promoter was studied by chromatin immuno-precipitation. Id4 was …
Cd4 And Cd8 T Cells Directly Recognize Murine Gammaherpesvirus 68-Immortalized Cells And Prevent Tumor Outgrowth, Xiaozhan Liang, Rebecca L. Crepeau, Weijun Zhang, Samuel H. Speck, Edward J. Usherwood
Cd4 And Cd8 T Cells Directly Recognize Murine Gammaherpesvirus 68-Immortalized Cells And Prevent Tumor Outgrowth, Xiaozhan Liang, Rebecca L. Crepeau, Weijun Zhang, Samuel H. Speck, Edward J. Usherwood
Dartmouth Scholarship
There has been extensive research regarding T cell recognition of Epstein-Barr virus-transformed cells; however, less is known regarding the recognition of B cells immortalized by gamma-2 herpesviruses. Here we show that B cells immortalized by murine gammaherpesvirus 68 (MHV-68, γHV-68) can be controlled by either CD4 or CD8 T cells in vivo. We present evidence for the direct recognition of infected B cells by CD4 and CD8 T cells. These data will help in the development of immunotherapeutic approaches combating gamma-2 herpesvirus-related disease.
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
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 …
Murine Gammaherpesvirus 68 Lana Acts On Terminal Repeat Dna To Mediate Episome Persistence, Aline C. Habison, Chantal Beauchemin, J. Pedro Simas, Edward J. Usherwood
Murine Gammaherpesvirus 68 Lana Acts On Terminal Repeat Dna To Mediate Episome Persistence, Aline C. Habison, Chantal Beauchemin, J. Pedro Simas, Edward J. Usherwood
Dartmouth Scholarship
Murine gammaherpesvirus 68 (MHV68) ORF73 (mLANA) has sequence homology to Kaposi’s sarcoma-associated herpesvirus (KSHV) latency-associated nuclear antigen (LANA). LANA acts on the KSHV terminal repeat (TR) elements to mediate KSHV episome maintenance. Disruption of mLANA expression severely reduces the ability of MHV68 to establish latent infection in mice, consistent with the possibility that mLANA mediates episome persistence. Here we assess the roles of mLANA and MHV68 TR (mTR) elements in episome persistence. mTR-associated DNA persisted as an episome in latently MHV68-infected tumor cells, demonstrating that the mTR elements can serve as a cis-acting element for MHV68 episome maintenance. In some …
Triterpenoid Modulation Of Il-17 And Nrf-2 Expression Ameliorates Neuroinflammation And Promotes Remyelination In Autoimmune Encephalomyelitis, Tej K. Pareek, Abdelmadjid Belkadi, Sashi Kesavapany, Anita Zaremba, Sook L. Loh, Lianhua Bai, Mark L. Cohen, Colin Meyer, Karen T. Liby, Robert H. Miller, Michael B. Sporn, John J. Letterio
Triterpenoid Modulation Of Il-17 And Nrf-2 Expression Ameliorates Neuroinflammation And Promotes Remyelination In Autoimmune Encephalomyelitis, Tej K. Pareek, Abdelmadjid Belkadi, Sashi Kesavapany, Anita Zaremba, Sook L. Loh, Lianhua Bai, Mark L. Cohen, Colin Meyer, Karen T. Liby, Robert H. Miller, Michael B. Sporn, John J. Letterio
Dartmouth Scholarship
Inflammatory cytokines and endogenous anti-oxidants are variables affecting disease progression in multiple sclerosis (MS). Here we demonstrate the dual capacity of triterpenoids to simultaneously repress production of IL-17 and other pro-inflammatory mediators while exerting neuroprotective effects directly through Nrf2-dependent induction of anti-oxidant genes. Derivatives of the natural triterpene oleanolic acid, namely CDDO-trifluoroethyl-amide (CDDO-TFEA), completely suppressed disease in a murine model of MS, experimental autoimmune encephalomyelitis (EAE), by inhibiting Th1 and Th17 mRNA and cytokine production. Encephalitogenic T cells recovered from treated mice were hypo-responsive to myelin antigen and failed to adoptively transfer the disease. Microarray analyses showed significant suppression of …
Β-Lactams Interfering With Pbp1 Induce Panton-Valentine Leukocidin Expression By Triggering Sara And Rot Global Regulators Of Staphylococcus Aureus, Oana Dumitrescu, Priya Choudhury, Sandrine Boisset, Cedric Badiou, Michele Bes, Yvonne Benito, Christiane Wolz, Francois Vandenesch, Jerome Etienne, Ambrose L. Cheung
Β-Lactams Interfering With Pbp1 Induce Panton-Valentine Leukocidin Expression By Triggering Sara And Rot Global Regulators Of Staphylococcus Aureus, Oana Dumitrescu, Priya Choudhury, Sandrine Boisset, Cedric Badiou, Michele Bes, Yvonne Benito, Christiane Wolz, Francois Vandenesch, Jerome Etienne, Ambrose L. Cheung
Dartmouth Scholarship
Previous articles reported that beta-lactam antibiotics increase the expression of Staphylococcus aureus Panton-Valentine leukocidin (PVL) by activating its transcription. We investigated the mechanisms underlying the inductor effect of beta-lactams on PVL expression by determining targets and regulatory pathways possibly implicated in this process. We measured PVL production in the presence of oxacillin (nonselective), imipenem (penicillin-binding protein 1 [PBP1] selective), cefotaxime (PBP2 s
Harnessing The Effect Of Adoptively Transferred Tumor-Reactive T Cells On Endogenous (Host-Derived) Antitumor Immunity, Yolanda Nesbeth, Jose R. Conejo-Garcia
Harnessing The Effect Of Adoptively Transferred Tumor-Reactive T Cells On Endogenous (Host-Derived) Antitumor Immunity, Yolanda Nesbeth, Jose R. Conejo-Garcia
Dartmouth Scholarship
Adoptive T cell transfer therapy, the ex vivo activation, expansion, and subsequent administration of tumor-reactive T cells, is already the most effective therapy against certain types of cancer. However, recent evidence in animal models and clinical trials suggests that host conditioning interventions tailored for some of the most aggressive and frequent epithelial cancers will be needed to maximize the benefit of this approach. Similarly, the subsets, stage of differentiation, and ex vivo expansion procedure of tumor-reactive T cells to be adoptively transferred influence their in vivo effectiveness and may need to be adapted for different types of cancer and host …
Proliferation Of Aneuploid Human Cells Is Limited By A P53-Dependent Mechanism, Sarah L. Thompson, Duane A. Compton
Proliferation Of Aneuploid Human Cells Is Limited By A P53-Dependent Mechanism, Sarah L. Thompson, Duane A. Compton
Dartmouth Scholarship
Most solid tumors are aneuploid, and it has been proposed that aneuploidy is the consequence of an elevated rate of chromosome missegregation in a process called chromosomal instability (CIN). However, the relationship of aneuploidy and CIN is unclear because the proliferation of cultured diploid cells is compromised by chromosome missegregation. The mechanism for this intolerance of nondiploid genomes is unknown. In this study, we show that in otherwise diploid human cells, chromosome missegregation causes a cell cycle delay with nuclear accumulation of the tumor suppressor p53 and the cyclin kinase inhibitor p21. Deletion of the p53 gene permits the accumulation …
Paracrine Sonic Hedgehog Signalling By Prostate Cancer Cells Induces Osteoblast Differentiation, Samantha M Zunich, Taneka Douglas, Maria Valdovinos, Tiffany Chang
Paracrine Sonic Hedgehog Signalling By Prostate Cancer Cells Induces Osteoblast Differentiation, Samantha M Zunich, Taneka Douglas, Maria Valdovinos, Tiffany Chang
Dartmouth Scholarship
Sonic hedgehog (Shh) and components of its signalling pathway have been identified in human prostate carcinoma and increased levels of their expression appear to correlate with disease progression and metastasis. The mechanism through which Shh signalling could promote metastasis in bone, the most common site for prostate carcinoma metastasis, has not yet been investigated. The present study determined the effect of Shh signalling between prostate cancer cells and pre-osteoblasts on osteoblast differentiation, a requisite process for new bone formation that characterizes prostate carcinoma metastasis.
Accumulation Of Rhodopsin In Late Endosomes Triggers Photoreceptor Cell Degeneration, Yashodhan Chinchore, Amitavo Mitra, Patrick J. Dolph, Norbert Perrimon
Accumulation Of Rhodopsin In Late Endosomes Triggers Photoreceptor Cell Degeneration, Yashodhan Chinchore, Amitavo Mitra, Patrick J. Dolph, Norbert Perrimon
Dartmouth Scholarship
Progressive retinal degeneration is the underlying feature of many human retinal dystrophies. Previous work using Drosophila as a model system and analysis of specific mutations in human rhodopsin have uncovered a connection between rhodopsin endocytosis and retinal degeneration. In these mutants, rhodopsin and its regulatory protein arrestin form stable complexes, and endocytosis of these complexes causes photoreceptor cell death. In this study we show that the internalized rhodopsin is not degraded in the lysosome but instead accumulates in the late endosomes. Using mutants that are defective in late endosome to lysosome trafficking, we were able to show that rhodopsin accumulates …
Programmed Death 1 Ligand Signaling Regulates The Generation Of Adaptive Foxp3+Cd4+ Regulatory T Cells, Li Wang, Kirina Pino-Lagos, Victor C. De Vries, Indira Guleria, Mohamed H. Sayegh, Randolph J. Noelle
Programmed Death 1 Ligand Signaling Regulates The Generation Of Adaptive Foxp3+Cd4+ Regulatory T Cells, Li Wang, Kirina Pino-Lagos, Victor C. De Vries, Indira Guleria, Mohamed H. Sayegh, Randolph J. Noelle
Dartmouth Scholarship
Although mature dendritic cells (DCs) are potent initiators of adaptive immune response, immature steady-state DCs contribute to immune tolerance. In this study, we show that ex vivo splenic DCs are capable of inducing conversion of naïve CD4(+) T cells to adaptive Foxp3(+)CD4(+) regulatory T cells (aTreg) in the presence of TGF-beta. In particular, when compared with splenic CD8alpha(-) DCs, the CD8alpha(+) DC subset were superior in inducing higher frequencies of conversion. This was not attributable to the difference in basal level of costimulation, because deficiency of CD40 or CD80/86 signaling did not diminish the differential induction of Foxp3. Conversion was …
The Nestin Progenitor Lineage Is The Compartment Of Origin For Pancreatic Intraepithelial Neoplasia, Catherine Carriere, Elliot S. Seeley, Tobias Goetze, Daniel S. Longnecker, Murray Korc
The Nestin Progenitor Lineage Is The Compartment Of Origin For Pancreatic Intraepithelial Neoplasia, Catherine Carriere, Elliot S. Seeley, Tobias Goetze, Daniel S. Longnecker, Murray Korc
Dartmouth Scholarship
To determine the cell compartment in which initial oncogenic mutations occur in pancreatic ductal adenocarcinoma (PDAC), we generated a mouse model in which endogenous expression of mutated Kras (Kras(G12D)) was initially directed to a population of pancreatic exocrine progenitors characterized by the expression of Nestin. Targeting of oncogenic Kras to such a restricted cell compartment was sufficient for the formation of pancreatic intraepithelial neoplasias (PanINs), putative precursors to PDAC. PanINs appeared with the same grade and frequency as observed when Kras(G12D) was targeted to the whole pancreas by a Pdx1-driven Cre recombinase strategy. Thus, the Nestin cell lineage is highly …
Transgenic Cyclin E Triggers Dysplasia And Multiple Pulmonary Adenocarcinomas, Yan Ma, Steven Fiering, Candice Black, Xi Liu, Ziqiang Yuan, Vincent A. Memoli, David J. Robbins, Heather A. Bentley, Gregory J. Tsongalis, Eugene Demidenko, Sarah J. Freemantle, Ethan Dmitrovsky
Transgenic Cyclin E Triggers Dysplasia And Multiple Pulmonary Adenocarcinomas, Yan Ma, Steven Fiering, Candice Black, Xi Liu, Ziqiang Yuan, Vincent A. Memoli, David J. Robbins, Heather A. Bentley, Gregory J. Tsongalis, Eugene Demidenko, Sarah J. Freemantle, Ethan Dmitrovsky
Dartmouth Scholarship
Cyclin E is a critical G(1)-S cell cycle regulator aberrantly expressed in bronchial premalignancy and lung cancer. Cyclin E expression negatively affects lung cancer prognosis. Its role in lung carcinogenesis was explored. Retroviral cyclin E transduction promoted pulmonary epithelial cell growth, and small interfering RNA targeting of cyclin E repressed this growth. Murine transgenic lines were engineered to mimic aberrant cyclin E expression in the lung. Wild-type and proteasome degradation-resistant human cyclin E transgenic lines were independently driven by the human surfactant C (SP-C) promoter. Chromosome instability (CIN), pulmonary dysplasia, sonic hedgehog (Shh) pathway activation, adenocarcinomas, and metastases occurred. Notably, …
Cdx4 Dysregulates Hox Gene Expression And Generates Acute Myeloid Leukemia Alone And In Cooperation With Meis1a In A Murine Model, Dimple Bansal, Claudia Scholl, Stefan Frohling, Elizabeth Mcdowell, Benjamin H. Lee, Konstanze Döhner, Patricia Ernst
Cdx4 Dysregulates Hox Gene Expression And Generates Acute Myeloid Leukemia Alone And In Cooperation With Meis1a In A Murine Model, Dimple Bansal, Claudia Scholl, Stefan Frohling, Elizabeth Mcdowell, Benjamin H. Lee, Konstanze Döhner, Patricia Ernst
Dartmouth Scholarship
HOX genes have emerged as critical effectors of leukemogenesis, but the mechanisms that regulate their expression in leukemia are not well understood. Recent data suggest that the caudal homeobox transcription factors CDX1, CDX2, and CDX4, developmental regulators of HOX gene expression, may contribute to HOX gene dysregulation in leukemia. We report here that CDX4 is expressed normally in early hematopoietic progenitors and is expressed aberrantly in approximately 25% of acute myeloid leukemia (AML) patient samples. Cdx4 regulates Hox gene expression in the adult murine hematopoietic system and dysregulates Hox genes that are implicated in leukemogenesis. Furthermore, bone marrow progenitors that …
Lack Of Il-15 Results In The Suboptimal Priming Of Cd4+ T Cell Response Against An Intracellular Parasite, Crescent L. Combe, Magali M. Moretto, Joseph D. Schwartzman, Jason P. Gigley, David J. Bzik, Imtiaz A. Khan
Lack Of Il-15 Results In The Suboptimal Priming Of Cd4+ T Cell Response Against An Intracellular Parasite, Crescent L. Combe, Magali M. Moretto, Joseph D. Schwartzman, Jason P. Gigley, David J. Bzik, Imtiaz A. Khan
Dartmouth Scholarship
IFN-gamma-producing CD4+ T cells, although important for protection against acute Toxoplasma gondii infection, can cause gut pathology, which may prove to be detrimental for host survival. Here we show that mice lacking IL-15 gene develop a down-regulated IFN-gamma-producing CD4+ T cell response against the parasite, which leads to a reduction in gut necrosis and increased level of survival against infection. Moreover, transfer of immune CD4+ T cells from WT to IL-15-/- mice reversed inhibition of gut pathology and caused mortality equivalent to levels of parental WT mice. Down-regulated CD4+ T cell response in the absence of IL-15, manifested as reduced …
A Novel Triterpenoid Induces Transforming Growth Factor Β Production By Intraepithelial Lymphocytes To Prevent Ileitis, Laurie A. Minns, Dominique Buzoni-Gatel, Kenneth H. Ely, Nicolas Rachinel, Souphalone Luangsay, Lloyd H. Kasper
A Novel Triterpenoid Induces Transforming Growth Factor Β Production By Intraepithelial Lymphocytes To Prevent Ileitis, Laurie A. Minns, Dominique Buzoni-Gatel, Kenneth H. Ely, Nicolas Rachinel, Souphalone Luangsay, Lloyd H. Kasper
Dartmouth Scholarship
The loss of homeostasis is a hallmark of inflammatory bowel disease. Oral infection of susceptible mice with Toxoplasma gondii results in an acute lethal ileitis characterized by increased interferon γ, tumor necrosis factor α, and inducible nitric oxide synthase; homeostasis results from transforming growth factor β production by intraepithelial lymphocytes. The synthetic oleanane triterpenoid 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid (CDDO) is a potent anti-inflammatory molecule previously shown in vitro to suppress the de novo synthesis of inducible nitric oxide synthase and to induce the transcription and activation of genes from the transforming growth factor β signaling pathway. We evaluated the immune response in …