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Malaria And Related Outcomes In Patients With Intestinal Helminths: A Cross-Sectional Study, Abraham Degarege, Mengistu Legesse, Girmay Medhin, Abebe Animut, Berhanu Erko Jan 2012

Malaria And Related Outcomes In Patients With Intestinal Helminths: A Cross-Sectional Study, Abraham Degarege, Mengistu Legesse, Girmay Medhin, Abebe Animut, Berhanu Erko

Journal Articles: Epidemiology

BACKGROUND: The effects of helminth co-infection on malaria in humans remain uncertain. This study aimed to evaluate the nature of association of intestinal helminths with prevalence and clinical outcomes of Plasmodium infection.

METHODS: A cross-sectional study involving 1,065 malaria suspected febrile patients was conducted at Dore Bafeno Health Center, Southern Ethiopia, from December 2010 to February 2011. Plasmodium and intestinal helminth infections were diagnosed using Giemsa-stained blood films and Kato-Katz technique, respectively. Haemoglobin level was determined using a haemocue machine.

RESULTS: Among 1,065 malaria suspected febrile patients, 28.8% were positive for Plasmodium parasites (P. falciparum =13.0%, P. vivax =14.5%, P. …


Nutrition, Inflammation, And Infectious Disease, Helieh S. Oz, Sung-Ling Yeh Jan 2012

Nutrition, Inflammation, And Infectious Disease, Helieh S. Oz, Sung-Ling Yeh

Physiology Faculty Publications

No abstract provided.


Methamphetamine Administration Targets Multiple Immune Subsets And Induces Phenotypic Alterations Suggestive Of Immunosuppression., Robert Z. Harms, Brenda M. Morsey, Craig W. Boyer, Howard S. Fox, Nora E. Sarvetnick Jan 2012

Methamphetamine Administration Targets Multiple Immune Subsets And Induces Phenotypic Alterations Suggestive Of Immunosuppression., Robert Z. Harms, Brenda M. Morsey, Craig W. Boyer, Howard S. Fox, Nora E. Sarvetnick

Journal Articles: Regenerative Medicine

Methamphetamine (Meth) is a widely abused stimulant and its users are at increased risk for multiple infectious diseases. To determine the impact of meth on the immune system, we utilized a murine model that simulates the process of meth consumption in a typical addict. Our phenotypic analysis of leukocytes from this dose escalation model revealed that meth affected key immune subsets. Meth administration led to a decrease in abundance of natural killer (NK) cells and the remaining NK cells possessed a phenotype suggesting reduced responsiveness. Dendritic cells (DCs) and Gr-1(high) monocytes/macrophages were also decreased in abundance while Gr-1(low) monocytes/macrophages appear …


There Is No Evidence For A Temporal Link Between Pathogen Arrival And Frog Extinctions In North-Eastern Australia., Ben L. Phillips, Robert Puschendorf, Jeremy Vanderwal, Ross A. Alford Jan 2012

There Is No Evidence For A Temporal Link Between Pathogen Arrival And Frog Extinctions In North-Eastern Australia., Ben L. Phillips, Robert Puschendorf, Jeremy Vanderwal, Ross A. Alford

School of Biological and Marine Sciences

Pathogen spread can cause population declines and even species extinctions. Nonetheless, in the absence of tailored monitoring schemes, documenting pathogen spread can be difficult. In the case of worldwide amphibian declines the best present understanding is that the chytrid fungus Batrachochytrium dendrobatidis (Bd) has recently spread, causing amphibian declines and extinction in the process. However, good evidence demonstrating pathogen arrival followed by amphibian decline is rare, and analysis of putative evidence is often inadequate. Here we attempt to examine the relationship between Bd arrival and amphibian decline across north-eastern Australia, using sites where a wave-like pattern of amphibian decline was …


Functional Genomics Reveals An Essential And Specific Role For Stat1 In Protection Of The Central Nervous System Following Herpes Simplex Virus Corneal Infection, Tracy J. Pasieka, Cristian Cilloniz, Victoria S. Carter, Pamela Rosato, Michael G. Katze, David A. Leib Dec 2011

Functional Genomics Reveals An Essential And Specific Role For Stat1 In Protection Of The Central Nervous System Following Herpes Simplex Virus Corneal Infection, Tracy J. Pasieka, Cristian Cilloniz, Victoria S. Carter, Pamela Rosato, Michael G. Katze, David A. Leib

Dartmouth Scholarship

Innate immune deficiencies result in a spectrum of severe clinical outcomes following infection. In particular, there is a strong association between loss of the signal transducer and activator of transcription (Stat) pathway, breach of the blood-brain barrier (BBB), and virus-induced neuropathology. The gene signatures that characterize resistance, disease, and mortality in the virus-infected nervous system have not been defined. Herpes simplex virus type 1 (HSV-1) is commonly associated with encephalitis in humans, and humans and mice lacking Stat1 display increased susceptibility to HSV central nervous system (CNS) infections. In this study, two HSV-1 strains were used, KOS (wild type [WT]), …


Innate And Adaptive Immunity To The Nematode Strongyloides Stercoralis In A Mouse Model., Sandra Bonne-Annee, Jessica A. Hess, David Abraham Nov 2011

Innate And Adaptive Immunity To The Nematode Strongyloides Stercoralis In A Mouse Model., Sandra Bonne-Annee, Jessica A. Hess, David Abraham

Department of Microbiology and Immunology Faculty Papers

Mice have been used to the study the mechanisms of protective innate and adaptive immunity to larval Strongyloides stercoralis. During primary infection, neutrophils and eosinophils are attracted by parasite components and kill the larvae by release of granule products. Eosinophils also function as antigen-presenting cells for the induction of a Th2 response. B cells produce both IgM and IgG that collaborate with neutrophils to kill worms in the adaptive immune response. Vaccine studies have identified a recombinant diagnostic antigen that induced high levels of immunity to infection with S. stercoralis in mice. These studies demonstrate that there are redundancies in …


Immunization With The Recombinant Antigen Ss-Ir Induces Protective Immunity To Infection With Strongyloides Stercoralis In Mice., David Abraham, Jessica A. Hess, Rojelio Mejia, Thomas J. Nolan, James B. Lok, Sara Lustigman, Thomas B. Nutman Oct 2011

Immunization With The Recombinant Antigen Ss-Ir Induces Protective Immunity To Infection With Strongyloides Stercoralis In Mice., David Abraham, Jessica A. Hess, Rojelio Mejia, Thomas J. Nolan, James B. Lok, Sara Lustigman, Thomas B. Nutman

Department of Microbiology and Immunology Faculty Papers

Human intestinal infections with the nematode Strongyloides stercoralis remain a significant problem worldwide and a vaccine would be a useful addition to the tools available to prevent and control this infection. The goal of this study was to test single antigens for their efficacy in a vaccine against S. stercoralis larvae in mice. Alum was used as the adjuvant in these studies and antigens selected for analysis were either recognized by protective human IgG (Ss-TMY-1, Ss-EAT-6, and Ss-LEC-5) or were known to be highly immunogenic in humans (Ss-NIE-1 and Ss-IR). Only mice immunized with the Ss-IR antigen demonstrated a significant …


Proliferating Cell Nuclear Antigen Is Required For Loading Of The Smcx/Kmd5c Histone Demethylase Onto Chromatin., Zhihui Liang, Marc Diamond, Johanna A Smith, Matthias Schnell, René Daniel Oct 2011

Proliferating Cell Nuclear Antigen Is Required For Loading Of The Smcx/Kmd5c Histone Demethylase Onto Chromatin., Zhihui Liang, Marc Diamond, Johanna A Smith, Matthias Schnell, René Daniel

Department of Medicine Faculty Papers

UNLABELLED: ABSTRACT:

BACKGROUND: Histone methylation is regulated by a large number of histone methyltransferases and demethylases. The recently discovered SMCX/KMD5C demethylase has been shown to remove methyl residues from lysine 4 of histone H3 (H3K4), and constitutes an important component of the regulatory element-1-silencing transcription factor (REST) protein complex. However, little is known about the cellular mechanisms that control SMCX activity and intracellular trafficking.

RESULTS: In this study, we found that small interfering RNA-mediated knockdown of proliferating cell nuclear antigen (PCNA) resulted in the reduction of the chromatin-bound SMCX fraction. We identified a PCNA-interaction protein motif (PIP box) in the …


Human Glial-Restricted Progenitor Transplantation Into Cervical Spinal Cord Of The Sod1 Mouse Model Of Als., Angelo C Lepore, John O'Donnell, Andrew S Kim, Timothy Williams, Alicia Tuteja, Mahendra S Rao, Linda L Kelley, James T Campanelli, Nicholas J Maragakis Oct 2011

Human Glial-Restricted Progenitor Transplantation Into Cervical Spinal Cord Of The Sod1 Mouse Model Of Als., Angelo C Lepore, John O'Donnell, Andrew S Kim, Timothy Williams, Alicia Tuteja, Mahendra S Rao, Linda L Kelley, James T Campanelli, Nicholas J Maragakis

Department of Neuroscience Faculty Papers

Cellular abnormalities are not limited to motor neurons in amyotrophic lateral sclerosis (ALS). There are numerous observations of astrocyte dysfunction in both humans with ALS and in SOD1(G93A) rodents, a widely studied ALS model. The present study therapeutically targeted astrocyte replacement in this model via transplantation of human Glial-Restricted Progenitors (hGRPs), lineage-restricted progenitors derived from human fetal neural tissue. Our previous findings demonstrated that transplantation of rodent-derived GRPs into cervical spinal cord ventral gray matter (in order to target therapy to diaphragmatic function) resulted in therapeutic efficacy in the SOD1(G93A) rat. Those findings demonstrated the feasibility and efficacy of transplantation-based …


Protective Cd8 Memory T Cell Responses To Mouse Melanoma Are Generated In The Absence Of Cd4 T Cell Help, Anik L. Côté, Katelyn T. Byrne, Shannon M. Steinberg, Peisheng Zhang, Mary Jo Turk Oct 2011

Protective Cd8 Memory T Cell Responses To Mouse Melanoma Are Generated In The Absence Of Cd4 T Cell Help, Anik L. Côté, Katelyn T. Byrne, Shannon M. Steinberg, Peisheng Zhang, Mary Jo Turk

Dartmouth Scholarship

Background: We have previously demonstrated that temporary depletion of CD4 T cells in mice with progressive B16 melanoma, followed by surgical tumor excision, induces protective memory CD8 T cell responses to melanoma/melanocyte antigens. We also showed that persistence of these CD8 T cells is supported, in an antigen-dependent fashion, by concurrent autoimmune melanocyte destruction. Herein we explore the requirement of CD4 T cell help in priming and maintaining this protective CD8 T cell response to melanoma.


Ecology And Genetic Structure Of A Northern Temperate Vibrio Cholerae Population Related To Toxigenic Isolates, Brian M. Schuster, Anna L. Tyzik, Rachel A. Donner, Megan J. Striplin, Salvador Almagro-Moreno Sep 2011

Ecology And Genetic Structure Of A Northern Temperate Vibrio Cholerae Population Related To Toxigenic Isolates, Brian M. Schuster, Anna L. Tyzik, Rachel A. Donner, Megan J. Striplin, Salvador Almagro-Moreno

Dartmouth Scholarship

Although Vibrio cholerae is an important human pathogen, little is known about its populations in regions where the organism is endemic but where cholera disease is rare. A total of 31 independent isolates confirmed as V. cholerae were collected from water, sediment, and oysters in 2008 and 2009 from the Great Bay Estuary (GBE) in New Hampshire, a location where the organism has never been detected. Environmental analyses suggested that abundance correlates most strongly with rainfall events, as determined from data averaged over several days prior to collection. Phenotyping, genotyping, and multilocus sequence analysis (MLSA) revealed a highly diverse endemic …


Bioluminescent Imaging Reveals Divergent Viral Pathogenesis In Two Strains Of Stat1-Deficient Mice, And In Αßγ Interferon Receptor-Deficient Mice, Tracy Jo Pasieka, Lynne Collins, Megan A. O'Connor, Yufei Chen, Zachary M. Parker, Brent L. Berwin, David R. Piwnica-Worms, David A. Leib Sep 2011

Bioluminescent Imaging Reveals Divergent Viral Pathogenesis In Two Strains Of Stat1-Deficient Mice, And In Αßγ Interferon Receptor-Deficient Mice, Tracy Jo Pasieka, Lynne Collins, Megan A. O'Connor, Yufei Chen, Zachary M. Parker, Brent L. Berwin, David R. Piwnica-Worms, David A. Leib

Dartmouth Scholarship

Pivotal components of the IFN response to virus infection include the IFN receptors (IFNR), and the downstream factorsignal transducer and activator of transcription 1 (Stat1). Mice deficient for Stat1 and IFNR (Stat12/2 and IFNaßcR2/2 mice) lack responsiveness to IFN and exhibit high sensitivity to various pathogens. Here we examined herpes simplex virus type 1 (HSV-1) pathogenesis in Stat12/2 mice and in IFNaßcR2/2 mice following corneal infection and bioluminescent imaging. Two divergent and paradoxical patterns of infection were observed. Mice with an N-terminal deletion in Stat1 (129Stat12/2(N-term)) had transient infection of the liver and spleen, but succumbed to encephalitis by day …


Altered Toll-Like Receptor 2-Mediated Endotoxin Tolerance Is Related To Diminished Interferon Beta Production., Ss Zaric, Wa Coulter, Ce Shelburne, Cr Fulton, Ms Zaric, A Scott, Mj Lappin, Dc Fitzgerald, Cr Irwin, Cc Taggart Aug 2011

Altered Toll-Like Receptor 2-Mediated Endotoxin Tolerance Is Related To Diminished Interferon Beta Production., Ss Zaric, Wa Coulter, Ce Shelburne, Cr Fulton, Ms Zaric, A Scott, Mj Lappin, Dc Fitzgerald, Cr Irwin, Cc Taggart

Peninsula Dental School

Induction of endotoxin tolerance leads to a reduced inflammatory response after repeated challenge by LPS and is important for resolution of inflammation and prevention of tissue damage. Enterobacterial LPS is recognized by the TLR4 signaling complex, whereas LPS of some non-enterobacterial organisms is capable of signaling independently of TLR4 utilizing TLR2-mediated signal transduction instead. In this study we report that Porphyromonas gingivalis LPS, a TLR2 agonist, fails to induce a fully endotoxin tolerant state in a human monocytic cell line (THP-1) and mouse bone marrow-derived macrophages. In contrast to significantly decreased production of human IL-8 and TNF-α and, in mice, …


Profound Early Control Of Highly Pathogenic Siv By An Effector Memory T-Cell Vaccine., Scott G. Hansen, Julia C. Ford, Matthew S. Lewis, Abigail B. Ventura, Colette M. Hughes, Lia Coyne-Johnson, Nathan Whizin, Kelli Oswald, Rebecca Shoemaker, Tonya Swanson, Alfred W. Legasse, Maria J. Chiuchiolo, Christopher L. Parks, Michael K. Axthelm, Jay A. Nelson, Michael A. Jarvis, Michael Piatak, Jeffrey D. Lifson, Louis J. Picker May 2011

Profound Early Control Of Highly Pathogenic Siv By An Effector Memory T-Cell Vaccine., Scott G. Hansen, Julia C. Ford, Matthew S. Lewis, Abigail B. Ventura, Colette M. Hughes, Lia Coyne-Johnson, Nathan Whizin, Kelli Oswald, Rebecca Shoemaker, Tonya Swanson, Alfred W. Legasse, Maria J. Chiuchiolo, Christopher L. Parks, Michael K. Axthelm, Jay A. Nelson, Michael A. Jarvis, Michael Piatak, Jeffrey D. Lifson, Louis J. Picker

School of Biomedical Sciences

The acquired immunodeficiency syndrome (AIDS)-causing lentiviruses human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) effectively evade host immunity and, once established, infections with these viruses are only rarely controlled by immunological mechanisms. However, the initial establishment of infection in the first few days after mucosal exposure, before viral dissemination and massive replication, may be more vulnerable to immune control. Here we report that SIV vaccines that include rhesus cytomegalovirus (RhCMV) vectors establish indefinitely persistent, high-frequency, SIV-specific effector memory T-cell (T(EM)) responses at potential sites of SIV replication in rhesus macaques and stringently control highly pathogenic SIV(MAC239) infection early after …


Microarray-Based Analysis Of Differential Gene Expression Between Infective And Noninfective Larvae Of Strongyloides Stercoralis., Roshan Ramanathan, Sudhir Varma, José M C Ribeiro, Timothy G Myers, Thomas J Nolan, David Abraham, James B Lok, Thomas B Nutman May 2011

Microarray-Based Analysis Of Differential Gene Expression Between Infective And Noninfective Larvae Of Strongyloides Stercoralis., Roshan Ramanathan, Sudhir Varma, José M C Ribeiro, Timothy G Myers, Thomas J Nolan, David Abraham, James B Lok, Thomas B Nutman

Department of Microbiology and Immunology Faculty Papers

BACKGROUND: Differences between noninfective first-stage (L1) and infective third-stage (L3i) larvae of parasitic nematode Strongyloides stercoralis at the molecular level are relatively uncharacterized. DNA microarrays were developed and utilized for this purpose.

METHODS AND FINDINGS: Oligonucleotide hybridization probes for the array were designed to bind 3,571 putative mRNA transcripts predicted by analysis of 11,335 expressed sequence tags (ESTs) obtained as part of the Nematode EST project. RNA obtained from S. stercoralis L3i and L1 was co-hybridized to each array after labeling the individual samples with different fluorescent tags. Bioinformatic predictions of gene function were developed using a novel cDNA Annotation …


Enhanced Neutralization Potency Of Botulinum Neurotoxin Antibodies Using A Red Blood Cell-Targeting Fusion Protein., Sharad P Adekar, Andrew T Segan, Cindy Chen, Rodney Bermudez, M D Elias, Bernard H Selling, B P Kapadnis, Lance L Simpson, Paul M Simon, Scott K Dessain Mar 2011

Enhanced Neutralization Potency Of Botulinum Neurotoxin Antibodies Using A Red Blood Cell-Targeting Fusion Protein., Sharad P Adekar, Andrew T Segan, Cindy Chen, Rodney Bermudez, M D Elias, Bernard H Selling, B P Kapadnis, Lance L Simpson, Paul M Simon, Scott K Dessain

Division of Infectious Diseases and Environmental Medicine Faculty Papers

Botulinum neurotoxin (BoNT) potently inhibits cholinergic signaling at the neuromuscular junction. The ideal countermeasures for BoNT exposure are monoclonal antibodies or BoNT antisera, which form BoNT-containing immune complexes that are rapidly cleared from the general circulation. Clearance of opsonized toxins may involve complement receptor-mediated immunoadherence to red blood cells (RBC) in primates or to platelets in rodents. Methods of enhancing immunoadherence of BoNT-specific antibodies may increase their potency in vivo. We designed a novel fusion protein (FP) to link biotinylated molecules to glycophorin A (GPA) on the RBC surface. The FP consists of an scFv specific for murine GPA fused …


Aspirin Treatment Of Mice Infected With Trypanosoma Cruzi And Implications For The Pathogenesis Of Chagas Disease, Shankar Mukherjee, Fabiana S. Machado, Huang Huang, Helieh S. Oz, Linda A. Jelicks, Cibele M. Prado, Wade Koba, Eugene J. Fine, Dazhi Zhao, Stephen M. Factor, J. Elias Collado, Louis M. Weiss, Herbert B. Tanowitz, Anthony W. Ashton Feb 2011

Aspirin Treatment Of Mice Infected With Trypanosoma Cruzi And Implications For The Pathogenesis Of Chagas Disease, Shankar Mukherjee, Fabiana S. Machado, Huang Huang, Helieh S. Oz, Linda A. Jelicks, Cibele M. Prado, Wade Koba, Eugene J. Fine, Dazhi Zhao, Stephen M. Factor, J. Elias Collado, Louis M. Weiss, Herbert B. Tanowitz, Anthony W. Ashton

Center for Oral Health Research Faculty Publications

Chagas disease, caused by infection with Trypanosoma cruzi, is an important cause of cardiovascular disease. It is increasingly clear that parasite-derived prostaglandins potently modulate host response and disease progression. Here, we report that treatment of experimental T. cruzi infection (Brazil strain) beginning 5 days post infection (dpi) with aspirin (ASA) increased mortality (2-fold) and parasitemia (12-fold). However, there were no differences regarding histopathology or cardiac structure or function. Delayed treatment with ASA (20 mg/kg) beginning 60 dpi did not increase parasitemia or mortality but improved ejection fraction. ASA treatment diminished the profile of parasite- and host-derived circulating prostaglandins in infected …


Impaired Memory Cd8 T-Cell Responses Against An Immunodominant Retroviral Cryptic Epitope, Melanie R. Rutkowski, Cynthia A. Stevens, William R. Green Feb 2011

Impaired Memory Cd8 T-Cell Responses Against An Immunodominant Retroviral Cryptic Epitope, Melanie R. Rutkowski, Cynthia A. Stevens, William R. Green

Dartmouth Scholarship

The immunodominant cryptic epitope SYNTGRFPPL, encoded within open reading frame 2 of the LP-BM5 retroviral gag gene, is critical for protection against retroviral-induced pathogenesis. The goal of this study was to dissect the memory response against this unique immunodominant cryptic epitope. Unlike the protective acute effector population of SYNTGRFPPL-specific CD8 T cells, long-lived SYNTGRFPPL-specific CD8 T cells lacked the ability to protect susceptible mice infected with LP-BM5 retrovirus. Compared to memory CD8 T cells against a conventional epitope with similar MHC-I specificity, primed and restimulated using similar conditions, long-lived SYNTGRFPPL-specific CD8 T cells were impaired in their ability to recall …


Animal Models For Periodontal Disease, Helieh S. Oz, David A. Puleo Jan 2011

Animal Models For Periodontal Disease, Helieh S. Oz, David A. Puleo

Center for Oral Health Research Faculty Publications

Animal models and cell cultures have contributed new knowledge in biological sciences, including periodontology. Although cultured cells can be used to study physiological processes that occur during the pathogenesis of periodontitis, the complex host response fundamentally responsible for this disease cannot be reproduced in vitro. Among the animal kingdom, rodents, rabbits, pigs, dogs, and nonhuman primates have been used to model human periodontitis, each with advantages and disadvantages. Periodontitis commonly has been induced by placing a bacterial plaque retentive ligature in the gingival sulcus around the molar teeth. In addition, alveolar bone loss has been induced by inoculation or …


The Hypoxia-Adenosine Link During Myocardial Ischemia—Reperfusion Injury, Diana Panesso, Maria C Montealegre, Sandra Rincón, Maria F Mojica, Louis B Rice, Kavindra V Singh, Barbara E Murray, Cesar A Arias Jan 2011

The Hypoxia-Adenosine Link During Myocardial Ischemia—Reperfusion Injury, Diana Panesso, Maria C Montealegre, Sandra Rincón, Maria F Mojica, Louis B Rice, Kavindra V Singh, Barbara E Murray, Cesar A Arias

Faculty, Staff and Student Publications

BACKGROUND: Plasmids containing hylEfm (pHylEfm) were previously shown to increase gastrointestinal colonization and lethality of Enterococcus faecium in experimental peritonitis. The hylEfm gene, predicting a glycosyl hydrolase, has been considered as a virulence determinant of hospital-associated E. faecium, although its direct contribution to virulence has not been investigated. Here, we constructed mutants of the hylEfm-region and we evaluated their effect on virulence using a murine peritonitis model.

RESULTS: Five mutants of the hylEfm-region of pHylEfmTX16 from the sequenced endocarditis strain (TX16 [DO]) were obtained using an adaptation of the PheS* system and were evaluated in a commensal strain TX1330RF to …


A Retinoic Acid–Dependent Checkpoint In The Development Of Cd4+ T Cell–Mediated Immunity, Karina Pino-Lagos, Yanxia Guo, Chrysothemis Brown, Matthew P. Alexander, Raúl Elgueta, Kathryn A. Bennett, Victor De Vries, Elizabeth Nowak, Rune Blomhoff, Shanthini Sockanathan, Roshantha A. Chandraratna, Ethan Dmitrovsky, Randolph J. Noelle Jan 2011

A Retinoic Acid–Dependent Checkpoint In The Development Of Cd4+ T Cell–Mediated Immunity, Karina Pino-Lagos, Yanxia Guo, Chrysothemis Brown, Matthew P. Alexander, Raúl Elgueta, Kathryn A. Bennett, Victor De Vries, Elizabeth Nowak, Rune Blomhoff, Shanthini Sockanathan, Roshantha A. Chandraratna, Ethan Dmitrovsky, Randolph J. Noelle

Dartmouth Scholarship

It is known that vitamin A and its metabolite, retinoic acid (RA), are essential for host defense. However, the mechanisms for how RA controls inflammation are incompletely understood. The findings presented in this study show that RA signaling occurs concurrent with the development of inflammation. In models of vaccination and allogeneic graft rejection, whole body imaging reveals that RA signaling is temporally and spatially restricted to the site of inflammation. Conditional ablation of RA signaling in T cells significantly interferes with CD4+ T cell effector function, migration, and polarity. These findings provide a new perspective of the role of …


Retention Time Variability As A Mechanism For Animal Mediated Long-Distance Dispersal, Vishwesha Guttal, Frederic Bartumeus, Gregg Hartvigsen, Andrew L. Nevai Jan 2011

Retention Time Variability As A Mechanism For Animal Mediated Long-Distance Dispersal, Vishwesha Guttal, Frederic Bartumeus, Gregg Hartvigsen, Andrew L. Nevai

Biology

Long-distance dispersal (LDD) events, although rare for most plant species, can strongly influence population and community dynamics. Animals function as a key biotic vector of seeds and thus, a mechanistic and quantitative understanding of how individual animal behaviors scale to dispersal patterns at different spatial scales is a question of critical importance from both basic and applied perspectives. Using a diffusion-theory based analytical approach for a wide range of animal movement and seed transportation patterns, we show that the scale (a measure of local dispersal) of the seed dispersal kernel increases with the organisms' rate of movement and mean seed …


Short-Term Exposure To Warm Microhabitats Could Explain Amphibian Persistence With Batrachochytrium Dendrobatidis., Joshua H. Daskin, Ross A. Alford, Robert Puschendorf Jan 2011

Short-Term Exposure To Warm Microhabitats Could Explain Amphibian Persistence With Batrachochytrium Dendrobatidis., Joshua H. Daskin, Ross A. Alford, Robert Puschendorf

School of Biological and Marine Sciences

Environmental conditions can alter the outcomes of symbiotic interactions. Many amphibian species have declined due to chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), but many others persist despite high Bd infection prevalence. This indicates that Bd's virulence is lower, or it may even be a commensal, in some hosts. In the Australian Wet Tropics, chytridiomycosis extirpated Litoria nannotis from high-elevation rain forests in the early 1990 s. Although the species is recolonizing many sites, no population has fully recovered. Litoria lorica disappeared from all known sites in the early 1990 s and was thought globally extinct, but a …


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 Jan 2011

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


Leishmania Major Survival In Selective Phlebotomus Papatasi Sand Fly Vector Requires A Specific Scg-Encoded Lipophosphoglycan Galactosylation Pattern, Deborah E. Dobson, Shaden Kamhawi, Phillip Lawyer, Salvatore J. Turco, Stephen M. Beverley, David L. Sacks Nov 2010

Leishmania Major Survival In Selective Phlebotomus Papatasi Sand Fly Vector Requires A Specific Scg-Encoded Lipophosphoglycan Galactosylation Pattern, Deborah E. Dobson, Shaden Kamhawi, Phillip Lawyer, Salvatore J. Turco, Stephen M. Beverley, David L. Sacks

Molecular and Cellular Biochemistry Faculty Publications

Phlebotomine sand flies that transmit the protozoan parasite Leishmania differ greatly in their ability to support different parasite species or strains in the laboratory: while some show considerable selectivity, others are more permissive. In "selective" sand flies, Leishmania binding and survival in the fly midgut typically depends upon the abundant promastigote surface adhesin lipophosphoglycan (LPG), which exhibits species- and strain-specific modifications of the dominant phosphoglycan (PG) repeat units. For the "selective" fly Phlebotomus papatasi PpapJ, side chain galactosyl-modifications (scGal) of PG repeats play key roles in parasite binding. We probed the specificity and properties of this scGal-LPG PAMP (Pathogen Associated …


The Armadillo Repeat Protein Pf16 Is Essential For Flagellar Structure And Function In Plasmodium Male Gametes, Ursula Straschil, Arthur M. Talman, David J. P. Ferguson, Karen A. Bunting, Zhengyao Xu, Elizabeth Bailes, Robert E. Sinden, Anthony A. Holder, Elizabeth F. Smith Sep 2010

The Armadillo Repeat Protein Pf16 Is Essential For Flagellar Structure And Function In Plasmodium Male Gametes, Ursula Straschil, Arthur M. Talman, David J. P. Ferguson, Karen A. Bunting, Zhengyao Xu, Elizabeth Bailes, Robert E. Sinden, Anthony A. Holder, Elizabeth F. Smith

Dartmouth Scholarship

Malaria, caused by the apicomplexan parasite Plasmodium, threatens 40% of the world's population. Transmission between vertebrate and insect hosts depends on the sexual stages of the life-cycle. The male gamete of Plasmodium parasite is the only developmental stage that possesses a flagellum. Very little is known about the identity or function of proteins in the parasite's flagellar biology. Here, we characterise a Plasmodium PF16 homologue using reverse genetics in the mouse malaria parasite Plasmodium berghei. PF16 is a conserved Armadillo-repeat protein that regulates flagellar structure and motility in organisms as diverse as green algae and mice. We show that …


Avirulent Uracil Auxotrophs Based On Disruption Of Orotidine-5′-Monophosphate Decarboxylase Elicit Protective Immunity To Toxoplasma Gondii, Barbara A. Fox, David J. Bzik Jul 2010

Avirulent Uracil Auxotrophs Based On Disruption Of Orotidine-5′-Monophosphate Decarboxylase Elicit Protective Immunity To Toxoplasma Gondii, Barbara A. Fox, David J. Bzik

Dartmouth Scholarship

The orotidine-5'-monophosphate decarboxylase (OMPDC) gene, encoding the final enzyme of the de novo pyrimidine biosynthesis pathway, was deleted using Toxoplasma gondii KU80 knockouts to develop an avirulent nonreverting pyrimidine auxotroph strain. Additionally, to functionally address the role of the pyrimidine salvage pathway, the uridine phosphorylase (UP) salvage activity was knocked out and a double knockout of UP and OMPDC was also constructed. The nonreverting DeltaOMPDC, DeltaUP, and DeltaOMPDC DeltaUP knockout strains were evaluated for pyrimidine auxotrophy, for attenuation of virulence, and for their ability to elicit potent immunity to reinfection. The DeltaUP knockout strain was replication competent and virulent. In …


Interleukin-10 Mediated Autoregulation Of Murine B-1 B-Cells And Its Role In Borrelia Hermsii Infection, Vishal Sindhava, Michael E Woodman, Brian Stevenson, Subbarao Bondada Jul 2010

Interleukin-10 Mediated Autoregulation Of Murine B-1 B-Cells And Its Role In Borrelia Hermsii Infection, Vishal Sindhava, Michael E Woodman, Brian Stevenson, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

B cells are typically characterized as positive regulators of the immune response, primarily by producing antibodies. However, recent studies indicate that various subsets of B cells can perform regulatory functions mainly through IL-10 secretion. Here we discovered that peritoneal B-1 (B-1P) cells produce high levels of IL-10 upon stimulation with several Toll-like receptor (TLR) ligands. High levels of IL-10 suppressed B-1P cell proliferation and differentiation response to all TLR ligands studied in an autocrine manner in vitro and in vivo. IL-10 that accumulated in cultures inhibited B-1P cells at second and subsequent cell divisions mainly at the G1/S interphase. …


Poisonous Rangeland Plants In San Luis Obispo County, Sara Litten, Amanda Ou Jun 2010

Poisonous Rangeland Plants In San Luis Obispo County, Sara Litten, Amanda Ou

Animal Science

Poisonous Rangeland Plants in San Luis Obispo County is a comprehensive educational guide to rangeland plants that are toxic to domestic livestock. This guide begins with an exploration of how the biological systems are affected by the poisonous plant toxins. The biochemistry behind these toxins is included in the discussion. Next, reference material for fourteen plants that inhabit San Luis Obispo County is provided. This information includes specific toxins found in poisonous plants, affected animals, symptoms of poisoning, stages of growth, lethal dose, and distribution of the plant in California. This section of the guide is filled with helpful photos …


Molecular Evidence For A Functional Ecdysone Signaling System In Brugia Malayi, George Tzertzinis, Ana L. Egaña, Subba Reddy Palli, Marc Robinson-Rechavi, Chris R. Gissendanner, Canhui Liu, Thomas R. Unnasch, Claude V. Maina Mar 2010

Molecular Evidence For A Functional Ecdysone Signaling System In Brugia Malayi, George Tzertzinis, Ana L. Egaña, Subba Reddy Palli, Marc Robinson-Rechavi, Chris R. Gissendanner, Canhui Liu, Thomas R. Unnasch, Claude V. Maina

Entomology Faculty Publications

BACKGROUND: Filarial nematodes, including Brugia malayi, the causative agent of lymphatic filariasis, undergo molting in both arthropod and mammalian hosts to complete their life cycles. An understanding of how these parasites cross developmental checkpoints may reveal potential targets for intervention. Pharmacological evidence suggests that ecdysteroids play a role in parasitic nematode molting and fertility although their specific function remains unknown. In insects, ecdysone triggers molting through the activation of the ecdysone receptor: a heterodimer of EcR (ecdysone receptor) and USP (Ultraspiracle).

METHODS AND FINDINGS: We report the cloning and characterization of a B. malayi EcR homologue (Bma-EcR). Bma-EcR dimerizes with …