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Articles 481 - 510 of 548

Full-Text Articles in Immunology of Infectious Disease

Critical Involvement Of The Atm-Dependent Dna Damage Response In The Apoptotic Demise Of Hiv-1-Elicited Syncytia, Jean-Luc Perfettini, Roberta Nardacci, Mehdi Bourouba, Frederic Subra, Laurent Gros, Claire Séror, Gwenola Manic, Filippo Rosselli, Alessandra Amendola, Peggy Masdehors, Luciana Chessa, Giuseppe Novelli, David M. Ojcius, Jan Konrad Siwicki, Magdalena Chechlinska, Christian Auclair, Jose R. Regueiro, Hughes De Thé, Marie-Lise Gougeon, Mauro Piacentini, Guido Kroemer Jun 2008

Critical Involvement Of The Atm-Dependent Dna Damage Response In The Apoptotic Demise Of Hiv-1-Elicited Syncytia, Jean-Luc Perfettini, Roberta Nardacci, Mehdi Bourouba, Frederic Subra, Laurent Gros, Claire Séror, Gwenola Manic, Filippo Rosselli, Alessandra Amendola, Peggy Masdehors, Luciana Chessa, Giuseppe Novelli, David M. Ojcius, Jan Konrad Siwicki, Magdalena Chechlinska, Christian Auclair, Jose R. Regueiro, Hughes De Thé, Marie-Lise Gougeon, Mauro Piacentini, Guido Kroemer

All Dugoni School of Dentistry Faculty Articles

DNA damage can activate the oncosuppressor protein ataxia telangiectasia mutated (ATM), which phosphorylates the histone H2AX within characteristic DNA damage foci. Here, we show that ATM undergoes an activating phosphorylation in syncytia elicited by the envelope glycoprotein complex (Env) of human immunodeficiency virus-1 (HIV-1) in vitro. This was accompanied by aggregation of ATM in discrete nuclear foci that also contained phospho-histone H2AX. DNA damage foci containing phosphorylated ATM and H2AX were detectable in syncytia present in the brain or lymph nodes from patients with HIV-1 infection, as well as in a fraction of blood leukocytes, correlating with viral status. Knockdown …

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Susceptibility Of Chlamydia Trachomatis To The Excipient Hydroxy-Ethylcellulose: Ph And Concentration Dependence Of Antimicrobial Activity, Ali A. Abdul-Sater, David M. Ojcius, M. P. Meyer Apr 2008

Susceptibility Of Chlamydia Trachomatis To The Excipient Hydroxy-Ethylcellulose: Ph And Concentration Dependence Of Antimicrobial Activity, Ali A. Abdul-Sater, David M. Ojcius, M. P. Meyer

All Dugoni School of Dentistry Faculty Articles

Hydroxyethyl cellulose (HEC) is used as a neutral excipient in microbicides used against sexually transmitted pathogens. However, HEC inhibits the infection of cervical epithelial cells by Chlamydia trachomatis at pH 5 in a concentration-dependent manner. At pH 7, infection is inversely dependent on the concentration of HEC, possibly due to pH-dependent calcium sequestration.

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Optimizing Qpcr For The Quantification Of Periodontal Pathogens In A Complex Plaque Biofilm, Sreenatha S. Kirakodu, M. Govindaswami, Michael John Novak, Jeffrey L. Ebersole, Karen F. Novak Jan 2008

Optimizing Qpcr For The Quantification Of Periodontal Pathogens In A Complex Plaque Biofilm, Sreenatha S. Kirakodu, M. Govindaswami, Michael John Novak, Jeffrey L. Ebersole, Karen F. Novak

Center for Oral Health Research Faculty Publications

Quantitative PCR (qPCR) has recently been used to quantify microorganisms in complex communities, including dental plaque biofilms. However, there is variability in the qPCR protocols being used. This study was designed to evaluate the validity of two of these variables with the intent of developing a more standardized qPCR protocol. The two variables evaluated were (1) the use of DNA content versus actual cell counts to estimate bacterial numbers in mixed plaque samples and (2) the effectiveness of three different universal primers versus species specific primers in amplifying specific target pathogens in these samples. Results lead to the development of …

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T-Cell Dysfunction By Hcv Core Protein Involves Pd-1/Pd-L1 Signaling., Billy Ellis King May 2007

T-Cell Dysfunction By Hcv Core Protein Involves Pd-1/Pd-L1 Signaling., Billy Ellis King

Electronic Theses and Dissertations

In 1989 the hepatitis C virus was identified as a significant cause of post-transfusion hepatitis. Nearly two decades later there is still no vaccine, inadequate treatment options, and limited understanding of how the virus establishes chronicity in the majority of the people it infects. Recent reports suggest that the interaction of a negative co-stimulatory pathway mediated by PD-1 and PDL-1 is associated with persistent viral infection. The role, if any, that PD-1/PDL-1 has in HCV infection is unknown. In this study we report that PD-1 is upregulated in T-cells from persons with chronic HCV infection when compared to healthy donors. …

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Atp Activates A Reactive Oxygen Species-Dependent Oxidative Stress Response And Secretion Of Pro-Inflammatory Cytokines In Macrophages, Christiane M. Cruz, Alessandra Rinna, Henry Jay Forman, Ana L. M. Ventura, Pedro M. Persechini, David M. Ojcius Feb 2007

Atp Activates A Reactive Oxygen Species-Dependent Oxidative Stress Response And Secretion Of Pro-Inflammatory Cytokines In Macrophages, Christiane M. Cruz, Alessandra Rinna, Henry Jay Forman, Ana L. M. Ventura, Pedro M. Persechini, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

Secretion of the proinflammatory cytokines, interleukin (IL)-1β and IL-18, usually requires two signals. The first, due to microbial products such as lipopolysaccharide, initiates transcription of the cytokine genes and accumulation of the precursor proteins. Cleavage and secretion of the cytokines is mediated by caspase-1, in association with an inflammasome containing Nalp3, which can be activated by binding of extracellular ATP to purinergic receptors. We show that treatment of macrophages with ATP results in production of reactive oxygen species (ROS), which stimulate the phosphatidylinositol 3-kinase (PI3K) pathway and subsequent Akt and ERK1/2 activation. ROS exerts its effect through glutathionylation of PTEN …

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Modulation Of Cd4 Co-Receptor Limits Spontaneous Autoimmunity When High-Affinity Transgenic Tcr Specific For Self-Antigen Is Expressed On A Genetically Resistant Background, Zsolt Illés, Hanspeter Waldner, Jay Reddy, Ana C. Anderson, Raymond A. Sobel, Vijay K. Kuchroo Jan 2007

Modulation Of Cd4 Co-Receptor Limits Spontaneous Autoimmunity When High-Affinity Transgenic Tcr Specific For Self-Antigen Is Expressed On A Genetically Resistant Background, Zsolt Illés, Hanspeter Waldner, Jay Reddy, Ana C. Anderson, Raymond A. Sobel, Vijay K. Kuchroo

Jay Reddy Publications

Myelin proteolipid protein (PLP) 139–151 is an immunodominant peptide that induces experimental autoimmune encephalomyelitis (EAE) in H-2s SJL/J mice. While PLP 139–151-specific TCR transgenic (tg) 4E3 mice develop fulminant spontaneous disease on the susceptible SJL/J background, spontaneous EAE is dramatically reduced on the H-2s congenic B10.S background. On this resistant background, we observed a high frequency of positively selected tg CD42CD82 (DN) thymocytes and peripheral DN tg T cells. Splenic DN tg T cells responded to anti-CD3 stimulation similarly to CD41 cells, but proliferative and cytokine responses to PLP 139–151 were blunted, implying that CD4 coreceptor down-regulation modulated …

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Characterization Of Host Cell Death Induced By Chlamydia Trachomatis, Songmin Ying, Silke F. Fischer, Matthew A. Pettengill, Debye Conte, Stefan A. Paschen, David M. Ojcius, Georg Hacker Nov 2006

Characterization Of Host Cell Death Induced By Chlamydia Trachomatis, Songmin Ying, Silke F. Fischer, Matthew A. Pettengill, Debye Conte, Stefan A. Paschen, David M. Ojcius, Georg Hacker

All Dugoni School of Dentistry Faculty Articles

Chlamydia are obligate intracellular bacteria that modulate apoptosis of the host cell. Strikingly, chlamydial infection has been reported both to inhibit and to induce apoptosis. Although the ability to inhibit apoptosis has been corroborated by the identification of cellular targets, confirmation of cell death induction has been complicated by a mixture of apoptotic features and atypical cell death during infection, as well as by differences in the experimental techniques used to measure cell death. Here we use a panel of well-established approaches in the study of apoptosis to define the form of cell death induced by Chlamydia trachomatis infection. Infected …

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Fisheries Research Contract Report No. 15 - Aquatic Animal Health Subprogram: Pilchard Herpesvirus Infection In Wild Pilchards (Frdc Project No. 2002/044) Final Report, Brian Jones, Melanie Crockford, Richard Whittington, Mark Crane, Graham Wilcox Oct 2006

Fisheries Research Contract Report No. 15 - Aquatic Animal Health Subprogram: Pilchard Herpesvirus Infection In Wild Pilchards (Frdc Project No. 2002/044) Final Report, Brian Jones, Melanie Crockford, Richard Whittington, Mark Crane, Graham Wilcox

Fisheries Research Contract Reports

In 1995 and again in 1998/9, millions of pilchards (Sardinops sagax neopilchardus) were found dead or dying off the coast of Australia. Some pilchards in New Zealand were also affected during the 1995 epizootic. The epizootics moved progressively in a "bushfire-like" manner against the prevailing currents at a rapid speed. An uncharacterised herpesvirus, pilchard herpesvirus (PHV), was associated with both mortality events and, based on its occurrence in affected fish and the disease pathogenesis, generally accepted as the causative agent, although experimental evidence of its role was not established. Until recently, rapid and sensitive methods to detect PHV were not …

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In Vivo Mature Immunological Synapses Forming Smacs Mediate Clearance Of Virally Infected Astrocytes From The Brain, Carlos Barcia, Clare Thomas, James Curtin, Gwendalyn King, Kolja Wawrowsky, Marianela Candolfi, Weidong Xiong, Chunyan Liu, Kurt Kroeger, Olivier Boyer, Jerzy Kupiec-Weglinski, David Klatzmann, Maria Castro, Pedro Lowenstein Sep 2006

In Vivo Mature Immunological Synapses Forming Smacs Mediate Clearance Of Virally Infected Astrocytes From The Brain, Carlos Barcia, Clare Thomas, James Curtin, Gwendalyn King, Kolja Wawrowsky, Marianela Candolfi, Weidong Xiong, Chunyan Liu, Kurt Kroeger, Olivier Boyer, Jerzy Kupiec-Weglinski, David Klatzmann, Maria Castro, Pedro Lowenstein

Articles

The microanatomy of immune clearance of infected brain cells remains poorly understood. Immunological synapses are essential anatomical structures that channel information exchanges between T cell–antigen-presenting cells (APC) during the priming and effector phases of T cells' function, and during natural killer–target cell interactions. The hallmark of immunological synapses established by T cells is the formation of the supramolecular activation clusters (SMACs), in which adhesion molecules such as leukocyte function-associated antigen 1 segregate to the peripheral domain of the immunological synapse (p-SMAC), which surrounds the T cell receptor–rich or central SMAC (c-SMAC). The inability so far to detect SMAC formation in …

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Recruitment Of Bad By The Chlamydia Trachomatis Vacuole Correlates With Host-Cell Survival, Philippe Verbeke, Lynn Welter-Stahl, S. Ying, J. Hansen, Georg Hacker, Toni Darville, David M. Ojcius May 2006

Recruitment Of Bad By The Chlamydia Trachomatis Vacuole Correlates With Host-Cell Survival, Philippe Verbeke, Lynn Welter-Stahl, S. Ying, J. Hansen, Georg Hacker, Toni Darville, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

Chlamydiae replicate intracellularly in a vacuole called an inclusion. Chlamydial-infected host cells are protected from mitochondrion-dependent apoptosis, partly due to degradation of BH3-only proteins. The host-cell adapter protein 14-3-3β can interact with host-cell apoptotic signaling pathways in a phosphorylation-dependent manner. In Chlamydia trachomatis-infected cells, 14-3-3β co-localizes to the inclusion via direct interaction with a C. trachomatis-encoded inclusion membrane protein. We therefore explored the possibility that the phosphatidylinositol-3 kinase (PI3K) pathway may contribute to resistance of infected cells to apoptosis. We found that inhibition of PI3K renders C. trachomatis-infected cells sensitive to staurosporine-induced apoptosis, which is accompanied by mitochondrial cytochrome c …

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Intercellular Spreading Of Porphyromonas Gingivalis Infection In Primary Gingival Epithelial Cells, Özlem Yilmaz, Philippe Verbeke, Richard J. Lamont, David M. Ojcius Jan 2006

Intercellular Spreading Of Porphyromonas Gingivalis Infection In Primary Gingival Epithelial Cells, Özlem Yilmaz, Philippe Verbeke, Richard J. Lamont, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

Porphyromonas gingivalis, an important periodontal pathogen, is an effective colonizer of oral tissues. The organism successfully invades, multiplies in, and survives for extended periods in primary gingival epithelial cells (GECs). It is unknown whether P. gingivalis resides in the cytoplasm of infected cells throughout the infection or can spread to adjacent cells over time. We developed a technique based on flow cytofluorometry and fluorescence microscopy to study propagation of the organism at different stages of infection of GECs. Results showed that P. gingivalis spreads cell to cell and that the amount of spreading increases gradually over time. There was a …

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Premature Induction Of An Immunosuppressive Regulatory T Cell Response During Acute Simian Immunodeficiency Virus Infection, Jacob D. Estes, Qingsheng Li, Matthew R. Reynolds, Stephen W. Wietgrefe, Lijie Duan, Timothy Schacker, Louis J. Picker, David I. Watkins, Jeffrey D. Lifson, Cavan Reilly, John V. Carlis, Ashley T. Haase Jan 2006

Premature Induction Of An Immunosuppressive Regulatory T Cell Response During Acute Simian Immunodeficiency Virus Infection, Jacob D. Estes, Qingsheng Li, Matthew R. Reynolds, Stephen W. Wietgrefe, Lijie Duan, Timothy Schacker, Louis J. Picker, David I. Watkins, Jeffrey D. Lifson, Cavan Reilly, John V. Carlis, Ashley T. Haase

Qingsheng Li Publications

Here we report the results of an investigation into the possibility that one mechanism responsible for the establishment of persistent human immunodeficiency virus infection is an early regulatory T (Treg) cell response that blunts virus- specific responses. Using the simian immunodeficiency virus (SIV)–infected rhesus macaque model, we show that, indeed, viral replication and immune activation in lymphatic tissue drive a premature immunosuppressive response, with dramatic increases in the frequencies of CD4+CD25+FOXP3+ Treg cells, transforming growth factor–β1+ cells, interleukin–10+ cells, and indoleamine 2,3-dioxygenase+CD3+ cells.When we compared SIV infection with rhesus cytomegalovirus (RhCMV) …

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A Role For Mitogen-Activated Protein Kinase (Erk1/2) Activation And Non-Selective Pore Formation In P2x7 Receptor-Mediated Thymocyte Death, Rodolphe Auger, Iris Motta, Karim Benihoud, David M. Ojcius, Jean M. Kanellopoulos Jul 2005

A Role For Mitogen-Activated Protein Kinase (Erk1/2) Activation And Non-Selective Pore Formation In P2x7 Receptor-Mediated Thymocyte Death, Rodolphe Auger, Iris Motta, Karim Benihoud, David M. Ojcius, Jean M. Kanellopoulos

All Dugoni School of Dentistry Faculty Articles

Extracellular ATP (ATPe) binds to P2X7 receptors (P2X7R) expressed on the surface of cells of hematopoietic lineage, including murine thymocytes. Activation of P2X7R by ATPe results in the opening of cation-specific channels, and prolonged ATPe exposure leads to the formation of non-selective pores enabling transmembrane passage of solutes up to 900 Da. In the presence of ATPe, P2X7R-mediated thymocyte death is due primarily to necrosis/lysis and not apoptosis, as measured by the release of lactate dehydrogenase indicative of a loss of plasma membrane integrity. The present study is focused on the identification of P2X7R signaling mediators in ATP-induced thymocyte necrosis/lysis. …

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Association Between Coinfection Of Porphyromonas Gingivalis, Actinobacillus Actinomycetemcomitans And Treponema Denticola And Periodontal Tissue Destruction In Chronic Periodontitis, L. L. Chen, Y. M. Wu, J. Yan, W. L. Sun, Y. Z. Sun, David M. Ojcius Jan 2005

Association Between Coinfection Of Porphyromonas Gingivalis, Actinobacillus Actinomycetemcomitans And Treponema Denticola And Periodontal Tissue Destruction In Chronic Periodontitis, L. L. Chen, Y. M. Wu, J. Yan, W. L. Sun, Y. Z. Sun, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

No abstract provided.

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Activation Of The Phosphatidylinositol 3-Kinase/Akt Pathway Contributes To Survival Of Primary Epithelial Cells Infected With The Periodontal Pathogen Porphyromonas Gingivalis, Özlem Yilmaz, Thomas Jungas, Philippe Verbeke, David M. Ojcius Jul 2004

Activation Of The Phosphatidylinositol 3-Kinase/Akt Pathway Contributes To Survival Of Primary Epithelial Cells Infected With The Periodontal Pathogen Porphyromonas Gingivalis, Özlem Yilmaz, Thomas Jungas, Philippe Verbeke, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

Porphyromonas gingivalis, an important periodontal pathogen, infects primary gingival epithelial cells (GECs). Despite the large number of bacteria that replicate inside the GECs, the host cell remains viable. We demonstrate that P. gingivalis triggers rapid and reversible surface phosphatidylserine exposure through a mechanism requiring caspase activation. However, after 1 day of infection, the bacteria no longer induce phosphatidylserine externalization and instead protect infected cells against apoptosis. Infection exerts its effect at the level of mitochondria, as P. gingivalis also blocks depolarization of the mitochondrial transmembrane potential and cytochrome c release. Interestingly, protein kinase B/Akt is phosphorylated during infection, which can …

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The Prevalence Of The Q-Fever Agent Coxiella Burnetii In Ticks Collected From An Animal Shelter In Southeast Georgia, John H. Smoyer Iii Jan 2004

The Prevalence Of The Q-Fever Agent Coxiella Burnetii In Ticks Collected From An Animal Shelter In Southeast Georgia, John H. Smoyer Iii

College of Graduate Studies: Theses & Dissertations

Author's abstract: Q-fever is a zoonosis caused by a worldwide-distributed bacterium Coxiella burnetii. Ticks are vectors of the Q-fever agent but play a secondary role in transmission because the agent is also transmitted via aerosols. Most Q-fever studies have focused on farm animals but not ticks collected from dogs in animal shelters. In order to detect the Q-fever agent in these ticks, a nested PCR technique targeting the 16S rDNA of Coxiella burnetii was used. A collection of 450 ticks from the animal shelter were screened via nested PCR and 144 (32%) were positives. The positive PCR products were also …

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Tolerance Of The Fetus By The Maternal Immune System: Role Of Inflammatory Mediators At The Feto-Maternal Interface, Colette Kanellopoulos-Langevin, Stephane M. Caucheteux, Philippe Verbeke, David M. Ojcius Dec 2003

Tolerance Of The Fetus By The Maternal Immune System: Role Of Inflammatory Mediators At The Feto-Maternal Interface, Colette Kanellopoulos-Langevin, Stephane M. Caucheteux, Philippe Verbeke, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

The adaptive immune system of placental mammals has evolved to tolerate the fetus. Rejection of the fetus by adaptive immune responses is therefore a rare event, with abortion being caused more frequently by inflammation in the placenta. This review will cover recent aspects of immune privilege and the innate immune system at the feto-maternal interface, citing examples of the role played by microbial infections in fetal demise.

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Lysosomal Membrane Permeabilization Induces Cell Death In A Mitochondrion-Dependent Fashion, Patricia Boya, Karine Andreau, Delphine Poncet, Naoufal Zamzami, Jean-Luc Perfettini, Didier Metivier, David M. Ojcius, Marja Jäättelä, Guido Kroemer May 2003

Lysosomal Membrane Permeabilization Induces Cell Death In A Mitochondrion-Dependent Fashion, Patricia Boya, Karine Andreau, Delphine Poncet, Naoufal Zamzami, Jean-Luc Perfettini, Didier Metivier, David M. Ojcius, Marja Jäättelä, Guido Kroemer

All Dugoni School of Dentistry Faculty Articles

A number of diseases are due to lysosomal destabilization, which results in damaging cell loss. To investigate the mechanisms of lysosomal cell death, we characterized the cytotoxic action of two widely used quinolone antibiotics: ciprofloxacin (CPX) or norfloxacin (NFX). CPX or NFX plus UV light (NFX*) induce lysosomal membrane permeabilization (LMP), as detected by the release of cathepsins from lysosomes. Inhibition of the lysosomal accumulation of CPX or NFX suppresses their capacity to induce LMP and to kill cells. CPX- or NFX-triggered LMP results in caspase-independent cell death, with hallmarks of apoptosis such as chromatin condensation and phosphatidylserine exposure on …

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Role Of Proapoptotic Bax In Propagation Of Chlamydia Muridarum (The Mouse Pneumonitis Strain Of Chlamydia Trachomatis) And The Host Inflammatory Response, Jean-Luc Perfettini, David M. Ojcius, Charles W. Andrews Jr., Stanley J. Korsmeyer, Roger G. Rank, Toni Darville Mar 2003

Role Of Proapoptotic Bax In Propagation Of Chlamydia Muridarum (The Mouse Pneumonitis Strain Of Chlamydia Trachomatis) And The Host Inflammatory Response, Jean-Luc Perfettini, David M. Ojcius, Charles W. Andrews Jr., Stanley J. Korsmeyer, Roger G. Rank, Toni Darville

All Dugoni School of Dentistry Faculty Articles

The BCL-2 family member BAX plays a critical role in regulating apoptosis. Surprisingly, bax-deficient mice display limited phenotypic abnormalities. Here we investigate the effect of BAX on infection by the sexually transmitted pathogen,Chlamydia muridarum (the mouse pneumonitis strain ofChlamydia trachomatis). Bax −/−cells are relatively resistant to Chlamydia-induced apoptosis, and fewer bacteria are recovered after two infection cycles from Bax −/− cells than from wild-type cells. These results suggest that BAX-dependent apoptosis may be used to initiate a new round of infection, most likely by releasingChlamydia-containing apoptotic bodies from infected cells that could be internalized by neighboring uninfected cells. Nonetheless, infected …

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Characterization Of A Gene Encoding Two Isoforms Of A Mitochondrial Protein Upregulated By Cyclosporin A In Activated T Cells, Laurent Mascarell, Rodolphe Auger, Andres Alcover, David M. Ojcius, Thomas Jungas, Veronique Cadet-Daniel, Jean M. Kanellopoulos, Paolo Truffa-Bacchi Mar 2003

Characterization Of A Gene Encoding Two Isoforms Of A Mitochondrial Protein Upregulated By Cyclosporin A In Activated T Cells, Laurent Mascarell, Rodolphe Auger, Andres Alcover, David M. Ojcius, Thomas Jungas, Veronique Cadet-Daniel, Jean M. Kanellopoulos, Paolo Truffa-Bacchi

All Dugoni School of Dentistry Faculty Articles

Cyclosporin A (CSA) is an immunosuppressor used in organ transplantation. A recent proteomic analysis has revealed that activation of T cells in the presence of CSA induces the synthesis of hundreds of new proteins. Here we used representational difference analysis to characterize some of the corresponding induced genes. After cDNA bank screening we focused on one of these genes, which we named CSA-conditional, T cell activation-dependent (CSTAD) gene. This gene produces two mRNAs resulting from alternative splicing events. They encode two proteins of 104 and 141 amino acids, CSTADp-S and CSTADp-L, for the short and long forms, respectively. FK506 had …

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Use Of Irradiated And Formalin-Fixed Trichomonas Vaginalis To Examine Protective Immune Responses In The Mouse Intraperitoneal Model, Terryl L. Hostetler, James J. Daly, Timothy J. O'Brien, Max L. Baker Jan 2003

Use Of Irradiated And Formalin-Fixed Trichomonas Vaginalis To Examine Protective Immune Responses In The Mouse Intraperitoneal Model, Terryl L. Hostetler, James J. Daly, Timothy J. O'Brien, Max L. Baker

Journal of the Arkansas Academy of Science

Gamma irradiated Trichomonas vaginalis was used to initiate a protective immune response in mice by intraperitoneal inoculation using host mortality as the measure of virulence. Irradiated trichomonads of a virulent strain gave some immune protection but no more so than the use of formalin-fixed, virulent trichomonads. A formalin-fixed virulent strain combined with complete Freund's adjuvant (CFA) gave complete protection. Metabolically produced antigens do not appear to be important in conferring protective immunity in these experiments. A common laboratory strain of T. vaginalis (ATCC 30001) was used as an avirulent control. It gave no protection against a virulent strain. Combining CFA …

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Glutathione Levels And Bax Activation During Apoptosis Due To Oxidative Stress In Cells Expressing Wild-Type And Mutant Cystic Fibrosis Transmembrane Conductance Regulator, Thomas Jungas, Iris Motta, Francis Duffieux, Pascale Fanen, Veronique Stoven, David M. Ojcius Aug 2002

Glutathione Levels And Bax Activation During Apoptosis Due To Oxidative Stress In Cells Expressing Wild-Type And Mutant Cystic Fibrosis Transmembrane Conductance Regulator, Thomas Jungas, Iris Motta, Francis Duffieux, Pascale Fanen, Veronique Stoven, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

Cystic fibrosis is characterized by chronic inflammation and an imbalance in the concentrations of alveolar and lung oxidants and antioxidants, which result in cell damage. Modifications in lung glutathione concentrations are recognized as a salient feature of inflammatory lung diseases such as cystic fibrosis, and glutathione plays a major role in protection against oxidative stress and is important in modulation of apoptosis. The cystic fibrosis transmembrane conductance regulator (CFTR) is permeable to Cl−, larger organic ions, and reduced and oxidized forms of glutathione, and the ΔF508 CFTR mutation found in cystic fibrosis patients has been correlated with impaired glutathione transport …

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Inhibition Of Apoptosis By Gamma Interferon In Cells And Mice Infected With Chlamydia Muridarum (The Mouse Pneumonitis Strain Of Chlamydia Trachomatis), Jean-Luc Perfettini, Toni Darville, Alice Dautry-Varsat, Roger G. Rank, David M. Ojcius May 2002

Inhibition Of Apoptosis By Gamma Interferon In Cells And Mice Infected With Chlamydia Muridarum (The Mouse Pneumonitis Strain Of Chlamydia Trachomatis), Jean-Luc Perfettini, Toni Darville, Alice Dautry-Varsat, Roger G. Rank, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

The effect of gamma interferon (IFN-γ) on apoptosis due to infection by Chlamydia muridarum (the mouse pneumonitis strain of Chlamydia trachomatis) was studied in epithelial cells in culture and in the genital tracts of mice. IFN-γ concentrations that induce the formation of aberrant, persistent chlamydiae inhibit apoptosis due to C. muridarum infection. In cells treated with an IFN-γ concentration that leads to the development of a heterogenous population of normal and aberrant Chlamydia vacuoles, apoptosis was inhibited preferentially in cells that contained the aberrant vacuoles. The inhibitory effect of IFN-γ appears to be due in part to expression of host …

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Comparison Of Tnf-A Levels Produced By Macrophages Treated With Brucella Abortus And Escherichia Coli Lps, Tajie Harris Apr 2002

Comparison Of Tnf-A Levels Produced By Macrophages Treated With Brucella Abortus And Escherichia Coli Lps, Tajie Harris

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.

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Characterization Of Host-Bacteria Interactions Contributing To Group B Streptococcus Colonization, Jennifer Marie Smith Jan 2002

Characterization Of Host-Bacteria Interactions Contributing To Group B Streptococcus Colonization, Jennifer Marie Smith

Theses, Dissertations and Capstones

Group B streptococcus (GBS) is the leading cause of life-threatening bacterial infections during the first three months of life. GBS is also a frequent cause of maternal postpartum infections. Both types of infections stem from maternal vaginal and/or rectal colonization with GBS in the perinatal period. Limited information is available concerning how the colonization process occurs and what role the host immune system may play in the establishment of persistent colonization by GBS. The complex interactions between the immune system and GBS normally should end in clearance of the bacteria. However, since colonization by GBS occurs in a large number …

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Role Of Bcl-2 Family Members In Caspase-Independent Apoptosis Due To Chlamydia Infection, Jean-Luc Perfettini, John C. Reed, Nicole Israel, Jean-Claude Martinou, Alice Dautry-Varsat, David M. Ojcius Jan 2002

Role Of Bcl-2 Family Members In Caspase-Independent Apoptosis Due To Chlamydia Infection, Jean-Luc Perfettini, John C. Reed, Nicole Israel, Jean-Claude Martinou, Alice Dautry-Varsat, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

Infection with an obligate intracellular bacterium, the Chlamydia trachomatis lymphogranuloma venereum (LGV/L2) strain or the guinea pig inclusion conjunctivitis serovar of Chlamydia psittaci, leads to apoptosis of host cells. The apoptosis is not affected by a broad-spectrum caspase inhibitor, and caspase-3 is not activated in infected cells, suggesting that apoptosis mediated by these two strains of Chlamydia is independent of known caspases. Overexpression of the proapoptotic Bcl-2 family member, Bax, was previously shown to induce caspase-independent apoptosis, and we find that Bax is activated and translocates from the cytosol to the mitochondria in C. psittaci-infected cells. C. psittaci-induced apoptosis is …

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Investigations Into The Innate Resistance Of The Tick, Dermacentor Variabilis, When Challenged With The Bacterium, Escherichia Coli, Shane Michael Ceraul Apr 2001

Investigations Into The Innate Resistance Of The Tick, Dermacentor Variabilis, When Challenged With The Bacterium, Escherichia Coli, Shane Michael Ceraul

Biological Sciences Theses & Dissertations

In addition to the soluble response, many invertebrates control bacterial infections by means of phagocytosis or melanotic encapsulation. In some insects, Escherichia coli growth is reported to be inhibited by aggregation/encapsulation. Soluble and phagocytic responses to bacterial challenge have been reported in ticks, but evidence of an aggregation/encapsulation response was reported only for inanimate (araldite) implants. This study was done to determine how ticks control infection by E. coli. Ticks were challenged by direct inoculation of bacteria into the hemocoel cavity. Using plate counts, no viable E. coli were detected I hour post-inoculation. A direct fluorescence assay (DF A) …

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La Notion De Danger, Jean M. Kanellopoulos, David M. Ojcius Aug 2000

La Notion De Danger, Jean M. Kanellopoulos, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

Pendant de nombreuses années, les recherches en immunologie ont été centrées sur la réponse immunitaire adaptative, et la plupart des immunologistes considéraient que sa fonction principale était de faire la distinction entre soi et non soi. Plus récemment, plusieurs équipes ont proposé que la fonction principale du système immunitaire est en réalité d’éliminer les agents pathogènes. Or, c’est le système immunitaire inné, longtemps négligé, qui joue un rôle essentiel dans l’induction d’une réponse contre les microorganismes. Ce système réagit précocement aux infections, voire instantanément, puis il induit et oriente la réponse du système adaptatif. Plusieursthéories ont été élaborées pour expliquer …

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Effect Of Chlamydia Trachomatis Infection And Subsequent Tnfa Secretion On Apoptosis In The Murine Genital Tract, Jean-Luc Perfettini, Toni Darville, Gabriel Gachelin, Philippe Souque, Michel Huerre, Alice Dautry-Varsat, David M. Ojcius Apr 2000

Effect Of Chlamydia Trachomatis Infection And Subsequent Tnfa Secretion On Apoptosis In The Murine Genital Tract, Jean-Luc Perfettini, Toni Darville, Gabriel Gachelin, Philippe Souque, Michel Huerre, Alice Dautry-Varsat, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

The pathology observed during Chlamydia infection is due initially to localized tissue damage caused by the infection itself, followed by deleterious host inflammatory responses that lead to permanent scarring. We have recently reported that the infection byChlamydia in vitro results in apoptosis of epithelial cells and macrophages and that infected monocytes secrete the proinflammatory cytokine interleukin-1β. At the same time, proinflammatory cytokines such as tumor necrosis factor alpha (TNF-α) can also trigger apoptosis of susceptible cells. To study the possible relationship between Chlamydia trachomatis infection and apoptosis in vivo, we used the terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling technique to …

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Pentoxifylline Modulation Of The Cytotoxic T-Cell Differentiation Pathway To Enhance Immunological Memory, Eric Goodspeed Jan 2000

Pentoxifylline Modulation Of The Cytotoxic T-Cell Differentiation Pathway To Enhance Immunological Memory, Eric Goodspeed

Inquiry: The University of Arkansas Undergraduate Research Journal

Immunological memory, acquired either by previous infection or vaccination, affords vertebrates a large margin of survival. Subsequent exposure to a "remembered" pathogen signals memory cells to undergo a rapid, clonal proliferation into armed effector cells. This rapidly mobilized clone mediates the specific clearance of the trespassing pathogen. Typically, this secondary recall response effectively dispatches the particular pathogen prior to any manifest disease pathology. This is the age-old, enjoyed benefit of immunity. Though this appreciation for immunological memory has been in documentation for nearly 3 millennia, our ability to intentionally increase its normal level of formation is only now beginning. The …

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