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Articles 1651 - 1680 of 1748

Full-Text Articles in Medicine and Health Sciences

Evaluation Of Cholera Vaccines Formulated With Toxin-Coregulated Pilin Peptide Plus Polymer Adjuvant In Mice, Jia-Yan Wu, William F. Wade, Ronald K. Taylor Dec 2001

Evaluation Of Cholera Vaccines Formulated With Toxin-Coregulated Pilin Peptide Plus Polymer Adjuvant In Mice, Jia-Yan Wu, William F. Wade, Ronald K. Taylor

Dartmouth Scholarship

Cholera is an acute diarrheal disease that is caused by the gram-negative bacterium Vibrio cholerae. The low efficacy of currently available killed-whole-cell vaccines and the reactinogenicity coupled with potential reversion of live vaccines have thus far precluded widespread vaccination for the control of cholera. Recent studies on the molecular nature of the virulence components that contribute to V. cholerae pathogenesis have provided insights into possible approaches for the development of a defined subunit cholera vaccine. Genetic analysis has demonstrated that the toxin-coregulated pilus (TCP) is the major factor that contributes to colonization of the human intestine by V. cholerae. In …


Immune Response Genes Modulate Serologic Responses To Vibrio Cholerae Tcpa Pilin Peptides, Michael D. Meeks, Terri K. Wade, Ronald K. Taylor, William F. Wade Dec 2001

Immune Response Genes Modulate Serologic Responses To Vibrio Cholerae Tcpa Pilin Peptides, Michael D. Meeks, Terri K. Wade, Ronald K. Taylor, William F. Wade

Dartmouth Scholarship

Cholera is an enteric disease caused by Vibrio cholerae. Toxin-coregulated pilus (TCP), a type 4 pilus expressed by V. cholerae, is a cholera virulence factor that is required for host colonization. The TCP polymer is composed of subunits of TcpA pilin. Antibodies directed against TcpA are protective in animal models of cholera. While natural or recombinant forms of TcpA are difficult to purify to homogeneity, it is anticipated that synthesized TcpA peptides might serve as immunogens in a subunit vaccine. We wanted to assess the potential for effects of the immune response (Ir) gene that could complicate a peptide-based …


Characterization Of Seca-Sod Operon In Borrellia Burgdorferi., Tonya Lynn Nichols Dec 2001

Characterization Of Seca-Sod Operon In Borrellia Burgdorferi., Tonya Lynn Nichols

Electronic Theses and Dissertations

Borrelia burgdorferi, the causative agent of Lyme disease, has been characterized as a microaerophilic spirochete. O2 consumption and utilization potentially yield reactive oxygen intermediates, such as superoxide, hydroxyl radicals, and hydrogen peroxide. This study investigated the expression of the sod gene, which encodes the only, identified oxidative defense mechanism in B. burgdorferi. Using primer extension analysis and RT-PCR, it was found that sod and secA are organized as a single transcriptional unit under the control of σ70-like promoter upstream of the secA open reading frame. Generally, gene expression decreases with increased distance from the promoter; however, secA expression was observed …


Sart, A Repressor Of Α-Hemolysin In Staphylococcus Aureus, Katherine A. Schmidt, Adhar C. Manna, Steven Gill, Ambrose L. Cheung Aug 2001

Sart, A Repressor Of Α-Hemolysin In Staphylococcus Aureus, Katherine A. Schmidt, Adhar C. Manna, Steven Gill, Ambrose L. Cheung

Dartmouth Scholarship

In searching the Staphylococcus aureus genome, we found several homologs to SarA. One of these genes, sarT, codes for a basic protein with 118 residues and a predicted molecular size of 16,096 Da. Northern blot analysis revealed that the expression of sarT was repressed by sarA and agr. An insertion sarT mutant generated in S. aureus RN6390 and 8325-4 backgrounds revealed minimal effect on the expression of sarR and sarA. The RNAIII level was notably increased in the sarT mutant, particularly in postexponential-phase cells, while the augmentative effect on RNAII was less. SarT repressed the expression of alpha-hemolysin, as determined …


A Novel Strategy Utilizing Co-Expression Of Murine Il-12 And Antisense Tgf-Pl Against H238 Tumor Formation, Craig A. Seheult Aug 2001

A Novel Strategy Utilizing Co-Expression Of Murine Il-12 And Antisense Tgf-Pl Against H238 Tumor Formation, Craig A. Seheult

Loma Linda University Electronic Theses, Dissertations & Projects

Cytokines have a profound effect on immune modulation, thus playing a significant role in cancer gene therapy. A variety of human carcinomas secrete transforming growth factor-beta (TGF-β), a cytokine with potent immunosuppressive properties. Suppressing TGF-β could be a key to successfully combating malignancies, such as gliomas, mammary, and colon cancers, that over-express TGF-β. Conversely, interleukin-12 (IL-12) is a potent immunostimulatory cytokine capable of regulating T and NK cell-mediated cytotoxic responses (Trinchieri, 1994) during an anti-tumor response. Activation of the immune system with such immunostimulatory cytokines renders it inert to the suppressive effects of TGF-β. To better understand these processes our …


Neuronal Cell Model And Methods Of Use Therefor, Craig S. Miller, Robert J. Danaher, Robert J. Jacob Jul 2001

Neuronal Cell Model And Methods Of Use Therefor, Craig S. Miller, Robert J. Danaher, Robert J. Jacob

Microbiology, Immunology and Molecular Genetics Faculty Patents

The present invention provides, inter alia, a PC12 cell quiescently infected with a neurotropic virus. Preferred quiescently-infected neural cells are those wherein the neurotropic virus is a neurotropic herpes virus. Methods related to these and other materials are also provided.


The Toxoplasma Gondii Protein Rop2 Mediates Host Organelle Association With The Parasitophorous Vacuole Membrane, Anthony P. Sinai, Keith A. Joiner Jul 2001

The Toxoplasma Gondii Protein Rop2 Mediates Host Organelle Association With The Parasitophorous Vacuole Membrane, Anthony P. Sinai, Keith A. Joiner

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Toxoplasma gondii replicates within a specialized vacuole surrounded by the parasitophorous vacuole membrane (PVM). The PVM forms intimate interactions with host mitochondria and endoplasmic reticulum (ER) in a process termed PVM–organelle association. In this study we identify a likely mediator of this process, the parasite protein ROP2. ROP2, which is localized to the PVM, is secreted from anterior organelles termed rhoptries during parasite invasion into host cells. The NH2-terminal domain of ROP2 (ROP2hc) within the PVM is exposed to the host cell cytosol, and has characteristics of a mitochondrial targeting signal. In in vitro assays, ROP2hc is …


Characterization Of The Cd154-Positive And Cd40-Positive Cellular Subsets Required For Pathogenesis In Retrovirus-Induced Murine Immunodeficiency, Kathy A. Green, Randolph J. Noelle, Brigit G. Durell, William R. Green Apr 2001

Characterization Of The Cd154-Positive And Cd40-Positive Cellular Subsets Required For Pathogenesis In Retrovirus-Induced Murine Immunodeficiency, Kathy A. Green, Randolph J. Noelle, Brigit G. Durell, William R. Green

Dartmouth Scholarship

Genetically susceptible C57BL/6 (B6) mice that are infected with the LP-BM5 isolate of murine retroviruses develop profound splenomegaly, lymphadenopathy, hypergammaglobulinemia, terminal B-cell lymphomas, and an immunodeficiency state bearing many similarities to the pathologies seen in AIDS. Because of these similarities, this syndrome has been called murine AIDS (MAIDS). We have previously shown that CD154 (CD40 ligand)-CD40 molecular interactions are required both for the initiation and progression of MAIDS. Thus, in vivo anti-CD154 monoclonal antibody (MAb) treatment inhibited MAIDS symptoms in LP-BM5-infected wild-type mice when either a short course of anti-CD154 MAb treatment was started on the day of infection or …


Ups And Downs Of Mucosal Cellular Immunity Against Protozoan Parasites, Lloyd H. Kasper, Dominique Buzoni-Gatel Jan 2001

Ups And Downs Of Mucosal Cellular Immunity Against Protozoan Parasites, Lloyd H. Kasper, Dominique Buzoni-Gatel

Dartmouth Scholarship

No abstract provided.


Vaccinia Virus-Mediated Glioma Gene Therapy Using P53, Il-2 And Il-12, Bing Chen Dec 2000

Vaccinia Virus-Mediated Glioma Gene Therapy Using P53, Il-2 And Il-12, Bing Chen

Loma Linda University Electronic Theses, Dissertations & Projects

Malignant brain tumors are generally lethal soon after their diagnosis, and the five-year survival rate for the patient is low in spite of neurosurgery, radiation therapy, and/or chemotherapy. Gene therapy has the potential to improve patient survival and quality of life by delivering specific combinations of therapeutic genes directly to the tumor for localized treatment.

We have based our cancer gene therapy for glioma on a highly attenuated variant of the Lister strain of vaccinia virus (VV) which has been proven to be a safe and effective vaccine vector. Other advantages include a wide host range, a strong promoter system, …


Lack Of Cd4+ T Cells Does Not Affect Induction Of Cd8+ T-Cell Immunity Against Encephalitozoon Cuniculi Infection, Magali Moretto, Lori Casciotti, Brigit Durell, Imtiaz A. Khan Nov 2000

Lack Of Cd4+ T Cells Does Not Affect Induction Of Cd8+ T-Cell Immunity Against Encephalitozoon Cuniculi Infection, Magali Moretto, Lori Casciotti, Brigit Durell, Imtiaz A. Khan

Dartmouth Scholarship

Cell-mediated immunity has been reported to play an important role in defense against Encephalitozoon cuniculi infection. Previous studies from our laboratory have underlined the importance of cytotoxic CD8+ T lymphocytes (CTL) in survival of mice infected with E. cuniculi. In the present study, immune response against E. cuniculi infection in CD4+T-cell-deficient mice was evaluated. Similar to resistant wild-type animals, CD4−/− mice were able to resolve E. cuniculi infection even at a very high challenge dose (5 × 107 spores/mouse). Tissues from infected CD4−/−mice did not exhibit higher parasite loads in comparison to …


Staphylococcus Aureus Rn6390 Replicates And Induces Apoptosis In A Pulmonary Epithelial Cell Line, Barbara C. Kahl, Mark Goulian, Willem Van Wamel, Mathias Herrmann, Sanford M. Simon, Gilla Kaplan, Georg Peters, Ambrose L. Cheung Sep 2000

Staphylococcus Aureus Rn6390 Replicates And Induces Apoptosis In A Pulmonary Epithelial Cell Line, Barbara C. Kahl, Mark Goulian, Willem Van Wamel, Mathias Herrmann, Sanford M. Simon, Gilla Kaplan, Georg Peters, Ambrose L. Cheung

Dartmouth Scholarship

Staphylococcus aureus frequently colonizes the airways of patients with compromised airway defenses (e.g., cystic fibrosis [CF] patients) for extended periods. Persistent and relapsing infections may be related to live S. aureus bacteria actively residing inside epithelial cells. In this study, we infected a respiratory epithelial cell line, which was derived from a CF patient, with S. aureus RN6390. Internalization of S. aureus was found to be time and dose dependent and could be blocked by cytochalasin D. Transmission electron microscopy revealed that internalized bacteria resided within endocytic vacuoles without any evidence of lysosomal fusion in a 24-h period. The results …


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 …


Anti-Gag Cytolytic T Lymphocytes Specific For An Alternative Translational Reading Frame-Derived Epitope And Resistance Versus Susceptibility To Retrovirus-Induced Murine Aids In F1 Mice, Shawn-Marie Mayrand, Patricia A. Healy, Bruce E. Torbett, William R. Green Apr 2000

Anti-Gag Cytolytic T Lymphocytes Specific For An Alternative Translational Reading Frame-Derived Epitope And Resistance Versus Susceptibility To Retrovirus-Induced Murine Aids In F1 Mice, Shawn-Marie Mayrand, Patricia A. Healy, Bruce E. Torbett, William R. Green

Dartmouth Scholarship

Murine AIDS (MAIDS) develops in susceptible mouse strains after infection with the LP-BM5 murine leukemia virus complex that contains causative defective, and ecotropic helper, retroviruses. We previously demonstrated that the MAIDSresistant H-2d strains BALB/cByJ and C57BL/KsJ generate MHC class I (Kd ) restricted virus-specific CD81 cytolytic T lymphocytes (CTLs) that lyse cells expressing either defective or ecotropic gag proteins. In contrast, the congenic BALB.B and closely related C57BL/6J MAIDS-susceptible H-2b strains were unable to serve as a source of gag-specific CTLs (Schwarz and Green, 1994), suggesting that anti-gag CTLs might provide a basis for resistance to MAIDS. Although its susceptibility …


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 …


Childhood Non-Hodgkin's Lymphoma: An Immunophenotypic Analysis., Sajid Hussain Shah, Suhail Muzaffar, Shahid Pervez, Sheema H. Hassan Mar 2000

Childhood Non-Hodgkin's Lymphoma: An Immunophenotypic Analysis., Sajid Hussain Shah, Suhail Muzaffar, Shahid Pervez, Sheema H. Hassan

Department of Pathology and Laboratory Medicine

Objective: To observe the frequency of histological subtypes of childhood non-Hodgkin`s lymphoma and its immunohistochemical profile.

Setting: All cases of non-Hodgkin’s lymphoma diagnosed in children (<15 years) in the section of histopithology at the Aga Khan University Hospital Karachi during the period of three years.

Methods: These consecutive cases were evaluated on H&E stained sections and then immunohistochemistry analysis of these tumors was performed by employing Peroxidase Anti-Peroxidase (PAP) technique.

Results: The present series included 61 cases of non-Hodgkin’s lymphoma. NHL was more common in males as compared to females with male to female ratio of 5.8:1. High grade NHL comprised 87% of childhood lymphoma. The mode of presentation in majority of NHL (57%) was extranodal. Burkitt’s lymphonia (33%) …


Naturally Occurring Tap-Dependent Specific T-Cell Tolerance For A Variant Of An Immunodominant Retroviral Cytotoxic T-Lymphocyte Epitope, Victor Kim, Jonathan W. Yewdell, William R. Green Jan 2000

Naturally Occurring Tap-Dependent Specific T-Cell Tolerance For A Variant Of An Immunodominant Retroviral Cytotoxic T-Lymphocyte Epitope, Victor Kim, Jonathan W. Yewdell, William R. Green

Dartmouth Scholarship

Upon immunization and restimulation with tumors induced by the endogenous AKR/Gross murine leukemia virus (MuLV), C57BL/6 mice generate vigorous H-2K(b)-restricted cytotoxic T-lymphocyte (CTL) responses to a determinant (KSPWFTTL) derived from the p15E transmembrane portion of the viral envelope glycoprotein. By contrast, the highly homologous determinant RSPWFTTL, expressed by tumor cells induced by Friend/Moloney/Rauscher (FMR) MuLV, is not immunogenic, even when presented to the immune system as vaccinia virus-encoded cytosolic or endoplasmic reticulum (ER)-targeted minigene products. Such minigene products are usually highly immunogenic since they bypass the need for cells to liberate the peptide or transport the peptide into the ER …


Identification Of The Transactivation Domain Of The Transcription Factor Sox-2 And An Associated Co-Activator, Tamara K. Nowling, Lance R. Johnson, Matthew S. Wiebe, Angie Rizzino Jan 2000

Identification Of The Transactivation Domain Of The Transcription Factor Sox-2 And An Associated Co-Activator, Tamara K. Nowling, Lance R. Johnson, Matthew S. Wiebe, Angie Rizzino

Nebraska Center for Virology: Faculty Publications

The importance of interactions between Sox and POU transcription factors in the regulation of gene expression is becoming increasingly apparent. Recently, many examples of the involvement of Sox-POU partnerships in transcription have been discovered, including a partnership between Sox-2 and Oct-3. Little is known about the mechanisms by which these factors modulate transcription. To better understand the molecular interactions involved, we mapped the location of the transactivation do-main of Sox-2. This was done in the context of its interaction with Oct-3, as well as its ability to transactivate as a fusion protein linked to the DNA-binding domain of Gal4. Both …


Telomerase Activity In Human Preimplantation Embryos, Diane Lynne Wright Jan 2000

Telomerase Activity In Human Preimplantation Embryos, Diane Lynne Wright

Theses and Dissertations in Biomedical Sciences

Telomerase, a ribonucleoprotein, has been described as an essential component of highly proliferative cells, which stabilizes the telomeres and avoids cellular senescence. Telomerase has been identified in various embryonic cell stages, hematopoietic cells, and in >85% of tumor tissue biopsies analyzed. The ability to measure the potential to proliferate successfully could provide an objective measure of an embryo's quality. The objectives of this study were to modify the telomeric repeat amplification protocol (TRAP) assay system for increased sensitivity to allow detection of telomerase activity in the single cell of an oocyte and embryo, obtain telomerase activity levels for the oocyte …


Monoclonal Antibody 1a7 And Related Polypeptides, Malaya Chatterjee, Kenneth A. Foon, Sunil K. Chatterjee Nov 1999

Monoclonal Antibody 1a7 And Related Polypeptides, Malaya Chatterjee, Kenneth A. Foon, Sunil K. Chatterjee

Microbiology, Immunology and Molecular Genetics Faculty Patents

The present invention relates to monoclonal antibody 1A7. This is an anti-idiotype produced by immunizing with an antibody specific for ganglioside GD2, and identifying a hybridoma secreting antibody with immunogenic potential in a multi-step screening process. Also disclosed are polynucleotide and polypeptide derivatives based on 1A7, including single chain variable region molecules and fusion proteins, and various pharmaceutical compositions. When administered to an individual, the 1A7 antibody overcomes immune tolerance and induces an immune response against GD2, which comprises a combination of anti-GD2 antibody and GD2-specific T cells. The invention further provides methods for treating a disease associated with altered …


Murine Anti-Idiotype Antibody 3h1, Malaya Chatterjee, Heinz Köhler, Sunil K. Chatterjee, Kenneth A. Foon Nov 1999

Murine Anti-Idiotype Antibody 3h1, Malaya Chatterjee, Heinz Köhler, Sunil K. Chatterjee, Kenneth A. Foon

Microbiology, Immunology and Molecular Genetics Faculty Patents

The present invention provides a monoclonal anti-idiotype antibody 3H1 that escapes immune tolerance and elicits a specific immune response to CEA in mice, rabbits, monkeys, and patients with advanced CEA-associated disease. This invention also provides compositions which can be used in the detection or treatment of CEA-associated tumors mimics a specific epitope on carcinoembryonic antigen and a hybridoma that produces 3H1.


Immune Responses Induced By Gene Gun Or Intramuscular Injection Of Dna Vaccines That Express Immunogenic Regions Of The Serine Repeat Antigen From Plasmodium Falciparum, Alexia A. Belperron, David Feltquate, Barbara A. Fox, Toshihiro Horii, David J. Bzik Oct 1999

Immune Responses Induced By Gene Gun Or Intramuscular Injection Of Dna Vaccines That Express Immunogenic Regions Of The Serine Repeat Antigen From Plasmodium Falciparum, Alexia A. Belperron, David Feltquate, Barbara A. Fox, Toshihiro Horii, David J. Bzik

Dartmouth Scholarship

The liver- and blood-stage-expressed serine repeat antigen (SERA) of Plasmodium falciparum is a candidate protein for a human malaria vaccine. We compared the immune responses induced in mice immunized with SERA-expressing plasmid DNA vaccines delivered by intramuscular (i.m.) injection or delivered intradermally by Gene Gun immunization. Mice were immunized with a pcdna3 plasmid encoding the entire 47-kDa domain of SERA (amino acids 17 to 382) or the N-terminal domain (amino acids 17 to 110) of SERA. Minimal antibody responses were detected following DNA vaccination with the N-terminal domain of SERA, suggesting that the N-terminal domain alone is not highly immunogenic …


Polynucleotides Related To Monoclonal Antibody 1a7 And Use For The Treatment Of Melanoma And Small Cell Carcinoma, Malaya Chatterjee, Kenneth A. Foon, Sunil K. Chatterjee Aug 1999

Polynucleotides Related To Monoclonal Antibody 1a7 And Use For The Treatment Of Melanoma And Small Cell Carcinoma, Malaya Chatterjee, Kenneth A. Foon, Sunil K. Chatterjee

Microbiology, Immunology and Molecular Genetics Faculty Patents

The present invention relates to monoclonal antibody 1A7. This is an anti-idiotype produced by immunizing with an antibody specific for ganglioside GD2, and identifying a hybridoma secreting antibody with immunogenic potential in a multi-step screening process. Also disclosed are polynucleotide and polypeptide derivatives based on 1A7, including single chain variable region molecules and fusion proteins, and various pharmaceutical compositions. When administered to an individual, the 1A7 antibody overcomes immune tolerance and induces an immune response against GD2, which comprises a combination of anti-GD2 antibody and GD2-specific T cells. The invention further provides methods for treating a disease associated with altered …


Dichotomy Between Naïve And Memory Cd4+ T Cell Responses To Fas Engagement, J. Desbarats, T. Wade, W. F. Wade, M. K. Newell Jul 1999

Dichotomy Between Naïve And Memory Cd4+ T Cell Responses To Fas Engagement, J. Desbarats, T. Wade, W. F. Wade, M. K. Newell

Dartmouth Scholarship

Engagement of Fas (APO-1, CD95), a member of the tumor necrosis factor receptor superfamily, can induce apoptotic cell death. However, Fas engagement also can costimulate lymphocyte proliferation. The physiologic regulation of these two outcomes is poorly understood. Here, we have used two systems, the first in vitro and the second in vivo, to demonstrate that naïve and memory CD4+ T cells display dichotomous responses to Fas ligation. Naïve CD4+ T cells (CD44lo, CD45RB+, CD62L+) die as a consequence of Fas ligation in the presence of anti-CD3 antibody, whereas memory T cells (CD44hi, CD45RB−, CD62L−), freshly isolated from the same …


Attachment Ligands Of Viable Toxoplasma Gondii Induce Soluble Immunosuppressive Factors In Human Monocytes, Jacqueline Y. Channon, Edward I. Suh, Rosanne M. Seguin, Lloyd H. Kasper May 1999

Attachment Ligands Of Viable Toxoplasma Gondii Induce Soluble Immunosuppressive Factors In Human Monocytes, Jacqueline Y. Channon, Edward I. Suh, Rosanne M. Seguin, Lloyd H. Kasper

Dartmouth Scholarship

Previous studies have demonstrated that surface antigen proteins, in particular SAG-1, of Toxoplasma gondii are important to this parasite as attachment ligands for the host cell. An in vitro assay was developed to test whether these ligands and other secretory proteins are involved in the immune response of human cells to toxoplasma. Human monocytes were infected with tachyzoites in the presence of antiparasite antibodies, and their effect on mitogen-induced lymphoproliferation was examined. The presence of antibody to either parasite-excreted proteins (MIC-1 and MIC-2) or surface proteins (SAG-1 and SAG-2) during infection neutralized the marked decrease seen in mitogen-induced lymphoproliferation in …


Signal Transducer And Activator Of Transcription (Stat)5 Activation By Bcr/Abl Is Dependent On Intact Src Homology (Sh)3 And Sh2 Domains Of Bcr/Abl And Is Required For Leukemogenesis., M Nieborowska-Skorska, M A Wasik, A Slupianek, P Salomoni, T Kitamura, B Calabretta, T Skorski Apr 1999

Signal Transducer And Activator Of Transcription (Stat)5 Activation By Bcr/Abl Is Dependent On Intact Src Homology (Sh)3 And Sh2 Domains Of Bcr/Abl And Is Required For Leukemogenesis., M Nieborowska-Skorska, M A Wasik, A Slupianek, P Salomoni, T Kitamura, B Calabretta, T Skorski

Department of Microbiology and Immunology Faculty Papers

Signal transducer and activator of transcription (STAT)5 is constitutively activated in BCR/ ABL-expressing cells, but the mechanisms and functional consequences of such activation are unknown. We show here that BCR/ABL induces phosphorylation and activation of STAT5 by a mechanism that requires the BCR/ABL Src homology (SH)2 domain and the proline-rich binding site of the SH3 domain. Upon expression in 32Dcl3 growth factor-dependent myeloid precursor cells, STAT5 activation-deficient BCR/ABL SH3+SH2 domain mutants functioned as tyrosine kinase and activated Ras, but failed to protect from apoptosis induced by withdrawal of interleukin 3 and/or serum and did not induce leukemia in severe combined …


Role Of Gamma Interferon In Cellular Immune Response Against Murine Encephalitozoon Cuniculi Infection, Imtiaz A. Khan, Magali Moretto Apr 1999

Role Of Gamma Interferon In Cellular Immune Response Against Murine Encephalitozoon Cuniculi Infection, Imtiaz A. Khan, Magali Moretto

Dartmouth Scholarship

Microsporidia are obligate intracellular protozoan parasites that cause a wide variety of opportunistic infection in patients with AIDS. Because it is able to grow in vitro, Encephalitozoon cuniculi is currently the best-studied microsporidian. T cells mediate protective immunity against this parasite. Splenocytes obtained from infected mice proliferate in vitro in response to irradiated parasites. A transient state of hyporesponsiveness to parasite antigen and mitogen was observed at day 17 postinfection. This downregulatory response could be partially reversed by addition of nitric oxide (NO) antagonist to the culture. Mice infected withE. cuniculi secrete significant levels of gamma interferon (IFN-γ). Treatment …


Identification Of Putative Cytoskeletal Protein Homologues In The Protozoan Host Hartmannella Vermiformis As Substrates For Induced Tyrosine Phosphatase Activity Upon Attachment To The Legionnaires' Disease Bacterium, Legionella Pneumophila, Chandrasekar Venkataraman, Lian-Yang Gao, Subbarao Bondada, Yousef Abu Kwaik Aug 1998

Identification Of Putative Cytoskeletal Protein Homologues In The Protozoan Host Hartmannella Vermiformis As Substrates For Induced Tyrosine Phosphatase Activity Upon Attachment To The Legionnaires' Disease Bacterium, Legionella Pneumophila, Chandrasekar Venkataraman, Lian-Yang Gao, Subbarao Bondada, Yousef Abu Kwaik

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The Legionnaires' disease bacterium, Legionella pneumophila, is a facultative intracellular pathogen that invades and replicates within two evolutionarily distant hosts, free living protozoa and mammalian cells. Invasion and intracellular replication within protozoa are thought to be major factors in the transmission of Legionnaires' disease. We have recently reported the identification of a galactose/N-acetyl-d-galactosamine (Gal/GalNAc) lectin in the protozoan host Hartmannella vermiformis as a receptor for attachment and invasion by L. pneumophila (Venkataraman, C., B.J. Haack, S. Bondada, and Y.A. Kwaik. 1997. J. Exp. Med. 186:537–547). In this report, we extended our studies to the …


Expression Of Toxoplasma Gondii-Specific Heat Shock Protein 70 During In Vivo Conversion Of Bradyzoites To Tachyzoites, Neide M. Silva, Ricardo T. Gazzinelli, Deise A. O. Silva, Eloisa A. V. Ferro, Lloyd H. Kasper, Jose R. Mineo Aug 1998

Expression Of Toxoplasma Gondii-Specific Heat Shock Protein 70 During In Vivo Conversion Of Bradyzoites To Tachyzoites, Neide M. Silva, Ricardo T. Gazzinelli, Deise A. O. Silva, Eloisa A. V. Ferro, Lloyd H. Kasper, Jose R. Mineo

Dartmouth Scholarship

Stage conversion between bradyzoites and tachyzoites was investigated in C57BL/6 mice chronically infected with the ME-49 strain of Toxoplasma gondii. In order to promote bradyzoite-tachyzoite conversion, mice were treated in vivo with neutralizing doses of anti-gamma interferon (IFN-gamma) or anti-tumor necrosis factor alpha (TNF-alpha) antibodies. Expression of parasite-specific antigens SAG-1, SAG-2, and heat shock protein 70 (Hsp-70) was visualized in the central nervous system by immunocytochemistry and measured by photometric assay. The immunosuppressive effect of anti-IFN-gamma or anti-TNF-alpha treatment was immediate, leading to parasite stage conversion as indicated by the increased expression of tachyzoite-specific antigens (SAG-1 and SAG-2) and by …


Expression Of Constitutively Active Raf-1 In The Mitochondria Restores Antiapoptotic And Leukemogenic Potential Of A Transformation-Deficient Bcr/Abl Mutant., P Salomoni, M A Wasik, R F Riedel, K Reiss, J K Choi, T Skorski, B Calabretta Jun 1998

Expression Of Constitutively Active Raf-1 In The Mitochondria Restores Antiapoptotic And Leukemogenic Potential Of A Transformation-Deficient Bcr/Abl Mutant., P Salomoni, M A Wasik, R F Riedel, K Reiss, J K Choi, T Skorski, B Calabretta

Department of Microbiology and Immunology Faculty Papers

The oncogenic BCR/ABL protein protects hematopoietic cells from apoptosis induced by growth factor deprivation, but the mechanisms are only partially understood. A BCR/ABL mutant lacking amino acids 176-426 in the BCR domain (p185DeltaBCR) failed to protect interleukin 3-deprived 32Dcl3 myeloid precursor cells from apoptosis, although it possessed tyrosine kinase activity and was capable of activating the Ras-Raf-MAP kinase pathway. Compared to p185 wild-type transfectants, p185DeltaBCR-transfected cells showed markedly reduced levels of Bcl-2 and expressed the hypophosphorylated, proapoptotic form of BAD. Bcl-2 expression in the mitochondrial fraction of p185DeltaBCR cells was also markedly diminished and mitochondrial RAF was undetectable. In p185DeltaBCR …