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Articles 931 - 960 of 976

Full-Text Articles in Medical Immunology

Cd46-Mediated Transduction Of A Species D Adenovirus Vaccine Improves Mucosal Vaccine Efficacy, Zenaido T. Camacho, Mallory A. Turner, Michael A. Barry, Eric A. Weaver Jan 2004

Cd46-Mediated Transduction Of A Species D Adenovirus Vaccine Improves Mucosal Vaccine Efficacy, Zenaido T. Camacho, Mallory A. Turner, Michael A. Barry, Eric A. Weaver

Nebraska Center for Virology: Faculty Publications

The high levels of preexisting immunity against Adenovirus type 5 (Ad5) have deemed Ad5 unusable for translation as a human vaccine vector. Low seroprevalent alternative viral vectors may be less impacted by preexisting immunity, but they may also have significantly different phenotypes from that of Ad5. In this study we compare species D Ads (26, 28, and 48) to the species C Ad5. In vitro transduction studies show striking differences between the species C and D viruses. Most notably, Ad26 transduced human dendritic cells much more effectively than Ad5. In vivo imaging studies showed strikingly different transgene expression profiles. The …


Phylogenetic Analyses Of Texas Isolates Indicate An Evolving Subtype Of The Clade B Feline Immunodeficiency Viruses, Eric A. Weaver, Ellen W. Collisson, Margaret Slater, Guan Zhu Jan 2004

Phylogenetic Analyses Of Texas Isolates Indicate An Evolving Subtype Of The Clade B Feline Immunodeficiency Viruses, Eric A. Weaver, Ellen W. Collisson, Margaret Slater, Guan Zhu

Nebraska Center for Virology: Faculty Publications

Rigorous phylogenetic analyses were used to compare the nucleotide sequences of feline immunodeficiency virus strains isolated from Texas and throughout the world. The envelope V3-V4 sequences and capsid gene of the Texas isolates formed a cluster between subtypes B and E. Statistical comparisons with other published sequences confirmed that the Texas group is a unique cluster, possibly a new subtype, arising from subtype B.


Determination Of The Optimal Form Of A Dna Vaccine To Induce An Effective Immune Response Against A Murine B-Cell Lymphoma, Deepti Aurora Dec 2003

Determination Of The Optimal Form Of A Dna Vaccine To Induce An Effective Immune Response Against A Murine B-Cell Lymphoma, Deepti Aurora

All-Inclusive List of Electronic Theses and Dissertations

Tumor vaccines are a promising alternative to chemotherapy for the treatment of cancer. To be effective and safe, a cancer vaccine should specifically target antigens expressed only on tumor cells. The B-cell tumor-derived Ig receptor may be considered a model tumor antigen for cancer vaccine development. Specifically the immunoglobulin idiotype (ld) encoded by the variable region genes (VH and VL) provides a target antigen. Promising results have been obtained in clinical studies of ld vaccination using ld proteins. However, ld protein is laborious and time-consuming to produce. Gene-based vaccines, on the other hand, are inexpensive and offer ease of manipulation …


Il-7 Enhances Peripheral T Cell Reconstitution After Allogeneic Hematopoietic Stem Cell Transplantation., Onder Alpdogan, Stephanie J Muriglan, Jeffrey M Eng, Lucy M Willis, Andrew S Greenberg, Barry J Kappel, Marcel R M Van Den Brink Oct 2003

Il-7 Enhances Peripheral T Cell Reconstitution After Allogeneic Hematopoietic Stem Cell Transplantation., Onder Alpdogan, Stephanie J Muriglan, Jeffrey M Eng, Lucy M Willis, Andrew S Greenberg, Barry J Kappel, Marcel R M Van Den Brink

Department of Medical Oncology Faculty Papers

We used clinically relevant murine allogeneic bone marrow transplantation (BMT) models to study the mechanisms by which IL-7 administration can improve posttransplant peripheral T cell reconstitution. After transplant we could distinguish two populations of mature donor T cells: (a) alloreactive T cells with decreased expression of CD127 (IL-7 receptor alpha chain) and (b) nonalloreactive T cells, which express CD127 and undergo homeostatic proliferation. IL-7 administration increased the homeostatic proliferation of nonalloreactive T cells, but had no effect on alloreactive T cells and the development of graft-versus-host disease. Allogeneic transplant of purified hematopoietic stem cells and adoptive transfer of thymocytes into …


Animal Anti-Apoptotic Genes Ameliorate The Loss Of Turgor In Water-Stressed Transgenic Tobacco, Tala Awada, D. D. Dunigan, M. B. Dickman Jan 2003

Animal Anti-Apoptotic Genes Ameliorate The Loss Of Turgor In Water-Stressed Transgenic Tobacco, Tala Awada, D. D. Dunigan, M. B. Dickman

Nebraska Center for Virology: Faculty Publications

Nicotiana tabacum L. ‘Glurk’ plants were transformed with antiapoptotic animal genes [chicken Bcl-xl; nematode CED-9; chicken Bcl-xl(GA) a mutant of Bcl-xl; and a 3’ non-coding region of human Bcl-2, referred to as 161-1]. Our objectives were to determine whether plant transformation with anti-apoptotic genes ameliorates drought tolerance in tobacco plants by subjecting the plants to a dry-down period. The non-transformed Glurk and the transgenic Glurk harboring G115, which expresses β-glucuronidase, served as controls. Transformation of tobacco plants with animal anti-apoptotic genes significantly impacted the rates of photosynthesis (A) and stomatal conductance (gs), but not to the same extent …


Identification Of Novel Domains Within Sox-2 And Sox-11 Involved In Autoinhibition Of Dna Binding And Partnership Specificity, Matthew S. Wiebe, Tamara K. Nowling, Angie Rizzino Jan 2003

Identification Of Novel Domains Within Sox-2 And Sox-11 Involved In Autoinhibition Of Dna Binding And Partnership Specificity, Matthew S. Wiebe, Tamara K. Nowling, Angie Rizzino

Nebraska Center for Virology: Faculty Publications

Sox transcription factors play key regulatory roles throughout development, binding DNA through a consensus (A/T)(A/T)CAA(A/T)G sequence. Although many different Sox proteins bind to this se-quence, it has been observed that gene regulatory elements are commonly responsive to only a small subset of the entire family, implying that regulatory mechanisms exist to permit selective DNA bind-ing and/or transactivation by Sox family members. To identify and explore the mechanisms modu-lating gene activation by Sox proteins further, we compared the function of Sox-2 and Sox-11. This led to the discovery that Sox proteins are regulated differentially at multiple levels, including trans-activation, protein partnerships …


Structural Analyses Of Phycodnaviridae And Iridoviridae, Alan A. Simpson, Narayanasamy Nandhagopal, James L. Van Etten, Michael G. Rossmann Jan 2003

Structural Analyses Of Phycodnaviridae And Iridoviridae, Alan A. Simpson, Narayanasamy Nandhagopal, James L. Van Etten, Michael G. Rossmann

Nebraska Center for Virology: Faculty Publications

The Phycodnaviridae, Iridoviridae and related viruses, with diameters of 1500±2000 A Ê , are formed from large trigonal arrays of hexagonally close-packed capsomers forming the faces of icosahedra [Yan et al. (2000), Nature Struct. Biol. 7, 101-103; Nandhagopal et al. (2002), Proc. Natl Acad. Sci. USA, 99, 14758-14763]. Caspar and Klug predicted that such structures could be assembled from hexameric capsomers [Caspar & Klug (1962), Cold Spring Harbor. Symp. Quant. Biol. 27, 1-24], as was subsequently found in numerous icosahedral viruses. During the course of evolution, some viruses, including the virus families …


Functional Implications In Apoptosis By Interferon Inducible Gene Product 1-8d, The Binding Protein To Adenovirus Preterminal Protein, Insil Joung, Peter C. Angeletti, Jeffrey A. Engler Jan 2003

Functional Implications In Apoptosis By Interferon Inducible Gene Product 1-8d, The Binding Protein To Adenovirus Preterminal Protein, Insil Joung, Peter C. Angeletti, Jeffrey A. Engler

Nebraska Center for Virology: Faculty Publications

Adenovirus (Ad) precursor to the terminal protein (pTP) plays an essential roles in the viral DNA

replication. Ad pTP serves as a primer for the synthesis of a new DNA strand during the initiation

step of replication. In addition, Ad pTP forms organized spherical replication foci on the nuclear

matrix (NM) and anchors the viral genome to the NM. Here we identified the interferon inducible

gene product 1-8D (Inid) as a pTP binding protein by using a two-hybrid screen of a HeLa cDNA

library. Of the clones obtained in this assay, nine were identical to the Inid, a 13-kDa polypeptide …


Toxoplasma Gondii Induces Granulocyte Colony-Stimulating Factor And Granulocyte-Macrophage Colony-Stimulating Factor Secretion By Human Fibroblasts: Implications For Neutrophil Apoptosis, Jacqueline Y. Channon, Kristin A. Miselis, Laurie A. Minns, Chaitali Dutta, Lloyd H. Kasper Nov 2002

Toxoplasma Gondii Induces Granulocyte Colony-Stimulating Factor And Granulocyte-Macrophage Colony-Stimulating Factor Secretion By Human Fibroblasts: Implications For Neutrophil Apoptosis, Jacqueline Y. Channon, Kristin A. Miselis, Laurie A. Minns, Chaitali Dutta, Lloyd H. Kasper

Dartmouth Scholarship

Human neutrophils are rescued from apoptosis following incubation with once-washed, fibroblast-derived Toxoplasma gondii tachyzoites. Both infected and uninfected neutrophils are rescued, implicating a soluble mediator. In this study we investigated the origin and identity of this soluble mediator. Neutrophils were incubated either with purified tachyzoites or with conditioned medium derived from T. gondii-infected human fibroblasts. Conditioned medium was found to be a potent stimulus that delayed neutrophil apoptosis up to 72 h, whereas purified and extensively washed tachyzoites had no effect. Delayed apoptosis correlated with up-regulation of the neutrophil antiapoptotic protein, Mcl-1, and the neutrophil interleukin 3 receptor alpha subunit …


Treatment With Soluble Interleukin-15ralpha Exacerbates Intracellular Parasitic Infection By Blocking The Development Of Memory Cd8+ T Cell Response, Imtiaz A. Khan, Magali Moretto, Xiao-Qing Wei, Martha Williams, Joseph D. Schwartzman, F Y. Liew Jun 2002

Treatment With Soluble Interleukin-15ralpha Exacerbates Intracellular Parasitic Infection By Blocking The Development Of Memory Cd8+ T Cell Response, Imtiaz A. Khan, Magali Moretto, Xiao-Qing Wei, Martha Williams, Joseph D. Schwartzman, F Y. Liew

Dartmouth Scholarship

Interferon (IFN)-γ–producing CD8+ T cells are important for the successful resolution of the obligate intracellular parasite Toxoplasma gondii by preventing the reactivation or controlling a repeat infection. Previous reports from our laboratory have shown that exogenous interleukin (IL)-15 treatment augments the CD8+ T cell response against the parasite. However, the role of endogenous IL-15 in the proliferation of activated/memory CD8+ T cells during toxoplasma or any other infection is unknown. In this study, we treated T. gondii immune mice with soluble IL-15 receptor α (sIL-15Rα) to block the host endogenous IL-15. The treatment markedly reduced the ability …


Cd8+-T-Cell Immunity Against Toxoplasma Gondii Can Be Induced But Not Maintained In Mice Lacking Conventional Cd4+ T Cells, Lori Casciotti, Kenneth H. Ely, Martha E. Williams, Imtiaz A. Khan Feb 2002

Cd8+-T-Cell Immunity Against Toxoplasma Gondii Can Be Induced But Not Maintained In Mice Lacking Conventional Cd4+ T Cells, Lori Casciotti, Kenneth H. Ely, Martha E. Williams, Imtiaz A. Khan

Dartmouth Scholarship

T-cell immunity is critical for survival of hosts infected with Toxoplasma gondii. Among the cells in the T-cell population, CD8+ T cells are considered the major effector cells against this parasite. It is believed that CD4+ T cells may be crucial for induction of the CD8+-T-cell response against T. gondii. In the present study, CD4−/− mice were used to evaluate the role of conventional CD4+ T cells in the immune response against T. gondii infection. CD4−/− mice infected with T. gondii exhibited lower gamma interferon (IFN-γ) messages in the majority of their …


Factors Influencing Immunization Status In Primary Care Clinics, David Page, Jan Meires, Amy B. Dailey Jan 2002

Factors Influencing Immunization Status In Primary Care Clinics, David Page, Jan Meires, Amy B. Dailey

Health Sciences Faculty Publications

Background and Objectives: National standards and goals for childhood immunization rates are well established. Yet, despite clear standards and goals, physicians do not achieve the desired rate (90%) for immunization coverage. This study examined factors related to immunization status for 2-year-old children in pediatric and family practice settings.

Methods: Specially trained personnel used computer software to audit 2,552 records from 42 practices in Northeast Florida throughout 1997–1999. Immunization records were judged as either complete or incomplete, and factors related to immunization status were studied. Clinic type and 18 immunization practice standards were reviewed for effect on immunization status.

Results: The …


Small Glutamine-Rich Protein/Viral Protein U–Binding Protein Is A Novel Cochaperone That Affects Heat Shock Protein 70 Activity, Peter C. Angeletti, Doriann Walker, Antonito T. Panganiban Jan 2002

Small Glutamine-Rich Protein/Viral Protein U–Binding Protein Is A Novel Cochaperone That Affects Heat Shock Protein 70 Activity, Peter C. Angeletti, Doriann Walker, Antonito T. Panganiban

Nebraska Center for Virology: Faculty Publications

Molecular chaperone complexes containing heat shock protein (Hsp) 70 and Hsp90 are regulated by cochaperones, including a subclass of regulators, such as Hsp70 interacting protein (Hip), C-terminus of Hsp70 interacting protein (CHIP), and Hsp70-Hsp90 organizing factor (Hop), that contain tetratricopeptide repeats (TPRs), where Hsp70 refers to Hsp70 and its nearly identical constitutive counterpart, Hsc70, together. These proteins interact with the Hsp70 to regulate adenosine triphosphatase (ATPase) and folding activities or to generate the chaperone complex. Here we provide evidence that small glutamine-rich protein/viral protein U–binding protein (SGT/UBP) is a cochaperone that negatively regulates Hsp70. By “Far-Western” and pull-down assays, SGT/UBP …


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 …


Evaluation Of A Tetracycline-Inducible Promoter In Staphylococcus Aureus In Vitro And In Vivo And Its Application In Demonstrating The Role Of Sigb In Microcolony Formation, B. T. Bateman, N. P. Donegan, T. M. Jarry, M. Palma Dec 2001

Evaluation Of A Tetracycline-Inducible Promoter In Staphylococcus Aureus In Vitro And In Vivo And Its Application In Demonstrating The Role Of Sigb In Microcolony Formation, B. T. Bateman, N. P. Donegan, T. M. Jarry, M. Palma

Dartmouth Scholarship

An inducible promoter system provides a powerful tool for studying the genetic basis for virulence. A variety of inducible systems have been used in other organisms, including pXyl-xylR-inducible promoter, the pSpac-lacI system, and the arabinose-inducible PBAD promoter, but each of these systems has limitations in its application to Staphylococcus aureus. In this study, we demonstrated the efficacy of a tetracycline-inducible promoter system in inducing gene expression in S. aureus in vitro and inside epithelial cells as well as in an animal model of infection. Using the xyl/tetO promoter::gfpuvr fusion carried on a shuttle …


Anti-Class Ii Monoclonal Antibody-Targeted Vibrio Cholerae Tcpa Pilin: Modulation Of Serologic Response, Epitope Specificity, And Isotype, Jia-Yan Wu, Ronald K. Taylor, William F. Wade Dec 2001

Anti-Class Ii Monoclonal Antibody-Targeted Vibrio Cholerae Tcpa Pilin: Modulation Of Serologic Response, Epitope Specificity, And Isotype, Jia-Yan Wu, Ronald K. Taylor, William F. Wade

Dartmouth Scholarship

Toxin-coregulated pilus (TCP) is a colonization factor required for cholera infection. It is not a strong immunogen when delivered in the context of whole cells, yet pilus subunits or TcpA derivative synthetic peptides induce protective responses. We examined the efficacy of immunizing mice with TCP conjugated to anti-class II monoclonal antibodies (MAb) with or without the addition of cholera toxin (CT) or anti-CD40 MAb to determine if the serologic response to TcpA could be manipulated. Anti-class II MAb-targeted TCP influenced the anti-TCP peptide serologic response with respect to titer and isotype. Responses to TcpA peptide 4 were induced with class …


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 …


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%) …


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 …


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 …


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 …


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 …


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 …


Antigen-Specific Cd8+ T Cells Protect Against Lethal Toxoplasmosis In Mice Infected With Neospora Caninum, Lloyd H. Kasper, Imtiaz A. Khan Apr 1998

Antigen-Specific Cd8+ T Cells Protect Against Lethal Toxoplasmosis In Mice Infected With Neospora Caninum, Lloyd H. Kasper, Imtiaz A. Khan

Dartmouth Scholarship

Neospora caninum is a coccidial protozoan parasite that appears morphologically indistinguishable from Toxoplasma gondii and that infects a large range of mammals. Both inbred and outbred strains of mice exhibit a high degree of resistance to infection with N. caninum. Three inbred strains of mice (A/J, BALB/c, and C57BL/6) that were infected intraperitoneally with N. caninum were protected against a lethal challenge from T. gondii. Vaccine-induced protection was Neospora dose dependent. A rise in the CD8+ T-cell population in mice that had been vaccinated with N. caninum and challenged with T. gondii was observed. Adoptive transfer of CD8+ T-cell splenocytes …


Chlamydia Trachomatis Infection In The Female Reproductive Tract Of The Rat: Influence Of Progesterone On Infectivity And Immune Response, Charu Kaushic, Andrew D. Murdin, Brian J. Underdown, Charles R. Wira Mar 1998

Chlamydia Trachomatis Infection In The Female Reproductive Tract Of The Rat: Influence Of Progesterone On Infectivity And Immune Response, Charu Kaushic, Andrew D. Murdin, Brian J. Underdown, Charles R. Wira

Dartmouth Scholarship

As the most common cause of sexually transmitted disease in women, chlamydial infections can lead to pelvic inflammatory disease, infertility, and ectopic pregnancy. To better understand the role played by sex hormones in modulating the immune response of the genital tract to microbial infections, we have developed a rat model to study Chlamydia trachomatis infection. Inbred female Lewis rats were primed with progesterone and inoculated by intrauterine instillation of C. trachomatis (mouse pneumonitis strain MoPn) into each uterine horn. When infected animals were examined for the presence of chlamydial antigens 14 days postinfection, both the uterus and vagina were found …


A Dichotomous Role For Nitric Oxide During Acute Toxoplasma Gondii Infection In Mice, Imtiaz A. Khan, Joseph D. Schwartzman, Tadashi Matsuura, Lloyd H. Kasper Dec 1997

A Dichotomous Role For Nitric Oxide During Acute Toxoplasma Gondii Infection In Mice, Imtiaz A. Khan, Joseph D. Schwartzman, Tadashi Matsuura, Lloyd H. Kasper

Dartmouth Scholarship

Production of nitric oxide by macrophages is believed to be an important microbicidal mechanism for a variety of intracellular pathogens, including Toxoplasma gondii. Mice with a targeted disruption of the inducible nitric oxide synthase gene (iNOS) were infected orally with T. gondii tissue cysts. Time to death was prolonged compared with parental controls. Histologic analysis of tissue from infected mice showed scattered small foci of inflammation with parasites in various tissues of iNOS−/− mice, whereas tissue from the parental C57BL/6 mice had more extensive tissue inflammation with few visible parasites. In particular, extensive ulceration and necrosis of distal small …


Metabolically Inactive Insulin Analog Prevents Type I Diabetes In Prediabetic Nod Mice, Dennis G. Karounos, J. Scott Bryson, D. A. Cohen Sep 1997

Metabolically Inactive Insulin Analog Prevents Type I Diabetes In Prediabetic Nod Mice, Dennis G. Karounos, J. Scott Bryson, D. A. Cohen

Internal Medicine Faculty Publications

The purpose of this study was to determine the relative importance of the metabolic effects of insulin for diabetes prevention by administering insulin or an inactive insulin analog by daily subcutaneous injections to prediabetic mice. A recombinant monomeric human insulin analog, which does not bind to the insulin receptor as a consequence of an alteration of a single amino acid at position 25 of the B chain, was shown to be equally effective at diabetes prevention as was intact insulin. In contrast to native insulin, the insulin analog did not cause hypoglycemia after subcutaneous injection. The insulin analog, however, protected …