Medical Immunology Commons^™

The Cd154/Cd40 Interaction Required For Retrovirus-Induced Murine Immunodeficiency Syndrome Is Not Mediated By Upregulation Of The Cd80/Cd86 Costimulatory Molecules, Kathy A. Green, W. James Cook, Arlene H. Sharpe, William R. Green

Dartmouth Scholarship

C57BL/6 (B6) mice infected with LP-BM5 retroviruses develop disease, including an immunodeficiency similar to AIDS. This disease, murine AIDS (MAIDS), is inhibited by in vivo anti-CD154 monoclonal antibody treatment. The similar levels of insusceptibility of CD40^−/− and CD154^−/− B6 mice indicate that CD154/CD40 molecular interactions are required for MAIDS. CD4⁺ T and B cells, respectively, provide the CD154 and CD40 expression needed for MAIDS induction. Here, the required CD154/CD40 interaction is shown to be independent of CD80 and CD86 expression: CD80/CD86^−/− B6 mice develop MAIDS after LP-BM5 infection.

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 …

Defective Cd19-Dependent Signaling In B-1a And B-1b B Lymphocyte Subpopulations., Goutam Sen, Hsin-Jung Wu, Gabriel Bikah, Chandrasekar Venkataraman, Darrell A Robertson, E Charles Snow, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Peritoneal and pleural cavities in mice and humans contain a unique population of B-lymphocytes called B-1 cells that are defective in B cell antigen receptor (BCR) signaling but have an increased propensity to produce autoantibodies. Several molecules such as Btk, Vav, and CD19 known to be important for BCR signaling have been shown to be critical for the development of B-1 cells from undefined precursors. Here we demonstrate that B-1 cell unresponsiveness to BCR cross-linking is in part due to defective signaling through CD19, a molecule known to modulate signaling thresholds in B cells. The defective CD19 signaling is manifested …

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 …

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 …

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 …

Short-Lived And Long-Lived Bone Marrow Plasma Cells Are Derived From A Novel Precursor Population, Brian P. O'Connor, Marilia Cascalho, Randolph J. Noelle

Dartmouth Scholarship

The contribution that long-lived bone marrow (BM) plasma cells (PCs) provide to enduring humoral immunity has been underscored by a number of recent studies. However, little is known about the immediate precursors that give rise to long-lived PCs in the BM of immune individuals. We have identified subsets of antigen-experienced B cells within the immune BM that are precursors to PCs. These PC precursors arise in the BM 14 days after immunization and persist for greater than 9 months. Phenotypically distinct subsets of PC precursors give rise to short-lived or long-lived PCs. The differentiation of PC precursors to PCs occurs …

Methods And Compositions For The Treatment Of Psoriasis, Kenneth A. Foon, Malaya Chatterjee

Microbiology, Immunology and Molecular Genetics Faculty Patents

This invention provides methods of treating psoriasis which entail eliciting an immune response in an individual against an antigen aberrantly expressed in psoriatic tissue, such as a ganglioside, in an individual. The anti-ganglioside immune response is elicited by administration of an antigen such as a ganglioside, an anti-idiotype moiety for a ganglioside, or a polynucleotide encoding an anti-idiotype moiety. Also described is a strategy for developing additional compositions for psoriasis. The compositions elicit an immunological response against a target antigen present on psoriatic tissue, which in turn can be detected using antibody affinity-purified from the serum of the treated subject. …

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 …

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 …

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 …

Positive And Negative Roles Of Cd72 In B Cell Function., Hsin-Jung Wu, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Regulation of B cell activation depends on integration of signals transmitted by the B cell receptor (BCR) and a variety of co-receptors. CD72 is a B cell co-receptor that is expressed in all stages of B cell development except plasma cells. Ligation of CD72 enhances B cell growth and differentiation. Recently, the class IV semaphoring, CD100, has been identified as the natural ligand for CD72. Cytoplasmic domain of CD72 has been shown to be associated with SHP-1 leading to the proposal that the positive effects of CD72 on B cell response may result from sequestration of negative signals from BCR. …

Increased Production Of Pro-Inflammatory Cytokines And Enhanced T Cell Responses After Activation Of Human Dendritic Cells With Il-1 And Cd40 Ligand, Amy Wesa, Anne Galy

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Various microbial, inflammatory and immune signals regulate the activation of dendritic cells (DC), determining their ability to interact with naïve T cells and to produce cytokines that direct T cell development. In particular, CD40L and IL-1 cooperatively activate DC to secrete high levels of IL-12. The immuno-stimulatory capacity of such DC is otherwise not well-defined prompting further characterization of the effects of IL-1 and family members on DC activation in comparison with other pro-inflammatory stimuli.

Results

Human DC co-activated in vitro by CD40L and IL-1β expressed numerous cytokine genes including IL-12β, IL-23 p19, IL-1β, IL-1α, IL-1Ra, IL-10, IL-6, …

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 …

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 …