bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gene Therapy of Experimental Autoimmune Thyroiditis by In Vivo Administration of Plasmid DNA Coding for Fas Ligand
Authors: Batteux Frédéric , Tourneur Léa , Trebeden Hélène , Charreire Jeannine , Chiocchia Gilles 
Published: December 2022

Abstract
Fas-Fas ligand (FasL) interaction is required for the maintenance of immune homeostasis and seems to be responsible for the privileged immune status of some tissues. Experimental autoimmune thyroiditis (EAT), which is characterized by autoreactive T and B cell responses and a marked lymphocytic infiltration of the thyroid, is a model of choice to study the therapeutic effects of FasL. Here, we provide evidence that direct injection of DNA expression vectors encoding FasL into the inflamed thyroid inhibited development of lymphocytic infiltration of the thyroid and induced death of infiltrating T cells. These results were paralleled by a total abrogation of anti-Tg cytotoxic T cell response in FasL-treated animals vs controls. In summary, our results show that FasL expression on thyrocytes may have a curative effect on ongoing EAT by inducing death of pathogenic autoreactive infiltrating T lymphocytes.
Stability of Naive and Memory Phenotypes on Resting CD4 T Cells In Vivo
Authors: Boursalian Tamar E. , Bottomly Kim 
Published: December 2022

AbstractThe reliable identification of naive and memory CD4 T cells is critical to understanding the cellular basis of immunological memory. However, it has long been a controversial issue whether naive and memory phenotypes are stable among resting CD4 T cells in the absence of overt stimulation or whether the proposed memory phenotype is a transient, reversible one that represents recently activated cells. In this study, adoptively transferred, purified populations of naive or memory phenotype CD4 T cells are monitored over time to assess the stability of phenotypes and the functional capabilities of transferred cells. Studying both TCR transgenic and nontransgenic CD4 T cell populations allows one to control for the capacity to respond to environmental Ags in vivo. Several findings are reported. The first is that in the absence of Ag, both naive and memory phenotypes remain unchanged over time. Second, when changes are seen in populations of transferred naive phenotype CD4 T cells, they take place only when there is a potential for antigenic challenge, suggesting that it is an Ag-driven event. Furthermore, when a change from naive to memory phenotype is observed, these transferred donor cells also function as memory cells. Third, the ability of memory CD4 T cells to retain the memory phenotype is independent of specific Ag.
Alleviation of Lipopolysaccharide-Induced Acute Liver Injury inPropionibacterium acnes-Primed IFN-γ-Deficient Mice by a Concomitant Reduction of TNF-α, IL-12, and IL-18 Production
Authors: Tsuji Hirokazu , Mukaida Naofumi , Harada Akihisa , Kaneko Shuichi , Matsushita Eiki , Nakanuma Yasuni , Tsutsui Hiroko , Okamura Haruki , Nakanishi Kenji , Tagawa Yoh-ichi , Iwakura Yoichiro , Kobayashi Ken-ichi , Matsushima Kouji 
Published: December 2022

AbstractThe present study was designed to investigate the role of IFN-γ in LPS-induced liver injury following priming with Propionibacterium acnes. At 1 week after priming BALB/c mice with P. acnes, a large number of macrophages (Mφ) and lymphocytes predominantly infiltrated the portal area, resulting in the intrahepatic formation of granulomas consisting of epithelioid and lymphoid cells. In comparison, in IFN-γ gene-disrupted BALB/c mice (IFN-γ knockout mice), the number of infiltrated Mφ was decreased, with a significant reduction in the number and size of granulomas. Subsequent elicitation with a low dose of LPS induced massive hepatic necrosis in wild-type BALB/c mice, with a marked increase in the serum levels of TNF-α, IL-12, and IL-18 and subsequently of alanine transferase. In contrast, IFN-γ knockout mice developed scattered focal necrosis of the liver with significantly lower levels of serum alanine transferase as well as drastic decreases in TNF-α, IL-12, and IL-18 production. The administration of an anti-IFN-γ neutralizing mAb at the eliciting phase significantly alleviated liver injury and reduced serum IL-12 and IL-18 levels. Thus, endogenously produced IFN-γ is involved in the pathogenesis of this liver injury model by regulating Mφ infiltration and granuloma formation in the priming phase as well as cytokine production in the eliciting phase.
A Role for Perforin in Activation-Induced T Cell Death In Vivo: Increased Expansion of Allogeneic Perforin-Deficient T Cells in SCID mice
Authors: Spaner David , Raju Kaliannan , Rabinovich Brian , Miller Richard G. 
Published: December 2022

AbstractDespite defective granule exocytosis, T cells from mice whose perforin gene was ablated by homologous recombination (pko mice) caused a similar degree of graft-vs-host disease as normal T cells after injection into sublethally irradiated C.B-17 SCID mice. Moreover host spleens contained significantly greater numbers of T cells from pko mice than from wild-type mice following their i.v. injection. This increase could not be explained by persistence of host APCs that were not cleared by defective donor cytotoxic effector cells. The absence of functional perforin-dependent suppressor cells or an altered cytokine profile of donor T cells could also not account for the behavior of pko cells. Spontaneous and Fas-mediated apoptosis of in vivo activated donor T cells were independent of donor origin. However, pko T blasts exhibited less growth inhibition and cell death after reactivation in vitro. The results are compatible with a model of a defective activation-induced cell death (AICD) pathway, controlled by perforin, accounting for the increased expansion of alloreactive pko T cells.
Rejection of Cardiac Xenografts by CD4+ or CD8+ T Cells
Authors: Lin Yuan , Soares Miguel P. , Sato Koichiro , Takigami Ko , Csizmadia Eva , Anrather Josef , Bach Fritz H. 
Published: December 2022

AbstractWe recently showed that brief complement inhibition induces accommodation of hamster cardiac transplants in nude rats. We have reconstituted nude rats carrying an accommodated xenograft with syngeneic CD4+ or CD8+ T cells to investigate the cellular mechanism of xenograft rejection. We show that CD4+ T cells can initiate xenograft rejection (10 ± 1.7 days) by promoting production of IgG xenoreactive Abs (XAb). These XAb are able to activate complement as well as to mediate Ab-dependent cell-mediated cytotoxicity. Adoptive transfer of these XAb into naive nude rats provoked hyperacute xenograft rejection (38 ± 13 min). The rejection was significantly (p &lt; 0.001) delayed by cobra venom factor (CVF; 11 ± 8 h in four of five cases) but was still more rapid than in control nude rats (3.3 ± 0.5 days). CVF plus NK cell depletion further prolonged survival (&gt;7 days in four of five cases; p &lt; 0.01 vs CVF only). CD8+ T cell-reconstituted nude rats rejected their grafts later (19.4 ± 5.8 days) and required a larger number of cells for transfer as compared with CD4+ T cell-reconstituted nude rats. However, second xenografts were rejected more rapidly than first xenografts in CD8+ T cell-reconstituted nude rats (9 ± 2 days), indicating that the CD8+ T cells had been activated. This study demonstrates that CD4+ and CD8+ T cells can both reject xenografts. The CD4+ cells do so at least in part by generation of helper-dependent XAb that act by both complement-dependent and Ab-dependent cell-mediated cytotoxicity mechanisms; the CD8+ cells do so as helper-independent cytotoxic T cells.
Nuclear Factor-κB p65 Mediates the Assembly and Activation of the TNF-Responsive Element of the Murine Monocyte Chemoattractant-1 Gene
Authors: Ping Dongsheng , Boekhoudt Gunther H. , Rogers Edward M. , Boss Jeremy M. 
Published: December 2022

Abstract
TNF-α transcriptionally regulates murine monocyte chemoattractant protein-1 (MCP-1) expression. Three approaches were used to determine the mechanism by which TNF regulates MCP-1. Mutation analysis showed that two distal κB sites, a novel dimethylsulfate-hypersensitive sequence, and a promoter proximal SP-1 site were required for TNF induction. Although the κB sites and the hypersensitive sequence function as a NF-κB-mediated enhancer, regulating induction by TNF, stereospecific alignment of the κB sites was not critical. Trans-activation studies conducted by cotransfection of p50 and/or p65 expression vectors with MCP-1 constructions showed that TNF regulates MCP-1 through NF-κB. Examination of MCP-1 induction in NF-κB-disrupted embryonic fibroblasts showed that p65 was necessary for both the induction and the TNF-induced protein occupancy of the enhancer in vivo. The action of the antioxidant inhibitor of NF-κB activation, pyrrolidine dithiocarbamate, in wild-type and NF-κB mutant cells was examined. The results suggested that TNF activates NF-κB through both pyrrolidine dithiocarbamate-sensitive and -insensitive mechanisms. This study illustrates the crucial role for NF-κB p65 in the induction of the MCP-1 gene by TNF and in the assembly of a NF-κB dependent enhancer in vivo.
Quantitative Analysis of the Effect of CD16 Ligation on Human NK Cell Proliferation
Authors: Warren Hilary S. , Kinnear Beverley F. 
Published: December 2022

AbstractCD16 (FcγRIIIA), the low affinity receptor for IgG, is expressed on the majority of human peripheral blood NK cells. Ligation of CD16 with mAb or immune complexes activates NK cell cytotoxicity and cytokine secretion, and stimulates death of activated NK cells by apoptosis. This study uses NK cells labeled with the stable intracytoplasmic fluorescent dye 5- and 6-carboxyfluorescein diacetate succinimidyl ester to provide quantitative data on the effect of CD16 ligation on NK cell division and NK cell survival. When NK cells are cultured with rIL-2 and CD16 is ligated, NK cell division is stimulated, but there also is a substantial loss of NK progenitor cells. When NK cell proliferation is stimulated by coculture with γ-irradiated MM-170 malignant melanoma cells and rIL-2, CD16 ligation enhances entry of NK cells into division. In some cases, CD16 ligation is essential for NK cell proliferation stimulated by MM-170 cells. In these cultures, there is no loss of NK progenitor cells. This study demonstrates that CD16 is an activation receptor for NK cell proliferation, and suggests that cellular costimulation alters the balance between NK cell death and NK cell proliferation stimulated by CD16 ligation.
Novel Splicing of the Human MHC-Encoded Peptide Transporter Confers Unique Properties
Authors: Yan Gang , Shi Lijia , Faustman Denise 
Published: December 2022

AbstractPresentation of intracellularly derived antigenic peptides to T cells requires their assembly together with MHC class I molecules in the endoplasmic reticulum (ER). Such peptides are delivered to the ER by an MHC-encoded transporter composed of TAP1 and TAP2 protein delivery. Here, the first alternative splicing of Tap2 is described. The human splice variant, termed Tap2iso, lacks exon 11 and original 3′ untranslated region and contains a newly identified exon 12 and 3′ untranslated region. The full-length Tap2iso cDNA (2496 bp) predicts a protein of 653 amino acids. Tap2iso mRNA was normally coexpressed with Tap2 mRNA in all human lymphocyte cell lines examined. Function of TAP2iso was evaluated at multilevel in TAP1/2iso and TAP1/2 cotransfected T2 cells, a mutant cell line deplete of endogenous Tap gene products. The TAP1-TAP2iso transporter facilitated the maturation of MHC class I molecules in the ER and restored surface expression of class I. Importantly, TAP1-TAP2iso transporters expressed in T2 cells exhibited distinct and opposing influences on peptide selectivities, at times exceeding 30-fold differences in competition experiments and attributable to diversity in the 3′-COOH tail. The common coexpression of an alternative splice product of the Tap2 gene may contribute to broaden immune diversity, a mechanism previously described to occur predominantly at the level of the TCR and MHC class I gene products.
Suppression of Host Immune Response by the Core Protein of Hepatitis C Virus: Possible Implications for Hepatitis C Virus Persistence
Authors: Large Mary Kathryn , Kittlesen David J. , Hahn Young S. 
Published: December 2022

AbstractHepatitis C virus (HCV) is a major human pathogen causing mild to severe liver disease worldwide. This positive strand RNA virus is remarkably efficient at establishing chronic infections. Although a high rate of genetic variability may facilitate viral escape and persistence in the face of Ag-specific immune responses, HCV may also encode proteins that facilitate evasion of immunological surveillance. To address the latter possibility, we examined the influence of specific HCV gene products on the host immune response to vaccinia virus in a murine model. Various vaccinia/HCV recombinants expressing different regions of the HCV polyprotein were used for i.p. inoculation of BALB/c mice. Surprisingly, a recombinant expressing the N-terminal half of the polyprotein (including the structural proteins, p7, NS2, and a portion of NS3; vHCV-S) led to a dose-dependent increase in mortality. Increased mortality was not observed for a recombinant expressing the majority of the nonstructural region or for a negative control virus expressing the β-galactosidase protein. Examination of T cell responses in these mice revealed a marked suppression of vaccinia-specific CTL responses and a depressed production of IFN-γ and IL-2. By using a series of vaccinia/HCV recombinants, we found that the HCV core protein was sufficient for immunosuppression, prolonged viremia, and increased mortality. These results suggest that the HCV core protein plays an important role in the establishment and maintenance of HCV infection by suppressing host immune responses, in particular the generation of virus-specific CTLs.
Regulation and Functional Involvement of Macrophage Scavenger Receptor MARCO in Clearance of Bacteria In Vivo
Authors: van der Laan Luc J. W. , Döpp Ed A. , Haworth Richard , Pikkarainen Timo , Kangas Maarit , Elomaa Outi , Dijkstra Christine D. , Gordon Siamon , Tryggvason Karl , Kraal Georg 
Published: December 2022

AbstractThe scavenger receptors expressed by macrophages are thought to play an important role in the immune response against bacteria by mediating binding and phagocytosis. A novel member of the class A scavenger receptor family, macrophage receptor with collagenous structure (MARCO), has recently been identified. In this study we have generated a panel of mAbs with specificities for different domains of this receptor. Two of those reacting with the C-terminal cysteine-rich domain block ligand binding of MARCO. The in vivo expression of this murine receptor is normally restricted to distinct populations of macrophages in the spleen and lymph nodes. During bacillus Calmette-Guérin (BCG) infection, during bacterial sepsis, or after the injection of purified LPS, however, the expression of MARCO is rapidly induced on macrophages in other tissues, including Kupffer cells in the liver. Using the mouse macrophage cell line J774.2, it was shown that LPS stimulation up-regulates surface expression of MARCO in a dose- and time-dependent fashion. The proinflammatory cytokines IL-1, IL-6, TNF-α, and IFN-γ had little or no effect. Using inhibitory mAbs, the relevance of MARCO for the clearance of circulating bacteria in vivo was determined. Although the overall elimination of live Escherichia coli and Staphylococcus aureus from the blood did not appear to be affected by treatment with these Abs, the capturing of heat-killed bacteria by macrophages in the marginal zone areas of the spleen was clearly inhibited. This study suggests a role for MARCO in the host antibacterial defense.
Role of IFN-γ-Induced Indoleamine 2,3 Dioxygenase and Inducible Nitric Oxide Synthase in the Replication of Human Cytomegalovirus in Retinal Pigment Epithelial Cells
Authors: Bodaghi Bahram , Goureau Olivier , Zipeto Donato , Laurent Lysiane , Virelizier Jean-Louis , Michelson Susan 
Published: December 2022

Abstract
An in vitro model of human CMV infection of primary retinal pigment epithelial (RPE) cells was used to study the effects of cytokines on CMV replication in these cells, which are targets of CMV infection in vivo. IFN-γ and IFN-β were potent inhibitors of CMV replication in RPE cells, while TNF-α, IL-1β, or TGF-β2 did not affect viral replication. Inhibition by IFN-γ, and to a lesser extent IFN-β, was almost completely reversed by addition of l-tryptophan to the culture medium, strongly implicating the indoleamine 2,3 dioxygenase (IDO) pathway. Polyadenylated IDO mRNA accumulation was detected as early as 2 h after IFN stimulation. Furthermore, CMV blocked the production of nitric oxide by the inducible form of nitric oxide synthase. This inhibition depended on a functional viral genome. However, exogenous nitric oxide significantly inhibited viral protein expression in RPE cells. Thus, CMV infection blocks the inducible nitric oxide synthase pathway activated by IFN-γ and IL-1β, but cannot counteract the IFN-induced IDO pathway, which ultimately controls its replication in primary human RPE cells.
IL-12 Is Not Required for Induction of Type 1 Cytokine Responses in Viral Infections
Authors: Oxenius Annette , Karrer Urs , Zinkernagel Rolf M. , Hengartner Hans 
Published: December 2022

AbstractTo investigate the physiological role of IL-12 in viral infections in terms of T cell cytokine responses involved in virus-specific Ig isotype induction and in antiviral protection, immune responses elicited upon infection of IL-12-deficient mice with lymphocytic choriomeningitis virus (LCMV) or vesicular stomatitis virus (VSV) were studied. Infection of IL-12-deficient mice with LCMV induced a virus-specific type 1 cytokine response as determined by in vitro cytokine secretion patterns as well as by in vivo intracellular cytokine staining of LCMV-specific CD4+ TCR transgenic T cells that had clonally expanded in LCMV-infected IL-12-deficient recipient mice. In addition, LCMV- and VSV-specific IgG responses exhibited normal serum IgG2a/IgG1 ratios, demonstrating again virus-specific CD4+ T cell induction of type 1 phenotype in IL-12-deficient mice upon viral infection. LCMV and VSV immune mice were found to be protected against challenge immunization with recombinant vaccinia viruses expressing either the LCMV- or the VSV-derived glycoprotein, respectively. This protection is known to be mediated by T cell-secreted type 1 cytokines IFN-γ and TNF-α. In contrast, IL-12-deficient mice showed impaired abilities to control infection with the facultative intracellular bacterium Listeria monocytogenes at early time points after infection. However, at later time points of infection, IL-12-deficient mice were able to clear infection. These findings may indicate that viruses are able to induce type 1 T cell responses in the absence of IL-12 as opposed to some bacterial or parasitical infections that are crucially dependent on the presence of IL-12 for the induction of type 1 immune responses.
Timing and Casting for Actors of Thymic Negative Selection
Authors: Dautigny Nicole , Le Campion Armelle , Lucas Bruno 
Published: December 2022

AbstractWe have recently proposed a new model for the differentiation pathway of αβ TCR thymocytes, with the CD4 and CD8 coreceptors undergoing an unexpectedly complex series of expression changes. Taking into account this new insight, we reinvestigated the timing of thymic negative selection. We found that, although endogenous superantigen-driven thymic negative selection could occur at different steps during double-positive/single-positive cell transition, this event was never observed among CD4lowCD8low TCRint CD69+ thymocytes, i.e., within the first subset to be generated upon TCR-mediated activation of immature double-positive cells. We confirm a role for CD40/CD40L interaction, and the absence of involvement of CD28 costimulation, in thymic deletion in vivo. Surprisingly, we found that thymic negative selection was impaired in the absence of Fas, but not FasL, molecule expression. Finally, we show involvement in opposing directions for p59fyn and SHP-1 molecules in signaling for thymic negative selection.
Protein Interactions of Src Homology 2 (SH2) Domain-Containing Inositol Phosphatase (SHIP): Association with Shc Displaces SHIP from FcγRIIb in B Cells
Authors: Tridandapani Susheela , Pradhan Madhura , LaDine James R. , Garber Stacey , Anderson Clark L. , Coggeshall K. Mark 
Published: December 2022

AbstractOur recent studies revealed that the inositol phosphatase Src homology 2 (SH2) domain-containing inositol phosphatase (SHIP) is phosphorylated and associated with Shc exclusively under negative signaling conditions in B cells, which is due to recruitment of the SHIP SH2 domain to the FcγRIIb. In addition, we reported that SHIP-Shc interaction involves both SHIP SH2 and Shc phosphotyrosine binding domains. These findings reveal a paradox in which the single SH2 domain of SHIP is simultaneously engaged to two different proteins: Shc and FcγRIIb. To resolve this paradox, we examined the protein interactions of SHIP. Our results demonstrated that isolated FcγRIIb contains SHIP but not Shc; likewise, Shc isolates contain SHIP but not FcγRIIb. In contrast, SHIP isolates contain both proteins, revealing two separate pools of SHIP: one bound to FcγRIIb and one bound to Shc. Kinetic studies reveal rapid SHIP association with FcγRIIb but slower and more transient association with Shc. Affinity measurements using a recombinant SHIP SH2 domain and phosphopeptides derived from FcγRIIb (corresponding to Y273) and Shc (corresponding to Y317) revealed an approximately equal rate of binding but a 10-fold faster dissociation rate for FcγRIIb compared with Shc phosphopeptide and yielding in an affinity of 2.1 μM for FcγRIIb and 0.26 μM for Shc. These findings are consistent with a model in which SHIP transiently associates with FcγRIIb to promote SHIP phosphorylation, whereupon SHIP binds to Shc and dissociates from FcγRIIb.
A Critical Tyrosine Residue in the Cytoplasmic Tail Is Important for CD1d Internalization But Not for Its Basolateral Sorting in MDCK Cells
Authors: Rodionov Dmitrii G. , Nordeng Tommy W. , Pedersen Ketil , Balk Steven P. , Bakke Oddmund 
Published: December 2022

Abstract
The CD1 family of polypeptides is divided into two groups, the CD1b and CD1d group. Both groups are involved in stimulation of T cell response. Molecules of the CD1b group can present Ag derived from bacterial cell walls to T cells; the process of Ag acquisition is thought to take place in endosomes. Little is known about Ag presentation by CD1d. We therefore studied the intracellular trafficking of human CD1d in Madin-Darby canine kidney (MDCK) and COS cells. CD1d was found in endosomal compartments after its internalization from the plasma membrane. It is therefore possible that CD1d acquires its yet unidentified exogenous ligand in the same compartments as the MHC class II and CD1b molecules. CD1d contains a tyrosine-based sorting signal in its cytoplasmic tail that is necessary for internalization. Furthermore, the cytoplasmic tail of CD1d also contains a signal for basolateral sorting that is, however, different from the internalization signal.