bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cutting Edge: Antisense Knockdown of Inducible Nitric Oxide Synthase Inhibits Induction of Experimental Autoimmune Encephalomyelitis in SJL/J Mice
Authors: Ding Minzhen , Zhang Ming , Wong Joyce L. , Rogers Norma E. , Ignarro Louis J. , Voskuhl Rhonda R. 
Published: December 2022

Abstract
We used an antisense oligodeoxynucleotide (ODN) complementary to inducible nitric oxide synthase (iNOS) to inhibit experimental autoimmune encephalomyelitis (EAE) in female SJL/J mice, an animal model for multiple sclerosis. The antisense ODN was administered intraventricularly to mice daily for 10 days beginning at the time of adoptive transfer of myelin basic protein-specific T lymphocytes. The antisense ODN treatment significantly reduced the clinical score of EAE and blocked iNOS mRNA and protein synthesis, as well as iNOS enzyme activity within the central nervous system. The levels of nitric oxide and cyclic guanosine monophosphate were also significantly reduced by the antisense ODN treatment. Neither sense nor random ODN affected clinical EAE or iNOS expression. Moreover, the protein and enzyme activity level of constitutive neuronal nitric oxide synthase was not affected by the antisense ODN. Thus, we have shown that the iNOS antisense ODN specifically blocked iNOS expression and ameliorated the induction of EAE.
Cutting Edge: The Induction of Acute Phase Proteins by Lipopolysaccharide Uses a Novel Pathway That Is CD14-Independent
Authors: Haziot Alain , Lin Xing Y. , Zhang Fan , Goyert Sanna M. 
Published: December 2022

AbstractLPS (endotoxin) and proinflammatory cytokines (IL-6, IL-1, and TNF-α) are potent inducers of acute phase proteins (APP). Since LPS induces high levels of these cytokines after its interaction with CD14, a protein expressed on the surface of monocytes and neutrophils, it has been assumed that CD14 mediates the LPS induction of APP expression. To test this hypothesis, CD14-deficient and control mice were injected with low doses of LPS, and the expression of several APP that are normally up-regulated by LPS was measured. CD14-deficient mice showed no alteration in the induction of APP, including serum amyloid A, LPS-binding protein, fibrinogen, or ceruloplasmin; in contrast, C3H/HeJ mice, which carry a mutation in the Lps gene, do not up-regulate the expression of these proteins. These studies show that the up-regulation of APP by LPS utilizes a non-CD14 receptor and requires a functional Lps gene.
Induction of Autoimmune Arthritis in HLA-DR4 (DRB1*0401) Transgenic Mice by Immunization with Human and Bovine Type II Collagen
Authors: Rosloniec1 Edward F. , Brand David D. , Myers Linda K. , Esaki Yukio , Whittington Karen B. , Zaller Dennis M. , Woods Andrea , Stuart John M. , Kang Andrew H. 
Published: December 2022

AbstractAlthough associations between the expression of particular HLA genes and the susceptibility to specific autoimmune diseases has been known for some time, the role that these HLA molecules play in the autoimmune response is unclear. Through the establishment of a chimeric HLA-DR/I-E transgene, we have examined the function of the rheumatoid arthritis (RA) susceptibility allele HLA-DR4 (DRB1*0401) in presenting antigenic peptides derived from the model Ag, type II collagen (CII), and in mediating an autoimmune response. As a transgene, the chimeric DR4 molecule conferred susceptibility to an autoimmune arthritis induced by immunization with human CII or bovine CII. These mice developed an inflammatory, autoimmune arthritis that was similar both histologically and in severity to that previously described for the collagen-induced arthritis model. The DR4-mediated autoimmune arthritis was accompanied by T cell and B cell responses to both the immunogen and the autoantigen, murine CII. The DR4-restricted T cell response to human CII was focused on an immunodominant determinant within CII263–270 and a minor determinant within CII286–300, the same CII determinants recently identified for yet another RA susceptibility allele, HLA-DR1 (DRB1*0101). Thus these data demonstrate that, like HLA-DR1, HLA-DR4 is capable of binding peptides derived from human CII and therefore probably plays a role in the autoimmune response to human CII observed in RA patients.
Intracellular Pathway for the Generation of Functional MHC Class II Peptide Complexes in Immature Human Dendritic Cells
Authors: Saudrais Cédric , Spehner Danièle , de la Salle Henri , Bohbot Alain , Cazenave Jean-Pierre , Goud Bruno , Hanau Daniel , Salamero Jean 
Published: December 2022

Abstract
Binding of antigenic peptides to MHC class II (MHC-II) molecules occurs in the endocytic pathway. From previous studies in B lymphocytes, it is believed that most but not all of the newly synthesized MHC-II molecules are directly targeted from the trans-Golgi network to endosomal compartments. By using pulse-chase metabolic labeling followed by cell surface biotinylation, we show here that in contrast to an EBV-transformed B cell line and human monocytes, the majority of newly synthesized MHC-II molecules (at least 55 ± 13%) are first routed to the plasma membrane of dendritic cells derived from human monocytes. They reach the cell surface in association with the invariant chain (Ii), a polypeptide known to target MHC-II to the endosomal/lysosomal system. Following rapid internalization and degradation of Ii, these αβIi complexes are converted into αβ-peptide complexes as shown by their SDS stability. These SDS-stable dimers appear as soon as 15 to 30 min after internalization of the αβIi complexes. More than 80% of αβ dimers originating from internalized αβIi complexes are progressively delivered to the cell surface within the next 2 h. Depolymerization of microtubules, which delays the transport to late endosomal compartments, did not affect the kinetics of conversion of surface αβIi into SDS-stable and -unstable αβ dimers. Altogether, these data suggest that newly liberated class II αβ heterodimers may bind peptides in different compartments along the endocytic pathway in dendritic cells derived from human monocytes.
Production of IL-10 by Human Natural Killer Cells Stimulated with IL-2 and/or IL-12
Authors: Mehrotra Priti T. , Donnelly Raymond P. , Wong Susan , Kanegane Hirokazu , Geremew Amare , Mostowski Howard S. , Furuke Keizo , Siegel Jay P. , Bloom Eda T. 
Published: December 2022

AbstractHuman NK cell activity can be augmented in vitro by stimulation with IL-2 or IL-12, both of which also induce the production of IFN-γ, TNF-α, and granulocyte-macrophage CSF by NK cells. For the first time, we demonstrate that freshly purified NK cells stimulated with IL-2 proliferated and produced IL-10 in a dose-dependent manner. IL-10 mRNA expression, as detected by semiquantitative reverse transcription-PCR, reached peak levels at 24 h. IL-10 protein was detectable on day 2 and further increased on days 3 and 6 as measured by ELISA. However, IL-12 alone induced neither substantial proliferation nor detectable IL-10 production by fresh NK cells, but it synergized with IL-2 in inducing IL-10 mRNA expression and protein synthesis. IL-10 production by activated NK cells was confirmed by intracytoplasmic cytokine staining by three-color immunofluorescence of CD16+ and/or CD56+ NK cells with anti-IL-10 antibody. IL-10 production by NK cells was further confirmed in the NK-like cell line, YT, which constitutively expressed IL-10 mRNA and protein. IL-12 alone did not induce NK proliferation, but it inhibited IL-2-induced proliferation. Neutralization of endogenously produced IL-10 with anti-IL-10 antibodies did not overcome the inhibition of IL-2-induced proliferation by IL-12. Together, these results demonstrate that IL-2 and IL-12 synergize to induce IL-10 production by human NK cells and that IL-12 inhibits IL-2 induced NK cell proliferation by an IL-10-independent mechanism.
A Role for Perforin in Activation-Induced Cell Death
Authors: Spaner David , Raju Kaliannan , Radvanyi Laszlo , Lin Yunping , Miller Richard G. 
Published: December 2022

Abstract
The granule exocytosis pathway of T cell cytotoxicity is absent in mice whose perforin gene has been ablated by targeted mutagenesis. The ability of activated naive T cells to undergo apoptosis in vitro following reaggregation of the TCR complex with anti-TCR mAbs via a Fas-independent pathway was found to be defective in the absence of perforin. Protection from death was most marked in CD8+ T cells. In wild-type cells, perforin was expressed at the same time that apoptosis occurred, and blockade of perforin expression by either incubation with perforin antisense oligonucleotides or with anti-IL-2 Abs resulted in increased viability of activated T cells. The role of perforin was not via perforin-dependent fratricidal killing. The results suggest a model in which perforin acts internally to cause a form of activation-induced T cell death distinct from that caused by members of the TNFR superfamily.
A Phosphorylcholine-Containing Filarial Nematode-Secreted Product Disrupts B Lymphocyte Activation by Targeting Key Proliferative Signaling Pathways
Authors: Deehan Maureen R. , Frame Mhairi J. , Parkhouse R. Michael E. , Seatter Sandra D. , Reid Steven D. , Harnett Margaret M. , Harnett William 
Published: December 2022

AbstractFilarial nematodes infect more than 100 million people in the tropics, causing elephantiasis, chronic skin lesions, and blindness. The parasites are long-lived as a consequence of being able to evade the host immune system, but an understanding of the molecular mechanisms underlying this evasion remains elusive. In this study, we demonstrate that ES-62 (2 μg/ml), a phosphorylcholine (PC)-containing glycoprotein released by the rodent filarial parasite Acanthocheilonema viteae, is able to polyclonally activate certain protein tyrosine kinase and mitogen-activating protein kinase signal-transduction elements in B lymphocytes. Although this interaction is insufficient to cause B lymphocyte proliferation per se, it serves to desensitize the cells to subsequent activation of the phosphoinositide-3-kinase and Ras mitogen-activating protein kinase pathways, and hence also to proliferation, via the Ag receptor. The active component of ES-62 appears to be PC, a molecule recently shown to act as an intracellular signal transducer, as the results obtained with ES-62 are broadly mimicked by PC alone. As PC-containing secreted products (PC-ES) are also released by human filarial parasites, our data suggest that PC-ES, by interfering with B cell function, could play a role in prolonging filarial infection in parasitized individuals.
Generation of Antigen-Specific Th2 Cells from Unprimed Mice In Vitro: Effects of Dexamethasone and Anti-IL-10 Antibody
Authors: Dozmorov Igor M. , Miller Richard A. 
Published: December 2022

AbstractWe describe a system for the in vitro production of Ag-specific mouse CD4 cell lines from unprimed mice. Purified CD4+CD45RBhigh T cells were exposed to Ag-pulsed accessory cells in serum-free medium for 24 h; cultured in the absence of Ag and in the presence of serum, IL-2, dexamethasone, and Abs to IL-10 for an additional 4 days; and then re-exposed to the original sensitizing Ag. The presence of dexamethasone and Abs to IL-10 during the initial expansion stage appeared to be critical for the ability of the stimulated and expanded T cells to respond to restimulation with the same Ag. Repeated cycles of in vitro stimulation led to increased specificity for the sensitizing Ag (in the current case, pigeon cytochrome c), a decline in production of IL-2 and IFN-γ, and increased production of IL-4, IL-5, and IL-10. This culture protocol provides a test system for exploration of factors that regulate the conversion of naïve cells to memory cells and the development of specific immune responses to protein Ags. The data are consistent with models that implicate glucocorticoids as regulators of immune response specificity.
Nucleic Acid Vaccine-Induced Immune Responses Require CD28 Costimulation and Are Regulated by CTLA4
Authors: Horspool James H. , Perrin Peter J. , Woodcock Juliana B. , Cox Josephine H. , King Christopher L. , June Carl H. , Harlan David M. , St. Louis Daniel C. , Lee Kelvin P. 
Published: December 2022

AbstractImmunization with plasmids expressing specific genes (DNA or nucleic acid vaccination (NAV)) elicits robust humoral and cell-mediated immune responses. The mechanisms involved in T cell activation by NAV are incompletely characterized. We have examined the costimulatory requirements of NAV. CD28-deficient mice did not mount Ab or CTL responses following i.m. immunization with eukaryotic expression plasmids encoding the bacterial gene β-galactosidase (βgal). Because these mice retained their ability to up-regulate the CTLA4 receptor (a negative regulator of T cell activation), we examined CTLA4’s role in the response of wild-type BALB/c mice to NAV. Intact anti-CTLA4 mAb but not Fab fragments suppressed the primary humoral response to pCIA/βgal without affecting recall responses, indicating CTLA4 activation inhibited Ab production but not T cell priming. Blockade of the ligands for CD28 and CTLA4, CD80 (B7-1) and CD86 (B7-2), revealed distinct and nonoverlapping function. Blockade of CD80 at initial immunization completely abrogated primary and secondary Ab responses, whereas blockade of CD86 suppressed primary but not secondary responses. Simultaneous blockade of CD80 + CD86 was less effective at suppressing Ab responses than either alone. Enhancement of costimulation via coinjection of B7-expressing plasmids augmented CTL responses but not Ab responses, and without evidence of Th1 to Th2 skewing. These findings suggest complex and distinct roles for CD28, CTLA4, CD80, and CD86 in T cell costimulation following nucleic acid vaccination.
Homeostasis Limits the Development of Mature CD8+ But Not CD4+ Thymocytes
Authors: van Meerwijk Joost P. M. , Marguerat Samuel , MacDonald H. Robson 
Published: December 2022

AbstractThe involvement of a variety of clonal selection processes during the development of T lymphocytes in the thymus has been well established. Less information, however, is available on how homeostatic mechanisms may regulate the generation and maturation of thymocytes. To investigate this question, mixed radiation bone marrow chimeras were established in which wild-type T cell precursors capable of full maturation were diluted with precursors deficient in maturation potential because of targeted mutations of the RAG1 or TCR-α genes. In chimeras in which the majority of thymocytes are blocked at the CD4−CD8−CD25+ stage (RAG1 deficient), and only a small proportion of T cell precursors are of wild-type origin, we observed no difference in the maturation of wild-type CD4−CD8−CD25+ cells to the CD4+CD8+ stage as compared with control chimeras. Therefore, the number of cell divisions occurring during this transition is fixed and not subject to homeostatic regulation. In contrast, in mixed chimeras in which the majority of thymocytes are blocked at the CD4+CD8+ stage (TCR-α deficient), an increased efficiency of development of wild-type mature CD8+ cells was observed. Surprisingly, the rate of generation of mature CD4+ thymocytes was not affected in these chimeras. Thus, the number of selectable CD8 lineage thymocytes apparently saturates the selection mechanism in normal mice while the development of CD4 lineage cells seems to be limited only by the expression of a suitable TCR. These data may open the way to the identification of homeostatic mechanisms regulating thymic output and CD4/CD8 lineage commitment, and the development of means to modulate it.
Induction of Jak/STAT Signaling by Activation of the Type 1 TNF Receptor
Authors: Guo DanQun , Dunbar James D. , Yang Chuan He , Pfeffer Lawrence M. , Donner David B. 
Published: December 2022

AbstractCellular responses to TNF are initiated by either of two cell surface receptors, the type 1 TNF receptor (TNFR1) and the type 2 TNF receptor (TNFR2). Although neither receptor contains an intrinsic protein tyrosine kinase, such activity has been implicated in TNF action. In this study, we show that murine TNF induces the tyrosine phosphorylation and activation of the intracellular Janus tyrosine kinases Jak1, Jak2, and Tyk2 in murine 3T3-L1 adipocytes. Activation of Jak kinases by TNF was associated with tyrosine phosphorylation of STAT1, STAT3, STAT5, and STAT6, but not STAT2 or STAT4, showing that TNF acts on a specific subset of these latent cytoplasmic transcription factors in 3T3-L1 adipocytes. Agonist antiserum to TNFR1 induced Jak kinase and STAT protein phosphorylation. Phosphorylation of Jak proteins was also induced by human TNF, which selectively binds to TNFR1 on murine cells. 35S-labeled Jak kinases were precipitated from a cell-free system and from lysates of 3T3-L1 adipocytes by a glutathione S-transferase fusion protein containing the cytoplasmic domain of TNFR1. These results suggest that the cytoplasmic domain of TNFR1 can directly interact with and form signaling complexes with Jak kinases. Jak2 was precipitated from HeLa cells by antiserum to TNFR1, directly demonstrating their association in vivo. Thus, TNF activates a Jak/STAT signal-transduction cascade by acting through TNFR1.
The A-Myb Transcription Factor Is a Marker of Centroblasts In Vivo
Authors: Golay Josée , Broccoli Vania , Lamorte Giuseppe , Bifulco Carlo , Parravicini Carlo , Pizzey Arnold , Thomas N. Shaun B. , Delia Domenico , Ferrauti Paola , Vitolo Domenico , Introna Martino 
Published: December 2022

AbstractThe A-Myb transcription factor is structurally related to the c-myb proto-oncogene and is involved in the control of proliferation and/or differentiation of mature B lymphocytes. We have shown previously by PCR analysis that A-myb is preferentially expressed in CD38+CD39−sIgM− mature B cells. We demonstrate here, using in situ hybridization, that A-mybexpression is restricted to the dark zone of human tonsils and lymph nodes. Furthermore, we show that A-Myb expression is cell cycle regulated both in tonsillar B cells and in Burkitt’s lymphoma cell lines, being detectable only in the S and G2/M phases of the cell cycle and not in G0/G1 phase. Strong proliferation of resting human B cells induced in vitro by a variety of physiologic signals, including anti-μ, CD40 ligand, IL-2, IL-4, IL-6, IL-13, IFN-γ, TNF-α, anti-CD19, and anti-CD20, failed to induce A-myb expression, suggesting that proliferation alone is not sufficient for A-myb expression in the absence of induction of a true centroblast phenotype. Finally, we show that differentiation of germinal center B cells in vitro toward either memory or plasma cells is accompanied by rapid down-regulation of A-myb expression. We conclude that A-myb is a marker of centroblasts generated in vivo.
The Lipophosphoglycan ofLeishmania donovaniUp-Regulates HIV-1 Transcription in T Cells Through the Nuclear Factor-κB Elements
Authors: Bernier Richard , Barbeau Benoı̂t , J. Tremblay Michel , Olivier Martin 
Published: December 2022

AbstractWe have recently demonstrated that the parasite Leishmania donovani and its surface molecule, lipophosphoglycan (LPG), can activate HIV-1 replication in monocytoid cells. Our present interest was to determine whether LPG could also up-regulate HIV-1 transcription in T cells. Using a CD4-positive human lymphoid T cell line (1G5) containing a stably integrated HIV-1 long terminal repeat (LTR)-luciferase construct, we found that LPG is a potent inducer of HIV-1 LTR activity. Treatment of 1G5 cells with signaling antagonists revealed that protein tyrosine kinase- and protein kinase A-dependent pathways were actively participating in the LPG-induced enhancement of HIV-1 LTR-driven activity. Transfection of Jurkat E6.1 cells with plasmids containing wild-type and nuclear factor-κB (NF-κB)-mutated HIV-1 LTR-luciferase constructs has suggested a role for NF-κB binding sites in the LPG-mediated induction of HIV-1 LTR activity. An LPG-induced binding factor specific to the NF-κB consensus sequences could be observed using electrophoretic mobility shift assay. Finally, transfection experiments performed with a vector containing HIV-1 κB binding sites only showed similar LPG-mediated induction, which was abrogated by sodium salicylate, a known NF-κB inhibitor. We thus demonstrate that the LPG-mediated induction of HIV-1 LTR activity in T cells involves several second messengers culminating in activation of HIV-1 LTR-driven transcription via NF-κB-binding consensus sequences. In conclusion, these results reinforce the idea that L. donovani is a putative cofactor in HIV-1 pathogenesis.
CTL Effector Function Within the Central Nervous System Requires CD4+ T Cells
Authors: Stohlman Stephen A. , Bergmann Cornelia C. , Lin Mark T. , Cua Daniel J. , Hinton David R. 
Published: December 2022

AbstractCTL responses induced during most viral infections are independent of help derived from the CD4+ T cell population. However, clearance of virus from the central nervous system (CNS) during infection with the neurotropic JHM strain of mouse hepatitis virus is inhibited in the absence of CD4+ T cells. Adoptive transfer of activated CD8+ T cells with virus-specific cytolytic activity into CD4+ T cell-depleted hosts demonstrated that CD4+ T cells were one component of the host response required for expression of CTL effector function(s) within the CNS. Analysis of mice infected with the JHM strain of mouse hepatitis virus demonstrated that, in contrast to CD8+ T cells, few CD4+ T cells entered the brain parenchyma. Although fewer CD8+ T cells entered the brain parenchyma in mice depleted of CD4+ T cells, access of CTL was not inhibited in the absence of CD4+ T cells. The number of apoptotic lymphocytes in the CNS increased in the absence of CD4+ T cells, suggesting that CTL enter the CNS during viral infection in a CD4-independent manner. However, these cells rapidly undergo apoptosis, indicating that expression of CTL effector function with the parenchyma of the CNS is CD4 dependent. These data raise the possibility that programmed cell death of CD8+ T cells within the CNS is due to the increased Ag present in the CNS of infected CD4 depleted mice or that autocrine cytokines, which maintain CTL activity within peripheral tissues, are inhibited in the microenvironment of the CNS.
Resistance to Melanoma in Mice Immunized with Semiallogeneic Fibroblasts Transfected with DNA from Mouse Melanoma Cells
Authors: de Zoeten Edwin F. , Carr-Brendel Victoria , Cohen Edward P. 
Published: December 2022

Abstract
Tumor-associated Ags (TAA) that characterize a population of malignant cells are recognized by CTLs in the context of determinants specified by the MHC class I locus. Nevertheless, most progressively growing neoplasms do not induce antitumor immune responses that can control tumor cell growth. The TAA may be insufficiently antigenic. We found previously that immunization of mice with a cellular immunogen prepared by transfecting tumor DNA into allogeneic mouse fibroblasts resulted in strong antitumor immune responses that were specific for the type of tumor from which the DNA was obtained. Since the fibroblasts differed at the MHC from the immunized mice, we postulated that the immunogenic properties of the allogeneic transfected cells might be enhanced if the cells were modified to express syngeneic class I determinants. In a mouse melanoma model system, the H-2Kb gene was introduced into LM mouse fibroblasts (H-2k). Afterward, the cells were transfected with DNA from B16 melanoma cells (H-2b). The transfected cells were tested for their immunotherapeutic properties in C57BL/6J mice (H-2b) with melanoma. Mice with melanoma treated solely by immunization with the semiallogeneic transfected cells developed strong, long-term resistance to the growth of the tumor. In some instances, the mice survived indefinitely. Intact rather than disrupted transfected cells were required to induce the antimelanoma response, consistent with direct presentation of TAA by the transfected cells. The augmented resistance to melanoma in mice treated with the semiallogeneic transfected cells points toward an analogous form of therapy for cancer patients.