bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence for Sulfate Modification of H-2Dd on N-Linked Carbohydrate(s): Possible Involvement in Ly-49A Interaction
Authors: Chang Chew Shun , Kane Kevin P. 
Published: January 2023

AbstractMurine class I molecules are ligands for Ly-49 molecules, a family of regulatory receptors expressed on murine NK cells. Since soluble sulfated mono- and polysaccharides interfere with the interaction of Ly-49A, a C-type lectin, and its class I ligand, Dd, it is possible that the oligosaccharides on class I molecules are sulfated and participate in Ly-49A binding. In this report, we show that H-2Dd expressed by activated T cells and various tumor cell lines is sulfated, as demonstrated by immunoprecipitation of Dd following Na235SO4 labeling. The 35SO4−2 label on Dd expressed by a representative tumor cell, NZB1.1, is removed by peptide N-glycosidase F, but is resistant to endoglycosidase H treatment, indicating that the sulfate group is located on mature N-linked oligosaccharides. Two-dimensional SDS-PAGE analysis revealed that all major mature glycosylation variants of the Dd expressed by NZB1.1 are sulfated. Sodium chlorate, a potent inhibitor of ATP-sulfurylase, which prevents the formation of the sulfate donor, 3′-phosphoadenosine 5′-phosphosulfate, inhibited metabolic sulfation of Dd. NZB1.1 binds isolated Ly-49A immobilized on solid phase through an interaction by cell surface Dd, since cell adhesion was blocked by Abs directed against Dd or Ly-49A. Treatment of the Dd-expressing NZB1.1 tumor cells with sodium chlorate reduced their ability to bind immobilized Ly-49A, particularly when Ly-49A density was limiting. These results provide evidence for sulfation of H-2Dd oligosaccharide moieties, and suggest a role for this posttranslational modification in the interaction of Dd with Ly-49A.
Down-Regulation of CXCR2 Expression on Human Polymorphonuclear Leukocytes by TNF-α
Authors: Asagoe Kohsuke , Yamamoto Kokichi , Takahashi Atsushi , Suzuki Kazuo , Maeda Akinori , Nohgawa Masaharu , Harakawa Nari , Takano Kuniko , Mukaida Naofumi , Matsushima Kouji , Okuma Minoru , Sasada Masataka 
Published: January 2023

Abstract
TNF-α is implicated in the initiation of cytokine cascades in various inflammatory settings. To assess the interactions of multiple cytokines at the level of inflammatory effector cells, we examined the effects of TNF-α on the expression of two IL-8Rs (CXCR1 and CXCR2) on polymorphonuclear leukocytes (PMNs). TNF-α decreased the surface expression of CXCR2 in a dose- and time-dependent manner. In contrast, CXCR1 expression was not affected by TNF-α. The release of CXCR2 into the supernatant of TNF-α-treated PMNs was detected by immunoblotting and immuno-slot-blot analyses, suggesting that the down-regulation of CXCR2 was caused mainly by shedding from the cell surface. The CXCR2 down-regulation was inhibited by PMSF and aprotinin, supporting the hypothesis that the shedding was mediated by serine protease(s). The intracellular Ca2+ mobilization and chemotaxis in response to IL-8 were suppressed by the pretreatment of PMNs with TNF-α, indicating that the decrease in CXCR2 was reflected in the decreased functional responses to IL-8. In contrast, the O2− release, which is mediated by CXCR1, was not suppressed by TNF-α. The treatment of whole blood with TNF-α also caused a significant reduction in CXCR2 and markedly suppressed intracellular Ca2+ mobilization and chemotaxis in response to IL-8, while enhancing the O2− release. These findings suggest that TNF-α down-regulates CXCR2 expression on PMNs and modulates IL-8-induced biologic responses, leading to the intravascular retention of PMNs with an enhanced production of reactive oxygen metabolites.
Involvement of CD14 and Complement Receptors CR3 and CR4 in Nuclear Factor-κB Activation and TNF Production Induced by Lipopolysaccharide and Group B Streptococcal Cell Walls
Authors: Medvedev Andrei E. , Flo Trude , Ingalls Robin R. , Golenbock Douglas T. , Teti Giuseppe , Vogel Stefanie N. , Espevik Terje 
Published: January 2023

AbstractThis study was undertaken to evaluate the role of CD14 and complement receptors type 3 (CR3) and 4 (CR4) in mediating TNF release and NF-κB activation induced by LPS and cell wall preparations from group B streptococci type III (GBS). LPS and GBS caused TNF secretion from human monocytes in a CD14-dependent manner, and soluble CD14, LPS binding protein, or their combination potentiated both LPS- and GBS-induced activities. Blocking of either CD14 or CD18, the common β-subunit of CR3 and CR4, decreased GBS-induced TNF release, while LPS-mediated TNF production was inhibited by anti-CD14 mAb only. Chinese hamster ovary cell transfectants (CHO) that express human CD14 (CHO/CD14) responded to both LPS and GBS with NF-κB translocation, which was inhibited by anti-CD14 mAb and enhanced by LPS binding protein. While LPS showed fast kinetics of NF-κB activation in CHO/CD14 cells, a slower NF-κB response was induced by GBS. LPS also activated NF-κB in CHO cells transfected with either human CR3 or CR4 cDNA, although responses were delayed and weaker than those of CHO/CD14 cells. In contrast to LPS, GBS failed to induce NF-κB in CHO/CR3 or CHO/CR4 cells. Both C3H/OuJ (Lpsn) and C3H/HeJ (Lpsd) mouse peritoneal macrophages responded to GBS with TNF production and NF-κB translocation, whereas LPS was active only in C3H/OuJ macrophages. Thus, LPS and GBS differentially involve CD14 and CR3 or CR4 for signaling NF-κB activation in CHO cells and TNF release in human monocytes, and engage a different set of receptors and/or intracellular signaling pathways in mouse macrophages.
Cutting Edge: The Expression In Vivo of a Second Isoform of pTα: Implications for the Mechanism of pTα Action
Authors: Barber Domingo F. , Passoni Lorena , Wen Li , Geng Liping , Hayday Adrian C. 
Published: January 2023

AbstractA second isoform of pTα, “pTαb,” is derived from the pTα locus by tissue-specific, alternative splicing. pTαb is coexpressed in the thymus with the previously characterized form of pTα (which we term pTαa) and is also expressed in peripheral cells without pTαa. While pTαa acts to retain most TCR β-chains intracellularly, pTαb permits higher levels of cell surface TCRβ expression and facilitates signaling from a CD3-TCRβ complex.
A Role for Heat Shock Protein 27 in CTL-Mediated Cell Death
Authors: Beresford Paul J. , Jaju Madhuri , Friedman Rachel S. , Yoon Margaret J. , Lieberman Judy 
Published: January 2023

Abstract
CTL exocytosis of granules containing perforin and granzyme proteases induces apoptotic cell death. Either granzyme A or B can act with perforin to trigger apoptosis. Granzyme B activates a ubiquitous apoptotic cascade induced by caspase cleavage, but the granzyme A pathway is largely unknown. Using affinity chromatography with recombinant mutant inactive granzyme A, we previously isolated two granzyme A-binding proteins, PHAP (putative HLA-associated protein) I and II. PHAP II, a substrate of granzyme A, is degraded within minutes of CTL attack. Two additional cytoplasmic proteins of 27 and 53 kDa bind strongly to the mutant granzyme A column, requiring 6 M urea to elute. Sequencing identified these as the monomer and dimer of hsp27, a small heat shock protein up-regulated by stress and cellular activation. Hsp27 coprecipitates with granzyme A from cytoplasmic lysates and is not a substrate of the enzyme. Hsp27 translocates to the detergent-insoluble fraction of target cells and relocalizes from diffuse cytoplasmic staining to long filamentous fibers, especially concentrated in a perinuclear region, within minutes of CTL attack. Hsp27 may participate in morphologic changes during granule-mediated lysis. Low or absent levels of hsp27 expression in T lymphocytes, even after heat shock, may play a role in CTL resistance to granule-mediated lysis.
CD4+ T Cells Mature in the Absence of MHC Class I and Class II Expression in Ly-6A.2 Transgenic Mice
Authors: Henderson S. Christine , Berezovskaya Alla , English Andrea , Palliser Deborah , Rock Kenneth L. , Bamezai Anil 
Published: January 2023

AbstractThe TCRs expressed on T lymphocytes recognize foreign peptides bound to MHC molecules. This reactivity is the basis of specific immune response to the foreign Ag. How such specificities are generated in the thymus is still being debated. Signals generated through TCR upon interaction with self MHC-peptide complexes are critical for maturation of the CD4+ helper and CD8+ cytotoxic subsets. We have observed maturation of CD4+ but not CD8+ T cells in Ly-6A.2 transgenic MHC null mice. Since there can be no interactions with MHC molecules in these mice, these CD4+ cells must express the T cell repertoire that exists before positive and negative selection. Interestingly, despite an absence of selection by MHC molecules, the CD4+ cells that mature recognize MHC molecules at a frequency as high as in CD4+ cells in normal mice. These results demonstrate that: 1) the germline sequences encoding TCRs are biased toward reactivity to MHC molecules; and 2) CD4+ cells as opposed to CD8+ cells have distinct lineage commitment signals. These results also suggest that signals originating from Ly-6 can promote or substitute for signals generated from TCR that are required for positive selection. Moreover, this animal model offers a system to study T cell development in the thymus that can provide insights into mechanisms of lineage commitment in developing T cells.
A Synthetic CD4-CDR3 Peptide Analog Enhances Skin Allograft Survival Across a MHC Class II Barrier
Authors: Koch Ute , Choksi Swati , Marcucci Lisa , Korngold Robert 
Published: January 2023

AbstractThe efficacy of a synthetic peptide analogue (rD-mPGPtide), mimicking the CDR3 region in the first domain of the CD4 surface molecule, was investigated in a murine model for CD4+ T cell-mediated skin allograft rejection. A single injection of rD-mPGPtide shortly before transplantation exhibited significantly prolonged graft survival in the B6 anti-B6.C-H2bm12 MHC class II-disparate strain combination. Long-term graft survival (&gt;100 days) was achieved when thymectomized adult recipient mice were transplanted along with rD-mPGPtide treatment. The peptide also affected secondary rechallenge responses with MHC class II allografts. In addition, the inhibitory effect of the rD-mPGPtide in this transplantation model was directed against CD4+ T cells and was exclusively specific toward donor alloantigen. In vitro analysis of CD4+ T cells isolated from the draining lymph nodes of rD-mPGPtide-treated recipients indicated a 450-fold decrease in precursor frequency in response to donor allostimulation compared with the untreated control group. There was also significant down-regulation of the frequency of IL-2-, IFN-γ-, and IL-4-producing CD4+ T cells upon in vitro allogeneic restimulation of host cells 4 days posttransplantation. However, these same CD4+ T cells maintained the capacity to produce normal cytokine levels upon third-party allostimulation. Thus, these studies demonstrate that a CD4-CDR3 peptide analogue can specifically and effectively prolong skin graft survival across MHC class II barriers.
Experimental Autoimmune Encephalomyelitis Induced with a Combination of Myelin Basic Protein and Myelin Oligodendrocyte Glycoprotein Is Ameliorated by Administration of a Single Myelin Basic Protein Peptide
Authors: Leadbetter Elizabeth A. , Bourque Cheryl R. , Devaux Brigitte , Olson Carl D. , Sunshine Geoffrey H. , Hirani Shirish , Wallner Barbara P. , Smilek Dawn E. , Happ Mary Pat 
Published: January 2023

AbstractMultiple sclerosis is an autoimmune disease of the central nervous system in which T cell reactivity to several myelin proteins, including myelin basic protein (MBP), proteolipid protein, and myelin oligodendrocyte glycoprotein (MOG), has been implicated in the perpetuation of the disease state. Experimental autoimmune encephalomyelitis (EAE) is used commonly as a model in which potential therapies for multiple sclerosis are evaluated. The ability of T cell epitope-containing peptides to down-regulate the disease course is well documented for both MBP- and proteolipid protein-induced EAE, and recently has been shown for MOG-induced EAE. In this study, we describe a novel EAE model, in which development of severe disease symptoms in (PL/J × SJL)F1 mice is dependent on reactivity to two different immunizing Ags, MBP and MOG. The disease is often fatal, with a relapsing/progressive course in survivors, and is more severe than would be predicted by immunization with either Ag alone. The MOG plus MBP disease can be treated postinduction with a combination of the MOG 41–60 peptide (identified as the major therapeutic MOG epitope for this strain) and the MBP Ac1–11[4Y] peptide. A significant treatment effect can also be obtained by administration of the MBP peptide alone, but this effect is strictly dose dependent. This MBP peptide does not treat the disease induced only with MOG. These results suggest that peptide immunotherapy can provide an effective means of mitigating disease in this model, even when the treatment is targeted to only one component epitope or one component protein Ag of a diverse autoimmune response.
Pentoxifylline Inhibits Adhesion and Activation of Human T Lymphocytes
Authors: González-Amaro Roberto , Portales-Pérez Diana , Baranda Lourdes , Redondo Juan M. , Martínez-Martínez Sara , Yáñez-Mó María , García-Vicuña Rosario , Cabañas Carlos , Sánchez-Madrid Francisco 
Published: January 2023

Abstract
We have herein studied the effect of pentoxifylline (PTX) on the adhesion and activation of human T lymphocytes. We found that PTX inhibited the adhesion of T cells to the β1 and β2 integrin ligands VCAM-1 and ICAM-1; this inhibitory activity was dose dependent, with a maximal effect from 12 to 24 h. We also found that PTX was able to interfere with the activation of β1 integrins induced by intracellular signals; however, the conformational change of β1 integrins induced by extracellular stimuli (e.g., activating mAbs, or Mn2+) was not significantly affected by this drug. In addition, the homotypic aggregation of T cells induced by anti-β1 and -β2 integrin chain mAbs was also inhibited by PTX. PTX had a significant inhibitory effect on the T lymphocyte expression of the activation Ags CD25 (IL-2Rα-chain), CD69 (activation-inducer molecule), and CD98 (4F2) induced by PHA. Accordingly, PTX also interfered with early cell activation events such as the rise in intracellular Ca2+ and the activation of the Na+/H+ antiporter induced by PHA and phorbol esters, respectively. Furthermore, this drug inhibited both the cell cycle progression and cell proliferation of T cells induced through the CD3/TCR complex. However, this drug did not show any effect on the cell activation/proliferation induced by PMA plus ionomycin. Our results indicate that PTX interferes efficiently with the activation and cell adhesion of human T lymphocytes. These effects may be of relevance for the clinical uses of this drug.
Cutting Edge: Ly-49D and Ly-49H Associate with Mouse DAP12 and Form Activating Receptors
Authors: Smith Kathleen M. , Wu Jun , Bakker Alexander B. H. , Phillips Joseph H. , Lanier Lewis L. 
Published: January 2023

AbstractSeveral members of the Ly-49 receptor family inhibit NK cell-mediated lysis of targets expressing appropriate MHC class I molecules. Ly-49D and Ly-49H, two Ly-49 molecules that lack immunoreceptor tyrosine-based inhibitory motifs (ITIM) in their cytoplasmic domains, associate with mouse DAP12, a molecule that possesses an immunoreceptor tyrosine-based activation motif (ITAM). Cotransfection of either Ly-49D or Ly-49H with DAP12 induces surface expression of both Ly-49 and DAP12. The Ly-49/DAP12 complex was coimmunoprecipitated from the transfected cells, demonstrating a physical association of DAP12 with Ly-49D or Ly-49H in the plasma membrane. Stimulation of transfectants with Abs recognizing either Ly-49D or Ly-49H results in cellular activation, as assessed by induction of tyrosine phosphorylation of multiple cellular substrates.
H2-M3 Presents a Nonformylated Viral Epitope to CTLs Generated In Vitro
Authors: Byers Derek E. , Fischer Lindahl Kirsten 
Published: January 2023

AbstractMost CTL responses to epitopes from influenza virus are restricted by MHC class Ia molecules. However, a synthetic peptide corresponding to residues 173 to 190 of influenza A/JAP/305/57 hemagglutinin (HA) can induce, in vitro, a CTL response to peptide presented by a mouse class Ib molecule encoded by a gene telomeric to H2-Q. Here, we identify the molecule as H2-M3 and show that the last five residues of HA173–190, MLIIW, is the minimal epitope for CTL recognition. Cells that express M3wt, from C57BL/6 or BALB/c mice, are sensitized by both MLIIW and the longer peptide HA173–190, whereas cells that express M3f, from A.CA or B10.M mice, are sensitized only by MLIIW; a single amino acid change at residue 31 (V→M) of M3 accounts for this difference. Although M3-restricted CTLs preferably recognize N-formylated epitopes, i.e., those of mitochondrial or prokaryotic origin, our findings show that M3-restricted primary CTL responses can be generated in vitro against nonformylated epitopes.
In Vivo Persistence of CD8 Polarized T Cell Subsets Producing Type 1 or Type 2 Cytokines
Authors: Cerwenka Adelheid , Carter Laura L. , Reome Joyce B. , Swain Susan L. , Dutton Richard W. 
Published: January 2023

AbstractNaive CD8 T cells can be polarized into effectors producing the type 1 cytokines IFN-γ and IL-2 or the type 2 cytokines IL-4, IL-5, and IL-10, respectively. To study whether the polarized cytokine phenotype of the effectors is stable, we generated highly cytotoxic hemagglutinin (HA) peptide-specific CD8 Tc1 and Tc2 (cytotoxic CD8 T cells producing type 1 or type 2 cytokines) effectors from Clone-4 TCR-transgenic mice, which were adoptively transferred into syngeneic adult thymectomized irradiated and bone marrow-reconstituted recipients. The highly activated blast-size, CD25+ Tc1 and Tc2 effectors gave rise to homogeneous resting CD25−CD44highLy6Chigh Ag-specific populations, which persisted for at least 13 wk after adoptive transfer. These memory CD8 T cells, recovered 13 wk after transfer of Tc1 or Tc2 effectors, still produced either the type 1 or type 2 cytokines, i.e., IFN-γ, or IL-4 and IL-5, respectively, upon restimulation with APCs loaded with the HA peptide, but not in the absence of Ag. The amounts of IL-2 detected in the supernatants of Tc1 and Tc2 memory populations were comparable to that in memory CD4 cells, and both Tc1 and Tc2 memory cells became cytotoxic upon restimulation. Thus, cytokine-polarized CD8 memory T cells are a source of a variety of cytokines, which were classically considered helper cytokines, opening new perspectives on their function as regulatory cells in an immune response.
Cutting Edge: CD19+ Pro-B Cells Can Give Rise to Dendritic Cells In Vitro
Authors: Björck Pia , Kincade Paul W. 
Published: January 2023

AbstractDendritic cells (DC) have the specific capacity of initiating primary T cell responses and ultimately derive from precursors in bone marrow. DC were originally thought to be only of myeloid origin, and myeloid precursor cells could be induced to differentiate into functional DC in response to granulocyte-macrophage (GM)-CSF. However, early CD4low precursor cells from the thymus can also develop into DC when cultured in IL-1β, IL-3, IL-7, TNF-α, stem cell factor, and Flt-3L. In that case, GM-CSF was not required. We now show that CD19+ pro-B cells develop into DC with T cell stimulatory properties when cultured under similar conditions. These pro-B cells acquired the DC-related markers CD11c and NLDC145/DEC205, along with CD80/B7-1, CD86/B7-2, and a high density of MHC class II Ags. The marrow-derived DC did not express CD4 or CD8α, which are markers related to thymic DC. These findings are consistent with a new pathway through which DC are generated from B lymphoid precursors.
Cutting Edge: A Role for p21ras/MAP Kinase in TCR-Mediated Activation of LFA-1
Authors: O’Rourke Anne M. , Shao Hui , Kaye Jonathan 
Published: January 2023

Abstract
LFA-1 is a β2 integrin that plays well-characterized roles in adhesion of T lymphocytes to APC, T cell-mediated cytolysis, and leukocyte-endothelial cell interactions. Although it is clear that LFA-1 must undergo affinity or avidity changes to bind its cellular ligand ICAM-1, the intracellular signaling pathways involved are not well characterized. Here, we show that the Ras-mitogen-activated protein kinase (MAPK) signaling pathway is also involved in TCR-activated LFA-1 adhesion. Expression of a dominant negative form of p21ras in a thymocyte cell line inhibits, while constitutively active p21ras both enhances and sustains, subsequent TCR-triggered adhesion to isolated ICAM-1. However, the Ras/MAPK pathway alone is not sufficient for activating T cell LFA-1, as inhibition of both downstream MAPK/extracellular regulated kinase kinase (MEK) activity and phosphatidylinositol 3-kinase activity is required for complete inhibition of adhesion.
Efficient Presentation of Multivalent Antigens Targeted to Various Cell Surface Molecules of Dendritic Cells and Surface Ig of Antigen-Specific B Cells
Authors: Serre Karine , Machy Patrick , Grivel Jean-Charles , Jolly Gilles , Brun Nicole , Barbet Jacques , Leserman Lee 
Published: January 2023

AbstractTo study the relation between the form of an Ag and the response to it, we compared presentation in vitro with hen egg lysozyme (HEL)-specific T cells from TCR transgenic mice of free HEL and liposome-encapsulated HEL by different APC. HEL-specific splenic B cells or bone marrow-derived dendritic cells were incubated with free HEL or HEL-containing liposomes targeted by Ab to either surface Ig, the Fc receptor, or MHC class I and II molecules. Ag presentation by HEL-specific B cells was at least 100-fold more efficient for HEL in surface Ig-targeted liposomes than free HEL taken up by the same receptor or HEL in liposomes targeted to class I or II molecules. Ag presentation by dendritic cells from Fc receptor-targeted vesicles was augmented 1,000–10,000-fold compared with free Ag or nontargeted liposomes, but presentation was also efficient when Ag was targeted to class I or II molecules. These results indicate that Ag-specific B cells and dendritic cells can be equally efficient in stimulating IL-2 production by Ag-specific T cells from unimmunized TCR transgenic mice when the Ag is multivalent and taken up by appropriate receptors. In contrast to B cells, which require engagement of surface Ig for optimal presentation, dendritic cells may present Ag by means of several different cell surface molecules.
Isolation and Quantitation of a Minor Determinant of Hen Egg White Lysozyme Bound to I-Ak by Using Peptide-Specific Immunoaffinity
Authors: Gugasyan Raffi , Vidavsky Ilan , Nelson Christopher A. , Gross Michael L. , Unanue Emil R. 
Published: January 2023

AbstractWe report here the identification and quantitation of a minor epitope from hen egg white lysozyme (HEL) isolated from the class II MHC molecule I-Ak of APCs. We isolated and concentrated the peptides from the I-Ak extracts by a peptide-specific mAba, followed by their examination by electrospray mass spectrometry. This initial step improved the isolation, recovery, and quantitation and allowed us to identify 13 different minor peptides using the Ab specific for the HEL tryptic fragment 34–45. The HEL peptides varied on both the amino and carboxy termini. The shortest peptide was a 13-mer (residues 33–45), and the longest peptide was a 19-mer (residues 31–49). The two most abundant were 31–47 (1.3 pmol) and 31–46 (1 pmol), while the least abundant were 31–45 (40 fmol) and 32–45 (4 fmol). Only 0.3% of the total class II molecules were occupied by this family of HEL peptides. The amount of the 31–47 peptide, the predominant member of this series, was 22 times lower than that of 48–62, the major epitope of HEL. The 31–47 peptide bound about 20-fold weaker to I-Ak compared with the dominant 48–62 peptide. Thus, the lower abundance of the minor epitope correlated with its weaker binding strength.