bluuebunny/crossref_metadata_2025_split huggingface dataset:
Remote T cell co‐stimulation via LFA‐1/ICAM‐1 and CD2/LFA‐3: Demonstration with immobilized ligand/mAb and implication in monocyte‐mediated co‐stimulation
Authors: Van Seventer Gijs A. , Shimizu Yoji , Horgan Kevin J. , Luce Gale E. Ginther , Webb Deborah , Shaw Stephen 
Published: March 2007

AbstractProliferative response of resting T cells generally requires not only cross‐linking of the T cell receptor (TcR) but also co‐stimulatory signals from accessory molecules. We here have used a “three‐cell” model consisting of: (a) resting human CD4+ T cells as responders; (b) CD3 monoclonal antibody (mAb) OKT3 on latex beads as surrogate stimulators; (c) autologous monocytes as source of co‐stimulation. As described by Kawakami et al. (J. Immunol. 1989. 142: 1818), T cell proliferation in this system is observed with paraformaldehyde‐fixed monocytes if they have been activated and interleukin (IL) 1β/IL6 is supplied. Since this three‐cell system provides TcR cross‐linking at a site spatially “remote” from co‐stimulation, they help distinguish adhesion from signal transduction but the molecules that mediate co‐stimulation in this system have not been identified. Our studies now demonstrate that co‐stimulation by the monocytes is dependent on each of two receptor/ligand pathways CD2/LFA‐3 and LFA‐1/ICAM‐1 since it is inhibited by each relevant mAb but not a variety of control mAb. The hypotheses that CD2 and LFA‐1 could each mediate co‐stimulation was tested in simplified model systems in which the monocyte was replaced with immobilized CD2 mAb or purified ICAM‐1 presented on a separate surface from the CD3 mAb. The results in these simplified models demonstrate that on resting T cells either CD2 or LFA‐1 molecules alone can mediate “remote” co‐stimulation unlike most other T cell surface molecules. Co‐stimulation requires IL 1β/IL6 both in the weaker LFA‐1 ligand‐mediated co‐stimulation and at lower CD2 mAb concentrations in the stronger CD2 mAb‐mediated co‐stimulation. Thus: (a) the accessory cell function of stimulated fixed monocytes in T cell proliferation requires both the LFA‐1/ICAM‐1 and CD2/LFA‐3 pathways; and (b) the T cell molecules CD2 and LFA‐1 can give co‐stimulatory signals that can act in a “remote” fashion.
Ontogeny of murine T cells: Thymus‐regulated development of T cell receptor‐bearing cells derived from embryonic yolk sac
Authors: Liu Chih‐Pin , Auerbach Robert 
Published: March 2007

AbstractPre‐thymic stem cells which arise extrinsically to the thymus differentiate into mature T cells after colonizing the fetal thymus, but the origin of the stem cells during mammalian embryogenesis remains unknown. More than one potential site has been proposed, including the liver, the omentum and the embryonic yolk sac (YS). Since the murine YS appears earliest in gestation and is the first site of hematopoiesis, our studies focus on the mouse YS as the early major source of pre‐thymic stem cells. Previous studies showed that freshly obtained YS cells expressing no known major T cell marker can develop into Thy‐1+ cells in vitro either transiently or stably. However, the critical steps leading to functional maturation of T cells involve the rearrangement and expression of the T cell receptor (TcR) genes. We report here that YS cells grown in short‐term cell culture show no detectable rearrangement or transcription at the TcRγ gene locus, although the TcRγ gene of in vitro transformed YS cells rearranges in the absence of the thymus. However, after seeding lymphocyte‐depleted thymuses in vitro, YS cells can differentiate into various subsets of cells appearing in the thymus, including CD3/TcR α/β‐ and γ/δ‐bearing cells. TcR Vγ3 which is expressed mainly on early fetal thymocytes and on Thy‐1+ dendritic cells can be detected on YS‐derived cells. TcR Vβ8‐expressing cells which appear later in thymic ontogeny are also detected. The kinetics for reconstituting the thymus varies among YS cells of different ages (day 10 to 13 gestation). These results indicate that a single wave of early mouse YS cells can undergo the molecular and cellular changes associated with T cell differentiation and acquire mature T cell characteristics in the absence of continuous inflow of other stem cells. The thymus acts in an inductive/regulatory role for that differentiation.
Diabetes‐prone BB rats express the RT6 alloantigen on intestinal intraepithelial lymphocytes
Authors: Fangmann Josef , Schwinzer Reinhard , Hedrich Hans‐Jürgen , Klöting Ingrid , Wonigeit Kurt 
Published: March 2007

AbstractThe RT6 alloantigen of the rat is expressed on most peripheral T cells but not on thymocytes and thus represents a marker for postthymic T lymphocyte maturation in this species. Diabetes‐prone (DP) BB rats exhibit a genetically determined T cell lymphopenia associated with a deficiency of RT6+ T cells. In this study we have analyzed the expression of RT6 on lymph node (LN) cells and intestinal intraepithelial lymphocytes (IEL) in two DP BB strains (BB/OK and BB/Mol) and two control strains (non‐lymphopenic BB/PhiK and LEW) by flow cytometry. In the DP BB rats the number of LN T cells was substantially reduced (< 25% TcR2+ cells) and completely lacked RT6 expression. The IEL population was also reduced in number and in marked contrast to normal rats consisted predominantly of CD4+ cells. The majority of IEL, however, clearly expressed RT6. Treatment with a phosphatidylinositol (PI)‐specific phospholipase C markedly reduced the RT6 density showing that PI‐mediated anchoring of RT6 in the cell membrane also applies to IEL of DP BB rats. The results demonstrate that the DP BB strains possess a functional RT6 gene and are also able to generate the PI anchor. The defect in RT6 expression is thus unlikely to be the primary cause of the T cell lymphopenia.
The binding affinity and dissociation rates of peptides for class I major histocompatibility complex molecules
Authors: Cerundolo Vincenzo , Elliott Timothy , Elvin John , Bastin Judy , Rammensee Hans‐Georg , Townsend Alain 
Published: March 2007

AbstractPeptides of various lengths derived from the influenza nucleoprotein (NP) bind to H‐2Db class I molecules with affinities at 4 °C between ∼3 × 105‐∼3 × 107 M−1. The peptide with the highest affinity corresponds to the sequence of nine amino acids (NP366–374) recently isolated from cells infected with influenza. This peptide forms stable complexes with half‐lives > 110 h at 4 °C, 39 h at 22 °C and 3 h at 37 °C. Small increases in length of the peptide greatly reduce the stability of the complex (t1/2 ∼1–10 h at 4 °C). These results may explain the homogeneous length of peptides isolated from class I molecules formed in vivo, and suggest that class I and II may differ in their dependence on the length of peptides for the formation of stable complexes.
Structure‐function studies on human C4b‐binding protein using monoclonal antibodies
Authors: Hessing Martin , Heijnen Harry F. G. , Hackeng Tilman M. , Sixma Jan J. , Bouma Bonno N. 
Published: March 2007

AbstractHuman C4b‐binding protein (C4BP) is a multimeric regulatory complement component interacting with vitamin K‐dependent protein S and complement C4b. Using hybridoma technology, a panel of monoclonal antibodies (mAb) specific for intact human C4BP and its 160‐kDa chymotryptic central core fragment were prepared to study the structure‐function relationships of C4BP. By Western blot analysis and competition experiments, four distinct groups of mAb were identified and mapped on the C4BP molecule. By‐rotary shadowing, spider‐like images of C4BP‐antibody complexes were obtained and immunoelectron microscopy provided some information on the stoichiometry of the antibody‐C4BP interaction. Certain antibodies interacted with C4BP molecules only at a ratio of 1:1. Others formed complexes of two or more antibodies bound to homologous sites on the C4BP molecule. Using an enzyme‐linked immunosorbent sandwich assay for the measurement of the complex formation between protein S and C4BP, mAb against the central core and the disulfide‐linked β chain of C4BP were identified that inhibited the binding of protein S to C4BP. In a binding assay using 125I‐labeled C4BP and soiid‐phase C4b, the inhibitory effect of one group of anti‐C4BP mAb on the binding of C4BP to C4b was demonstrated.
Molecular cloning of cDNAs for the rat interleukin 2 receptor α and β chain genes: Differentially regulated gene activity in response to mitogenic stimulation
Authors: Page Theresa H. , Dallman Margaret J. 
Published: March 2007

AbstractWe have isolated, by transient expression and screening using an oligonucleotide probe, cDNA clones encoding the rat interleukin 2 receptor (IL 2R) α and β chains, respectively. Both chains are approximately 60% identical at the amino acid level to their human counterparts. In common with the human and mouse IL 2R β chains, the rat β chain is a member of the cytokine receptor family. The rat IL 2R β chain contains no conventional signal transduction machinery and, like the mouse IL 2R β chain, has a significant number of deletions in its cytoplasmic tail in comparison to the human protein. Northern analysis indicates that the rat β chain message is constitutively transcribed in normal resting lymphocytes, whereas the α chain message is absent. Transcription of both chains of the receptor is up‐regulated by cellular activation. However, kinetic studies have shown that whereas α chain message is rapidly induced, and can be detected 5 h after the addition of phytohemagglutinin, levels of β chain mRNA increase at a much later time point and are not seen to rise until approximately 24 h after the addition of mitogen. These data suggest that the expression of high‐affinity IL 2R is controlled by factors which influence transcription of both the α and the β chain genes.
Expansion and high proliferate potential of the macrophage system throughout life time of lupus‐prone NZB/W and MRL lpr/lpr mice. Lack of down‐regulation of extramedullar macrophage proliferation in the postnatal period
Authors: Müller Meike , Emmendörffer Andreas , Lohmann‐Matthes Marie‐Luise 
Published: March 2007

AbstractSystemic lupus erythematosus is an autoimmune disease, characterized by high liters of autoantibodies against many cell‐membrane and intracellular antigens. Polyclonal B cell activation and alterations in the T cell compartment have been described. The present report deals with the organ‐associated macrophage (MΦ) system of two lupus‐prone mouse strains (NZB/W and MRL lpr/lpr) and demonstrates that in both mouse strains the MΦ compartment of liver and spleen is clearly expanded. In the liver the number of F 4/80+ MΦ is strongly elevated. In addition, presence of early MΦ precursors and of extramedullary organassociated monocyte proliferation in response to colony‐stimulating factor (CSF) is documented in liver and spleen of these mice. Further, in normal animals during the first two weeks of life extramedullar monocytopoiesis is present in liver and spleen, which is then down‐regulated in the third week of life. In the two lupus‐prone mouse strains down‐regulation does not occur but extramedullar monocyte proliferation is sustained at high level throughout life time. As possible correlates for the expansion of the MΦ system elevated CSF‐1 mRNA levels are demonstrated in kidney, spleen and liver of NZB/W mice and elevated CSF serum levels are documented in MRL lpr/lpr mice. The possible contribution of the expanded MΦ system to B and T cell dysregulation is discussed.
Distinction of naive and memory BoCD4 lymphocytes in calves with a monoclonal antibody, CC76, to a restricted determinant of the bovine leukocyte‐common antigen, CD45
Authors: Howard Chris J. , Sopp Paul , Parsons Keith R. , McKeever Declan J. , Taracha Evans L N. , Jones Brenda V. , MacHugh Niall D. , Morrison W. Ivan 
Published: March 2007

AbstractA murine IgG1 monoclonal antibody (mAb), CC76, has been produced that, based on findings of the relative molecular mass of polypeptides that it recognized, staining of leukocytes in blood and tissues, and the biological properties of the T lymphocyte subpopulations with which it reacts, is considered to identify an isoform of the leukocyte common antigen (LCA) family of molecules in cattle. The mAb is more similar to human CD45R which detect products requiring the presence of the B exon within the LCA gene and to the anti‐rat mAb MRC‐OX22, than to CD45RA or CD45RO. mAb CC76 reacts with an antigen expressed by subpopulations of cells in bovine blood that express BoCD2 and either the BoCD4 or BoCD8 antigens. T cells that express the γ/δ T cell receptor identified with mAb to BoWC1 antigen did not react with CC76. The molecule detected is expressed on B cells but not on monocytes or granulocytes. Only 2% of cells in thymic suspensions stained with mAb CC76. Immature cortical thymocytes that were BoCD1+ did not react with CC76 and 90% of the cells in thymic suspensions that were CC76+ had the phenotype of mature thymocytes. These cells were primarily in the medulla. The LCA isoform detected thus appears to be acquired by mature cells shortly before emigration from the thymic medulla into the periphery. Expression of the molecule detected by mAb CC76 on cells from lymph nodes was similar to that in blood, but expression on cells from the gut mucosa was quite different. Almost all, 95% and 93% respectively, of the BoCD4+ cells in the gut mucosa or discrete Peyer's patches were CC76−. A greater proportion of BoCD8+ cells from these sites, 35% and 26%, expressed the antigen.Lymphocytes from animals that had been immunized with Trypanosoma brucei were sorted into BoCD4+, CC76+ and BoCD4+, CC76− populations and cultured in vitro with the variable surface glycoprotein antigen from the parasite. Lymphocyte transformation responses were entirely within the CC76− population indicating that the mAb distinguished naive from memory BoCD4+ T cells in cattle. Major histocompatibility complex (MHC) class I‐restricted cytotoxic precursor cells that expressed the BoCD8 antigen sorted from cattle that were immune to Theileria parva were both CC76+ and CC76− indicating that different isoforms of the LCA may be expressed on MHC class 1‐ and class II‐restricted memory cells and that BoCDS memory cells are heterogeneous with respect to the LCA isoform that they express.
Interleukin 4 receptor targeted cytotoxicity: Genetic construction and in vivo immunosuppressive activity of a diphtheria toxin‐related murine interleukin 4 fusion protein
Authors: Lakkis Fadi , Steele Alan , Pacheco‐Silva Alvaro , Rubin‐Kelley Vicki , Strom Terry B. , Murphy John R. 
Published: March 2007

AbstractThe interleukin 4 (IL 4) receptor is expressed on various cells of the immune system, including T and B lymphocytes, macrophages and mast cells. We have constructed a recombinant protein, DAB389‐mIL 4, that is composed of the enzymatically active and membrane translocation domains of diphtheria toxin fused to murine IL 4. We demonstrate that this fusion toxin selectively inhibits protein synsthesis in eukaryotic cells which express the murine IL 4 receptor. The cytotoxic potency of this fusion toxin is shown to be directly proportional to the reported number of IL 4 receptors on the surface of target cells. Since the action of DAB389‐mIL 4 can be blocked with either excess mIL 4 or antibody to mIL 4, we conclude that its entry into target cells is mediated through the mIL 4 receptor. A mutant form of DAB389‐mIL 4, DA(197)B389‐mIL 4, in which the fragment A‐associated ADP‐ribosyltransferase is inactive, is not cytotoxic to murine IL 4 receptor‐bearing cells. Finally, we demonstrate that DAB389‐mIL 4 administered subcutaneously to DBA/2 mice results in suppression of delayed‐type hypersensitivity (DTH); whereas, the non‐toxic DA(197)B389‐mIL 4 fails to dampen the DTH response.
Late treatment with anti‐LFA‐1 (CD11a) antibody prevents cerebral malaria in a mouse model
Authors: Falanga Pierre B. , Butcher Eugene C. 
Published: March 2007

AbstractCBA/Ca mice injected with Plasmodium berghei develop cerebral malaria (CM) characterized by ataxia and progressive paralysis leading to death 7–9 days after experimental infection. The development of cerebral symptoms is a function of the immune response in susceptible strains, and depends on cell‐cell interactions involving T helper cells and mononuclear phagocytes. Here we ask whether antibodies to cell adhesion receptors of the immune system can influence the development of CM in this mouse model. When administrated on day 6 after infection, antibody to the leukocyte integrin leukocyte function‐antigen‐1 (LFA‐1) but not antibodies to MAC‐1, LECAM‐1 (the MEL‐14 antigen), α4 integrin or ICAM‐1 dramatically reduced the incidence of CM, leading to survival of most mice until the later onset of anemia. Anti‐LFA‐1 treatment did not result in a substantial decrease in the monocyte accumulation observed in cerebral vessels of susceptible mice. Its efficacy may be related to the broader roles of LFA‐1 in cell‐cell interactions important in the later pathogenic stages of the immune response to the parasite. Perturbation of immune cell function through interference with cell adhesion mechanisms may offer an important therapeutic tool in acute, life‐threatening immune‐mediated disorders.
CD4+CD8+CD3high thymocytes appear transiently during ontogeny: evidence from phenotypic and functional studies
Authors: Hugo Patrice , Boyd Richard L. , Waanders Gary A. , Scollay Roland 
Published: March 2007

AbstractDuring T cell development thymocyte subsets emerge in a defined order, reflective of their maturational stage. In this study we determined the timing of appearance of CD4+CD8+CD3high thymocytes during in vivo and in vitro embryonic development, and thymic reconstitution after cortisone treatment. In these models, CD4+CD8+CD3high cells followed CD4+CD8+CD3low and preceded mature CD4+CD8+CD3high/CD4+CD8+CD3high thymocytes, while cortisone resistance was first seen among CD4+CD8+CD3high cells. CD4+CD8+CD3high thymocytes were also shown to display a pattern of antigen receptor‐mediated calcium influx intermediate between that induced in other CD4+CD8+ cells and mature thymocytes. These results are consistent with a precursor‐progeny relationship between CD4+CD8+CD3low and CD4+CD8+CD3high thymocytes, the latter developing to mature thymocytes (Hugo, P. et al., Int. Immunol. 1991. 3: 265).
Effect of ubiquitin on platelet functions: possible identity with platelet activity suppressive lymphokine (PASL)
Authors: Pancré Véronique , Pierce Raymond J. , Fournier Franck , Mehtali Majid , Delanoye Anne , Capron André , Auriault Claude 
Published: March 2007

AbstractIn an attempt to clone a suppressive lymphokine of platelet function (PASL), we have obtained a cDNA clone coding for the previously described human ubiquitin‐80 amino acid fusion protein. Our clone differs from the described sequence in that it contains the complete amino acid sequence of ubiquitin as well as a short (25 bp) 5′ noncoding region. In addition the 3′ untranslated region is slightly longer than that previously shown. Like PASL, purified ubiquitin can inhibit the cytotoxic properties of platelets and the production of oxygen metabolites by these cells. Moreover, this molecule is able to act as a proaggregating factor and seems of a great interest in pathologies involving defects in platelet aggregation. Ubiquitin could also have a potential use in the regulation of immunological disorders in which platelets seem to be implicated such as hymenoptera venom hypersensitivity and aspirin‐sensitive asthma, since in both situations, ubiquitin is able, as is PASL, to inhibit the cytotoxic function of platelets. Indeed ubiquitin possesses important pharmacological potentialities which have not been previously described. This molecule and PASL share several similarities in their functional and physicochemical properties. PASL could therefore belong to the family of ubiquitins.
In vivo induction of γ/δ T cells with highly potent and selective anti‐tumor cytotoxicity
Authors: Ericsson Per‐Olof , Hansson Johan , Widegren Bengt , Dohlsten Mikael , Sjögren Hans‐Olov , Hedlund Gunnar 
Published: March 2007

AbstractHigh frequencies of CD5+TcR α/β− T cells were induced in the peritoneal cavity of rats immunized with syngeneic W439 lymphoma cells. These TcR α/β− cells expressed TcR δ mRNA as analyzed by the polymerase chain reaction technique. The δ+ (TcR γ/δ+) T cells were of the CD2+, CD3+, CD4−, CD8+, CD45RB+ phenotype and showed stronger anti‐tumor cytotoxicity compared to the TcR α/β+ T cells. The cytotoxic effects of both α/β and γ/δ T cells were selective for the W439 lymphoma cells and were not directed to other syngeneic tumors, natural killer targets and syngeneic or allogeneic normal cells. T cells, including both α/β and γ/δ cells, were induced when WF rats were immunized with allogeneic BN spleen cells. In this case the γ/δ T cells showed allo‐selective cytotoxicity, although weaker compared to the TcR α/β+ T cells. The γ/δ T cells, induced by immunization with either W439 cells or BN spleen cells, were selective for the immunogen used and had no effect on irrelevant target cells, indicating that these effector cells were not activated by a shared γ/δ T cell‐related superantigen. Since highly potent tumor‐selective γ/δ cytotoxic T lymphocytes could be induced by syngeneic lymphoma cells, we suggest a role for γ/δ T cells in the defense against certain types of tumors.
The use of the polymerase chain reaction to map CD4+ T cell epitopes
Authors: Nakagawa Terry Y. , Grafenstein Hermann Von , Sears Jonathan E. , Williams John , Janeway Charles A. , Flavell Richard A. 
Published: March 2007

AbstractCD4+ T cells recognize processed exogenous antigen in the form of peptides bound to syngeneic major histocompatibility complex class II molecules on antigen‐presenting cells. We have developed a novel and convenient method to synthesize and map CD4+ T cell epitopes of cloned antigens using polymerase chain reaction (PCR)‐directed construction of genes expressing recombinant protein fragments. Unique restriction sites incorporated into the PCR primers were employed for the unidirectional cloning of gene fragments into a bacterial expression vector that can be induced to high‐level expression. The bacterial lysate could be used directly in T cell proliferation assays. Overlapping recombinant fragments spanning the entire protein were generated and tested. The length of the sequence containing the epitope was further reduced by utilizing PCR to generate 3′ truncations. Finally, a small number of overlapping peptides spanning a sequence of 39 amino acids were synthesized to identify a thirteen‐amino acid peptide epitope within chicken transferrin that stimulates the T helper cell clone D10.G4.1. PCR‐directed construction of fragments of antigen allows for optimal design of strategies for the mapping and analysis of CD4+ T cell epitopes.