bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anti‐CD40 plus interleukin‐4‐activated human naive B cell lines express unmutated immunoglobulin genes with intraclonal heavy chain isotype variability
Authors: Galibert Laurent , van Dooren Joelle , Durand Isabelle , Rousset Françoise , Jefferis Royston , Banchereau Jacques , Lebecque Serge 
Published: March 2007

AbstractCombination of anti‐CD40 antibody and interleukin‐4 (IL‐4) induces B cell clonal expansion reminiscent of the T‐dependent proliferation following antigenic challenge in vivo. We have analyzed the usage of CH genes and the presence or absence of somatic mutations within the progeny of a single human naive B cell activated with anti‐CD40+IL‐4. To address this issue, single‐cell cultures of naive (sIgD+) tonsillar B lymphocytes expressing the VH1‐restricted G8 idiotype were set up. After culture and RNA extraction, VH1+ Ig mRNA were reverse‐transcribed, amplified by polymerase chain reaction and sequenced. A single sIgD+ B cell could generate clones expressing μ, γ1, γ3 or ε, illustrating that the progeny of a single cell can express different isotypes in response to the same stimulus in vitro. The rate of somatic mutations affecting the immunoglobulin variable heavy chain gene was indistinguishable from the background of errors introduced by Taq polymerase.
Integration vectors for antibody chimerization by homologous recombination in hybridoma cells
Authors: Kardinal Christian , Hooijberg Erik , Lang Peter , Zeidler Reinhard , Mocikat Ralph 
Published: March 2007

AbstractGene targeting in hybridoma cells provides a tool for generating chimeric antibodies with great ease and at high yield. We present an evaluation of integration vectors for the chimerization of the immunoglobulin heavy chain locus which are universally applicable to hybridomas of different isotypes and mouse strains. There are three problems arising with vector integration: (i) the frequent persistence of the parental isotype; (ii) an isotype‐dependent aberrant replacement‐like recombination giving rise to antibodies devoid of the CH1 domain; and (iii) secondary recombinations leading to excision of the integrated sequence. To overcome these problems, we have systematically evaluated the consequences of extending the vector flank. Although the homology length clearly determines the recombination frequency, this effect is counteracted by the secondary recombination, which also correlates to the homology length. In contrast, the truncating recombination events are not dependent on the homology length and never lead to re‐excision of the construct. To take advantage of the increased genetic stability obtained with short flanks, we constructed an enrichment vector which yields high recombination efficiencies despite using a short flanking sequence. In addition, irradiation of the cells enhanced homologous recombination. The problem of the co‐production of two isotypes was overcome by a two‐step targeting reaction.
Clonal expansion of myelin basic protein‐reactive T cells in patients with multiple sclerosis: Restricted T cell receptor V gene rearrangements and CDR3 sequence
Authors: Vandevyver Caroline , Mertens Nadja , van den Elsen Peter , Medaer Robert , Raus Jef , Zhang Jingwu 
Published: March 2007

AbstractMyelin basic protein (MBP)‐reactive T cells are thought to play an important role in the pathogenesis of multiple sclerosis (MS). In some patients with MS, these autoreactive T cells display a limited heterogeneity in their epitope recognition and T cell receptor (TCR) variable (V) gene usage. These individual‐dependent properties of MBP‐reactive T cells have led to the speculation that they may represent clonal expansion in vivo in some MS patients. In the present study, 51 MBP‐reactive T cell clones derived from patients with MS and healthy individuals were examined for their epitope recognition and the TCR Vα and Vβ gene rearrangements. The V gene junctional region sequences of identified α and β genes were further analyzed to probe their clonal origins, as the sequences are unique for individual clones. Our data showed that 26 clones derived from nine patients with MS shared a predominant reactivity to the immunodominant regions of MBP, 84–102, 110–129 and 143–168, and used various TCR Vα and Vβ rearrangements. The V gene usage of the clones was restricted to certain Vα Vβ combination(s) in a given MS patient, but varied among different patients. The sequence analysis revealed that the clones generated from a given patient shared a limited or a single junctional region sequence pattern(s), indicating their oligoclonal or monoclonal origin(s). In contrast, 25 MBP‐reactive T cell clones derived from normal individuals exhibited unfocused epitope recognition and V gene usage. Thus, the limited heterogeneity of MBP‐reactive T cells in their structural and functional charactertistics reflects their clonal expansion in vivo in some patients with MS.
Intranasal immunization with liposomes induces strong mucosal immune responses in mice
Authors: Vadolas Jim , Davies John K. , Wright Peter J. , Strugnell Richard A. 
Published: March 2007

AbstractBALB/c mice were immunized intranasally with either soluble ovalbumin (OVA) or OVA entrapped in liposomes. The effect of adding Sigma cholera toxin B subunit (sCT‐B), which contained low amounts of cholera holotoxin (CT), or recombinant CT‐B (rCT‐B) which was free from CT, as mucosal adjuvants was also investigated. The mucosal [lung enzyme‐linked immunospot assay (ELISPOT), lung washing] and systemic (serum antibody and spleen ELISPOT) responses of immunized mice to OVA and CT‐B were determined. Results showed that soluble OVA and liposome‐entrapped OVA were poor inducers of mucosal or systemic responses unless CT‐B was added as adjuvant. The types of responses augmented by sCT‐B and rCT‐B were different. CT‐B containing low levels of CT (i.e. sCT‐B) boosted both mucosal and systemic IgA and IgG responses, whereas rCT‐B only increased IgG responses, unless antigen was entrapped in liposomes. Although rCT‐B was unable to adjuvant IgA responses against soluble OVA, it was able to induce IgA responses against itself. These data show that mucosal responses can be increased by addition of CT‐B containing low levels of CT to antigen preparations given intranasally, suggesting a direct role for CT‐A in isotype switching. Furthermore, the ability of CT‐B to adjuvant IgA responses against added antigens and its ability to induce responses against itself appear to be separate phenomena. The results from this study should assist the rational formulation of mucosal vaccines which induce potent mucosal and systemic immune responses.
Chronic relapsing experimental autoimmune encephalomyelitis with a delayed onset and an atypical clinical course, induced in PL/J mice by myelin oligodendrocyte glycoprotein (MOG)‐derived peptide: Preliminary analysis of MOG T cell epitopes
Authors: de Rosbo Nicole Kerlero , Mendel Itzhack , Ben‐Nun Avraham 
Published: March 2007

AbstractMyelin basic protein (MBP) and proteolipid protein (PLP), the most abundant proteins of central nervous system (CNS) myelin, have been extensively studied as possible primary target antigens in multiple sclerosis (MS), a primary demyelinating autoimmune disease of the CNS. However, there is increasing evidence to suggest that autoimmune reactivity against the quantitatively minor myelin component, myelin oligodendrocyte glycoprotein (MOG), can also play a role in the pathogenicity of MS. We recently demonstrated a predominant response to MOG by peripheral blood lymphocytes from patients with MS tested for their reactivity against various myelin antigens, including MBP and PLP. To ascertain whether or not T cell reactivity to MOG in MS is a potentially pathogenic response, we have tested the ability of synthetic MOG peptides (pMOG) representing potential T cell epitopes, to induce neurological disease in mice. Both strains of mice tested (SJL/J and PL/J mice) were able to mount a primary T cell response to some of the five MOG peptides synthesized, pMOG 1–21, 35–55, 67–87, 104–117 and 202–218. T cell lines could be raised in both strains to pMOG 35–55 and 67–87, but epitope definition revealed that each strain recognized a different minimal epitope within these two peptides. T cell lines to pMOG 1–21 and 202–218 could also be raised in SJL/J and PL/J mice, respectively. T cell reactivity to pMOG 104–117 was not observed in either mouse strain. None of the peptides tested induced detectable clinical signs in SJL/J mice. In contrast, an MS‐like chronic relasping‐remitting disease could be induced in PL/J mice with pMOG 35–55. The disease presented with a delayed onset and with clinical signs which differed significantly in their progression and expression from the typical ascending paralysis of experimental autoimmune encephalomyelitis induced with other myelin components, such as MBP and PLP. Histological examination of CNS tissue from mice injected with pMOG 35–55 revealed only mild neuropathological signs with few inflammatory foci in brain and spinal cord. Some myelin splitting and edema were detected upon electron microscopic examination in the spinal cord and cerebellum. Transfer of pMOG 35–55 reactive T cells into naive PL/J mice resulted in pathological changes characterized by inflammatory foci in the brain and spinal cord. This passively induced disease was clinically silent, as was also reported for Lewis rats injected with T cells specific for the same MOG peptide. These data, which demonstrate unequivocally the encephalitogenic activity of MOG, support our contention that MOG may be as important as MBP or PLP in disease pathogenesis and could be a primary target antigen in autoimmune diseases of the CNS.
Selective induction of interleukin‐1 receptor antagonist and interleukin‐8 in human monocytes by normal polyspecific IgG (intravenous immunoglobulin)
Authors: de Souza Valéria Ruiz , Carreno Marie‐Paule , Kaveri Srinivas V. , Ledur Annick , Sadeghi Hoss , Cavaillon Jean‐Marc , Kazatchkine Michel D. , Haeffner‐Cavaillon Nicole 
Published: March 2007

AbstractWe have investigated the effects of intravenous immunoglobulin (IVIg), a therapeutic preparation of normal human polyspecific IgG, on the synthesis and release of cytokines by peripheral blood monocytes. IVIg was found to selectively induce gene transcription and secretion of interleukin‐1 receptor antagonist (IL‐1ra) and IL‐8 in cultures of normal human monocytes. The addition of IVIg to cultures of purified monocytes induced a dose‐dependent secretion of IL‐1ra and IL‐8 without stimulating the production of IL‐1α, IL‐1β, tumor necrosis factor‐α or IL‐6. The effects of IVIg required both the Fc and F(ab′)2 portions of IgG. IVIg‐induced production of IL‐8 by monocytes was enhanced by lipopolysaccharide (LPS), although LPS inhibited the secretion of IL‐1ra, suggesting that IVIg and LPS stimulate distinct intracellular pathways in monocytes. Induction of IL‐1ra and IL‐8 by IVIg was enhanced in the presence of autologous T lymphocytes. Our observations document the selectivity of the effects of IVIg on the synthesis of cytokines and cytokine antagonists by human monocytes. Induction of IL‐1ra and IL‐8 by IVIg may contribute to the anti‐inflammatory effects of immunoglobulin therapy in patients with autoimmune and systemic inflammatory disorders.
Inhibition of natural killer cell‐mediated bone marrow graft rejection by allogeneic major histocompatibility complex class I, but not class II molecules
Authors: Öhlén Claes , Höglund Petter , Sentman Charles L. , Carbone Ennio , Ljunggren Hans‐Gustaf , Koller Beverly , Kärre Klas 
Published: March 2007

AbstractThe role of major histocompatibility complex (MHC) class I and class II molecules in natural killer (NK) cell‐mediated rejection of allogeneic, semi‐syngeneic and MHC‐matched bone marrow grafts was investigated. The use of β2‐microglobulin (β2m) ‐/‐ and β2m +/‐ mice as bone marrow donors to MHC‐mismatched recipients allowed an analysis of whether the presence of semi‐syngeneic and allogeneic MHC class I gene products would be triggering, protective or neutral, in relation to NK cell‐mediated rejection. Loss of β2m did not allow H‐2b bone marrow cells to escape from NK cell‐mediated rejection in allogeneic (BALB/c) or semi‐allogeneic (H‐2Dd transgenic C57BL/6) mice. On the contrary, it led to stronger rejection, as reflected by the inability of a larger bone marrow cell inoculum to overcome rejection by the H‐2‐mismatched recipients. In H‐2‐matched recipients, loss of β2m in the graft led to a switch from engraftment to rejection. At the recipient level, loss of β2m led to loss of the capability to reject H‐2‐matched β2m‐deficient as well as allogeneic grafts. When MHC class II‐deficient mice were used as donors, the response was the same as that against donors of normal MHC phenotype: allogeneic and semi‐syngeneic grafts were rejected by NK cells, while syngeneic grafts were accepted. These data suggest a model in which allogeneic class I molecules on the target cell offer partial protection, while certain syngeneic class I molecules give full protection from NK cell‐mediated rejection of bone marrow cells. There was no evidence for a role of MHC class II molecules in this system.
The role of bcl‐xL in CD40‐mediated rescue from anti‐μ‐induced apoptosis in WEHI‐231 B lymphoma cells
Authors: Choi Michael S. K. , Boise Lawrence H. , Gottschalk Alexander R. , Quintans José , Thompson Craig B. , Klaus Gerry G. B. 
Published: March 2007

AbstractThe phenotypically immature B cell lymphoma WEHI‐231 undergoes apoptotic cell death when cultured with anti‐immunoglobulin (Ig) antibodies, via a bcl‐2‐independent mechanism. We have therefore studied the role of the bcl‐2‐related protein bcl‐x in controlling cell death in WEHI‐231. We find that overexpression of the long form of bcl‐x (bcl‐xL) renders these cells refractory to anti‐Ig‐induced cell death. Stimulation of WEHI‐231 via CD40 has similar protective effects. We show here that ligation of CD40 rapidly induces the appearance of the bcl‐xL protein in WEHI‐231, while stimulation via sIgM, sIgD, CD5 or CD45 receptors, or with phorbol esters plus ionomycin does not. WEHI‐231 cells also rapidly undergo massive apoptosis following culture with thapsigargin, a specific inhibitor of the Ca2+‐ATPase of the endoplasmic reticulum: this is also reversed by anti‐CD40, or by overexpression of bcl‐xL. We, therefore, conclude that bcl‐xL plays a key role in the regulation of antigen receptor‐mediated apoptosis via CD40 in WEHI‐231. In addition, the fact that this protein is not induced in WEHI‐231 in response to phorbol dibutyrate plus ionomycin points to a fundamental signaling defect in these cells, which could conceivably be a reflection of their immature, apoptosis‐susceptible phenotype.
Suppression of experimental autoimmune encephalomyelitis in Lewis rats by antibodies against CD2
Authors: Jung Stefan , Toyka Klaus , Hartung Hans‐Peter 
Published: March 2007

AbstractThe immunotherapeutic potential of three anti‐rat CD2 monoclonal antibodies (mAb) (OX34, OX54, OX55) and the combination of OX54 with OX55 was tested in Lewis rat experimental autoimmune encephalomyelitis (EAE). In actively induced EAE, a single injection of OX34 2 days before immunization with myelin basic protein (MBP) in complete Freund's adjuvant (CFA) completely prevented or greatly attenuated EAE in all animals. Injection of OX54 acted moderately suppressive while OX55 or OX54/55 did not affect disease severity. Abrogation of EAE by OX34 was not restricted to its application before immunization. Therapeutic administration of all three mAb and the Ab combination from onset of first clinical signs efficiently blocked progression of disease and prevented all animals from developing hind limb paresis. In adoptive transfer EAE induced with in vitro activated cells of an encephalitogenic T helper line, clinical and histological signs were completely prevented by injection of OX34 on the day of cell transfer and 4 days later, underlining the strong impact of anti‐CD2 mAb on the effector phase of disease.Immunocytofluorometric analysis of peripheral blood lymphocytes after a single Ab injection demonstrated that all mAb induced a variable degree of transient reduction in T cell numbers and modulation of CD2 antigens. In contrast to the other mAb, OX34 persisted on lymphocytes for at least 11 days, which may explain its unique suppressive effect on EAE after a single injection before immunization. The assumption that prophylactic administration of OX34 also inhibits MBP‐induced EAE, due to persistence into the effector phase, was substantiated by the finding that none of the mAb prevented generation of an antigen‐specific cellular response in MBP/CFA‐immunized animals. Since none of the Ab induced T cell unresponsiveness or inhibited T cell activation by antigen‐ or Ab‐mediated stimulation of the T cell receptor, we suggest that their marked action on the effector phase of EAE may rely on inhibition of T cell infiltration into the central nervous system. The demonstrated efficacy of these anti‐CD2 mAb in EAE suggests a potential therapeutic role that may be equal to that of anti‐CD4 or anti‐T cell receptor Ab.
HIV‐1 glycoprotein gp120 disrupts CD4‐p56lck/CD3‐T cell receptor interactions and inhibits CD3 signaling
Authors: Hubert Pascale , Bismuth Georges , Körner Marie , Debré Patrice 
Published: March 2007

AbstractUsing the CD4+ human T cell clone P28, we demonstrated that the HIV‐1 glycoprotein gp120 inhibited CD3‐induced inositol trisphosphate production, calcium influx and T cell proliferation. Additionally, gp120 was shown to dissociate the tyrosine kinase p56lck from CD4 in CEM cells, with a concommittant inhibition of CD4‐linked kinase activity. We have addressed the question whether disruption of CD4/p56lck or CD4/CD3‐T cell receptor interactions, or both, could account for the inhibitory effect of gp120 in P28 cells. By comparing the effects of various anti‐CD4 monoclonal antibodies (mAb) with those of gp120, we show that gp120 and IOT4a modulate CD4 expression, and decrease CD4‐associated p56lck and CD4‐linked kinase activity at the plasma membrane. In contrast, OKT4A and OKT4 anti‐CD4 mAb have no inhibitory effect. Interestingly, gp120 also inhibits CD3‐induced Lck activation and cellular tyrosine phosphorylation, particularly of phosphoinositide‐specific phospholipase C‐γ‐1. Kinetic experiments reveal that the inhibitory effect of gp120 on CD3‐induced tyrosine phosphorylation appears as early as 30 min, but culminate when CD4‐p56lck complexes disappear from the cell surface after 4 h. These results suggest that a negative signal is triggered by gp120 that results, after a few hours, in down‐modulation of CD4‐p56lck complexes and the impairment of CD3 signaling. Supporting this hypothesis, gp120 inhibits CD3‐linked kinase activity as shown by the inhibition of the phosphorylation of CD3 chains, leading to the inhibition of subsequent signal transduction.
Characterization of the human interleukin‐5 gene promoter: involvement of octamer binding sites in the gene promoter activity
Authors: Gruart‐Gouilleux Valérie , Engels Peter , Sullivan Michael 
Published: March 2007

AbstractTo investigate the human interleukin(IL)‐5 gene promoter, we have constructed a plasmid with the firefly luciferase reporter gene linked to human IL‐5 5′ flanking sequence (nucleotides −507 to + 44). We have used this plasmid to transfect the mouse EL4 T cell line, which can, under certain conditions, produce IL‐5 transcripts. Phorbol 12‐myristate 13‐acetate, A23187 and N6,2′‐O‐dibutyryl‐adenosine 3′:5′‐cyclic monophosphate co‐stimulation of EL4 cells transfected with the human IL‐5/luciferase reporter gene construct resulted in maximal induction of the luciferase gene. Deletion analysis of the IL‐5 promoter revealed the presence of negative regulatory elements between nucleotides −404 and −312 and two regions, located between nucleotides −312 and −227 and between nucleotides −80 and −35, that are involved in the positive regulation of the IL‐5 promoter. Using electrophoretic mobility shift assays, we show that the positive element located between nucleotides −312 and −227 involves the binding of factors antigenically related to Oct1, Oct2A and Oct2B, to a perfect octamer motif located at position −244/−237. Introduction of three point mutations in the octamer motif of the IL‐5/luciferase reporter gene plasmid, which results in the loss of competition for the factors binding to the IL‐5 promoter sequence, reduced the production of luciferase from stimulated, transfected EL4 cells, by 90%. Octamer factors can also bind within the second positive regulatory region.
A 17‐kDa CD4‐binding glycoprotein present in human seminal plasma and in breast tumor cells
Authors: Autiero Monica , Cammarota Giancarlo , Friedlein Arno , Zulauf Martin , Chiappetta Gennaro , Dragone Vincenzo , Guardiola John 
Published: March 2007

AbstractWe previously isolated gp17, a human seminal plasma glycoprotein, which specifically interacts with the D1‐D2 region of CD4, a T cell surface molecule involved in antigen recognition mediated by helper T cells also acting as a receptor for the human immunodeficiency virus. In this study we report that monoclonal antibodies (mAb) reacting with gp17 are able to inhibit the binding of gp17 to immobilized soluble CD4. An immunohistochemical analysis shows that gp17 is also expressed in mammary tumor cells upon hormone treatment and in biopsies from breast cancer patients. A structural characterization of gp17, including amino acid sequencing, indicates that the protein has an extensive structural similarity with a glycoprotein designated as seminal actin‐binding protein (SABP), also secreted by male sexual glands. SABP is in turn identical to gross cystic disease fluid protein‐15 (GCDFP‐15) or prolactin‐inducible protein (PIP), a factor known as a highly specific and sensitive marker of primary and metastatic apocrine breast cancer. To establish further the correspondence of gp17 and GCDFP‐15/PIP/SABP, the latter was expressed in bacteria from a cloned cDNA and purified by affinity chromatography to either anti‐gp17 mAb‐Sepharose or CD4‐Sepharose. The purified recombinant protein is shown to inhibit the binding of labeled, pure g17 to immobilized soluble CD4. The finding that breast cancer cells express a protein able to interact with the CD4 domains involved in the recognition of class II major histocompatibility antigens suggests a possible mechanism by which a tumor may affect the activity of tumor‐infiltrated CD4+ T cells.
No role of interleukin‐4 in CD23/IgE‐mediated enhancement of the murine antibody response in vivo
Authors: Hjulström Susanna , Landin Andreas , Jansson Liselotte , Holmdahl Rikard , Heyman Birgitta 
Published: March 2007

AbstractAntigen‐specific IgE up‐regulates the specific IgM, IgG1, IgG2a and IgE response in vivo when given to mice together with antigen. The enhancement is mediated by the low‐affinity receptor for IgE, FcϵRII or CD23, as demonstrated both in CD23‐deficient mice and by blocking CD23 with anti‐CD23 monoclonal antibodies. A possible mechanism behind the regulatory effects of CD23 is that the IgE/CD23/antigen complex is endocytosed by B cells, leading to increased antigen processing and presentation on major histocompatibility complex (MHC) class II molecules toT helper cells. In the present study we have found that the expression of CD23 is reduced fivefold on splenic B cells in mice genetically deficient for IL‐4. When IL‐4‐deficient mice and normal littermates were immunized with 2,4,6‐trinitrophenyl (TNP)‐specific IgE followed by bovine serum albumin (BSA)‐TNP or with BSA‐TNP alone, the BSA‐specific IgG1 and IgG2a responses were equally well augmented by IgE in all mice. In addition, a low but significant IgE response was seen even in the IL‐4‐deficient mice. Thus, enhancement of the antibody response through IgE and CD23 occur in the absence of IL‐4 and is not dependent on CD23 up‐regulation.