bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of the human type I interferon receptor by ligand blotting
Authors: Schwabe Michael , Princler Gerald L. , Faltynek Connie R. 
Published: March 2007

AbstractThe human type I interferon (IFN) receptor was characterized by ligand blotting. In this method, plasmalemma proteins or detergent‐lysed whole‐cell extracts from human Burkitt lymphoma cell lines were separated on polyacrylamide gels and subsequently transferred onto nitrocellulose sheets. Probing the blots with 3 × 10−10 M 125I‐labeled recombinant IFN‐αA (125I‐rIFN‐αA) revealed an IFN‐α‐binding protein with an apparent molecular mass of 95 kDa (p95). Performing the electrophoretic run under reducing conditions completely abrogated the signal on the blot, indicating that the type I IFN receptor contains a'disulfide bond essential for IFN binding. Optimal binding of 125I‐rIFN‐αA occurred at pH 9. The specificity of the binding reaction was established by simultaneously adding an excess of unlabeled IFN during incubation of the blots with 125I‐rIFN‐αA. The addition of either unlabeled IFN‐α or IFN‐β, but not IFN‐γ, abolished the binding of 125I‐rIFN‐αA to p95. 125I‐rIFN‐γ at 1.25 × 10−11 M bound to two proteins distinct from p95 with apparent molecular mass of 92 and 87 kDa, respectively. Saturability of 125I‐rIFN‐αA binding was demonstrated by probing a constant amount of membrane proteins with increasing amounts of 125I‐rIFN‐αA. Scatchard analysis of the binding data yielded an apparent Kd of 5.4 × 10−10 M for the immobilized type I IFN receptor. The expression of p95 on IFN‐α‐resistant and ‐sensitive cells was indistinguishable. We conclude that p95 is the IFN‐α/β receptor and that two proteins (p92 and p87) can specifically bind IFN‐γ. These results indicate that ligand blotting is a versatile method for characterization of unmodified IFN receptors and IFN‐receptor interaction and could also provide a new investigational approach for other cytokine receptor systems.
Orientation of epitopes influences the immunogenicity of synthetic peptide dimmers
Authors: Cox Josephine H. , Ivanyi Juraj , Young Douglas B. , Lamb Jonathan R. , Syred Andrew D. , Francis Michael J. 
Published: March 2007

AbstractThe immunogenicity of synthetic peptide dimers based on epitope sequences derived from the mycobacterial 65‐kDa antigen and the foot and mouth disease virus (FMDV) VP1 protein was examined in inbred mice. The analysis was directed towards the potential helper role of a T cell stimulatory mycobacterial epitope (65–85) with respect to poorly immunogenic sites either from the same molecule (422–436) or from VP1 (141–160). The 65–85 repeat homodimer induced an antibody response in CBA/ca but not in C57BL/6 mice, both nonresponders to the 65–85 monomer, and amplified the antibody response in BALB/c, monomer‐responder mice. Analysis of the immunogenicity of hybrid dimers in BALB/c mice showed that the orientation of peptides within the dimer is critical for the extent of the produced antibody response. Only the 422–436/65–85 but not the 65–85/422–436 induced antibodies binding to the 422–436 sequence which was nonimmunogenic when injected either as a monomer or dimer. Despite the striking difference in immunogenicity, both tested hybrid dimers reacted equally in the solid‐phase immunoassay with antisera raised to 65–85‐dimer or 422–436/65–85 peptides or with a monoclonal antibody to the 422–436 epitope. The described differences in antibody responsiveness also cannot be attributed merely to the extent of T cell stimulation since the proliferative responses were uniformly expressed for all relevant combinations of peptides. Antisera to 65–85 dimer and 422–436165–85 hybrid also reacted with the native 65‐kDa protein. Furthermore, the production of FMDV‐neutralizing antibodies in response to the 141–160 (VP1‐derived)/ 65–85 hybrid peptide in 141–160 nonresponder B10.D2 mice also confirmed the helper activity of the 65–85 epitope. Thus, combining heterologous peptides with the N‐terminal of the mycobacterial 65–85 sequence may be generally applicable for the potentiation of peptide vaccines.
Comparison of interleukin 2 and 12‐O‐tetradecanoyl‐phorbol 13‐acetate as signals for protein kinase C activation in purified human T lymphocytes
Authors: Mahé Yann , Piau Jean‐Pierre , Wakasugi Naomi , Tursz Thomas , Gacon Gerard , Wakasugi Hiro 
Published: March 2007

AbstractInterleukin 2 (IL2) and 12‐O‐tetradecanoylphorbol 13‐acetate (TPA) have been compared for their ability to induce translocation of protein kinase C (PKC) in T lymphocytes prestimulated with anti‐CD3 monoclonal antibody (mAb), either in the presence or absence of monocytes.TPA alone did not promote purified T cell growth, but it was able to induce a transient, within 30 min, translocation of PKC activity. The profiles of PKC association with the membrane of the T cells under TPA stimulation were quite similar when either the anti‐CD3 mAb or the fixed monocytes, or both, were added to the T cells. The decrease of cytosolic PKC under TPA stimulation was less pronounced for the purified T cells stimulated with anti‐CD3 mAb, fixed monocytes alone or both than for unstimulated purified T cells. Even in the absence of monocytes, the addition of exogenous IL2 to the anti‐CD3 mAb‐treated T cells resulted in PKC translocation, with a transient increase in the PKC activity found in both the particulate and cytosolic fractions. When exogenous IL2 was added to the proliferating T cells, the association of PKC with the membrane was prolonged and the activity did not reach a plateau during the first 2 h after the IL2 stimulation.In parallel, the level of PKC associated with the membrane was higher in proliferating cells than in resting cells even 4 days after stimulation. These results suggest that activation of PKC by IL2 might be different from the direct activation of PKC by TPA and that a specific activation pathway, at least kinetically distinct from the classical phosphatidyl inositol diphosphate degradation by phospholipase C, might be involved during IL2 stimulation of T lymphocytes through high‐affinity IL2 receptors.
Phenotypical characterization of the cells invading pancreatic islets of diabetic BB/OK rats: effect of interleukin 2 receptor‐targeted immunotherapy
Authors: Hahn Hans J. , Gerdes Johannes , Lucke Sake , Liepe Larissa , Kauert Christiane , Voik Hans D. , Wacker Hans H. , Brocke Stephan , Stein Harald , Diamantstein Tibor 
Published: March 2007

AbstractWe investigated immunohistochemically the phenotypes of mononucleated cells invading pancreatic islets of diabetic BB/OK rats in comparison to the diabetesresistant parental strain, and 12 and 120 days after a temporary treatment (10 days) with a monoclonal antibody (1 mg/kg b.w.) directed against interleukin 2 receptor (IL 2R) combined with a subtherapeutic dose of cyclosporin A (1.5 mg/kg b.w.). Using a panel of monoclonal antibodies (OX‐19, OX‐8, W3125, KI‐M2R, OX‐6, OX‐17, ART‐18) and the alkaline phosphatase anti‐alkaline phosphatase system to visualize the bound primary antibodies, we observed an even distribution of mono‐nucleated cells across the endocrine pancreas at a “background” level when obtained from diabetes‐resistant parental rat strain. Diabetic BB/OK rats, characterized by a moderate hyperglycemia and a marked decrease of pancreatic insulin content, displayed a remarkable accumulation of mononucleated cells in the endocrine pancreas. Morphometric studies revealed an increase of all phenotypes investigated, nearly all mononucleated cells expressed class I1 histocompatibility antigens (OX‐6+, OX‐17+) and the number of cells expressing the IL 2R (ART‐18+) was markedly enhanced. Sixty‐seven percent of the immunotherapeutically treated BB/OK rats normalized plasma glucose and enhanced pancreatic insulin content. The successfully treated animals are characterized by a decrease of cells invading pancreatic islets (OX‐19+, OX‐8+, W3/25+, KI‐M2R+), a decrease of class II histocompatibility antigen and IL 2R expression. The number of IL 2R cells is also diminished in the endocrine pancreas of unsuccessfully treated BB rats.
Reversal by interferon‐γ of inhibition of delay ed‐type hypersensitivity induction by anti‐CD4 or antiinterleukin 2 receptor (CD25) monoclonal antibodies. Evidence for the physiological role of the CD4+ TH1+ subset in mice
Authors: Diamantstein Tibor , Eckert Rolf , Volk Hans‐Dieter , Kupier‐Weglinski Jerz‐W. 
Published: March 2007

AbstractIn mice, induction of delayed‐type hypersensitivity (DTH) and of antibody formation to sheep red blood cells (SRBC) was inhibited by the anti‐CD4 monoclonal antibody (mAb) GK1.5. However, anti‐interleukin 2 mAb AMT‐13 inhibited DTH response but not antibody formation. The inhibitory action of the mAb on DTH, but not an antibody formation, was reversed by concomitant injection of recombinant mouse interferon‐y. These data provide the first in vivo evidence for the postulated physiological role of the CD4+ TH1 lymphocyte subset and indicate that the action of anti‐interleukin 2 receptor mAb is restricted to this T helper subset.
Mechanism of skin allograft enhancement across an H‐2 class I mutant difference. Evidence for involvement of veto cells
Authors: Martin Kast W. , Twuyver Esther Van , Mooijaart Rob J. D. , Verveld Marieke , Kamphuis Alfons G. A. , Melief Cornelis J. M. , De Waal Leo P. 
Published: March 2007

AbstractIntravenous injection of spleen cells across mutant class I H‐2 incompatibility results in a drastic donor‐specific prolongation of skin allograft survival and a marked decrease in the donor‐specific cytotoxic T lymphocyte precursor (CTLp) frequency. This immunosuppressive effect depends on the presence of radiosensitive T cells in the donor cell inoculum. It was excluded that a graft‐vs.‐host reaction was responsible for the observed effects. In mixing experiments, spleen cells from animals transfused with allogeneic lymphocytes could not suppress a normal CTL response against the alloantig, despite an excess of putative recipient‐derived spleen suppressor cells. The data are compatible with the idea that donor T cells function as veto cells which inactivate recipient CTLp directed against the alloantigen expressed by the veto cell.
Monoclonal antibodies which react with the T cell receptor γ/δ recognize different subsets of CD3WT31‐ T lymphocytes
Authors: Ferrini Silvano , Prigione Ignazia , Bottino Cristina , Ciccone Ermanno , Tambussi Giuseppe , Mammoliti Serafina , Moretta Lorenzo , Moretta Alessandro 
Published: March 2007

AbstractA polyclonal CD34‐8‐WT31‐ cell line (termed SFG) was utilized for mice immunization in order to produce monoclonal antibodies (mAb) specific for the T cell receptor (TcR) γ/δ. Hybrid supernatants were screened for their ability to induce SFG cells (but not conventional TcR α/β CTL lines) to kill the murine Fc receptor‐positive P815 target cell line. Three hybrids, termed G1, A13 and F11, were isolated according to this screening. By indirect immunofluorescence G1 mAb reacted with 65% of SFG cells, while A13 stained 26% and F11 75% of cells. Double‐fluorescence analysis revealed that G1 and A13 mAb identify two distinct, non‐overlapping subsets of cells present in the SFG cell line. The reactivity of the mAb was also analyzed on a panel of representative TcR α/β clones. G1 mAb reacted with 5 clones, that were also stained by the previously described BB3 mAb (recognizing the disulfide‐linked form of TcRα/β). These clones failed to react with A13 and δ‐TCS‐1 mAb (the latter of which is known to react with a non‐disulfide‐linked form of TcR α/β). Out of six clones that reacted with A13 mAb, four were also δ‐TCS‐1, whereas two were δ‐TCS‐1‐ and none of them reacted with G1, (or BB3) mAb. In contrast to the mAb above, F11 brightly stained the G1A13‐ clones and more weakly the G1‐A13 clones. Moreover, F11 efficiently triggered both types of clones to kill the P815 target cells while G1 and A13 were able to trigger only G1 or A13 clones, respectively. None of the mAb above reacted with a large number of CD3WT31 clones. Antibodyinduced surface antigen modulation experiments indicated that molecules recognized by G1, A13 and F11 were physically associated on cell surface with CD3 determinants. In addition, immunoprecipitation followed by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis analysis (performed on 125I‐surface‐labeled TcRα/β clones) revealed that molecules recognized by G1, A13 and F11 displayed an apparent mol. wt. corresponding to that of CD3‐associated TcR molecules, immunoprecipitated by anti‐CD3 mAb from the same clones.
T cell immunity or tolerance as a consequence of self antigen presentation
Authors: Lin Rong Hwa , Stockinger Brigitta 
Published: March 2007

AbstractIn this study we investigated the basis for immunity or tolerance to a mouse serum protein, the fifth component of complement (C5). In C5‐deficient mice this protein is absent from serum and therefore they are not tolerized. Immunization of C5‐deficient mice with C5‐sufficient serum generates CD4 T cells, which recognize C5 presented in the context of class II. No C5‐specific responses were observed in T cells from C5‐sufficient mice. We show that this self protein is processed and presented with class II by cells from C5‐sufficient tolerant mice and can be recognized by C5‐specific T cell clones and hybrids in the absence of exogenously added antigen. The stimulation of C5‐specific T cells by C5‐sufficient antigen‐presenting cells is not a consequence of C5 secretion and subsequent processing in vitro but rather employs C5 peptide/class II complexes generated in vivo. We conclude that this self antigen is presented in normal mice in a form recognizable by T cells to induce and maintain immunological tolerance.
Isolation of rat IgM to IgG hybridoma isotype switch variants and analysis of the efficiency of rat Ig in complement activation
Authors: Pluschke Gerd , Bordmann Gerard , Daoudaki Maria E. , Lambris John D. , Achtman Mark , Neibert Michael 
Published: March 2007

AbstractSequential sublining was used in combination with enzyme‐linked immunosorbent assays to isolate μ → γ isotype switch variants of the rat IgM secreting mouse‐rat B cell hybridoma line BA1.8. Switch variants to all four subclasses of IgG were obtained. The variant antibodies retained the antigen specificity of the parental IgM for the O18 (lipopolysaccharide) antigen of Escherichia coli. In sodium dodecyl sulfate‐polyacrylamide gels the apparent molecular mass of the γ heavy chains decreased in the order γ2b > γ1 > γ2c > γ2a.IgM, IgG1, IgG2a, IgG2b and IgG2c of the BA1.8 variant family and IgG2b, IgE and IgA of the previously described BA1.2 family were used for a comparative analysis of the capacity of rat Ig to activate complement. Efficient lysis of sheep erythrocytes coated with the O18 antigen was observed with IgM and all IgG subclasses, but no lysis was triggered by IgE or IgA. One hundred to 1000 IgG molecules were required to mediate the same hemolytic activity as one IgM molecule. The four IgG subclasses were equally efficient at mediating lysis by rat or human complement, while IgG2a was less efficient with guinea pig complement than the other three IgG subclasses.Antibody‐triggered binding of C3 to pathogenic O18: K1 E. coli bacteria was measured using serum containing 125I‐labeled C3. K1‐encapsulated strains did not fix C3 efficiently in the absence of specific antibodies while acapsular mutants fixed C3 via the alternative pathway. IgM and all IgG subclasses triggered C3 binding to the K1 encapsulated bacteria. The capacity of IgM to mediate C3 fixation was not greater than that observed with IgG.
A murine nephritogenic monoclonal anti‐DNA autoantibody binds directly to mouse laminin, the major non‐collagenous protein component of the glomerular basement membrane
Authors: Sabbaga Jorge , Line Sergio Roberto Peres , Potocnjak Pedro , Madaio Michael P. 
Published: March 2007

AbstractThe interaction of the murine monoclonal anti‐DNA antibody H241 with extracellular glomerular antigens was found to be due to the binding of this antibody to laminin, the major non‐collagenous protein constituent of the glomerular basement membrane. This interaction is specific, since it is inhibited by laminin, double‐stranded DNA and single‐stranded DNA in solution. Furthermore, the binding of H241 to mouse laminin is mediated by conformational properties of the antigen because mild denaturation of laminin strongly decreases the binding capacity of H241, while exposure of laminin to sodium dodecyl sulfate, completely abolishes this interation. H241 is able to bind to both, human and mouse laminin. These findings are in agreement with the ligand binding specificities of the autoantibodies spontaneously produced, that differ from those generated by artificial immunization. We conclude that the polyreactivity of H241 that confers to it the capacity to bind laminin, may account for its ability to form immune deposits by binding directly to non‐DNA glomerular antigens.
Intradomain H‐2 Kd/Dd recombinants define the same regions as crucial for recognition by alloreactive or major histocompatibility complex‐restricted cytolytic T cells
Authors: Maryanski Janet L. , Abastado Jean‐Pierre , Robson MacDonald H. , Kourilsky Philippe 
Published: March 2007

AbstractTo identify residues on class I major histocompatibility complex (MHC) antigens that are important in T cell recognition, we analyzed a series of 11 intradomain recombinant mouse MHC (H‐2) molecules in which N‐terminal H‐2Kd segments of varying lengths are followed by H‐2Dd segments. Lysis of L cell transfectant target cells by a series of alloreactive cytolytic T cell (CTL) clones specific for Kd or for Dd revealed several regions that contain residues critical for specific recognition. These residues map within the presumed antigen‐binding site of the MHC molecule. Of particular interest was the finding that the two regions identified as important for Kd allorecognition match those that influence the recognition of synthetic peptide antigens by Kd ‐restricted CTL.
Expression of the p75 interleukin 2‐binding protein on CD34‐8‐Tac‐ cells from autoimmune MRL/MP‐lpr/lpr mice
Authors: C. gutierrez‐Ramos José , Pezzi Luis , Palacios Ronald , Martínez‐A. Carlos 
Published: March 2007

AbstractThe recently described (Sharon, M. et al., Science 1986. 234: 859) interleukin 2 (IL 2)‐binding molecule p75 was detected in the CD34‐8‐Tac‐ “double‐negative” cell population selectively expanded in lupus‐like autoimmune mice MRL/MP‐lpr/lpr using cross‐linking studies. Scatchard analysis of the IL2 binding revealed the existence of approximately 4700 sites per cell with an apparent Kd of 1500 pM. The cell line LD1.T3B, derived from this population, shared surface markers and the p75 presence/p55 absence of IL 2‐binding proteins with its in vivo counterpart, displaying around 3100 sites per cell with a Kd of about 1300 pM. Functional studies showed that high doses of IL 2 had an inhibitory effect on the autonomous growth of this cell line in the absence of the development of killer activity. This study provides evidence of the functional abilities of p75, and shows that the use of Tac/p55 surface expression only to evaluate IL 2 receptors and T cell activation can be an oversimplification as well as misleading.
Human T cell clones with specificity for insulinoma cell antigens
Authors: Vliet Els Van , Roep Bart O. , Meulenbroek Lex , Jan Bruining G. , De Vries René R. P. 
Published: March 2007

AbstractSeveral lines of evidence suggest that islet‐specific T cells are important in the pathogenesis of the insulitis resulting in insulin‐dependent diabetes mellitus (IDDM). Therefore, we decided to analyze islet‐specific T cell reactivity in the peripheral blood of IDDM patients. With the use of insulinoma membranes as antigen, T cell lines were generated from peripheral blood mononuclear cells of patients with recent onset of the disease. In a proliferation assay such T cell lines responded to insulinoma membranes and, though to a lesser extent, also to fibroblast membranes, the control antigen used. One of the T cell lines was cloned. Eight clones were isolated that respond to insulinoma antigens. Five of these eight clones appeared to be specific for insulinoma membranes, i.e. they demonstrated proliferation in response to insulinoma but not fibroblast membranes. These insulinoma‐specific proliferative responses are HLA‐DR restricted.
Differential activation of cytokine genes in normal CD4‐bearing T cells is stimulus dependent
Authors: Carding Simon R. , West Jeffrey , Woods Andrea , Bottomly Kim 
Published: March 2007

AbstractStudies of cloned CD4 T cell lines have shown that they can be separated into two distinct subsets with distinctions in their functional capabilities and by the differential release of either interleukin 2 (IL 2) (TH1/inflammatory type) or IL 4 (TH2/helper type) upon activation. To establish if in vivo‐derived CD4 T cells can exhibit distinct subsets we have investigated whether normal CD4 T cells demonstrate differential expression of IL 2 and IL 4 mRNA, and secretion of IL 2 and IL 4 after primary stimulation in vitro.
Utilizing the technique of in situ hybridization IL 2 and IL 4 gene expression in individual CD4 T cells was readily detectable after concanavalin A (Con A) phytohemagglutinin (PHA) or pokeweed mitogen (PWM)‐mediated activation. The frequencies of activated T cells producing IL 2 and IL 4 mRNA after Con A or PHA activation were approximately equivalent (30–40% of cells); however, after PWM activation the number of CD4 T cells expressing IL 4 mRNA (78%) was more than twofold greater than the number of cells producing IL 2 mRNA (30%). Maximal levels of IL 2 gene expression occurred 24 h after mitogen activation whereas the highest levels of IL 4 mRNA were not detected until 48 h after mitogen activation. Similar distinctions in the kinetics of IL 2 and IL 4 secretion after mitogen activation were also found demonstrating good concordance in the observed expression of IL 2 and IL 4 mRNA and the levels of secreted lymphokines detected by bioassay. Most importantly, we have shown by in situ hybridization analysis that the majority of individual CD4 T cells produce only IL 2 or IL 4 mRNA, and not both, after primary activation in vitro. By contrast, most CD4 T cells activated in the presence of PMA and ionophore express both IL 2 and IL 4 mRNA.Our studies demonstrate that in normal, non‐clonal populations of CD4 T cells, the production of IL 2 and IL 4 is independently regulated in the majority of cells and appears to be stimulus dependent.
Cytotoxic T lymphocytes in reticuloendotheliosis virus‐infected chickens
Authors: Weinstock Daniel , Schat Karel A. , Calnek Bruce W. 
Published: March 2007

AbstractCytotoxic T lymphocytes were functionally demonstrated in spleen cells from chickens 7 days post inoculation with reticuloendotheliosis virus using a Cr‐release assay. Major histocompatibility complex (MHC)‐restricted cytotoxicity was demonstrated using effector and target cells from two different strains of chickens of known avian MHC haplotype. Anti‐viral specificity was shown and in vivo generation of MHC‐restricted cytotoxicity was evaluated. Cytotoxic T cells were distinguished from macrophages and natural killer cells. Their cytotoxicity was not antibody dependent. Higher levels of cytolysis were found with cytotoxic T cells from embryonally bursectomized vs. intact chickens over a large range of effector to target cell ratios. Using monoclonal antibodies, cytotoxic T cells were further defined as Ia T cells by immunofluorescence, antibody plus complement‐mediated lysis of effector cells and blocking of cytolysis in the Cr‐release assay.