bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional and biochemical characteristics of a murine interleukin 2 receptor‐inducing factor
Authors: Hardt Conny , Sato Nobuko , Wagner Hermann 
Published: March 2007

AbstractHigh density (resting) murine Lyt‐2+ T cells exposed in vitro to the ligand concanavalin A (Con A) remain interleukin 2 (IL2) unresponsive, i.e. do not express functional IL2 receptors, unless reconstituted with accessory cells. This finding provides a bio‐assay to define functional and biochemical characteristics of an IL2 receptor‐inducing factor (RIF). RIF bioactivity as secreted from the macrophage cell line P388‐D1 is associated with a trypsin‐sensitive protein of 44 kDa which does not need to be glycosylated and which binds to and can be eluted from hydroxylapatite and phenyl‐Sepharose. While both RIF and IL1 are produced by accessory cells the lymphokines separate from each other according to functional and biochemical criteria.Either accessory cells, RIF or the protein kinase C activator phorbol myristate acetate can substitute for each other and are equally active for the induction of IL2 responsiveness in high‐density Lyt‐2+ T cells exposed to Con A. To explain these results we conclude that in the mitogen system used, induction of IL2 responsiveness (activation) represents a two‐step event in which first cross‐linking of cell surface structures by the ligand Con A excites the responder T cells, which subsequently respond to the accessory cell product RIF.
A synthetic vaccine constructed by copolymerization of B and T cell determinants
Authors: Leclerc Claude , Przewlocki Grzegorz , Schutze Marie‐Paule , Chedid Louis 
Published: March 2007

AbstractSynthetic vaccines are based on the identification of short peptide sequences responsible for inducing a protective immune response. These sequences could contain B and/ or T cell determinants. In this study, we have examined the recognition by B and T mouse lymphocytes of several synthetic peptides corresponding to regions of a bacterial and two viral proteins. These include a streptococcal S‐34 peptide, H(99‐121) and two other synthetic hepatitis B virus surface peptides. A lymph node proliferation assay was employed to detect T cell determinants. Limiting dilution analysis was used to estimate the frequency of clonal precursor B cells specific for an antigenic determinant.This study indicates that the synthetic hepatitis B virus surface peptides are recognized by B cells but not by T cells, whereas the S‐34 peptide possesses both B and T epitopes. The copolymerization of the B determinant H(99‐121) with S‐34 has conferred immunogenicity to the H(99‐121) peptide. After copolymerization, the synthetic hybrid molecule retained the S‐34 T epitope and acquired a new determinant recognized by T cells. These results demonstrate that synthetic vaccines could be constructed by appropriate selection and organization of B and T determinants.
A chicken leukocyte common antigen: biochemical characterization and ontogenetic study
Authors: Houssaint Elisabeth , Tobin Stephen , Cihak Josef , Lösch Uli 
Published: March 2007

AbstractA monoclonal antibody, designated CL‐1, was produced by immunizing mice with chicken peripheral blood lymphocytes (PBL) and selected in an indirect immuno‐fluorescence assay. CL‐1 characterizes a cell surface antigen expressed on all chicken hemopoietic cells except mature erythrocytes. Cells stained by CL‐1 were detected at early stages of embryonic development in the various hemopoietic compartments. CL‐1 reacts with two chicken PBL proteins of 200 kDa and 215 kDa which are probably the homologues of the T‐200 and B‐220 antigens previously described in the mouse. Moreover, CL‐1 does not react with quail hemopoietic tissues and can be useful in experiments using quail‐chick chimeras to study the ontogeny of the hemopoietic system.
Activation of the alternative pathway of complement by human serum IgA
Authors: Hiemstra Pieter S. , Gorter Arko , Stuurman Marly E. , Van Es Leendert A. , Daha Mohamed R. 
Published: March 2007

AbstractIn order to study the activation of complement by soluble aggregates of human polyclonal serum IgA, lysis of sheep erythrocytes (E) coated with several IgA preparations was used as a model. A complement nonactivating monoclonal mouse IgG1 against IgA was used to coat the cells. IgA, isolated from normal human serum, was aggregated by either N‐succinimidyl 3‐(2‐pyridyldithio)propionate (SPDP), glutaraldehyde, carbodiimide or heating. Depending on the size of the aggregates, and on the method of aggregation, E coated with aggregated IgA (Eγ1.AIgA) could be lysed. The alternative pathway of complement appeared to mediate the lysis because the latter was observed in the presence of EGTA containing 5 mM Mg2+ (MgEGTA) and properdin (P) was deposited on the cells. Furthermore, no lysis was observed in C3‐deficient serum. In the absence of AIgA the cells were not lysed, and no P deposition was observed. In another set of experiments Eγ1.AIgA were first reacted with purified C3, B, D and P for 30 min at 30°C, and subsequently in rat serum EDTA at 37°C. Lysis occurred when Eγ1.AIgA were prepared using SPDP‐, glutaraldehyde‐ or carbodiimide‐AIgA. Incubation of 100 μg/ml SPDP‐AIgA with normal human serum for 30 min at 37°C in the presence or absence of MgEGTA also induced consumption of total complement. The other soluble AIgA preparations were less effective in activating complement. These results suggest that polymeric serum IgA is capable of activating the alternative pathway of complement.
Blocking of interleukin 2 (IL 2) binding to the IL 2 receptor is not required for the in vivo action of anti‐IL 2 receptor monoclonal antibody (mAb). I. The production, characterization and in vivo properties of a new mouse anti‐rat IL 2 receptor mAb that reacts with an epitope different to the one that binds to IL 2 and the mAb ART‐18
Authors: Mouzaki Athanasia , Volk Hans‐Dieter , Osawa Hisao , Diamantstein Tibor 
Published: March 2007

AbstractA mouse anti‐rat interleukin 2 (IL 2) receptor (IL 2R) monoclonal antibody (mAb), ART‐65, has been developed. As shown by fluorescence‐activated cell sorter analysis and immunoprecipitation studies, ART‐65 recognizes in a species‐specific manner the same molecule as does ART‐18, a mAb which has been shown previously to recognize the rat receptor for IL 2. ART‐65 and ART‐18 do not competitively inhibit the binding of each other to activated T cells. ART‐65, in contrast to ART‐18, does not inhibit the binding of IL 2 to cells nor does it have any inhibitory effect in vitro on IL 2‐driven proliferation of rat T lymphoblasts. Therefore, ART‐65 is another mAb recognizing the rat IL 2 receptor, but binding to an epitope distinct from that recognized by either IL 2 or ART‐18. We compared the in vivo activity of the mAb ART‐65 and ART‐18 with that of the W3/25 mAb in a local graft‐vs‐host reaction (GVHR). Similar to the anti‐W3/25 treatment, ART‐65 and ART‐18 inhibited GVHR. The results demonstrate that GVHR depends on a small subpopulation of IL 2R+ cells present in the W3/25+ T cell population because IL 2R‐targeted therapy was as effective as the treatment with W3/25 mAb which reacts with the entire T helper cell population. Moreover, the results argue against the possibility that anti‐IL 2R mAb act via blockade of the IL 2 binding to IL 2R+ cells and/or by inhibiting the IL 2‐driven expansion of the antigen‐activated clones. The results support the view that IL 2R‐targeted therapy results in the elimination of the IL 2R+ cells.
Enumeration of T cells reactive with Mycobacterium tuberculosis organisms and specific for the recombinant mycobacterial 64‐kDa protein
Authors: Kaufmann Stefan H. E. , Väth Ulla , Thole Jelle E. R. , Van Embden Jan D. A. , Emmrich Frank 
Published: March 2007

AbstractThe major goal of the present study was to develop a limiting dilution system for the enumeration of T cells which respond to mycobacterial antigens. Purified T cells from M. tuburculosis‐immune mice were restimulated with mycobacterial antigens and accessory cells, and after 4 days expanded with antigen, accessory cells and T cell growth factor. After another 3 days, proliferative responses were determined. Similar cultures performed without antigen served as controls. Limiting dilution analysis revealed that approximately 1/2000 to 1/3000 T cells from M. tuberculosis‐immune mice responded to whole M. tuberculosis organisms while T cells from normal mice did not respond. Similar T cell numbers reacted with several mycobacterial strains indicating expression of shared T cell antigens. Using a semi‐purified recombinant 64‐kDa protein from M. bovis the frequency of T cells generated after immunization with M. tuberculosis which reacted with a single mycobacterial protein could be estimated. We found that approximately 1/5 of the M. tuberculosis‐reactive T cells recognized this particular antigen. Immunization with the recombinant 64‐kDa protein in an adjuvant containing trehalose dimycolate, monophosphoryl lipid A and mycobacterial cell wall skeleton stimulated an equally high number of M. tuberculosis‐reactive T cells (1/2000). These findings demonstrate (a) that a high proportion of tuberculosis‐responsive T cells are directed against the 64‐kDa protein and (b) that immunization with this antigen in an appropriate adjuvant system is capable of stimulating high numbers of M. tuberculosis‐reactive T cells. Limiting dilution analysis with a panel of mycobacterial proteins or peptides may allow their ranking from immunodominant to immunosilent and facilitate identification of antigens or epitopes relevant to protection.
High efficiency antigen presentation by thyroglobulinprimed murine splenic B cells
Authors: Hutchings Patricia , Rayner David C. , Champion Brian R. , Marshall‐Clarke Stuart , Macatonia Steven , Roitt Ivan , Cooke Anne 
Published: March 2007

AbstractB cells primed in vivo with mouse or rat thyroglobulin present these antigens at very low concentrations to CH9, an Ly 1+2− T cell hybridoma specific for mouse and rat thyroglobulin. Presentation measured by interleukin 2 release from CH9 is sensitive to treatment with a monoclonal antibody eliminating splenic B cells but is unaffected by anti‐Thy‐1.2 or 33D1 (which destroy T cells and dendritic cells, respectively). Presentation is specific for the priming antigen and is blocked by preincubation of the B cells with sheep anti‐mouse F(ab′)2. We suggest that in this system, primed B cells present thyroglobulin and that this may represent a means by which an initial triggering event priming both B and T cells could allow maintenance of autoreactive responses in vivo in the presence of low concentrations of circulating antigen.
High connectivity, natural antibodies preferentially use 7183 and QUPC52 VH families
Authors: Holmberg Dan 
Published: March 2007

AbstractTwenty‐seven B cell hybridomas derived from spleen cells of nonimmunized, 6‐day‐old BALB/c mice and previously characterized serologically were screened for VH‐ gene expression: hybridomas expressing the two most D‐proximal VH‐gene families, 7183 and QUPC 52 were over‐represented in this sample. Strikingly, clones serologically characterized by high degree of degenerate “specificity” and high idiotypic connectivity were found to use almost exclusively these two VH‐gene families. As these serological properties are a unique feature of “natural” antibody repertoires, the results may reflect a functional relationship between expression of these VH genes and activation of B cells in the internal environment, particularly in the context of idiotypic interactions.
Ir gene control of the murine secretory IgA response to cholera toxin
Authors: Elson Charles O. , Ealding Wendy 
Published: March 2007

AbstractIn these experiments we examined the genetic control of the secretory IgA (sIgA) response to cholera toxin (CT) after CT feeding. Inbred, congenic and intra‐H‐2I region recombinant mouse strains were immunized with intragastric application of 10 μg CT on days 0 and 14. Samples of intestinal secretions and plasma were collected 1 week after the second dose and antibodies to CT measured in them by antigen‐ and isotype‐specific enzyme‐linked immunosorbent assay. In three different sets of H‐2‐congenic strains the intestinal IgA anti‐CT response clearly depended on the H‐2 haplotype rather than on background or IgH genes. H‐2b (B10, A.BY/SnJ, C3H.SW) and H‐2q (B10.T(6R), DBA/1J) strains were high responders, H‐2k (B10.BR, C3H/He), H‐2s (A.SW/SnJ) and H‐2d (B10.D2) strains were low responders. Within the H‐2 complex the intestinal IgA anti‐CT response was mapped to the I‐A subregion with the use of congenic intra‐H‐2I region recombinant strains: B10.A(3R) and B10.A(5R) were high responders and B10.A(4R), B10.MBR and B10.GD were low responders. Plasma IgG anti‐CT after CT feeding paralleled the sIgA results. Surprisingly, the sIgA and plasma IgG anti‐CT responses in individual mice of the various strains tested showed a highly significant positive correlation. We conclude that both the sIgA response and plasma IgG anti‐CT response after CT feeding is controlled by the I‐A subregion of H‐2.
Accessory molecules and T cell activation II. Antibody binding to L3T4a inhibits Ia‐independent mouse T cell proliferation
Authors: Pont Suzanne , Régnier‐Vigouroux Anne , Marchetto Sylvie , Pierres Michel 
Published: March 2007

AbstractMonoclonal antibody (mAb) blocking assays using L3T4‐ and lymphocyte function‐associated antigen‐1 (LFA‐1)‐specific reagents were used as an approach to investigate the involvement of these accessory molecules in various T cell activation pathways. As previously reported, rat mAb to L3T4a and LFA‐1A functional epitopes efficiently blocked antigen‐driven T helper cell proliferation. In contrast, antigen‐ and Ia‐independent T cell triggering induced by appropriate mAb to the Thy‐1 or the T cell receptor molecules were found to be inhibitable by L3T4a‐ but not LFA‐1A‐specific mAb, although the extent of inhibition varied, depending on the cell type and the activating signal examined. These results provide further evidence that the inhibiting effects of L3T4‐specific mAb on T cell responses may be due, in addition to an impairment of L3T4‐class II major histocompatibility complex molecular interaction, to a down regulatory signal possibly transmitted by the L3T4 molecule itself.
Inhibition of binding of rat IgE to rat mast cells by synthetic IgE peptides
Authors: Burt David S. , Stanworth Denis R. 
Published: March 2007

AbstractSeven synthetic peptides corresponding to amino acid sequences located within various surface regions of the CH3 and CH4 domains of rat IgE were tested for their capacity to compete with intact rat IgE for binding sites on mast cells. Peptides representing rat IgE sequences 414–428 (P129), 459–472 (P124), 491–503 (P128) and 542–557 (P123) inhibited the binding of 125I‐labeled rat IgE to mast cells by between 25–50% at concentrations between 10−5–10−4 M. Three other rat IgE sequences, 378–396 (P130), 522–535 (P122) and 560–571 (P131), and three non‐IgE peptides demonstrated no inhibitory activity. On a molar basis, the most active peptide, P129, was approximately 1000‐times less active than native rat IgE. Furthermore, extensive washing of cells incubated with this peptide did not reduce its ability to inhibit the subsequent binding of 125I‐labeled rat IgE. These results suggest that residues within sequences 414–428, 459–473, 491–503 and 542–557 may contribute towards the mast cell receptor binding site on rat IgE.
Functional α and β T cell chain receptor messages can be detected in old but not in young athymic mice
Authors: Kishihara Kenji , Yoshikai Yasunobu , Matsuzaki Goro , Mak Tak W. , Nomoto Kikuo 
Published: March 2007

AbstractThe expression and sequences of T cell antigen receptor (TcR) α and β‐chain genes were investigated in the spleens from congenitally athymic (nude) mice. A small number of Thy‐1+ cells (∼7.0%) was found in nylon wool‐enriched spleen cells from young (8 weeks old) nude mice but no L3T4 or Lyt‐2 surface antigens were detected. These nude mice expressed only a low level of 1.0‐kb β‐chain mRNA and little or no α‐gene transcripts. On the other hand the number of Thy‐1+ spleen cells increased slightly (to 24%) in old (20 weeks old) nude mice and a small number of L3T4+ (10%) and/or Lyt‐2+ (5%) cells were detectable. “Full length” 1.7‐kb α‐chain and 1.3‐kb β‐chain messages could be found in nylon wool‐enriched spleen cells from old nude mice. Sequence analysis of the cDNA revealed that no functional α and β‐chain genes can be detected in the spleen cells of young athymic mice while some of the old mice with nu/nu genotype are composed of completely rearranged V‐(D)‐J‐C‐gene segments which encode potentially functional proteins. Interestingly, two of three independent cDNA clones encoding the α chain used the same Vα and Jα‐gene segments. These results suggest that extrathymic TcR α and β‐chain gene rearrangements do occur, though slowly, to some extent, in nude mice and may be responsible for the limited antigen and/or H‐2‐related T cell functions in these old athymic mice. The data further suggests that the TcR repertoire in athymic mice may also be limited.
Activation of human platelets through gp140, the C3d/EBV receptor (CR2)
Authors: Nunez Daniele , Charriaut‐Marlangue Christiane , Barel Monique , Benveniste Jacques , Frade Raymond 
Published: March 2007

Abstractgp140, the C3d/EBV receptor (CR2), previously isolated and characterized from human B lymphocytes, was identified on human platelets: (a) by measuring the specific binding of either polyclonal anti‐gp140 IgG and monoclonal anti‐C3d/EBVR antibodies, as OKB‐7 and HB‐5, or human C3d; (b) by isolating gp140 from solubilized platelet components with polyclonal anti‐gp140 IgG or monoclonal OKB‐7, using immunoprecipitation and electro‐immunoblotting assays; (c) by inducing specific activation of human platelets. Cross‐linking of this receptor by polyclonal anti‐gp140 IgG induced aggregation of human platelets and stimulated ATP release. Absence of lactate dehydrogenase release and inhibition by EDTA and prostacyclin of anti‐gp140‐induced aggregation, support strongly active aggregation and absence of lysis. Platelet aggregation by anti‐gp140 required metabolic activities and was modulated by fibrinogen, paf‐acether or thrombin. OKB‐7 triggered human platelet aggregation when cross‐linked by anti‐mouse second‐step antibodies. In the same way, platelet activation by C3d fragment was detected, in presence of fibrinogen, only when C3d was cross‐linked on the cell surface by anti‐C3d F(ab′)2 fragments.
Cross‐linking of the T cell receptor complex with the subset‐specific differentiation antigen stimulates interleukin 2 receptor expression in human CD4 and CD8 T cells
Authors: Emmrich Frank , Kanz Lothar , Eichmann Klaus 
Published: March 2007

AbstractNonpolymorphic interactions between the T cell differentiation antigens CD4 or CD8 and major histocompatibility complex (MHC)‐encoded molecules have been postulated to participate in antigen recognition of MHC‐restricted T cells. This would imply simultaneous binding of CD4/8 and of the T cell receptor complex (Ti/CD3) to MHC molecules on the stimulator or target cell. In this report experimental evidence is provided that simultaneous binding by antibodies of Ti/CD3 and of CD4 or CD8 leads to the expression of interleukin 2 (IL2) receptors in resting human T cells and to their subsequent proliferation in the presence of recombinant IL2 (rIL2). This could be shown by using a novel anti‐CD3 monoclonal antibody (BMA 030) which alone only marginally stimulates highly purified human T cells even when applied in cross‐linked form. However, human T cell subpopulations could be stimulated to grow in the presence of rIL 2 when BMA 030 was fixed to a solid support in combination with antibodies to either CD4 or CD8. In limiting dilution experiments, the frequencies of CD4 and CD8 T cells activated by the antibody combinations were similar to those activated by phytohemagglutinin in the presence of irradiated adherent cells. No stimulation was achieved if both or one antibody was applied in soluble form. In contrast, soluble antibodies inhibited activation by solid‐phase antibodies. Taken together, cross‐linking of Ti/CD3 with CD4/8 seems to be essential for T cell activation in cases of ligands that bind but do not activate T cells on their own — a situation that may reflect the interaction of T cell receptors with MHC‐encoded molecules in association with antigen.
T cell receptor‐homologous mRNA from a suppressor T cell clone directs the synthesis of antigen‐specific suppressive products
Authors: De Santis Rita , Palmieri Gabriella , Doria Gino , Adorini Luciano 
Published: March 2007

AbstractThe LH8‐105 T cell clone, obtained by radiation leukemia virus‐induced transformation of hen egg‐white lysozyme (HEL)‐specific mouse suppressor T lymphocytes, constitutively releases in the culture supernatant products able to induce specific suppression of the immune response to HEL. LH8‐105 cells rearrange and express the genes encoding the α and β chains of the antigen‐specific T cell receptor and display membrane T cell receptor structures. LH8‐105 mRNA specific for the α and β chains of the T cell receptor were positively selected on filter‐bound cDNA encoding constant regions of α and β chains, eluted and translated into Xenopus laevis oocytes. Translation products were then tested in vivo for specific suppression of the anti‐HEL antibody response. LH8‐105 culture supernatant and translation products of LH8‐105 poly(A)+ RNA or a mixture of α and β chain‐homologous mRNA induce HEL‐specific suppression whereas translation products of LH8‐105 mRNA eluted from irrelevant DNA or unrecombined mRNA eluted from α and β cDNA do not exert suppressive activity. These results indicate that α and β chain‐homologous mRNA expressed in LH8‐105 cells direct the synthesis of molecules able to induce HEL‐specific suppression.
Characterization and structural analysis of Fcγ receptors of human monocytes, a monoblast cell line (U937) and a myeloblast cell line (HL‐60) by a monoclonal antibody
Authors: Frey Jürgen , Engelhardt Waltraud 
Published: March 2007

AbstractA monoclonal antibody, FR51, raised against the IgG Fc receptor (FcγR) of the human monoblast cell line U937 was used to analyze the distribution of this antigen on various human cells. This antibody inhibited the binding of human IgG to the FcγR on U937 cells, HL‐60 cells and human peripheral blood monocytes. In contrast, the FcγR on human granulocytes (neutrophil cells) and on an Epstein‐Barr virustransformed human lymphoblastoid cell line (Raji) were not recognized, indicated by the failure of blocking the binding of human IgG ligand to the FcγR on these cells. By affinity chromatography of detergent‐containing cell free lysates of surface‐iodinated U937 cells, HL‐60 cells and monocytes, a protein of 70‐kDa was isolated. This protein was identified as the FcγR by rebinding the isolated protein to immobilized human IgG. Removal of the carbohydrate moiety with endo‐ß‐N‐acetylglucosaminidase F demonstrated that the receptors consist of a 40‐kDa polypeptide. Analysis of the polypeptide patterns obtained by proteolytic digestion of either mature (70‐kDa) or deglycosylated (40‐kDa) receptors isolated from monocytes, U937 cells and HL‐60 cells strongly suggests that the FcγR are identical. The monoclonal antibody FR51 specifically reacts with FcγR on human monocytes, a myeloblast and a monoblast cell line but not with the receptors on a B cell line and neutrophil cells.