bluuebunny/crossref_metadata_2025 huggingface dataset:
Guanosine Analogue in the Pyrido[2,3‐d]pyrimidine Ring System as a Potential Toll‐Like Receptor Agonist.
Authors: Jin Guangyi , Wu Christina C. N. , Carson Dennis A. , Cottam Howard B.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Cytostatic and Antiviral 6‐Arylpurine Ribonucleosides. Part 8. Synthesis and Evaluation of 6‐Substituted Purine 3′‐Deoxyribonucleosides.
Authors: Hocek Michal , Silhar Peter , Pohl Radek
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Isolation and Identification of Anthraquinones of Caloplaca cerina and Cassia tora.
Authors: Manojlovic I. , Bogdanovic‐Dusanovic G. , Gritsanapan W. , Manojlovic N.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Paecilaminol, a New NADH‐Fumarate Reductase Inhibitor, Produced by Paecilomyces sp. FKI‐0550
Authors: Shiomi Kazuro , et al. et al.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Practical Method for Phosphorylation of Combretastatin A‐4 with Phosphorus Oxychloride.
Authors: Gill Gurmit S. , Grobelny Damian , Flynn Bernard
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
The Influence of Heat Treatment Regime on the Microstructure and Magnetic Properties of Melt‐spun Nd—Fe—B with Nd Low Content
Authors: Talijan N. , Stajic‐Trosic J. , Grujic A. , Cosovic V. , Nedeljkovic D. , Aleksic R.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
TiO2/SiO2 Based Catalysts
Authors: Cozzolino Mariangela , Tesser Riccardo , Di Serio Martino
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
How Can Moessbauer Spectrometry Contribute to the Characterization of Nanocrystalline Alloys?
Authors: Miglierini M.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Substituted Cyclobutenes, Their Preparation, and Their Versatility in Synthesis
Authors: Gauvry Noelle , Lescop Cyrille , Huet Francois
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Adventures in Sulfur—Nitrogen Chemistry
Authors: Davis Franklin A.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Approaches to Crystallization from Ionic Liquids: Complex Solvents—Complex Results, or, a Strategy for Controlled Formation of New Supramolecular Architectures?
Authors: Reichert W. Matthew , Holbrey John D. , Vigour Kate B. , Morgan Tonya D. , Broker Grant A. , Rogers Robin D.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Oxidative Aromatization Using Molecular Oxygen Promoted by Activated Carbon
Authors: Hayashi Masahiko , Kawashita Yuka
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Total Syntheses of Bioactive Natural Products from Carbohydrates
Authors: Tatsuta Kuniaki , Hosokawa Seijiro
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis and Use of Nitrocyclopropane Derivatives
Authors: Ballini Roberto , Palmieri Alessandro , Fiorini Dennis
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis and Biological Activity of Akt/PI3K Inhibitors
Authors: Redaelli C. , Granucci F. , De Gioia L. , Cipolla L.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Fluorinated Nucleosides as Antiviral and Antitumor Agents
Authors: Meng Wei‐Dong , Qing Feng‐Ling
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Natural Cyclic α,β‐Enone Monoterpenoids in Nucleophilic Addition Reactions
Authors: Ishmuratov G. Yu. , Kharisov R. Ya. , Latypova E. R. , Talipov R. F.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
From α‐Cedrene to Crinipellin B and Onward: 25 Years of the Alkene—Arene meta‐Photocycloaddition Reaction in Natural Product Synthesis
Authors: Chappell David , Russell Andrew T.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Catalytic Applications of Metal Nanoparticles in Imidazolium Ionic Liquids
Authors: Migowski Pedro , Dupont Jairton
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Interrogating the Druggable Genome with Structural Informatics
Authors: Hambly Kevin , Danzer Joseph , Muskal Steven , Debe Derek A.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Structure‐Based Organic Synthesis of Drug Prototypes: A Personal Odyssey
Authors: Hanessian Stephen
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Derivatization in Mass Spectrometry. Part 8. Soft Ionization Mass Spectrometry of Small Molecules
Authors: Zaikin Vladimir G. , Halket John M.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Diminished climbing fiber innervation of Purkinje cells in the cerebellum of myosin Va mutant mice and rats
Authors: Takagishi Yoshiko , Hashimoto Kouichi , Kayahara Tetsuro , Watanabe Masahiko , Otsuka Hiroyuki , Mizoguchi Akira , Kano Masanobu , Murata Yoshiharu
Published: March 2007

Myosin Va is an actin‐based molecular motor that is involved in organelle transport and membrane trafficking. Here, we explored the role of myosin Va in the formation of synaptic circuitry by examining climbing fiber (CF) innervation of Purkinje cells (PCs) in the cerebella of dilute‐neurological (d‐n) mice and dilute‐opisthotonus (dop) rats that have mutations in dilute‐encoded myosin Va. Anterograde labeling of CFs with biotinylated dextran amine (BDA) revealed that they arborized poorly and that their tips extended only half way through the thickness of the molecular layer (ML) in adult d‐n mice. Using immunohistochemistry specific for vesicular glutamate transporter 2 (VGluT2) to visualize CF synaptic terminals, we found that during development and in adulthood, these terminals did not ascend as far along the proximal shaft dendrites of PCs in d‐n mice and dop rats as they did in normal animals. An irregular distribution of BDA‐labeled bulbous varicosities and VGluT2 spots along CF branches were also noted in these animals. Finally, VGluT2‐positive CF terminals were occasionally localized on the PC somata of adult d‐n cerebella. These phenotypes are consistent with our electrophysiological findings that CF‐mediated excitatory postsynaptic currents (EPSCs) were significantly smaller in amplitude and faster in decay in adult d‐n mice, and that the regression of multiple CFs was slightly delayed in developing d‐n mice. Taken together, our results suggest that myosin Va is essential for terminal CF extension and for the establishment of CF synapses within the proper dendritic territories of PCs. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007.
Normal T splenocytes are able to induce immunoglobulin allotypic suppression in F1 hybrid mice
Authors: Benaroch Philippe , Bordenave Guy
Published: March 2007

A chronic suppression of Igh‐1b and Igh‐3b (IgG2a and IgG2b of b haplotype) allotype expression has been induced by injecting T splenocytes from normal BALB/c or BC8 mice into newborn F1 hybrids of appropriate Igh congenic strains: BALB/c into (BALB/c Igha × CB20 Ighb)F1 and BC8 into (BC8 Igha × C57BL/6 Ighb)F1 or (C57BL/6 × BC8)F1. This suppression does not affect IgM (Igh‐6b) or IgA (Igh‐2b) expression. When the Ighb haplotype is paternally transmitted, the proportion of T splenocyte recipients showing allotypic suppression increases with time reaching 70% 40 weeks after birth. We also succeeded in inducing this pattern of suppression in 2 out of 13 cases when the Ighb was inherited from the mother. These normal T splenocytes are therefore clearly allotype specific. As Igh‐6b production is not affected by the suppression, these T splenocytes are believed to influence B cells more or less committed to Igh‐1b or Igh‐3b production rather than more precocious Igh‐6b (IgM of b haplotype) carrying precursors in the classical IgM‐IgG filiation pathway.
Functional and biochemical characteristics of a murine interleukin 2 receptor‐inducing factor
Authors: Hardt Conny , Sato Nobuko , Wagner Hermann
Published: March 2007

High 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

Synthetic 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

A 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

In 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

A 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

The 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

B 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

Twenty‐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

In 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

Monoclonal 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

Seven 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

The 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

gp140, 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

Nonpolymorphic 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

The 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

A 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.
The T cell‐specific serine proteinase TSP‐1 is associated with cytoplasmic granules of cytolytic T lymphocytes
Authors: Fruth Ulli , Prester Marlot , Golecki Jochen R. , Hengartner Hans , Simon Hans Georg , Kramer Michael D. , Simon Markus M.
Published: March 2007

This study describes the localization of the previously purified T cell‐specific serine proteinase, termed TSP‐1 (M. M. Simon et al., EMBO J. 1986. 5: 3267), within cytoplasmic granules of cytolytic T cell lines (CTLL). Subcellular fractionation of disintegrated CTLL (ruptured by nitrogen cavitation) was accomplished by Percoll density gradient centrifugation of cell lysates (postnuclear supernatant). Individual fractions were tested for proteinase activity on chromogenic peptide substrates and for the presence of TSP‐1 by Western blot analysis. In addition, each fraction was assayed for cytolytic activity against sheep red blood cells (SRBC), for protein and for additional marker enzymes to assess the enrichment for cellular organells. All serine enzyme‐type molecules including TSP‐1 expressed by CTLL were identified by labeling cell lysates or gradient fractions with the serine proteinase‐specific affinity ligand tritiated diisopropyl fluorophosphate ([3H]DFP) in the presence or in the absence of class‐specific or enzyme‐specific proteinase inhibitors and subsequent sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. The data demonstrate that the Percoll gradient fraction, which was shown by morphological examination in the electron microscope to be highly enriched for cytoplasmic granules, also contained > 80% of proteinase activity in addition to the granule‐associated structures cytolysin and aryl‐sulfatase. The identity of the granule‐associated proteinase in two independent cell lines, CTLL HY3‐Ag3 and CTLL 1.D.9, with the serine proteinase TSP‐1 is indicated by (a) its specificity for the chromogenic substrate H‐D‐Pro‐Phe‐Arg‐p‐nitroanilide, (b) its sensitivity to class‐specific as well as TSP‐1‐specific enzyme inhibitors and (c) by its reactivity with a polyvalent TSP‐1‐specific rabbit antiserum. Both CTLL contain a [3H]DFP‐labeled protein that migrates with a molecular mass of 60 kDa under nonreducing conditions and with 30 kDa under reducing conditions and which can be inactivated by the TSP‐1‐specific inhibitor H‐D‐Pro‐Phe‐Arg‐chloromethylketone. CTLL HY3‐Ag3 (a long‐term culture CTLL with natural killer‐like activity) but not CTLL 1.D.9 (an antigen‐specific short‐term cultured CTLL) express in addition a further [3H]DFP‐binding protein which migrates with 27 kDa under nonreducing or reducing conditions. No substrate specificity was found for this molecule. The possible function of the granule‐associated serine proteinase TSP‐1 is discussed.
Development of natural killer cells in human thymocyte culture: regulation by accessory cells
Authors: Blue Marie‐Luise , Levine Herbert , Daley John F. , Craig Kimberly A. , Schlossman Stuart F.
Published: March 2007

In vitro culture of human thymocytes resulted in the development of cells with natural killer (NK) activity and the acquisition of a pan‐NK antigen (NKH1) by a large number of thymocytes. The ability to kill the NK‐sensitive target, K562, was restricted to thymocytes expressing the NKH1 antigen. All NKH1+ thymocytes displayed a mature T cell phenotype, T3+T11+T8+T4−. Both the acquisition of NK activity and the development of cells with the NKH1+ phenotype could be suppressed by culturing thymocytes in the presence of adherent mononuclear cells. These results suggest that adherent accessory cells have the ability to regulate the development of T cell lineage NK cells.
Interleukin 2 pathway is autonomously activated in human T11+3−4−6−8− thymocytes
Authors: De La Hera Antonio , Toribio Maria Luisa , Marcos Miguel A. R. , Marquez Carlos , Martinez‐A Carlos
Published: March 2007

Mitogenic membrane ligands have been shown to activate interleukin 2 (IL2) production only in mature T cells, IL2 constitutive secretion having not yet been demonstrated. Here we have isolated a population of T11+3−4−6−8− human thymocytes and CD7+/T11−3−4−6−8− prothymocytes which produce and consume IL2 upon phytohemagglutinin triggering. Interestingly, their proliferation in the absence of any exogenous stimulating agent was related to an autonomous use of the IL2 system (IL2 secretion and binding to its specific receptor, whose constitutive, functional expression in human early thymocytes was recently shown). The internal activation of this system before T cell receptor acquisition stresses the relevance of the understanding of the alternative activation pathway(s) in T cell development. These findings, together with the demonstration of IL2‐promoted differentiation of human early thymocytes into mature T cells, suggest that IL2 may also be a growth and differentiation factor acting specifically early in T cell development.
Induction of human B cell proliferation and differentiation by the combination of phorbol ester and ionomycin
Authors: Roifman Chaim M. , Benedict Stephen H. , Cheung Roy K. , Gelfand Erwin W.
Published: March 2007

Phorbol esters and Ca2+ ionophores are known to mimic intracellular messengers involved in cell activation. We studied the effects of 12‐O‐tetradecanoylphorbol 13‐acetate (TPA) and ionomycin on tonsil and peripheral blood‐derived B lymphocytes. We show that TPA and ionomycin are co‐mitogenic and induce B lymphocyte differentiation. Although TPA in high concentrations is mitogenic to B lymphocytes by itself, submitogenic concentrations of TPA in combination with ionomycin trigger 50% of B lymphocytes to synthesize DNA. Stimulation of B lymphocytes with TPA plus ionomycin resulted in increased magnitude and a shift in the kinetics of c‐fos and c‐myc expression compared with either agent used alone. Activation markers such as the transferrin and interleukin 2 (IL 2) receptors were markedly increased after 24 h incubation with TPA and ionomycin. In parallel to the rapid proliferative burst, we observed evidence for B lymphocyte differentiation with an increase in the number of cells expressing cytoplasmic immunoglobulin (Ig) and the disappearance of the B1 surface marker. Since the cells remained surface Ig+ and secreted only small quantities of Ig, our results suggest that the combination of TPA and ionomycin is a potent inducer of B cell proliferation and early differentiation; terminal differentiation to an Ig‐secreting state, however, is not achieved.
The inflammation mediators interleukin 1 and hepatocyte‐stimulating factor are differently regulated in human monocytes
Authors: Northoff Hinnak , Andus Tilo , Tran‐Thi Thuy‐Anh , Bauer Joachim , Decker Karl , Kubanek Bernd , Heinrich Peter C.
Published: March 2007

Human peripheral monocytes can be induced by bacterial lipopolysaccharide to produce the inflammatory mediators interleukin 1 (IL1) and hepatocyte‐stimulating (HS) activity. IL 1 and HS activities were separated by gel permeation chromatography. It is also shown that the two monokines are differently regulated. Evidence for this stems from the finding that monocytes cultured for 24 h lose their ability to produce IL 1 in response to lipopolysaccharide, while synthesis of HS activity remains essentially unaffected.
Cytotoxic T lymphocyte clone recognizing self idiotype: its regulatory role in antibody production
Authors: Yamamoto Hiroshi , Araki Kiyonori , Bitoh Soji , Takata Masaru , Takahashi Seuchi , Fujimoto Shigeyoshi
Published: March 2007

MOPC 104E idiotype‐specific cytotoxic T lymphocyte (CTL) clones were established. The clone KA1.02 specifically killed MOPC 104E cells and inhibited anti‐dextran antibody production in an idiotype‐specific manner. Both cytotoxicity and antibody inhibition were restricted to the cross‐reactive idiotype and class I histocompatibility antigen. The data presented here provide definitive evidence that the self idiotype is the immunogenic determinant recognized by T lymphocytes in association with the major histocompatibility complex product. A regulatory role of CTL in antibody response is proposed.
The effect of recombinant interferon‐γ on human monocyte‐derived macrophages
Authors: Jungi Thomas W. , Lerch Peter G. , Brcic Marija
Published: March 2007

The effect of recombinant interferon‐gamma (rIFN‐γ) on human macrophage functions was studied, using monocytes which had matured to macrophages within hydrophobic containers. Following exposure to rIFN‐γ, the number of surface‐expressed specific IgG‐binding sites was increased. This increase was restricted to high‐affinity Fc receptors (FcR), however; low‐affinity FcR were not increased in number. Exposure to rIFN‐γ led to an enhanced chemiluminescence (CL) signal in the presence of luminol and a variety of respiratory burst stimuli, such as zymosan, phorbol 12‐myristate 13‐acetate or IgG‐sensitized sheep erythrocytes (EA). In contrast, phagocytosis of EA was markedly depressed in rIFN‐γ‐treated cells. Both increase in CL response and decrease in phagocytic activity were manifest after 1 day of treatment and were more pronounced after 2 days. While 5 U/ml of rIFN‐γ was an insufficient dose, 50 to 5000 U/ml yielded significant dose‐dependent changes in both functional assays. Thus, using rIFN‐γ as a biological response‐modifier, FcR expression and FcR‐mediated CL can be dissociated from FcR‐mediated phagocytosis.
A programmed functional and phenotypic development of bone marrow‐derived cytotoxic cell precursors in vitro
Authors: Hurwitz Julia L.
Published: March 2007

An analysis of function and marker expression during cytotoxic cell differentiaton in vitro from T cell‐depleted bone marrow precursors is described. Cytotoxic activity is not detectable during the first five days of culture, but rises abruptly soon after. Antibody plus complement depletion studies show that cytotoxic cells derive from Thy‐1‐negative precursors and undergo a continual increase in Thy‐1 and Lyt‐2 marker expression as the culture progresses. A reciprocal decrease in asialo‐GM1 antigen expression on effector cells is seen. The J11d‐negative precursor cells acquire J11d (an antigen known to mark cortical thymocytes) at an intermediate stage of culture, but revert to the J11d‐negative phenotype prior to functional acquisition. At least some effectors are T cell receptor positive as illustrated by an anti‐T cell receptor antibody‐mediated killing assay. These patterns precisely correlate with those detected among developing T cells in vivo. Results may indicate that a programmed course of differentiation inherent to bone marrow cells may be triggered in the absence of a thymic environment.
Expression of Fcϵ receptors on activated human T lymphocytes
Authors: Prinz Jörg Christoph , Endres Nicole , Rank Gertrud , Ring Johannes , Rieber Ernst Peter
Published: March 2007

Our results clearly demonstrate that the low‐affinity receptor for IgE (FcϵR) is an activation antigen transiently expressed on a subpopulation of human T lymphocytes. It can be selectively induced by stimulation with certain antigens or lectins, but it is not found on resting T cells. The increased numbers of activated FcϵR+ T cells observed after stimulation of peripheral blood mononuclear cells (PBMC) from bee venom allergic patients with the specific allergen phospholipase A2 (PLA2) suggest that FcϵR+ T cells might very well be involved in the regulation of the human IgE response against the respective antigen. These results were obtained by the use of two monoclonal antibodies, M‐L25 and M‐L47, which were raised against the human low‐affinity FcϵR in our laboratory. After stimulation of PBMC with phytohemagglutinin a peak of 7,6 ± 6% FcϵR+ T cells was observed on day 3, with pokeweed mitogen of 0.8 ± 0.8% on days 2 and 3, and with concanavalin A of 0.6 ± 0.7% FcϵR+ T cells on day 2. Stimulation of PBMC with tetanus toxoid (TT) induced FcϵR on maximally 0.6 ± 0.8% of the total T cells (day 4), stimulation with purified protein derivative from tuberculin (PPD) on 0.2 ± 0.6% of the T cells (day 2). In contrast to these antigens, stimulation of PBMC from bee venom allergic patients with PLA2 induced as a peak 2.5 ± 2.5% of the total T cells to express FcϵR (day 5), although the stimulated T cell population was much smaller than with TT or PPD, as was shown by their stimulation indices. The allergen‐stimulated FcϵR+ T cells were exclusively T4+. The FcϵR‐expression index was determined, which for a specific antigen or lectin correlates the percentage of FcϵR+ T cells to the stimulated T cell population, respectively.