bluuebunny/crossref_metadata_2025_split huggingface dataset:
Avian B cell precursors: Surface immunoglobulin expression is an early, possibly bursa‐independent event
Authors: Ratcliffe Michael J. H. , Lassila Olli , Pink J. Richard L. , Vainio Olli 
Published: February 2007

AbstractThe avian bursa of Fabricius contains about 1 × 104 discrete follicles, each of which is colonized by a small number of lymphoid progenitor cells during embryonic life. We have previously shown (J. R. L. Pink et al., Eur. J. Immunol. 1985. 15: 617) that all, or almost all B cell progenitors in the bursae of 4‐day‐old chicks express cell surface IgM. In this report, we have analyzed the distribution of cell surface (s)IgM‐1 allotypes within individual follicles of (M‐1a/M‐1b) allotype heterozygous birds. Although the majority of follicles contained a mixture of sIgM‐1a+ and sIgM‐1b+ cells, a significant proportion of isolated follicles contained exclusively sIgM‐1a+ or sIgM‐1b+ cells. Statistical analysis of the frequency of such “M‐1a” and “M‐1b” follicles demonstrated that the sIg+ B cells in the bursae of 4–8‐week‐old birds are derived from 2–4 allotypically committed precursor cells per follicle. Since we have previously shown that each bursal follicle is colonized by 2–5 pre‐bursal stem cells, these cells must be committed to the eventual expression of one or other allotypic haplotype before they have undergone extensive proliferation within the bursa.In addition, we show that almost all B progenitor cells from the bursae of chicks which had been allotype suppressed as embryos were committed to synthesis of the nonsuppressed allotype, showing that this commitment was essentially complete at the time of suppression (i.e. before 19 days of incubation). Finally the bone marrow of 16‐day embryos was used to reconstitute the bursal lymphocytes of cyclophosphamide‐treated host embryos. Reconstitution was inhibited by anti‐Ig antiserum indicating that most 16‐day embryonic BM‐derived bursal cell precursors also express sIgM. These results raise the possibility that expression of sIgM may be controlled by a “biological clock” rather than by any inductive capacity of the bursal microenvironment. Furthermore, these results provide further evidence that in normal birds a self‐renewing sIg+ B cell population in the hatched chicken is the sole source of B cells in the adult.
Quantitative and qualitative differences in HLA‐DR molecules correlated with antigen‐presentation capacity
Authors: Bontrop Ronald , Ottenhoff Tom , Miltenburg Rob Van , Elferink Diënne , De Vries René , Giphart Marius 
Published: February 2007

AbstractThe monoclonal antibodies 7.3.19.1 (anti‐DRw52‐like) and B8.11.2 (anti‐DR framework) were used for the isolation and characterization of HLA class II molecules expressed by HLA‐DR3 and DR5 homozygous B cell lines. Sequential immunoprecipitation studies demonstrated that from these cells class II molecules can be isolated which are characterized by the presence or absence of DR framework (DR) and DRw52‐like (DRw62) determinants: (DR+, DRw52+), (DR+, DRw52−) and (DR−, DRw52+). The DR3 donor cells appeared to express only the (DR+, DRw52+) and (DR−, DRw52+) class II molecules whereas DR5‐positive cells express only the (DR+, DRw52+) and (DR+, DRw52−) class II molecules.Besides qualitative differences some of the above‐mentioned molecules appeared to differ in their levels of expression. To investigate whether this might have functional implications, cells with the HLA‐DR3 and −5 haplotypes were used to present antigen purified protein derivative of tuberculin (PPD) to PPD‐specific T cell lines and the blocking capacity of the two monoclonal antibodies 7.3.19.1 and B8.11.2 was determined. A remarkable correlation was observed between the type of class II molecule blocked by these monoclonal antibodies and its quantitative expression. However, (DR−, DRw52+) molecules, clearly expressed by DR3 cells, were not involved in the presentation of PPD. This indicates that not only quantitative but also qualitative aspects may play a role in the selection of the type of class II molecule that will be involved in antigen presentation.
Transfer of immune complexes from lymphocytes to follicular dendritic cells
Authors: Heinen Ernst , Braun Michel , Coulie Pierre G. , Van Snick Jacques , Moeremans Marc , Cormann Nadine , Kinet‐Denoël Cécile , Simar Léon J. 
Published: February 2007

AbstractAntigens in the form of immune complexes are retained on the membranes of follicular dendritic cells (FDC) for long periods of time. To examine how immune complexes reach germinal centers, where FDC are located, we injected mice with anti‐2,4‐dinitrophenyl (DNP) antibodies complexed to DNP‐myoglobin‐coated gold particles. The distribution of the particles in spleens or draining lymph nodes was then determined with the electron microscope. The vast majority of the particles were cell bound. Shortly after injection they were phagocytized by macrophages or fixed on lymphocytes. The latter were found even in the corona of lymph follicles but not in germinal centers. Already 30 min after injection, FDC in contact with the corona were faintly positive but were negative in the center. FDC precursor cells were occasionally observed but in too small a number to account for the transport of immune complexes to the germinal centers. Twenty‐four hours after injection colloidal gold particles were found in phagolysosomes of macrophages or on cytoplasmic extensions of FDC in all parts of the germinal centers.Experiments performed on isolated FDC showed that they are not only able to take up free immune complexes but are also able to adsorb immune complexes from pulsed lymphocytes. These results strengthen the idea that lymphoid cells binding immune complexes by their Fc receptors may transport these complexes inside germinal centers.
A monoclonal antibody against altered LFA‐1 induces proliferation and lymphokine release of cloned T cells
Authors: Pircher Hanspeter , Groscurth Peter , Baumhütter Susanne , Aguet Michel , Zinkernagel Rolf M. , Hengartner Hans 
Published: February 2007

AbstractA murine monoclonal antibody (I‐17, IgM) has the following functional effects on murine long‐term T cell clones: inhibition of cell‐mediated lysis, induction of proliferation, release of lymphokines and change of the cell morphology. The determinant detected by I‐17 is expressed on long‐term T lines but not on thymocytes, lymph node cells and spleen cells. I‐17 precipitated proteins with apparent molecular mass of 220 kDa, 170 kDa, 150 kDa and 100 kDa. Biochemical studies indicate that the determinant recognized by I‐17 is tunicamycin sensitive and that I‐17 binds to the a chain of the lymphocyte function‐associated antigen (LFA‐1).
The influence of phagocytic stimuli on the expression of HLA‐DR antigens; role of reactive oxygen intermediates
Authors: Gruner Stefan , Volk Hans‐Dieter , And Peter Falck , Baehr Rudiger Von 
Published: February 2007

AbstractHuman peripheral blood mononuclear cells show after one day of culture with opsonized zymosan a decreased expression of HLA‐DR (but not HLA‐A, B, C) antigens, which can be prevented by the scavenger of reactive oxygen intermediates β‐carotene, or superoxide dismutase or indomethacin. Mononuclear cells of a patient with a heterozygous form of chronic granulomatous disease show no alterations in HLA‐DR antigen expression after culture with opsonized zymosan. Possible roles of reactive oxygen intermediates or prostaglandins in the modulation of HLA‐DR antigens are discussed.
Antibody recognition of ragweed allergen Ra3: Localization of the full profile of the continuous antigenic sites by synthetic overlapping peptides representing the entire protein chain
Authors: Atassi Hammad , Atassi M. Zouhair 
Published: February 2007

AbstractA comprehensive synthetic approach, for the localization of the full profile of the continuous antigenic sites on proteins, previously introduced by this laboratory, was applied here to localize the continuous antigenic sites of ragweed allergen, Ra3. The following 10 consecutive peptides, each comprising 15 residues (except for peptide 91–101) and overlapping each of its neighbors by 5 residues, were synthesized and purified: 1–15, 11–25, 21–35, 31–45, 41–55, 51–65, 61–75, 71–85, 81–95 and 91–101. Quantitative radiometric titrations of protein and peptide adsorbents were performed with 125I‐labeled anti‐Ra3 IgG antibodies from rabbit, outbred mouse and human antisera. The specificity of antibody binding to peptide adsorbents was confirmed by inhibition experiments. These studies established the full profile of antigenic (IgG‐binding) sites of Ra3 and permitted comparison with the allergenic (IgE‐binding) sites recently localized. It was found that the recognition by IgG antibodies was independent of the host species in which the antibodies were raised. Furthermore, the regions recognized by human IgE antibodies coincided with those recognized by IgG antibodies in three different species. Thus, Ra3 was found to have 4 continuous antigenic sites which occupy the same locations as the allergenic sites.
The p150,95 molecule is a marker of human mononuclear phagocytes: Comparison with expression of class II molecules
Authors: Hogg Nancy , Takacs Laszlo , Palmer David G. , Selvendran Yogi , Allen Catherine 
Published: February 2007

AbstractA new monoclonal antibody (mAb), named 3.9, is described that is specific for the p150,95 molecule, a member of the LFA‐1, CR3, p150,95 family of human leukocyte differentiation antigens. The LFA‐1 molecule participates in a variety of T cell interactions and the CR3 molecule is the receptor for the complement component iC3b, but little is known about the p150,95 molecule. Here we show that the expression of p150,95 is confined to myeloid cells. mAb 3.9 reacts variably with neutrophils, more strongly with monocytes and is most strongly expressed on tissue macrophages. Using this mAb and others, we have examined the heterogeneity of tissue macrophages. Cells such as Langerhans' cells, dendritic reticulum cells and osteoclasts failed to react with these mAb and thus, probably do not belong to the mononuclear phagocyte lineage. Using a new double‐labeling technique, we investigated lymphoid tissue for dendritic cells bearing class II molecules which might function in interactions with T cells. In T cell areas macrophages expressing class II markers were seen but there was no evidence for other types of dendritic or interdigitating cells which expressed class II molecules but not macrophage epitopes. The conclusion from this survey was that the most prominent cell with dendritic morphology found in the T cell areas of lymphoid tissue was a macrophage.
Regulation of thymocyte proliferation and survival by deoxynucleosides. Deoxycytidine produced by thymic accessory cells protects thymocytes from deoxyguanosine toxicity and stimulates their spontaneous proliferation
Authors: Penit Claude , Papiernik Martine 
Published: February 2007

AbstractDeoxyguanosine (dGuo) inhibits thymic blast DNA synthesis and then induces thymocyte cell death. The dGuo inhibitory action, measured with four different assays (spontaneous thymidine incorporation, immunofluorescent detection of 5‐bromodeoxyuridine incorporation, dye exclusion, tetrazolium salt cleavage), was suppressed in the presence of supernatants from cultures containing phagocytic cells. In particular, we studied the anti‐dGuo activity in supernatants from thymic reticulum cultures (TRS) and in those from phagocytic cells isolated from TR cultures (P‐TR). The anti‐dGuo substance was identified as deoxycytidine (dCyd) by high performance liquid chromatography and other physicochemical studies. Secretion of dCyd by P‐TR is accompanied by thymidine but not by purine nucleoside secretion. A dual mechanism of thymocyte rescue by dCyd was demonstrated by a study of the dose‐dependencies of dCyd‐mediated prevention and reversal, respectively, of the dGuo inhibition. In addition to this exogenously added anti‐dGuo action, dCyd and dCyd‐containing TRS induced significant stimulation of spontaneous thymic blast proliferation, and the kinetics of both effects were identical.These findings might suggest that a major role of thymic phagocytic cells is the supply of pyrimidine nucleosides to thymocytes resulting in the maintenance of proliferation and protection of at least some thymic blasts from the toxic effects of dGTP accumulation. The role of this system in the intrathymic selection process is discussed.
The receptor for IgE on blood platelets
Authors: Joseph Michel , Capron André , Ameisen Jean‐Claude , Capron Monique , Vorng Han , Pancré Véronique , Kusnierz Jean‐Pierre , Auriault Claude 
Published: February 2007

AbstractHighly purified blood platelets from man and rat could be induced into cytotoxic effectors against schistosome larvae by an IgE‐dependent mechanism. Such a process implied the existence of a receptor for the Fc part of IgE on the surface of these blood elements. Normal platelets, incubated in the serum of infected individuals as well as in the IgE‐rich serum from asthmatic patients, showed similar capabilities. Flow cytofluorometric analysis evidenced that the platelets bearing IgE receptors represented a subpopulation (20%), the percentage of which was significantly increased (up to 50%) in rats or patients with high levels of circulating IgE. Radiolabeled IgE, whose binding was specifically inhibited by an excess of unlabeled IgE or by anti‐Fcϵ receptor antibody, allowed the demonstration that the receptor for this isotype on the platelet surface was saturable. The binding of increasing amounts of IgE followed a bimodal curve, with less than 1000 sites per platelet showing an affinity coefficient of 3.3 × 107 M−1 at low concentrations, and a Ka of 7.8 × 105 M−1 for higher concentrations. Beyond their interest in the demonstration of cytotoxic properties of thrombocytes, these observations place emphasis on the potential role of the platelets in immediate‐type allergic reactions by their direct interaction with IgE antibody molecules, through a specific receptor.
The role of immunoglobulin receptors in “cognate” T‐B cell collaboration
Authors: Pereira Pablo , Forsgren Stina , Portnoi Denis , Bandeira António , Martinez‐A. Carlos , Coutinho António 
Published: February 2007

AbstractThe functional effects of anti‐Ig antibodies have been investigated, using an experimental system where B cell activation is brought about by direct and specific interactions with T helper (Th) cells without participation of surface Ig releptors on the responding B cell. We have used Th cell lines and clones directed to class II major histocompatibility complex antigens of the responding B cells, and titrated into cooperative cultures either purified rabbit anti‐mouse μ, or monoclonal mouse anti‐δ antibodies. Both types of antibodies greatly enhanced B lymphocyte responses to suboptimal concentrations of functionally efficient Th cells, while they had no effect in cultures containing optimal Th: B cell ratios. In contrast, helper activity by low efficiency Th was, at all Th: B cell ratios, enhanced by appropriate concentrations of anti‐Ig antibodies. Anti‐Ig effects were exclusively observed when B cells were the targets for “cognate” recognition by Th cells. We conclude that ligand binding to surface Ig receptors on resting B cells fails, in our experimental conditions, to overcome “linked” collaboration, but it greatly facilitates productive Th−B cell interactions. Whatever the mechanisms underlying this facilitation, the observations imply roles of surface Ig in Th−dependent B lymphocyte activation other than either passive “focusing” of antigen or activation into reactivity to soluble, unspecific factors.
In situ identification of idiotype‐positive cells participating in the immune response to phosphorylcholine
Authors: Razzeca Kristin J. , Pillemer Eric , Weissman Irving L. , Rouse Robert V. 
Published: February 2007

AbstractThe phosphorylcholine idiotype (Id)/anti‐Id system has been used to study the role of antigen‐specific cells in antigen‐induced microenvironmental changes. Anti‐Id staining of lymph nodes following PC immunization shows the presence of Id on follicular dendritic cells at 12 h and in plasma cells beginning at day 3. Germinal centers began to form at day 3, peaking in size and number at days 8‐10. Scattered Id‐positive small lymphocytes are present in germinal centers but with rare exceptions over 98% of germinal center cells are Id‐negative. Idiotype‐positive small lymphocytes are depleted from primary follicles adjacent to germinal centers but not from distant, unstimulated nodes.These results extend previous studies showing architectural alterations in lymph nodes following antigenic stimulation and demonstrate antigen‐specific cells are a prominent component of these antigen‐induced microenvironmental changes.
Effector functions and specificities of normal murine T cells stimulated by syngeneic blasts
Authors: Björklund Mariana , Beretta Alberto , Coutinho Antonio , Gullberg Martin 
Published: February 2007

AbstractLarge numbers of syngeneically stimulated T cells are easily obtained by stimulation of splenic T cell populations with irradiated lipopolysaccharide (LPS) blasts. Thus, proliferative T cell responses were obtained after stimulation with allogeneic LPS blasts, concanavalin A (Con A) blasts, normal spleen cells or peritoneal macrophages while only LPS and Con A blasts were competent syngeneic stimulators. The cytolytic activity of T cells stimulated with allogeneic LPS blasts was H‐2 specific, while that of T cells stimulated with syngeneic LPS blasts was often completely nonspecific, and higher for LPS than for Con A blast target cells. In other experiments, “self” H‐2K‐and I‐A‐specific cytotoxic T cells were obtained, without apparent reasons for the development of either type of cytolytic cells. Stimulation of Lyt‐2− T cells with syngeneic LPS blasts led to the generation of T helper effector cells which induced normal B cell proliferation in an H‐2 restricted manner. This restriction was overcome, the proliferative responses were augmented and plaque‐forming cell responses generated, through addition of Con A to the cultures. The results imply the ability of B blasts to induce stimulation of syngeneic T cells, and generation of effector cells displaying cytolytic and helper activity. This phenomenon might play a role in the regulation of the immune system.
NK‐9, a distinct sialylated antigen of the T200 family
Authors: Nieminen Pekka , Saksela Eero 
Published: February 2007

AbstractThe nature and properties of antigens detected by a novel monoclonal antibody, NK‐9, were studied. The NK‐9 antigens had apparent molecular masses of 190, 200 and 220 kDa and were sensitive to neuraminidase and sodium metaperiodate treatments, which destroy the sialic acid residues of the cell surface glycoproteins. Trypsin treatment also removed the NK‐9 reactivity, but the antigens were restored within a few hours thereafter. Tunicamycin, which inhibits the N‐linked glycosylation after neuraminidase treatment, had no effect on the reappearance of the NK‐9 positivity. Neither did endoglycosidase F, which removes the N‐linked sugars, abolish the NK‐9 antigenity. Monensin, which blocks the cellular secretion, inhibited the restoration of the antigens, and monensin block also without preceding treatment with neuraminidase led to the disapperance of NK‐9 reactivity, suggesting possible recycling molecules as carriers of the NK‐9 detected epitopes. The NK‐9 antigens appear to belong to the T200 antigen family, but are distinct from the antigens reactive with the available anti‐T200 antibodies anti‐LC, T29/33 and HLe‐1, based on their different cell type distribution and absence of cross‐reactivity in sequential immunoprecipitations.
Construction of chimeric thymuses in the mouse fetus by in utero surgery
Authors: Salaün Josselyne , Calman Françoise , Coltey Monique , Le Douarin Nicole M. 
Published: February 2007

AbstractNormal thymuses develop in the coelomic cavity of mice following grafts carried out in utero into embryonic day 16 to 17 fetuses of the third branchial arch region removed from 10‐day embryos. The recipients were killed at various times (up to 29 days after birth) and the thymic lobes which developed from the graft were recovered. Microscopical examination and immunocytochemistry revealed that these thymuses developed normally whether the grafts involved syngeneic or allogeneic (between BALB/c and C3H) strain combinations. Two major populations of class II‐expressing cells could be recognized by the Ia allotype they expressed: epithelial cells of donor type anti accessory cells of host origin.
Characteristics and functional aspects of nonlymphoid cells in rat germinal centers, recognized by two monoclonal antibodies ED5 and ED6
Authors: Jeurissen Suzanne H. M. , Dijkstra Christine D. 
Published: February 2007

AbstractIn this study two newly developed monoclonal antibodies, ED5 and ED6, are described, which specifically recognize nonlymphoid cells in B cell follicles of spleen and lymph nodes. Enzyme and immunocytochemical techniques demonstrated that ED5 and ED6 stain two different types of reticulum cells. The staining patterns were compared with those of the monoclonal antibody Ox2.ED5+ cells are able to retain immune complexes and are considered to be the follicular dendritic cell; in contrast ED6+ lack this capacity. Peyer's patches contain many ED6+ and Ox2+ cells but are completely devoid of ED5+ cells. After the application of immunomodulatory agents, like X‐irradiation, cyclophosphamide and lipopolysaccharide, ED5+ and ED6+ cells remain detectable. The nature of the new type of dendritic reticulum cell in lymphoid follicles, recognized by ED6, is discussed.
Human monoclonal antibody to purified protein derivative of tuberculin produced by hybrids constructed with Epstein‐Barr virus‐transformed B lymphocytes and mouse myeloma cells
Authors: Garzelli Carlo , Puglisi Carla , Falcone Giuseppe 
Published: February 2007

AbstractA method of producing human monoclonal antibody by combining somatic cell hybridization technology with the capability of Epstein‐Barr virus (EBV) to transform human B lymphocytes is described.Peripheral blood lymphocytes from a donor with positive tuberculin skin test reaction were transformed by EBV and then tested for antibody production to mycobacterial purified protein derivative (PPD) by an enzyme‐linked immunosorbent assay. Two EBV‐transformed lymphoblastoid cell lines making IgM antibodies to PPD were obtained. One of these cell lines was fused by polyethylene glycol with a murine hypoxanthine‐guanine phosphoribosyl transferase‐deficient myeloma cell line that had been selected for resistance to ouabain. The human‐mouse hybrids were selected in ouabain‐containing HAT medium and 11 heterohybridomas producing IgM antibody to PPD were obtained. one of these was cloned by limiting dilution with efficiency at least 20‐fold higher than parent EBV‐transformed cell line. Heterohybridoma subclones reached levels of IgM antibody as high as 75.0 μg/ml of culture medium, whereas IgM production of EBV‐transformed B cell clones ranged between 3.0 and 4.0 μg/ml.
Expression on human thymocytes of the idiotypic structures (Ti) from two leukemia T cell lines Jurkat and HPB‐ALL
Authors: Carrel Stefan , Isler Patrick , Schreyer Magali , Vacca Angelo , Salvi Susanne , Giuffre Laura , Mach Jean‐Pierre 
Published: February 2007

AbstractThe expression on a significant number of thymocytes of idiotypic structures (Ti) restricted to HPB‐ALL or Jurkat cells is demonstrated. As many as 2‐4% of thymocytes were stained with anti‐Ti HPB‐ALL or anti‐Ti Jurkat monoclonal antibodies, when analyzed by flow microfluorometry. Immunohistochemical localization studies performed on frozen thymus specimens of either fetal or pediatric origin indicated a scattered distribution of Ti‐positive cells in both the cortex and the medulla. From lysates of 125I‐labeled pediatric thymocytes, anti‐Ti HPB‐ALL and anti‐Ti Jurkat monoclonal antibodies precipitated disulfide‐linked heterodimers comparable to those precipitated from 125I‐labeled HPB‐ALL or Jurkat cells as shown by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis analysis.