bluuebunny/crossref_metadata_2025_split huggingface dataset:
Absence of demonstrable phospholipid turnover in B cells stimulated by low mitogenic concentrations of dextran‐anti‐immunoglobulin conjugates
Authors: Brunswick Mark , Bonvini Ezio , Francis Mark , Felder Christian C. , Hoffman Thomas , Mond James 
Published: March 2007

AbstractPreviously we have demonstrated that when anti‐immunoglobulin (Ig) is conjugated to high molecular weight dextran (Dex) it stimulates B cell activation at pg/ml concentrations in the absence of detectable phosphoinositide hydrolysis or increases in intracellular ionized calcium. To study carefully whether anti‐Ig‐Dex recruited a phosphoinositide‐dependent pathway of activation, we stimulated B cells that were labeled with 32P and [3H]glycerol with anti‐Ig‐Dex conjugates at concentrations ranging from 1—1 × 10−4 μg/ml. Thirty seconds to thirty minutes after stimulation lipids were extracted and analyzed by thin layer chromatography and spots correlating with known lipid standards were isolated and counted. There was a four‐ and tenfold increase in the ratio of 32P/3H incorporated into phosphatidic acid (a metabolite of diacylglycerol) and phosphatidylinositol, respectively, when cells were stimulated with 0.1–1.0 μg/ml of anti‐Ig‐Dex for 30 min. Below 1 ng/ml there was no detectable increase in the turnover of these metabolites despite the fact that in parallel cultures B cells were stimulated to proliferate by this concentration of anti‐Ig‐Dex. To determine whether a cAMP‐dependent pathway was recruited by low concentrations of conjugates, we evaluated cAMP levels from B cells that were stimulated with anti‐Ig‐Dex for 5–60 min using a radioimmunoassay. While cholera toxin stimulated a 50–100‐fold increase in the levels of cAMP, we observed no alteration in cAMP in anti‐Ig‐stimulated cells. These results support and extend our previous findings by demonstrating that B cell activation that is induced by cross‐linking of surface Ig may not stimulate phosphoinositide‐dependent or cAMP‐dependent pathways of activation. Possible alternative mechanisms of activation will be discussed.
Protein sequence and gene structure for mouse leukosialin (CD43), a T lymphocyte mucin without introns in the coding sequence
Authors: Cyster Jason , Somoza Chamorro , Killeen Nigel , Williams Alan F. 
Published: March 2007

AbstractA partial cDNA clone for mouse leukosialin was isolated by use of a rat leukosialin cDNA probe. The mouse cDNA was then used to isolate genomic clones that corresponded to the two mouse genes detected in Southern blots. One gene encoded an open reading frame for the homologue of rat leukosialin and this gene was notable for the absence of introns within the coding sequence. A lack of introns has previously been observed for the human leukosialin gene (Shelley, C. S., Remold‐O'Donnell, E., Rosen, F. S. and Whitehead, A. S., Biochem. J., submitted). The other mouse gene was an intronless pseudogene for a leukosialinrelated sequence. The presence of only one functional gene that lacked coding‐region introns established that molecular heterogeneity in mouse leukosialin could not arise from multiple genes or alternative splicing of exons. The sequence of mouse leukosialin suggested an extracellular segment with a high content of O‐linked carbohydrate, as is the case in the rat and human. In addition the mouse molecule had one possible N‐linked glycosylation site. The cytoplasmic domain of 124 amino acids was highly conserved between rodent and human leukosialins for the functional genes but not for the pseudogene. This suggests an important functional role for the cytoplasmic domain.
Microheterogeneity of human interleukin 6 synthesized by transfected NIH/3T3 cells: Comparison with human monocytes, fibroblasts and endothelial cells
Authors: Schiel Xaver , Rose‐John Stefan , Dufhues Gabi , Schooltink Heidi , Gross Volker , Heinrich Peter C. 
Published: March 2007

AbstractA cDNA containing the entire coding region of human interleukin 6 (IL 6) was stably expressed in murine NIH/3T3 fibroblasts using a bovine papilloma virus‐based expression vector with a metallothionein promoter. Expression of IL 6 in transfected cells was highly inducible by heavy metals like cadmium as measured at mRNA and protein levels. Cadmium‐stimulated transfected NIH/3T3 cells synthesized and exported biologically active IL 6 (1.7 × 104 U/106 cells/24 h). IL 6 from the culture medium of transfected NIH/3T3 cells exhibited at least eight bands on Western blots after sodium dodecyl sulfate‐polyacrylamide gel electrophoresis, indicating that human IL 6 expressed in NIH/3T3 cells shows a complex glycosylation pattern. Using glycosidases and the N‐glycosylation inhibitor tunicamycin it was possible to discriminate between five species carrying N‐linked carbohydrate side chains and two species carrying only O‐linked side chains. In addition, a substantial amount of unglycosylated IL 6 was observed. IL 6 from transfected NIH/3T3 cells differed markedly in its glycosylation pattern from those of stimulated human monocytes, fibroblasts and endothelial cells.
Absolute numbers of lymphocyte subsets migrating through the compartments of the normal and transplanted rat spleen
Authors: Willführ Karl Ulrich , Westermann Jürgen , Pabst Reinhard 
Published: March 2007

AbstractLymphocyte migration is one of the basic principles of the immune system. Up to now lymphocyte migration experiments have been performed either in a quantitative way, determining whole organ recoveries of radiolabeled lymphocytes without histologic localization, or based on autoradiography which does not provide absolute numbers of immigrant lymphocytes. In this study the traffic of lymphocyte subsets through the splenic compartments: red pulp (RP), marginal zone (MZ), periarteriolar lymphatic sheath (PALS) and follicle was evaluated in absolute numbers. In normal spleens and splenic transplants fluorescein isothiocyanate (FITC)‐labeled immigrant lymphocytes were localized and characterized immunohistochemically in cryostat sections by light microscopy. In addition morphometry of the splenic compartments was performed and the recovery of 51Cr‐labeled lymphocytes in the spleen was determined. The combination of these methods allowed total numbers of immigrant subset cells to be calculated in individual splenic compartments.At 15 min about 17% of the injected B lymphocytes were found in the MZ. This is the largest fraction of an injected lymphocyte subset found in a single splenic compartment. At 24 h immigrant B cells were not only found in the follicle, but they had reached comparable numbers in the three compartments: follicle, RP and MZ. Most immigrant T lymphocytes were found in the PALS, which from 6 h after injection onwards contained more T cell immigrants than any single organ of the body. CD4+ and CD8+ lymphocytes showed a similar distribution throughout the splenic compartments at early time points. At 24 h CD4+ lymphocytes homed preferentially to the PALS, whereas CD8+ cells seemed to prefer the RP and MZ. Both CD4+ and CD8+ cells also migrated into the follicles. In regenerated splenic tissue after autotransplantation lymphocyte immigration was reduced in all compartments and to the MZ in particular. An impaired lymphocyte migration to the MZ in splenic transplants may be one reason for the lack of protection provided against bacterial infections. Thus examining lymphocyte migration in absolute numbers provides additional information which cannot be gained by determining labeling indices or percentages of lymphocyte subsets alone.
Selective expression of CD8α (Ly‐2) subunit on activated thymic γ/δ cells
Authors: Robson MacDonald H. , Schreyer Magali , Howe Rawleigh C. , Bron Claude 
Published: March 2007

AbstractAlthough most cells of the T cell receptor (TcR) γ/δ lineage are CD4−CD8−, some γ/δ cells express CDS. We show here that mouse thymic γ/δ cells express CD8 following in vitro activation by concanavalin A. Staining with monoclonal and polyclonal antibodies to the CD8 α (Ly‐2) and CD8 β (Ly‐3) subunits indicates that only CD8 α is expressed by these activated TcRγ/δ cells. Furthermore, immunoprecipitation and reduced/nonreduced gel analysis reveals that thymic γ/δ cells express CD8 α as a homodimer. In contrast, similarly activated TcR δ/β cells express a conventional CD8 α/CD8 β heterodimer.
Type II collagen‐specific human T cell lines established from healthy donors
Authors: Lacour Michael , Rudolphi Ulrike , Schlesier Michael , Peter Hans‐Hartmut 
Published: March 2007

AbstractFour type II collagen‐specific T cell lines established from the peripheral blood of a healthy donor were studied in detail. These CD4+ T cell lines with an α/β T cell receptor proliferated in response to native and denatured human and chicken type II collagen and human type I collagen, but not to human type IV collagen or other potentially arthritogenic antigens. The T cell response showed typical dose response characteristics, peaked between 30 and 48 h, was major histocompatibility complex class II restricted and not due to a mitogenic effect. Type II collagen‐reactive T cells could hardly be detected in freshly isolated peripheral blood mononuclear cells from healthy donors, as revealed by limiting dilution analysis (frequency < 1/100000). By prestimulation in bulk cultures for 10 days, type II collagen‐reactive T cells could be approximately 1000‐fold enriched. However, in these limiting dilution cultures, collagen‐reactive T cells could only be observed in a narrow window of cell concentrations, suggesting that type II collagen‐reactive T cells may be controlled by suppressive mechanisms in healthy persons.
Production and regulation of interleukin 6 in human B lymphoid cells
Authors: Hutchins David , Cohen Brian B. , Michael Steel C. 
Published: March 2007

AbstractHuman B cell lines were screened for production of interleukin 6 (IL 6) by the B9 hybridoma cell bioassay. Some long‐established lines such as RPMI 1788, CESS and recently established early‐passage Epstein‐Barr virus (EBV)‐transformed lymphoblastoid lines were constitutive IL 6 producers. Other long‐established lymphoblastoid lines such as RPMI 8866 and SKW6.4 and all Burkitt lymphomalines tested were nonproducers of IL 6.Constitutive production of IL 6 in early passage lines could be enhanced by the phorbol ester phorbol 12‐myristate 13‐acetate (PMA) and recombinant (r)IL 4 but not by rIL 1α or rIL 1β. Nonproducing EBV‐transformed lymphoblastoid cell lines could be induced to IL 6 production by PMA, rIL 1α, IL 1β and IL 4. Amongthe nonproducing lines SKW6.4 was induced to IL 6 production by PMA, rIL 1α, rIL 1β and rIL 4, whereas RPMI 8866 was induced only by PMA, to a limited extent by rIL 1α and rIL 1β but not at all by rIL 4. There was no induction of IL 6 by any recombinant cytokine in the two Burkitt lymphoma lines but measurable production of IL 6 was induced by PMA in one of them (EB4). Cytokines which wereneither enhancers nor inducers of cell lines on their own included rIL 2, rIL 5, interferon (rIFN)‐γ, native purified IFN‐α, tumor necrosis factor (rTNF)‐α, rTNF‐β and purified platelet‐derived transforming growth factor‐β. rIL 4 synergized with either rIL 1α or rIL 1β in the induction of IL 6 in the nonproducing line SKW6.4. Similar effects were also seen in this line with combinations of (a) rIFN‐γ and rIL 4 and (b) IFN‐α and both rIL 1α and rIL 1β. rIL 4, with or without rIL 1, was more effective than rIL 6 in the induction of IgM synthesis in SKW6.4 and the effect was only partially inhibited by anti‐IL 6antiserum at a dose which totally inhibited IL 6‐induced IgM production.Normal peripheral blood lymphocyte populations pre‐activated by anti‐immunoglobulin rosetting exhibited enhanced production of IL 6 in the presence of rIL 4 and PMA but not in the presence of rIL 1, in contrast to the behavior of adherent mononuclear blood cells which showed IL 4‐induced down‐regulation of IL 6 production. Human B lymphoblastoid cell‐derived IL 6 was shown by Western blotting (using a polyvalent goat antiserum) to be composed of at least three distinct bands between 21 and 30 kDa, andboth constitutively produced and induced activities were neutralized by the same antiserum.The finding that human B cell lines differ in their constitutive and inducible productionof IL 6, a cytokine implicated in both the growth and differentiation of these cells, is discussed with respect to its possible role as an autocrine factor.
Effect of bacterial toxins on human B cell activation I. Mitogenic activity of pertussis toxin
Authors: Kolb Jean‐pierre , Genot Elisabeth , Petit‐koskas Elisabeth , Paul‐eugene Nathalie , Dugas Bernard 
Published: March 2007

AbstractPertussis toxin (PT) was found to elicit an increased thymidine uptake in resting B lymphocytes purified from human peripheral blood. A significant mitogenic effect was detected for toxin concentrations > 100 ng/ml (1 nM) and a plateau of stimulation was reached at 1000 ng/ml (10 nM). B cell blasts, activated by a first signal such as Staphylococcus aureus Cowan I or insolubilized anti‐μ chain antibody, were also stimulated to DNA synthesis by PT in the same range of concentrations. At lower sub‐mitogenic concentrations, the toxin potentiated the response to the low‐molecular weight B cell growth factor (LMW‐BCGF or 12‐kDa BCGF), a progression factor for activated B cells. The “A” or catalytic subunit was devoid of any activity on B cells, suggesting the stimulatory effect of the toxin might be associated with the binding or “B” subunit, as it has been shown for T cells. This hypothesis was strengthened by the observation that, as in T cell, the whole toxin but not the “A” promoter, was able to induce calcium influx in these cells. In addition, the purified “B” oligomer alone was found to promote DNA synthesis in B cells. Finally, a fragment of the soluble cleaved form of the CD23 molecule (FcϵRII) could be involved in the process of PT mitogenicity for B cells.
Selective peripheral expansion and activation of B cells expressing endogenous immunoglobulin in μ‐transgenic mice
Authors: Grandien Alf , Coutinho António , Andersson Jan 
Published: March 2007

AbstractTwo different lines of C57BL/6 mice (IgHb) carrying complete rearranged μ chain genes from BALB/c (IgMa) were analyzed for the expression and secretion of endogenous as well as transgenic immunoglobulins at the level of single cells. Quantitation of B cells expressing endogenous IgMb by cytofluorometry, limiting dilution analyses of clonal precursors and secretory cell assays revealed a marked selective expansion, activation and terminal differentiation of those cells producing endogenous immunoglobulins. Thus, the very infrequent IgMb−bearing B cells produced in bone marrow of transgenic mice accumulate in spleen, where they are activated and account for roughly half of all natural immunoglobulin‐secreting cells.These observations indicate that μ‐transgenic mice are valuable in studies of the antibody repertoire selection operating in unprimed animals but their use could be misleading in the analyzing ''monoclonal'' immune system.
Induction of cell‐associated interleukin 1 through stimulation of the adhesion‐promoting proteins LFA‐1 (CD11a/CD18) and CR3 (CD11b/CD18) of human monocytes
Authors: Couturier Christine , Haeffner‐cavaillon Nicole , Weiss Laurence , Fischer Elisabeth , Kazatchkine Michel D. 
Published: March 2007

AbstractSerum‐free culture of human monocytes in the presence of monoclonal antibodies to the LFA‐1 α chain (CD11a), CR3 α chain (CD11b) or β chain (CD18) bound to Sepharose induced the dose‐dependent production of cell‐associated interleukin (IL) 1 activity and of IL 1α and IL 1β antigens, but no release of extracellular IL 1 activity or antigen in the culture medium. Triggering of IL 1 production was also observed with insolubilized anti‐CD11/CD18 F(ab')2 antibodies. Two cross‐linked antibodies recognizing distinct epitopes on the CD11b molecule induced cell‐associated IL 1. Soluble antibodies did not induce IL 1 production. The kinetics of induction of IL 1 by stimulation of adhesion‐promoting proteins differed from those of IL 1 induction by adhesion to plastic. The lack of induction of IL 1 release by stimulation of the CD11/CD18 molecules resembled the intracellular accumulation of IL 1 induced by lipid A. Induction of IL 1 by adhesive processes may be a mechanism by which T cells trigger IL 1 production by monocytes during antigen presentation.
Antigen‐induced inhibition of autoimmune response to rat male accessory glands: distinct role of I‐A and I‐E‐positive peritoneal cells
Authors: Ferro Maria Elena , Romero‐piffiguer Marta , Riera Clelia M. 
Published: March 2007

AbstractThe present report describes the structural and functional characteristics of the population of peritoneal cells (PC) from rats injected intraperitoneally (i.p.) 2 h or 24 h previously with a suppressor dose of a purified fraction (FI) of rat male accessory glands (RAG; FI‐PC2h and FI‐PC24h, respectively). Both populations of PC showed the presence of the autoantigens of RAG on their membrane. The study of cell surface marker showed increase of OX17 (I‐E) in FI‐PC2h and OX6 (I‐A) in FI‐PC24h. I.p. injection of FI‐PC2h 10 and 3 days prior to immunization with chemically modified (diazotized arsanilic and sulfanilic acid) RAG (MRAG) in complete Freund's adjuvant induced suppression of the delayed‐type hypersensitivity (DTH) response to MRAG, whereas the i.p. injection of FI‐PC24h induced potentiation of DTH responseto MRAG when compared with controls (animals injected 10 and 3 days prior to immunizationwith PC from rats injected i.p. with an unrelated antigen). The treatment of FI‐PC2h with OX17 and FI‐PC24h with OX6 prior to the transfer blocked the suppression and potentiation described above. These findings show that the i.p. injection of an FI of RAG at a suppressor dose induces PC with immunologically opposite characteristics, depending on the time of obtention.
Antigenic phenotyping of human follicular dendritic cells isolated from nonmalignant and malignant lymphatic tissue
Authors: Petrasch Stephan , Perez‐alvarez Carmelo , Schmitz Jörn , Kosco Marie , Brittinger Günter 
Published: March 2007

AbstractFollicular dendritic cells (FDC) are located within follicles of secondary lymphoid tissue and in lymph nodes of patients with germinal center cell‐derived non‐Hodgkin lymphomas. Reliable antigenic phenotyping of FDC within tissue sections has been difficult due to simultaneous labeling of the surrounding germinal center cells. Using anenzyme cocktail to digest human tonsils and cervical lymph nodes with subsequent fractionation by albumin gradient centrifugation, cell isolates containing up to 20% FDC were obtained. This preparation allowed the determination of antigenic phenotype on individual FDC. Molecules expressed by FDC were detected by an isotype‐specific immunocytochemical double‐labeling procedure, i.e. a monoclonal antibody (mAb) specific for FDC (KiM4 or DRC1) in conjunction with a mAb reactive against an additional antigenic determinant. Nonspecific binding of mAb to immunoglobulin Fc receptors located on FDC membranes was avoided by incubation of cells with human IgG aggregates prior to immunostaining. The results revealed that isolated FDC from these lymphoid tissues express transferrinreceptors, the intercellular adhesion molecule 1, class II antigens, the B cell antigens CD20 and CD21, and the myelomonocytic properties CD11b and CD14. Immunoglobulin μ or γ heavy chains and the B cell antigens CD23 and CD24 are detected on 50% of an isolated FDC population. These FDC are negative for the T helper cell antigen CD4, the B cell cell antigens CD19 and CD22, the immunolobulinα and δ chains and the S‐100 protein.FDC isolated from lymph nodes of patients with low‐grade malignant non‐Hodgkin lymphoma, identified by DRC1 or KiM4 mAb, presented the same antigenic profile as seen on FDC from nonmalignant tissue. This suggests that FDC from lymphoma tissue isolated in this manner have the same properties as those found in normal tissue.
VH gene family repertoires of “viable motheaten” (mev) mice
Authors: Freitas Antonio A. , Sidman Charles L. 
Published: March 2007

AbstractMutant viable motheaten (mev) mice provide an useful experimental model to study the origin and molecular properties of autoantibodies. In the present investigation we have compared by in situ hybridization VH gene family usage in lipopolysaccharide‐activated B cells (available repertoire) and spontaneously immunoglobulin‐secreting (actual repertoire) B cells in the spleen of 6—8‐week‐old BALB/c and mutant BALB/c‐mev mice. We have found that while sharing identical available splenic repertoires and expressing a diversified set of VH families, mev mice differ from control BALB/c animals in VH family representation in the actual plasma cell repertoires where they showed a decreased utilization of VH7183 genes and an increased representation of the VHJ606 family when compared to control BALB/c animals. These results indicate that selection of actual repertoires may indeed differ between autoimmuneand control mice, but do not establish whether such changes are the primary cause of the disease or whether they are secondary to the initiating of the autoimmune process.
Analysis of type II collagen‐reactive T cells in the mouse I. Different regulation of autoreactive vs. non‐autoreactive anti‐type II collagen T cells in the DBA/1 mouse
Authors: Andersson Mikael , Holmdahl Rikard 
Published: March 2007

AbstractThe T cell reactivity against type II collagen (CII) was analyzed in the collagen‐induced arthritis‐susceptible mouse strain DBA/1. It was shown that the proliferative response in lymph node cells from rat CII‐immunized mice was mainly directed against a foreign determinant present on all heterologous CII tested but not on autologous CII. A T cell line with this reactivity reacted with high sensitivity with CII and the determinant was mapped to the CB11 fragment of CII. A weak autoreactive response could be detected in the primary cultures using high concentrations of mouse CII and this reactivity remained after several stimulations with high concentrations of rat CII but not with low concentrations of rat CII. A similar response against mouse CII but with only limited cross‐reactivity to rat CII was seen when culturing the cells with mouse CII as antigen. The optimal concentration for the autoreactive response was always more than 100‐fold higher than for the response of the T cells specific for heterologous CII. An anti‐CII T cell response could also be detected in spleen cells from unimmunized mice and the strongest response was obtained using autologous CII. These results suggest that T cells recognizing self CII are normally activated in the DBA/1 mouse and possibly as a consequence exhibit a clonal anergy pattern with a weak proliferative response only at high concentrations of CII.
Phytohemagglutinin induces major short‐term protease‐sensitive lymphocyte traffic involving high endothelium venule‐like blood vessels in acute delayed‐type hypersensitivity‐like reactions in skin and other tissues
Authors: Binns Richard M. , Licence Stephen T. , Peter Wooding F. B. 
Published: March 2007

AbstractInjection of phytohemagglutinin induces dose‐dependent acute delayed‐type hypersensitivity‐like reactions in young pig skin which attract large numbers of labeled peripheral blood lymphocytes and lymphoblasts but not red cells. Similar reactions are induced in the gut wall, joints, and draining lymph nodes, and also in the skin of sheep and cattle, and by concanavalin A. Labeled peripheral blood lymphocyte entry starts within 2 h, is maximal at 6—18 h and is effectively over by 48 h and, both earlyand late, is markedly inhibited in a selective way by trypsinization, like high endothelium venule‐mediated entry to lymphoid tissues. Electron microscopy showed development of high endothelium venule‐like blood vessels with intramural lymphoid cells inmononuclear infiltrates. Inductive processes in this model short‐term peripheral defense mechanism are being investigated.