bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunoglobulin diversification in bursal duct‐ligated chickens
Authors: Lassila Olli , Lefkovits Ivan , Alanen Anna 
Published: March 2007

AbstractThe role of external antigen contact on immunoglobulin (Ig) diversification occurring in chicken bursal cells was evaluated. The entry of environmental antigens into the lumen of the bursa of Fabricius was prevented by ligating the bursal duct prior to hatching (BDL: bursal duct ligation). We used two‐dimensional gel electrophoresis to compare the heterogeneity of Ig molecules from bursa cells of normal and BDL chickens. We have found that Ig diversity obtained from BDL chickens' bursae in two‐dimensional gel analysis was similar to that of control birds. Furthermore, by using two monoclonal anti‐idiotype antibodies to study intrabursal Ig diversification we have shown that frequencies of the Cld‐1 and Cld‐2 idiotypes were also unaltered following bursal ligation. We conclude that primary B cell diversification in the bursa is independent of the external antigen flow from the bursal lumen.
Characterization of a novel myeloid antigen regulated during differentiation of monocytic cells
Authors: Cabañas Carlos , Sanchez‐Madrid Francisco , Bellon Teresa , Figdor Carl G. , Velde Anje A. Te , Fernandez Jesus M. , Acevedo Augustin , Bernabeu Carmelo 
Published: March 2007

AbstractThe monoclonal antibody HC1/6 generated against phorbol 12‐myristate 13‐acetatetreated U‐937 cells recognizes a new cell surface antigen with a broad relative molecular mass ranging from 100 to 150 kDa. This antigen is also present on monocytes, platelets and endothelial cells and is weakly expressed by granulocytes. In contrast, it is absent from T, B and erythroblastoid cells. The antigen HC1/6 is also expressed by normal tissue macrophages in tonsil, lung and kidney, as well as in skin biopsies from pathologies such as sarcoidosis and lepromatous leprosy. The expression of the HC1/6 antigen is increased up to 5‐fold when U‐937 (promonocytic) and HL‐60 (myelomonocytic) cell lines are stimulated with phorbol 12‐myristate 13‐acetate. Conversely, the expression of the HC1/6 antigen is down‐regulated in monocytes upon treatment with interferon‐γ. These findings are discussed in relation with other myeloid cell surface markers.
FcγRII expression in resting and activated B lymphocytes
Authors: Amigorena Sebastian , Bonnerot Christian , Choquet Daniel , Fridman Wolf Herman , Teillaud Jean‐Luc 
Published: March 2007

AbstractIn this report, we analyze the expression of the type II receptor for the Fc region of IgG (FcγRII) in resting and lipopolysaccharide (LPS)‐activated murine B lymphocytes. FcγRII is encoded by two genes, α and β. The β gene encodes two mRNA, β1 and β2, which are generated by alternative splicing. Using an S1 nuclease protection assay, we found that resting and activated B lymphocytes express predominantly the β1 transcript. Very low levels of the β2 mRNA were detected in this assay, while no expression of the α transcript could be detected. Quantitative Northern blot analysis showed that the amount of FcγRII β mRNA was increased 9‐fold in LPS‐activated B lymphocytes. The expression of FcγRII during the various phases of B cell activation was then studied by immunofluorescence using the monoclonal antibody 2.4G2. LPS stimulation induced an increase of the FcγRII cellular pool as well as of its expression at the surface of B lymphocytes. The rise in FcγRII surface expression occurred after the induction of class II antigens (la) and before transferrin receptor induction. FcγRII expression was found to be enhanced during the G1 phase of the cell cycle since (a) only large cells (i.e. those that had entered the G1 phase) expressed an increased amount of FcγRII and (b) blocking the entry of activated cells into the S phase (with the ion channel blocker quinine) did not affect the FcγRII induction by LPS. Furthermore, only B cell activators that induced cells to enter into G1 [LPS and F(ab')2 anti‐IgM antibodies, but not interleukin 4] caused an increase in the expression of FcγRII. These results show that the increase in the membrane expression of FcγRII occurs during the early G1 phase, establishing it as a marker for the entry of B lymphocytes into the cell cycle.
Interception of the development of self tolerance in fetal lambs
Authors: Mccullagh Peter 
Published: March 2007

AbstractInvestigation of the nature of immunological self tolerance has usually relied upon experimental protocols in which the tolerant state is interrupted in mature animals with the production of autoimmune disease. While such research has improved the understanding of those processes operative in overt autoimmunity, it has not been informative in relation to events associated with the establishment of self tolerance. Any description of this state which is to be based on observation will necessitate the use of experimental systems that permit observation of animals during the development of self tolerance.The present experiment entailed intervention approximately one third of the way through the gestation period of fetal lambs. An earlier experiment had established that 54‐day fetal lambs would accept allografts of adult skin. This indicated that the capacity to discriminate between self and non‐self had not been acquired at that age. Fetuses at this stage of gestation were submitted to either partial or total removal of the thyroid gland. The excised tissue was then implanted in nude mice for periods of 5 to 9 weeks. It was subsequently replaced subcutaneously, either in the original donor or in another fetus at a comparable stage of gestation. At postmortem examination, several weeks later, self implants in lambs from which the thyroid gland had been completely removed displayed autoimmune thyroiditis of varying degrees of severity. However, self implants in partially thyroidectomized animals were uniformly free from autoimmune manifestations. This implied that these reactions had not been directed against contaminating murine tissues in the implants replaced in completely thyroidectomized lambs. All allogeneic implants were subject to vey heavy lymphocytic infiltration, usually with accompanying necrosis consistent with allograft rejection. This was taken as an indication that hypothyroid fetal lambs had become immunocompetent by the time of thyroid reimplantation. Spontaneous immunological reactivity against reimplanted self thyroid tissue by thyroidectomized lambs was interpreted as a failure to acquire the capacity for self recognition as a result of antigen deprivation.
Complex Ca2+ flux inhibition as primary mechanism of staurosporine‐induced impairment of T cell activation
Authors: Kubbies Manfred , Goller Bernhard , Russmann Eberhard , Stockinger Hubertus , Scheuer Werner 
Published: March 2007

AbstractThe inhibitory effect of the highly effective drug staurosporine on the early activation signal Ca2+ flux was investigated via multiparameter flow cytometry in human peripheral blood T lymphocytes. Staurosporine has been reported to be a specific inhibitor of protein kinase C. However, we show that it inhibits the Ca2+ influx in anti‐CD3 and phytohemagglutinin‐stimulated human CD4+ and CD8+ lymphocytes at concentrations between 1.0 and 10.0 ng/ml. Staurosporine decreases the number of Ca2+‐positive CD4+ and CD8+ lymphocytes as well as the Ca2+ influx per cell; the drug also delays the time of the maximum response to polyclonal stimulation. In addition, we demonstrate that staurosporine affects the primary Ca2+ response via inhibition of the release of the membrane‐bound Ca2+ from the endoplasmic reticulum in CD4+ and CD8+ lymphocytes. Binding studies of the anti‐CD3 antibody to T lymphocytes indicate normal binding capacities in the presence of staurosporine. With respect to the classical scheme of T cell activation via phospholipase C, our data suggest that staurosporine may inhibit T cell activation primarily by its effect on the early Ca2+ flux signal.
Regulation of hepatic synthesis of C3 and C4 during the acute‐phase response in the rat
Authors: Anthony Robert , El‐Omar Emad , Lappin David F. , Macsween Roderick N. M. , Whaley Keith 
Published: March 2007

AbstractFollowing the i.p. injection of casein, rats showed increased serum levels of C4 and C3. C4 levels peaked on day 2 and returned to normal by day 4, while C3 levels peaked on day 3 before returning to normal on day 4. These changes were paralleled by changes in the hepatocyte synthesis rates of these two proteins.Macrophages, isolated from the peritoneal cavities of rats on days 1 to 7 (day‐1 to day‐7 macrophages) following i.p. injection of casein, were cultured in vitro, and the peritoneal macrophage‐conditioned media (PMCM) assayed for their abilities to stimulate synthesis of C4 and C3 by hepatocytes from control rats. Day‐2 PMCM selectively stimulated synthesis of C4, while day‐3 and day‐4 PMCM selectively stimulated C3 synthesis. These activities were called C4‐hepatocyte stimulating factor (C4‐HSF) and C3‐HSF, respectively.The addition of anti‐interleukin (IL) 1, tumor necrosis factor (TNF)‐α, TNF‐β, IL 6 or interferon (IFN)‐γ antibodies to day‐2 PMCM did not affect C4‐HSF activity, and none had any effect on C3‐HSF activity in day‐4 PMCM. However, the addition of anti‐IL 1 to day‐4 PMCM resulted in the re‐expression of C4‐HSF activity as well as loss of thymocyte proliferative activity. C4‐HSF activity could also be detected in day‐4 PMCM by separating it from IL1 activity using gel filtration chromatography. Furthermore the addition of recombinant IL1β to day‐2 PMCM prevented the expression of C4‐HSF activity. Thus IL 1 appears to play a regulatory role in the acutephase response in the rat, by preventing the expression of C4‐HSF activity.The identities of C4‐HSF activity and C3‐HSF are still unknown but we believe that C3‐HSF activity could be IL 6 as it has a similar molecular weight (30 kDa) and purified human IL 6 was more effective than IL 1, TNF‐α or TNF‐β in stimulating C3 synthesis by rat hepatocytes. C4‐HSF activity appears to be a property of a previously undescribed cytokine. It is not IL 1α or β, TNF‐α or ‐β, IL 6 or IFN‐γ.
Endogenous interleukin 6 plays an obligatory role in interleukin 4‐dependent human IgE synthesis
Authors: Vercelli Donata , Jabara Haifa H. , Arai Ken‐Ichi , Yokota Takashi , Geha Raif S. 
Published: March 2007

AbstractThe lymphokine interleukin (IL) 4 plays a crucial role in the regulation of IgE synthesis. In the present study, the cellular and cytokine requirements for the IL 4‐dependent induction of IgE synthesis in humans were analyzed. Recombinant IL4 could induce IgE synthesis by peripheral blood mononuclear cells and autologous T/B cell mixtures, but not by highly purified B cells. IgE induction by IL4 was strongly decreased in monocyte‐depleted peripheral blood mononuclear cells. These results show that the induction of IgE synthesis by recombinant IL 4 is T cell dependent and optimal in the presence of monocytes. IL5 and IL6, but not IL2, IL1 and tumor necrosis factor‐α, strongly up‐regulated the IL4‐dependent synthesis of IgE, with modest effects on cell proliferation. An anti‐IL6 polyclonal antibody strongly inhibited IL4‐driven IgE production. Endogenous IL6 plays, therefore, an obligatory role in the IL4‐dependent induction of IgE. However, a combination of IL 4, IL 5 and IL 6 (with or without IL 1) at optimal concentrations could not induce IgE synthesis by purified normal B cells, indicating that cytokine‐mediated signals, although essential, are not sufficient for the IL 4‐dependent induction of IgE synthesis.
Activation of human B lymphocytes through CD40 and interleukin 4
Authors: Vallé Alain , Zuber Caroline E. , Defrance Thierry , Djossou Odile , Riem Menno De , Banchereau Jacques 
Published: March 2007

AbstractWe have produced and characterized a new CD40 monoclonal antibody, mAb 89, which in the presence of anti‐IgM antibodies co‐stimulates to induce B cell proliferation. mAb 89 activates resting B cells as shown by an increase in cell volume and an enhanced subsequent proliferation of B cells in response to anti‐IgM antibody. However, mAb 89 does not prepare B cells to respond to the growth‐promoting activity of interleukin (IL) 2 or IL4. Unlike IL 2 and IL 4, mAb 89 only weakly stimulates the proliferation of anti‐IgM pre‐activated B cells. Thus, the activating properties of anti‐CD40 are likely to explain its co‐stimulatory effect on B cells.Interestingly, the anti‐CD40 mAb 89 was found to act in synergy with IL 4, but not with IL 2, in co‐stimulation and restimulation assays. In this respect, anti‐CD40 does not induce a significant increase of B cell surface IL 4 receptors while IL 4, but not IL 2, induces a twofold increase of the CD40 antigen expression. Thus the synergistic interaction between IL 4 and anti‐CD40 may be related to the IL 4‐dependent increase of CD40 antigen expression.
Molecules relevant for T cell‐target cell interaction are present in cytolytic granules of human T lymphocytes
Authors: Peters Peter J. , Geuze Hans J. , Van Donk Hans A. Der , Slot Jan W. , Griffith Janice M. , Stam Nico J. , Clevers Hans C. , Borst Jannie 
Published: March 2007

AbstractAn ultrastructural analysis of human cytotoxic T lymphocyte‐target cell (CTL‐TC) interaction has been undertaken to enable a better understanding of the killing mechanism. Attention was focused on granules in the CTL, which are known to contain lethal compounds. Within the membrane‐delimited cytotoxic granule an electron‐dense core as well as numerous membrane vesicles were identified. In CTL‐TC conjugates, specific membrane interactions take place, allowing the formation of intercellular clefts into which the granule cores and internal vesicles are released. T cell surface membrane molecules known to be involved in CTL‐TC interaction (T cell receptor, CD3 and CD8) are present on the membranes of the granule cores and internal vesicles, facing outward. An explanation for this localization of the membrane may be found in the fact that the granule is connected with an endocytotic pathway. Moreover, the lumen of the granule is rich in the enzyme cathepsin D, which indicates an association with a lysosomal compartment. Exocytosed vesicles and cores are seen to adhere to the plasma membrane of the TC. Although the exact contents of the granule vesicles and core remain to be identified, we suggest that specific interaction of CTL membrane molecules on the cytolytic granule components with molecules on the plasma membrane of the TC may ensure the unidirectional delivery of the lethal hit.
γ/δ T cells express a unique surface molecule appearing late during thymic development
Authors: Mackay Charles R. , Beya Marie‐Françoise , Matzinger Polly 
Published: March 2007

AbstractThe vast majority of T cells in man and mouse use the α/β form of T cell receptor (TcR), and express either CD4 or CD8, whereas the small subset of γ/δ T cells are usually CD4‐CD8‐. In contrast to man and mouse, the γ/δ subset in sheep, defined here using an anti‐γ/δ monoclonal antibody (mAb), comprises 30%–60% of T cells. We show that γ/δ T cells in sheep express a unique surface molecule termed T19 which is 215 kDa in size and unrelated to either CD45 or the TcR. The T19 molecule was expressed at a distinct stage during γ/δ T cell ontogeny within the thymus, since γ/δ thymocytes which appeared early in fetal ontogeny were T19‐ and also major histocompatibility complex (MHC) class I‐ and localized almost exclusively to the outer cortex and cortex of the thymus. “Mature‐type” γ/δ thymocytes which emerged late in thymic development were T19+ and MHC class I+ and localized predominantly to the thymic medulla. The sequence of events indicated that these cells were most likely derived from the early γ/δ thymocytes. These medullary γ/δ thymocytes showed a very distinctive association with Hassall's corpuscles, suggesting a role for these structures in γ/δ thymocyte maturation.In the periphery, T19 was expressed exclusively within the γ/δ T cell subset, however some γ/δ T cells were T19‐. In particular, a large proportion of γ/δ T cells within intestinal epithelium lacked T19, indicating a correlation between T19 expression and either function or homing patterns of γ/δ T cells. Both T19+ and T19‐ γ/δ T cells were CD2‐, and expressed low levels of LFA‐1 and CD5. In addition, γ/δ T cells recirculated differently from other T cells, and appeared not to enter mesenteric lymph nodes at all from the blood. We propose that T19 is a maturation marker for γ/δ T cells. In addition, the exclusive expression of T19 by γ/δ T cells indicates that this molecule most likely serves a fundamental role in the interactions and function of γ/δ T cells.
Alleviation of autoimmunity in BXSB mice by monoclonal alloantibody to Ly‐5 (CD45)
Authors: Yakura Hidetaka , Ashida Tomofumi , Kawabata Isao , Katagiri Makoto 
Published: March 2007

AbstractOne of the hallmarks of immunological abnormalities in mice that are prone to syndromes resembling systemic lupus erythematosus is polyclonal activation of B cells and a switch of serum immunoglobulins or autoantibodies from IgM to IgG that coincides with onset of autoimmune disease. Therefore, we investigated whether the development of autoimmunity can be alleviated in such mice by administration of monoclonal alloantibody directed against Ly‐5, because this was known to reduce levels of polyclonal IgG antibody without affecting other immunoglobulin isotypes. Our results indicate that at least some forms of autoimmune disease may be effectively treated by thus reducing the concentration of IgG autoantibody in this manner.
Identical forms of the CD2 antigen expressed by mouse T and B lymphocytes
Authors: Altevogt Peter , Michaelis Marion , Kyewski Bruno 
Published: March 2007

AbstractA monoclonal antibody (12‐15) reactive with the mouse CD2 was used to study the expression of the antigen in different lymphoid cell subsets. By two‐color immunofluorescence using B or T cell‐specific reagents and cell sorting in combination with biochemical analysis we provide evidence that the CD2 antigen is present on mouse B and T cells. The antigen is expressed by both subsets at similar density and appears to be biochemically indistinguishable.
Murine enterocytes can present soluble antigen to specific class II‐restricted CD4+ T cells
Authors: Kaiserlian Dominique , Vidal Karine , Revillard Jean‐Pierre 
Published: March 2007

AbstractHighly purified mature epithelial cells (EC) from murine small intestinal villi (excluding Peyer's patch epithelium) were examined for their capacity to present foreign antigen to T cells. Cell suspensions composed of 99% Ia+T200‐ EC were able to present keyhole limpet hemocyanin to an antigen‐specific class II‐restricted L3T4+ T cell hybridoma, and stimulate interleukin 2 production. Antigen presentation by EC was inhibited by major histocompatibility complex class II‐specific monoclonal antibodies. It is concluded that EC express functional class II molecules and may activate adjacent CD4+ T cells to induce lymphokine synthesis.
Lymphokine gene expression related to CD4 T cell subset (CD45R/CDw29) phenotype conversion
Authors: Bettens Florence , Walker Christoph , Gauchat Jean‐François , Gauchat Dominique , Wyss Toni , Pichler Werner J. 
Published: March 2007

AbstractIn this study, we investigated whether the phenotype‐related differentiation of human 2H4+ (CD45R) naive cells to 2H4‐ (CDw29) memory CD4 cells corresponded to modulation of interleukin (IL) 2, IL 4, interferon (IFN)‐γ and granulocyte‐monocyte colony‐stimulating factor (GM‐CSF) gene expression, a phenomenon which might correlate to the distinct functional activities of naive cells or memory cells. To mimic in vitro CD4 T cell subset differentiation, freshly isolated 2H4+ and 2H4‐ CD4 cells were stimulated with the anti‐CD3 antibody (Leu‐4), expanded in IL 2‐containing medium and restimulated with Leu‐4 after 7 and 13 days. Absence of monocyte‐T cell interaction was compensated by adding monocyte supernatant to the culture medium and by cross‐linking the anti‐CD3 antibodies with goat anti‐mouse antibody coated on culture dishes.It has been previously shown that in vitro stimulated 2H4+ cells acquire CDw29 surface antigens. Measurement of lymphokine gene expression by dot‐blot hybridization revealed that although stimulated 2H4+ cells proliferated less than stimulated 2H4‐ cells, and expressed less actin mRNA, they expressed more IL 2 but less IL 4 and GM‐CSF than 2H4‐ cells. No significant difference was observed between the two subsets for the expression of IFN‐γ. If subsets were restimulated with Leu‐4 antibodies, expression of IL 2 was decreased and expression of IL 4 was increased in both subsets; however, the differences among the subsets persisted. They were even more enhanced for IL 2 but less pronounced for GM‐CSF.Thus, in spite of phenotype conversion, CD4 T cell subsets maintained a distinct capacity to express IL 2 and IL 4 genes.
Enumeration of cytokine‐secreting cells at the single‐cell level
Authors: Skidmore Barry J. , Stamnes Susan A. , Townsend Kay , Glasebrook Andrew L. , Sheehan Kathleen C. F. , Schreiber Robert D. , Chiller Jacques M. 
Published: March 2007

AbstractA sensitive assay utilizing enzyme‐linked immunosorbent assay methodology has been developed for the quantitation of single cells secreting interferon (IFN)‐γ or tumor necrosis factor (TNF). Cloned T cells or cells from lymphoid organs were stimulated with antigen, concanavalin A, or phorbol myristate acetate and ionomycin in microwells coated with antibodies specific for IFN‐γ. Discrete “spots” overlying areas where cells secrete IFN‐γ were then developed by incubation with a second antibody to IFN‐γ, followed by an enzyme‐labeled antibody conjugate and substrate. Similarly, using TNF‐specific antibody reagents, TNF‐secreting cells were detected and quantitated in cell populations obtained from normal lymphoid tissues, bone marrow and peripheral blood, following activation with phorbol myristate acetate and ionomycin. Provided specific antibodies are available, this method has the potential to measure the frequency of cells secreting any cytokine.
C1q binding to chimeric monoclonal IgG3 antibodies consisting of mouse variable regions and human constant regions with shortened hinge containing 15 to 47 amino acids
Authors: Sandlie Inger , Aase Audun , Westby Christina , Michaelsen Terje E. 
Published: March 2007

AbstractWe have constructed four different deletion mutants of a chimeric mouse‐human IgG3 anti‐(4‐hydroxy‐3‐nitrophenyl)acetyl/(5‐iodo‐4 hydroxy‐3 nitrophenyl) acetyl (NP/NIP) antibody lacking one or more of the four exons coding for the hinge region. The mutant variants all retained intact hinge region epitopes since they all reacted with IgG3 hinge‐specific antibodies. Surprisingly, all the deletion mutants bound C1q equally well or even better than the wild type. Thus the high C1q binding activity of IgG3 compared to IgG1 is apparently not due to the total length of the IgG3 hinge, which is 62 amino acids, nor is it due to the length of the upper hinge which is the stretch from the end of CH1 to the first inter‐heavy chain disulfide bond.