bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response of human B cells to different anti‐immunoglobulin isotypes: Absence of a correlation between early activation events and cell proliferation
Authors: Roifman Chaim M. , Mills Gordon B. , Stewart David , Cheung Roy K. , Grinstein Sergio , Gelfand Erwin W. 
Published: March 2007

AbstractCross‐linking of surface immunoglobulin (sIg) by antibodies against IgM, IgG and IgD activates B cells and in some circumstances can induce cell proliferation. We studied the potential link between anti‐Ig‐induced changes in the cytosolic free Ca2+ concentration ([Ca2+]i), inositol phosphate production and the ability to induce cell proliferation in the presence or absence of the phorbol ester 12‐O‐tetradecanoylphorbol 13‐acetete (TPA). Anti‐IgM, but not anti‐IgD or anti‐IgG, induced cell proliferation in the presence but not the absence of TPA. Each of the antibodies induced a rapid increase in [Ca2+]i which appeared to be due to release of Ca2+ from internal stores. This was followed by a sustained increase in [Ca2+]i, apparently due to Ca2+ uptake from the extracellular medium. Anti‐IgD induced the greatest increase in [Ca2+]i, anti‐IgM induced intermediate changes and anti‐IgG the lowest change. Since inositol 1,3,5‐trisphosphate (IP3) can release Ca2+ from internal stores, we tested the ability of each anti‐Ig isotype to increase concentrations of IP3. In contrast to the change in [Ca2+]i and proliferation, anti‐IgG induced the most significant increase in IP3 concentrations. Taken together these data indicate that changes in [Ca2+]i, inositol phosphate production and anti‐Ig‐induced human B cell proliferation are not directly linked. They also demonstrate that changes in [Ca2+]i, inositol phosphate production and activation of protein kinase C are not sufficient to induce proliferation of human B cells. It appears that anti‐IgM induces an additional Ca2+‐independent, inositol phosphate‐independent and protein kinase C‐independent activation signal which can collaborate with TPA to induce B cell proliferation. The molecular events involved in this signal remain to be identified.
Recombinant human interleukin 5 is an eosinophil differentiation factor but has no activity in standard human B cell growth factor assays
Authors: Clutterbuck Elaine , Shields John G. , Gordon John , Smith Susan H. , Boyd Andrew , Callard Robin E. , Campbell Hugh D. , Young Ian G. , Sanderson Colin J. 
Published: March 2007

AbstractFollowing the observation that mouse interleukin 5 (IL 5) is active as a B cell growth factor (BCGF) as well as an eosinophil differentiation factor, this work was carried out to test recombinant human IL 5 for BCGF activity. A highly active, partially purified batch of recombinant human IL 5 was prepared and tested for BCGF activity in four laboratories. This batch gave a 50% endpoint of 1:77450 in the human eosinophil differentiation assay, 1:983 in the mouse eosinophil differentiation assay and 1:42 in the mouse BCL1 assay, thus demonstrating that, like mouse IL 5, human IL 5 has cross‐species activity. By comparison with the assays in the mouse this batch would be expected to have 50% maximal human BCGF activity of about 1:4000. In each assay a known positive factor was used as a positive control, and there was no inhibitory activity in the preparation. However, despite the activity towards the mouse B cell lymphoma, the results showed no detectable activity in a panel of assays used to identify human BCGF and B cell differentiation factors. These assays included (a) proliferation assays with tonsillar or splenic B cells in the presence of the co‐stimulators anti‐μ or phorbol myristate acetate; (b) a restimulation assay in which tonsillar B cells are first activated with either Staphylococcus aureus Cowan 1 or a mixture of phorbol dibutyrate and ionomycin, or splenic B cells are first activated with anti‐μ; (c) production of immunoglobulin by B cells in a restimulation assay with Staphylococcus aureus Cowan 1; (d) production of immunoglobulin by the Epstein‐Barr virus‐transformed B lymphoblastoid CESS cell line; (e) the ability to stimulate proliferation of chronic lymphocytic leukemia (B‐CLL) cells freshly explanted from three different patients; (f) the ability to stimulate the B lymphoma (L4) cell line and the mature B cell (HBF1) line, and (g) the ability to replace T cells in specific antibody responses.It therefore seems unlikely that recombinant human IL 5 is either a growth or a differentiation factor for human B cells, and raises the interesting question of the biological significance of the BCGF activity of this factor in the mouse.
Idiotypic characteristics of λ1‐bearing anti‐α(1→3)dextran response in wild mice: high frequency of responder strains and co‐expression of IdI 558 and IdI 104 on the same molecule
Authors: Juy Dominique , Drapier Anne‐Marie , Guenet Jean‐Louis , Cazenave Pierre‐André 
Published: March 2007

AbstractIn laboratory mouse strains, only mice with the IghCa phenotype are able to mount an immune response against the α(1→3) glycosidic linkage of the B1355 dextran. The response is highly restricted with respect to utilization of only Vγ1 and a few related members of the VH558 family, and characterized by the production of cross‐reacting (IdX), and individual (IdI) 104 and 558 idiotopes. We report in this study data showing a large degree of polymorphism in the anti‐α(1→3)Dex response among 35 wild‐derived mouse strains belonging to 4 different species. In contrast to the anti‐α(1→3)Dex response of common laboratory strains, neither this response nor expression of the IdX, and IdI 104 and 558 idiotopes are linked to the IghCa haplotype. We also demonstrate co‐expression on the same molecule of IdI 104 and IdI 558 idiotopes in wild mouse‐derived hybridomas. These data challenge the idea of the exclusive expression at the molecular level of IdI 104 or IdI 558.
Induction of sporozoite‐specific memory cells in mice immunized with a recombinant Plasmodium vivax circumsporozoite protein
Authors: Nardin Elizabeth H. , Barr Philip J. , Gibson Helen L. , Collins William E. , Nussenzweig Ruth S. , Nussenzweig Victor 
Published: March 2007

AbstractA recombinant Plasmodium vivax circumsporozoite (CS) protein (rPvCS‐1) has been investigated as a possible malaria sporozoite vaccine candidate. Experiments were carried out to determine whether sporozoite‐specific memory cells develop in Swiss Webster mice immunized with rPvCS‐1. Challenge of rPvCS‐1‐immunized mice with P. vivax sporozoites resulted in a 100‐fold increase in the mean serum anti‐sporozoite antibody titer. The presence of parasite‐specific T helper cells was demonstrated using an in vitro assay. Anti‐CS antibodies were detected in the culture supernatants of spleen cells of rPvCS‐1‐immunized mice following in vitro challenge with P. vivax sporozoite extract. Immune spleen cells depleted of T cells did not produce antibodies when challenged with sporozoite extract in vitro. In conclusion, immunization of mice with the rPvCS‐1 protein induced memory T cells which recognized native CS antigen and functioned as T helper cells in the production of anti‐sporozoite antibodies both in vivo and in vitro.
Evidence that murine hematopoietic cell subset marker J11d is attached to a glycosyl‐phosphatidylinositol membrane anchor
Authors: Pierres Michel , Naquet Philippe , Barbet Jacques , Marchetto Sylvie , Marics Irène , Devaux Christian , Barad Marc , Hyman Robert , Rougon Geneviève 
Published: March 2007

AbstractGlycosyl‐phosphatidylinositol (G‐PI) has been shown to serve as membrane anchor for cell surface molecules such as Thy‐1, Ly‐6‐controlled ThB and Qa antigens. Here, we present several lines of evidence indicating that the hematopoietic cell lineage (i.e. thymocytes, B cell subset and red blood cells) marker defined by the rat monoclonal antibody J11d is also a G‐PI‐linked structure. First, surface expression of the J11d‐defined molecules, and that of the related antigen B2A2, was found to be specifically reduced by treatment of thymocytes and B lymphoma or hybridoma cells with excess of Staphylococcus aureus PI‐specific phospholipase C; this enzyme also solubilizes a 35–40‐kDa material from erythrocyte microsomal membranes corresponding to the predominant J11d‐reactive red cell surface molecules. Second, Thy‐1− mutants of the BW5147, T1M1, S1A or S49 murine T lymphoma cells of the complementary classes A, B, C and E (i.e. shown to be defective in the enzymatic machinery that posttranslationally modify Thy‐1 molecules) also lack J11d, or express it at a very low level. Although directed at a G‐PI‐linked structure, the J11d monoclonal antibody, unlike other reagents to Thy‐1 or Ly‐6‐controlled antigens, failed to induce thymocyte proliferation even in the presence of phorbol myristate acetate and cross‐linker monoclonal antibody.
Human T cells from autoimmune and normal individuals can produce tumor necrosis factor
Authors: Turner Martin , Londei Marco , Feldmann Marc 
Published: March 2007

AbstractT cell clones derived from patients with autoimmune diseases were found to be capable of producing tumor necrosis factor (TNF). This was demonstrated by stimulating the clones, in the absence of accessory cells, with antibodies against the Ti/T3 complex and with recombinant interleukin 2 (IL 2). Analysis of RNA extracted from these clones showed that TNF mRNA was more abundant than lymphotoxin (LT) mRNA. We also found that TNF protein in the supernatants of these clones was generally more abundant than LT as assessed by using the murine L929 cell assay. TNF production was not limited to T cells from autoimmune individuals, since the T cell tumor HUT 78 and T cells purified from the peripheral blood of healthy individuals also made TNF. Unlike the T cell clones, HUT 78 produced greater amounts of LT mRNA than TNF mRNA. Induction of TNF mRNA in T cells from healthy individuals displayed a two‐signal requirement (phorbol myristate 13‐acetate and phytohemagglutinin or OKT3 and phorbol myristate 13‐acetate), similar to that described for the induction of the T cell lymphokines IL2 and interferon‐gamma (IFN‐γ). Additionally we found that IL 2 alone was sufficient to induce TNF in these cells when they had been precultured with phytohemagglutinin for 7 days to express IL 2 receptors. The cloned T cells we have characterized also produce IFN‐γ which was detected in the supernatants of the clones using a radioimmunoassay. The evidence suggests that T cells can produce TNF and have the potential to deliver by themselves the dual and synergistic signals of TNF/LT and IFN‐γ to target cells, a process which may be of importance in the pathogenesis of human autoimmunity.
CD3+4−8−WT31− (T cell receptor γ+) cells and other unusual phenotypes are frequently detected among spontaneously interleukin 2‐responsive T lymphocytes present in the joint fluid in juvenile rheumatoid arthritis. A clonal analysis
Authors: De Maria Andrea , Malnati Mauro , Moretta Alessandro , Pende Daniela , Bottino Cristina , Casorati Giulia , Cottafava Franco , Melioli Giovanni , Mingari Maria Cristina , Migone Nicola , Romagnani Sergio , Moretta Lorenzo 
Published: March 2007

AbstractT lymphocytes (E rosetting cells) isolated from the joint fluid of four patients with juvenile rheumatoid arthritis (JRA) were first analyzed for surface antigen expression. Approximately 15% of cells were CD25+ (interleukin, IL, 2 receptor positive), in addition, a remarkable proportion of cells expressed the CD2+3− phenotype. CD3+ cells outnumbered the sum of CD4+ and CD8+ cells as well as the cells reactive with the WT31 monoclonal antibody (which recognizes a framework determinant of the α/β T cell receptor). Purified T cells were cloned under culture conditions (1% phytohemagglutinin, PHA plus IL 2) which allow clonal expansion of most peripheral blood T lymphocytes. Under these conditions proliferating cells ranged from 25 to 65%; clones (derived from microcultures containing 0.5 or 0.25 cells/well) were tested for cytolytic activity against P815 cells (in the presence of PHA) or against the natural killer (NK)‐sensitive K562 target cells. Fifty‐four percent and 73% of clones obtained from the two patients with the polyarticular form of the disease displayed cytolytic activity in the lectin‐dependent assay. Cytolytic clones were 22 and 29% in the two patients with single joint involvement. About half of all cytolytic clones displayed NK‐like activity. Surface antigen analysis revealed that, in addition to conventional CD3+4+8− and CD3+4−8+, a noticeable fraction of clones (50/202) displayed unusual surface phenotypes. In particular, 33/50 coexpressed CD4 and CD8 antigens; 7/50 were CD2+3−4−8− and displayed NK‐like activity; 10/50 expressed CD3 but lacked both CD4 and CD8 antigen and did not react with the WT31 monoclonal antibody. In order to allow selective growth of IL 2‐responsive cells, T lymphocytes were also cloned directly in IL 2. As much as 57% of all clones thus obtained (48/84) displayed cytolytic activity. Moreover, about half expressed unusual surface phenotypes including CD2+3−4−8−, CD3+4+8+ and CD3+4−8−WT31−. Given the accumulation at the site of the joint involvement of unusual T cells, most of which displayed cytolytic activity and were likely to represent cells activated in vivo (IL 2 responsive), one may speculate that these cells may be involved in the injury process.
gp140, the EBV/C3d receptor (CR2) of human B lymphocytes, is involved in cell‐free phosphorylation of p120, a nuclear ribonucleoprotein
Authors: Delcayre Alain X. , Fiandino Anny , Barel Monique , Frade Raymond 
Published: March 2007

Abstractgp140, the EBV/C3d receptor (EBV/C3dR; CR2), is a membrane site involved in human B cell regulation. Cross‐linking of this receptor on the cell surface by its specific ligands led to the enhancement of B cell proliferation in synergy with T cell factors. In vitro activation of human peripheral B lymphocytes by cross‐linking membrane immunoglobulins with anti‐μ antibody induced EBV/C3dR phosphorylation. These studies were pursued by analyzing cell‐free phosphorylation of EBV/C3dR isolated from Raji cell fractions, and immobilized on OKB7, a monoclonal anti‐EBV/C3dR antibody. Three EBV/C3dR‐related antigens which could be cell‐free phosphorylated were detected: gp140, the EBV/C3dR, p130 and p120. gp140, the mature form of EBV/C3dR, was isolated from plasma membrane and from purified nuclei. p130 was identified as an intracellular intermediate of EBV/C3dR glycosylation, localized in low‐density microsomes. Phosphoamino acid analysis of EBV/C3dR allowed the detection of phosphotyrosine and phosphoserine residues. These data suggest that EBV/C3dR could carry an autophosphorylation activity and could be associated to serine kinases. Using polyclonal anti‐p120 antibody and anti‐120 kDa nuclear ribocucleoprotein monoclonal antibody (mAb), p120 was identified as a nuclear ribonucleoprotein antigenically not related to EBV/C3dR. Detection of p120 on EBV/C3dR, immobilized on OKB7, was due to interactions between both antigens, instead of anti‐EBV/C3dR mAb cross‐reactivity with p120. Cell‐free phosphorylation of p120 was under the control of EBV/C3dR. However, it is not yet established whether other nuclear or membrane components were involved in the control of p120 cell‐free phosphorylation by EBV/C3dR. From the data presented herein, we propose that phosphorylation of a 120‐kDa nuclear ribonucleoprotein by EBV/C3dR‐associated kinases could represent a crucial step in in vivo regulation of human B cell activation.
Recombinant tumor necrosis factor can induce interleukin 2 receptor expression and cytolytic activity in a rat × mouse T cell hybrid
Authors: Plaetinck Geert , Declercq Wim , Tavernier Jan , Nabholz Markus , Fiers Walter 
Published: March 2007

AbstractTumor necrosis factor (TNF), an endotoxin‐induced macrophage monokine, is known for its cytotoxic and cytostatic effect on some tumor cell lines. Here we show that highly purified recombinant TNF, in combination with interleukin 2 (IL 2), can induce IL 2 receptor expression and cytolytic activity in a rat × mouse T cell hybrid (PC60). Previously, it was shown that IL 1 had a similar effect on PC60 cells. The ability of TNF to co‐induce IL 2 receptor expression suggests that it may play a role in the activation of certain lymphoid effector cells. This observation augments the growing list of biological activities attributed to TNF.
CD4+ helper T cells are required for resistance to a highly metastatic murine tumor
Authors: Schild Hans‐Jörg , Kyewski Bruno , von Hoegen Paul , Schirrmacher Volker 
Published: March 2007

AbstractA role of CD4+ T helper cells in induction of tumor transplant rejection leading to complete regression of a highly metastatic DBA/2 mouse lymphoma was analyzed. Using an anti‐CD4 monoclonal antibody (GK1.5) which eliminates T helper cells in vivo and in vitro, we found that CD4+ cells are required for tumor resistance in syngeneic DBA/2 mice or allogeneic but major histocompatibility complex‐identical B10.D2 mice. In contrast, in allogeneic C57BL/6 mice tumor rejection was independent of CD4+ cells. An analogous requirement for immune CD4+ cells for in vitro induction of CD8+ tumor‐specific cytotoxic T cells was found in these respective strains. The requirement for immune CD4+ cells in vitro could be replaced by recombinant interleukin 2. These results demonstrate a role of CD4+ regulatory T cells and T‐T cell cooperation in the induction of anti‐tumor immunity and tumor rejection, and point to possible therapeutic interventions in the afferent phase of anti‐tumor immune responses.
Human monoclonal immunoglobulins that bind the human acetylcholine receptor
Authors: Eng Hubert , Lefvert Ann Kari , Mellstedt Håkan , Österborg Anders 
Published: March 2007

AbstractMyeloma immunoglobulins, once thought to be without any immunological function, are now known to be reactive with many antigens, including self components. We have screened 149 monoclonal immunoglobulin samples and found 14 (9%) to react with the human acetylcholine receptor (AChR). Such anti‐AChR antibodies are often associated with the autoimmune disease myasthenia gravis (MG). The anti‐AChR binding of the myeloma components was restricted to the F(ab′)2 fragment and the affinities were similar to anti‐AChR antibodies isolated from MG patients. Despite the presence of anti‐AChR antibodies none of the patients exhibited any symptoms of MG.
Expression of Fcγ receptors on splenic T cells of mice infected with Plasmodium chabaudi adami
Authors: Langhorne Jean , Titus Julie A. 
Published: March 2007

AbstractIn previous studies, it was shown that mice infected with Plasmodium chabaudi adami have a deficiency in their production of IgG1 immunoglobulin, suggesting isotype‐specific immunoregulation. In order to examine this phenomenon in further detail the expression of Fcγ receptors (FcγR) on T cells obtained from mice infected with P. chabaudi was studied by flow cytometry. There was an increase in the number of splenic T cells which expressed FcγR during infection. At the peak of the acute stage of infection (10–15 days) up to 40% of T cells were positive for FcγR expression. These FcγR were present on about 40% of both Lyt‐2+and L3T4+ T cells. The isotype preference of these receptors on control Thy‐l+ T cells is IgG1 IgG2b > IgG2a as determined by an inhibition assay and fluorescence‐activated cell sorter (FACS) analysis. However, 2 to 3 weeks after infection this pattern was altered such that IgG2b and IgG2a represented the major isotypes binding to the FcγR of the L3T4+ T cell. At this stage of infection FcγR on L3T4+ cells fail to bind IgG1. In the Lyt‐2+ T cells IgG1 and IgG2b remained the best inhibitors. These data suggest that there may be changes in FcγR expression on T cells during infection reflected particularly in a decreased ability of IgG1 to bind to the FcγR of L3T4+ cells.
A new antigen identified by the monoclonal antibody UCHB1 delivers a costimulatory signal to a subset of human B cells
Authors: Armitage Richard J. , Rowe Deborah J. , Beverley Peter C. L. 
Published: March 2007

AbstractA novel anti‐B cell monoclonal antibody UCHB1 is described which detects an antigen present on a selected subpopulation of both normal and leukemic B cells. Approximately 20% of normal tonsil and peripheral blood (PB) B cells are UCHB 1+ and the majority of B cells from all cases of prolymphocytic leukemia (PLL) tested, together with a low, variable percentage of PB B cells from non‐Hodgkin's lymphoma patients with centroblastic centrocytic leukemia also express this antigen.Chronic lymphocytic leukemia and hairy cell leukemia B cells, pre‐B acute lymphoblastic leukemia and Epstein‐Barr virus transformed cell lines all lack UCHB1 positivity as do all non‐B lineage leukocytes and cell lines so far tested.In tonsil sections UCHB 1 staining is almost completely confined to surface IgM+ mantle zone lymphocytes and follicular dendritic cells, but not B cells, within the germinal centers. UCHB 1 can induce a rise in the level of intracellular free calcium ([Ca2+]i) in PLL B cells and low concentrations of monoclonal antibody can result in the entry of these cells into cell cycle in the absence of additional factors. The proliferative effect of UCHB 1 is greatly enhanced in the presence of Staphylococcus aureus Cowan and, to a lesser extent, phorbol ester. A similar costimulatory effect is exerted on a proportion of normal tonsil B cells although here, despite inducing a rise in [Ca2+]i, UCHB1 alone does not cause cells to proliferate. UCHB 1 may well prove to be a useful antibody both to distinguish between different B cell leukemias and to study the phenotype and function of leukemic and normal B cell subpopulations.
Establishment of mouse cell lines which constitutively secrete large quantities of interleukin 2, 3, 4 or 5, using modified cDNA expression vectors
Authors: Karasuyama Hajime , Melchers Fritz 
Published: March 2007

AbstractMouse cell lines of different lineages have been established which constitutively secrete large quantities of recombinant mouse interleukins (mIL2, mIL3, mIL4 or mIL5). An existing bovine papilloma virus‐based expression vector, pBV‐lMTHA, was modified to allow transformed X63Ag8‐653 myeloma cells, NIH 3T3 fibroblasts and C127 mammary tumor cells to stably carry multiple copies of the vector, to express the inserted cDNA encoding a single interleukin constitutively, and to secrete the interleukin in high quantities.Cell lines transformed with mIL2 cDNA stably carried 30–100 copies of the plasmid per cell and constitutively secreted biologically active mIL2 in quantities similar to those produced by murine EL4 thymoma cells or rat spleen cells stimulated with mitogens. Deletion of the 3′ untranslated region containing AT‐rich sequences from the mIL2 cDNA resulted in a 100‐fold increase in the constitutive production and secretion of mIL2 by the transformants. Addition of a heavy metal further increased the production 2 to 6‐fold. Cells transformed with 3′‐deleted mIL3 cDNA constitutively secreted 300–1000 times higher activities of mIL3 than the myelomonocytic leukemia line WEHI 3. mIL 4 produced by the similar transformants induced [3H]thymidine uptake of a T cell line, a mast cell line and B leukemia cells, and enhanced the production of IgG1 by B cells. IL 4 liters were 150 times higher than those produced by the concanavalin A‐stimulated T cell line 2.19. mIL 5 was secreted by similar transformants at 10‐fold higher titers than those produced by concanavalin A‐stimulated 2.19 T cells, as judged by the proliferation and maturation of B cell leukemia BCL1. The expression vectors should be useful in establishing eukaryotic cell lines producing proteins from full length cDNA clones at higher rates. The established cell lines secreting IL2, 3, 4 or 5 at high rate should be useful sources for these interleukins in the investigation of their function in the immune system.