bluuebunny/crossref_metadata_2025_split huggingface dataset:
Production of granulocyte colony‐stimulating factor (G‐CSF) by human cells: T lymphocyte‐dependent and T lymphocyte‐independent release of G‐CSF by blood monocytes
Authors: Nioche Sophie , Tazi Abdellatif , Lecossier Denise , Hance Allan J. 
Published: March 2007

AbstractTo evaluate the production of granulocyte colony‐stimulating factor (G‐CSF) by human immune and inflammatory cells, an assay specifically measuring G‐CSF activity in the presence of other cytokines was developed which was based on the proliferation of 32Dcl cells induced by G‐CSF. Successful use of the 32Dcl cells to specifically measure G‐CSF activity required the selection of cells highly responsive to G‐CSF and with reduced responsiveness to interleukin 2 (IL2) by intennittant culture in medium containing G‐CSF. Furthermore, the addition of exogenous IL2 to standards and experimental samples was necessary to ensure that the concentration of IL2 was similar in all samples, since IL 2 directly stimulated the proliferation of 32Dcl cells and increased their responsiveness to G‐CSF. A variety of stimuli were found to induce G‐CSF release by blood monocytes. Lipopolysaccharide and monocyte adherence appeared to directly stimulate G‐CSF release, whereas stimulation of G‐CSF release from monocytes by mitogenic lectins required the presence of T lymphocytes. In all cases, release of G‐CSF was detectable as soon as 4 h after stimulation and was essentially complete after 48 h. These findings indicate that G‐CSF release can be initiated by a variety of pathways, and therefore suggest that the production of this mediator may occur in the course of many immune and inflammatory reactions.
Interleukin 1α acts as an autocrine growth factor for RPMI1788, an Epstein‐Barr virus‐transformed human B cell line
Authors: Vandenabeele Peter , Jayaram Bettadapura , Devos René , Shaw Alan , Fiers Walter 
Published: March 2007

AbstractThe Epstein‐Barr virus‐transformed B cell line RPMI 1788 constitutively produces autocrine growth factors with molecular masses of 17 kDa, 24 kDa and 35 kDa. All three molecular forms were completely neutralized with anti‐interleukin (IL) lα anti‐serum. Although IL1α and IL1β mRNA were both equally detectable by Northern blotting, no IL 1β activity was found in partially purified RPMI 1788 supernatant. The growth of low density‐seeded RPMI 1788 cells is specifically dependent on the presence of either IL1α or IL1β. Since no other cytokine was found to be capable of sustaining proliferation, this cell line is suitable for the identification and quantification of IL1, even in the presence of other cytokines.
Restriction fragment haplotypes in the human immunoglobulin IGHG locus and their correlation with the Gm polymorphism
Authors: Ghanem Nada , Dugoujon Jean‐Michel , Bensmana Mylène , Huck Sylvie , Lefranc Marie‐Paule , Lefranc GéRard 
Published: March 2007

AbstractOf the four human IgG subclass heavy chain (IGHG) genes, three ‐ IGHG1, IGHG2 and IGHG3 ‐ have allelic forms which encode antigenic determinants called Glm, G2m and G3m allotypes for markers of the IgG1, IgG2 and IgG3 molecules. The alleles at these three closely linked loci are transmitted as Gm haplotypes, together with the IGHG4 and the TGHGP (or pseudo gamma) genes. Restriction Fragment Length Polymorphisms (RFLPs) have been described for all these IGHG genes, allowing us to define at least 15 RFLP alleles (N. Ghanem et al., Eur. J. Immunol. 1988.18:1059). In this article, we determine unambiguously the Gm alleles and haplotypes and the associated RFLPs in French, Lebanese and Tunisian families, chosen for the various Gm phenotypes of their members, in order to correlate both these polymorphisms and to know the evolution of the IGHG multigene family. We were able to assign all the IGHG alleles to the Gm alleles and to their linked IGHG4 and IGHGP genes allowing us to define restriction fragment haplotypes of the IGHG gene family.
Rearrangement and expression of T cell receptor and immunoglobulin loci in immortalized CD4−CDS−T cell lines
Authors: Primi Daniele , Clynes Raphael A. , Jouvin‐Marche Evelyne , Marolleau Jean‐Pierre , Barbier Eliane , Cazenave Pierre‐André , Marcu Kenneth B. 
Published: March 2007

AbstractInjection of newborn mice with mixtures of wild‐type moloney murine leukemia (Mo‐MuLV) virus and other recombinant retroviruses harboring the myc oncogene alone or in combination with the H‐ras oncogene resulted in a 100% incidence of lymphatic leukemias from which permanent cell lines could be established in vitro. These cells are immunoglobulin (Ig)−, Thy‐1+BP− and CD8−CD4− indicating that they are early thymocytes. Such transformed pre‐T lines lack retroviral myc and ras genes but occasionally possess proviral insertion near to their endogenous myc and pim genes. We show that both Ig heavy chain (Igh) and T cell receptor (TcR) genes are rearranged in most of these lines. In some cases, a primary recombination was followed by a secondary rearrangement at the same locus. We show that VTγ genes can rearrange outside of their known cluster suggesting that TcRγ diversification in such pre‐T cells may be different to that in more mature T cells. Ig D‐JH recombinations may precede TcR gene recombination in these early T cell lines, and some but not all express sterile Cu transcripts. Some of these lines express surface heterodimers that appear composed of α and β chains that can be immunoprecipitated with a monoclonal anti‐T3 antibody but not with the anti‐Vβ8 monoclonal antibody F23.1. This established pre‐T cell line represents novel biological material for the dissection of T cell development and function analogous to A‐MuLV transformed pre‐B cells.
Activation signals via CD2 molecule and interleukin 2 receptor act in synergy for helper function induction
Authors: Hu Jian , Vaquero Catherine , Bismuth Georges , Eljaafari Assia , Bernard Alain , Levy Jean Paul , Sterkers Ghyslaine 
Published: March 2007

AbstractThe membrane CD2 molecule appears to play an important role in T cell activation. Indeed, T cell stimulation by some combinations of anti‐CD2 monoclonal antibodies (mAb) can result in antigen‐independent expression of helper function as assessed by proliferation and lymphokine secretion. We report here that T cell stimulation by a combination of two anti‐CD2 mAb recognizing GT2 and T111 epitopes, respectively, cannot alone induce T helper clones to proliferate when preincubated in culture medium devoid of exogenous interleukin 2 (IL2). The concerted action of both anti‐GT2 + T111 mAb and exogenous recombinant IL2 is required to induce cloned helper T cells to produce IL 2 and interferon‐γ to significantly increase IL 2 receptors (IL2R) and finally to divide by an autocrine mechanism, whereas each signal alone has no effect. This therefore suggests that, under some conditions of CD2 stimulation, two minimal signals may be delivered through CD2 and IL 2R and act synergistically to achieve a complete expression of T helper cell functions. Moreover, analysis of phosphatidylinositol and phosphatidic acid metabolic changes mediated by each signal separately or together suggests that, in this model, IL2 increases the phosphoinositid turnover induced by anti‐CD2 antibodies up to a level required for helper function acquisition.
Tolerance in rats by transplacental transfer of Dipetalonema viteae microfilariae: recognition of putative tolerogen(s) by antibodies that inhibit antigen‐Specific lymphocyte proliferation
Authors: Haque Azizul , Cuna Washington , Pestel Joel , Capron André , Bonnel Bernadette 
Published: March 2007

AbstractWe have previously reported (Nature 1982. 299: 361) that the transplacental transfer of Dipetalonema viteae microfilariae (mf) can induce an antigen‐specific tolerance in rats. Rats thus tolerized have serum factor(s) which block(s) antigen‐specific lymphocyte proliferation. The results of experiments involving fractionation of antisera from tolerant animals indicate that the inhibitory activity for antigen‐specific blastogenesis resides in IgG antibodies. Absorption of IgG (eluted from protein A) with specific filarial antigens reduced the inhibition from 58% to 9% whereas a similar immunosorption of IgG size fraction (obtained by applying to AcA 34 Ultrogel) resulted in a decrease from 72% to 35%. This suggests that IgG size fraction might include factor(s) derived from mf and was partially blocking the blastogenic response. Since the tolerant animals harbor only mf, we have used radiolabeled mf surface antigens for immunoprecipitation by antisera from tolerant animals. Antibodies from tolerant animals have a different specificity for filarial antigens compared to those from immunocompetent and mf‐resistant rats.
Two subsets of human CD4+T helper cells differing in kinetics and capacities to produce interleukin 2 and interferon‐γ can be defined by the Leu‐18 and UCHLl monoclonal antibodies
Authors: Dohlsten Mikael , Hedlund Gunnar , Sjögren Hans‐Olov , Carlsson Roland 
Published: March 2007

AbstractHuman CD4T helper cells were separated into CD4+45R+and CD4+45R− cells. When stimulated with the polyclonal activator staphylococcal enterotoxin A in the presence of autologous monocytes, these two subsets exhibited a striking difference in production of interleukin 2 (IL2) and interferon‐gamma (IFN‐γ). While the CD4+45R_ subset produced maximal amounts of IL2 within 24 h and IFN‐γ within 72 h, the CD4+45R+ subset produced no IL2 within 24 h and merely marginal amounts of IFN‐γ as assayed after 24 to 96 h. This discrepancy between the subsets was found when the cells were stimulated by other accessory cell‐dependent activators and by the accessory‐independent combination of the calcium ionophore A23187 and the phorbol ester 12‐O‐tetradecanoylphorbol 13‐acetate as well. The inability of the CD4′+45R− cells to produce IL2 during the first day of culture was not due to any modulation of either the CD4+or the CD45R antigens, as purified CD4+45R− cells obtained by negative panning selection with the reciprocal UCHLl monoclonal antibody responded in a similar manner as the positively selected sorted CD4+45R− cells. Analysis of the kinetics of IL2 production by the two T helper cell subsets clearly demonstrated that the IL2 recorded after 1 day of culture was entirely produced by the CD4+45R− cells, whereas the CD4+45R− cells produced IL2 during and after the second day of culture. This discrepancy in kinetics was not due to an increased absorption of IL2 by the CD4+45R− cells during the first day of culture. In contrast, the rate of absorption of IL2 during the first and second day of culture and the expression of IL2 receptors were higher in the CD4+45R− than in the CD4+45R− cell cultures. Despite these findings the CD4+45R− cells consistently showed a stronger proliferative response than the other cell subset. Addition of recombinant IL 2 (rIL 2) did not render the CD4′45R′ cells capable of producing IFN‐γ, but small amounts of RIL2 enhanced their proliferative response more efficiently than that of the CD4+45R− cells. Addition of anti‐Tac resulted in a reduction of IFN‐y production and of DNA synthesis by the CD4+45R− cells. Similarly the DNA synthesis and the small amounts of IFNγ produced by activated CD4+45R− cells were inhibited by anti‐Tac.
The required interaction between monocytes and peripheral blood T lymphocytes (T‐PBL) upon activation via CD2 or CD3. Role of HLA class I molecules from accessory cells and the differential response of T‐PBL subsets
Authors: Huet StéPhane , Bournsell Laurence , Dausset Jean , Degos Laurent , Bernard Alain 
Published: March 2007

AbstractPreviously, we have shown that paraformaldehyde‐fixed monocytes are able to fully complement, in terms of [3H]dThd incorporation, a primary stimulus delivered to purified T cells by monoclonal antibodies (mAb) reacting with CD3 or CD2 molecules. Here, we show that depending on the stimulus used (CD3 mAb or different pairs of CD2 mAb) HLA class I molecules from monocytes are directly involved in complementary signals provided to T cells. This was evidenced by the following observations: (a) mAb reacting with the heavy or light chain of class I molecules, or their Fab fragments, completely blocked proliferation of peripheral blood lymphocytes (PBL) activated by CD3 mAb; (b) mAb against the heavy chain of HLA class I but not against p2‐microglobulin partially blocked (= 50%) PBL activation by the CD2 "GT2 + T1l1" mAb pair but did not block activation by CD2 "D66 + T111" mAb; (c) this pattern of inhibition was observed when anti‐class I mAb were used in the soluble phase or when they were bound to monocytes subsequently fixed with paraformaldehyde and cultivated with purified autologous T cells; (d) fixed monocytes are able to restore interleukin (IL) 2 receptor expression on purified T cells stimulated by CD3 mAb or CD2 "GT2 + T111 contrary to anti‐HLA class I mAb‐pretreated monocytes. The inhibitory effects of anti‐HLA class I mAb bound to monocytes were not found to be reversed by recombinant IL2 or recombinant IL1. We assume that HLA class I would be involved in two or more signals delivered to T cells by monocytes, the requirement in those signals depending on the initial stimulus applied to T cells. Transmission of one signal would require a conformation of the HLA molecule inhibitable by both or either anti‐heavy and anti‐light chain mAb. In searching for the counterpart to the accessory cell HLA class I molecule, we found that both CD4+ and CD8+ cells responded to stimulation via CD2 or CD3 mAb. However, within the CD4 subsets, the CD4+w29− subset did not respond while the reciprocal subset did. This was not due to a lack of IL2, as shown by adding rIL2. Since the CD4+w29− subset is committed to the induction of suppression while the reciprocal subset to the induction of help, one can forsee how the immune response could develop in one direction or the other depending on the type of interaction that occurs during T cell activation.
Molecular mechanisms underlying lymphocyte recirculation I. Functional, phenotypical and morphological characterization of high endothelial cells culturedin vitro
Authors: Ise Yayoi , Yamaguchi Kazuhito , Sato Koei , Yamamura Yasuko , Kitamura Fujiko , Tamatani Takuya , Miyasaka Masayuki 
Published: March 2007

AbstractLarge‐scale extravasation of lymphocytes takes place in vivo under physiological conditions in lymph nodes at very specialized vascular segments called high endothelial venules (HEV). When circulating lymphocytes leave the blood, they first bind to endothelial cells of HEV (HE cells) and subsequently enter lymph nodes by crossing the endothelial lining of HEV. Although the lymphocyte‐HEV interaction has recently been the subject of intense research by many laboratories, it has been studied almost exclusively by the use of the lymphocyte‐binding assay in which lymphocyte binding is examined on nonviable HEV present on frozen sections and, hence, no dynamic interaction between HE cells and lymphocytes has been studied. We report herein that endothelial cells of rat HEV can be grown in vitro and that the lymphocyte‐HEV interaction can be studied dynamically using viable cells in culture vessels. The identification of the cultured line, termed Ax, as HE cells was based on their phenotypic, morphological, cytochemical and biochemical characteristics, and most importantly on its in vitro behavior, particularly in terms of its specific ability to interact with mature lymphocytes. Phenotypic analysis demonstrated that not only did monoclonal antibodies, known to react with HE cells, recognize the Ax but also a monoclonal antibody raised against the Ax specifically recognized HE cells in vivo, as determined by an immunoperoxidase staining of frozen sections, supporting the notion that the cell strain, Ax, is derived from HEV. This Ax, even after long‐term culture (>50 passages), allowed mature, but not immature, lymphocytes to bind to the cell surface and subsequently transport bound cells underneath their cytoplasm. This phenomenon was inhibited in a dose‐dependent manner by various reagents known to inhibit lymphocyte recirculation in vivo. The cultured line derived from HE cells should provide a means to investigate the biochemical nature of lymphocyte‐HEV interaction, and to understand the molecular mechanisms underlying the large‐scale lymphocyte traffic taking place in vivo.
Characterization of T cell receptors on resident murine dendritic epidermal T cells
Authors: Steiner Georg , Koning Frits , Elbe Adelheid , Tschachler Erwin , Yokoyama Wayne M. , Shevach Ethan M. , And Georg Stingl , Coligan John E. 
Published: March 2007

AbstractCell lines derived from Thy‐1 dendritic epidermal cells (Thy‐1DEC) display a marked heterogeneity in T cell receptor (TcR) expression including CD3‐associated α/β, Cγ2/δ or Cγ2/δ and Cγ4/δ TcR. In order to investigate whether this heterogeneity is primarily imposed by in vitro culture conditions or, alternatively, is already present within the epidermis, we studied TcR expression by Thy‐1 DEC in situ and on freshly isolated epidermal cell suspensions greatly enriched for Thy‐1DEC. Immunolabeling experiments showed that resident Thy‐lDEC are CD45, Thy‐l, CD3, TcR Vβ8−, CD5−, CD4− CD8−, CD25− lymphocytes. Immunoprecipitation of lysates from 1251‐surface‐labeled Thy‐1DEC‐enriched epidermal cells with anti‐CD3 ε, anti‐Cγ 1,2,3 and anti‐Cγ4 antibodies, respectively, and subsequent analysis of the precipitates by two‐dimensional sodium dodecyl sulfate‐polyacrylamide gel electrophoresis revealed only CD3‐associated 35 kDa/45 kDa γ/δ heterodimers. The demonstration of TcR heterodimers on resident Thy‐1DEC strongly implies that these cells are functional T cells. The selective expression of Cγ1/δ (C57BL/6) and Cγ1/δ or Cγ2/δ (C3HkIe) TcR makes these cells useful for the study of γ/δ TcR function.
T cell response to myoglobin: a comparison of T cell clones in high‐responder and low‐responder mice
Authors: Gorai Itsuo , Aihara Michiko , Bixler Garvin S. , Zouhair Atassi M. , Walden Peter , Klein Jan 
Published: March 2007

AbstractMice carrying the H‐2b haplotype (e.g., inbred strains C57BL/6 and C57BL/10) are low responders to sperm whale myoglobin when tested in the T cell proliferation assay. Their response is improved by the removal of the Ly‐2 cells from the lymph node population, but it still remains significantly lower than that of cells from high‐responder strains (e.g., DBA/2, H‐2d). To determine whether T cells from the low and high‐responder mice recognize the same or different epitopes on the immunizing antigen, we obtained sets of T cell clones from both strains and tested them against peptides representing different regions of the myoglobin molecule, as well as against myoglobins from species other than the sperm whale. Four types of T cell clones were obtained from the DBA/2 mice: 3 types responded to the peptide 107–120 (9 clones altogether), and 1 type responded to the peptide 133–149 (4 clones altogether). The 3 types responding to the peptide 107–120 could be distinguished by their response to horse myoglobin or by the restriction of the response (Ad vs. Ed). Similarly, 5 types of T cell clones were obtained from the C57BL/6 mice: 2 types responded to the peptide 10–22 (1 type, but not the other, responded to horse myoglobin); 1 type responded to the peptide 133–149; and 2 types did not respond to any of the peptides used (1 type, but not the other, responded to dog myoglobin). All 5 types (13 clones altogether) were presumably Ab restricted. These results demonstrate the diversity of epitopes in single antigenic regions and show equivalent heterogeneity of T cell repertoires in high and low responder mice. Attempts to demonstrate specific T cell suppression in the low responder mice failed; only partial, nonspecific suppression was observed.
Cyclic AMP‐mediated alteration of the CD2 activation process in human T lymphocytes. Preferential inhibition of the phosphoinositide cycle‐related transduction pathway
Authors: Bismuth Georges , Theodorou Ioannis , Gouy Helene , Gouvello Sabine Le , And Main Bernard , Debré Patrice 
Published: March 2007

AbstractActivation of human T lymphocytes via the CD2 molecule produces an enhanced turnover of phosphatidylinositol (PI) cycle‐related phospholipids accompanied by the increased production of diacylglycerol (DG) and phosphorylated derivatives of inositol (IP). In this report we demonstrate that increased levels of intracellular cyclic AMP induced in human T lymphocytes by prostaglandin E2 or dibutyryl cAMP antagonize these early biochemical events of the CD2 activation process. Thus, a substantial inhibition of the CDZinduced increase in 32P‐phosphatidic acid and 32P‐PI values is observed. In parallel, both the DG production and the IP release triggered by the CD2 signal are strongly reduced contrasting with an almost conserved Ca2+ response. We also report here that cAMP does inhibit the CDZinduced proliferation in a dose‐dependent manner while the proliferation generated independently of DG and 1P production by a combination of Ca2+ ionophore A23187 and 12–0‐tet‐radecanoylphorbol 13‐acetate is not affected. These results therefore suggest that (a) intracellular cAMP levels may participate in the regulation of the PI cycle‐related transduction pathway involved in the activation process of human T lymphocytes via the CD2 molecule; (b) the observed CAMP‐mediated functional inhibitory effects are mainly related to an alteration of this cellular transduction signal; and (c) considering the putative critical second messenger role in the T cell proliferative response of DG and IP, respectively thought to activate the protein kinase C and to raise the intracellular free Ca2+, the lowering of DG production may be the key event responsible for this CAMP‐mediated effect.
B cell‐stimulating activity of lymphoid cell membrane fractions*
Authors: Sekita Ken‐Ichi , Straub Cedric , Hoessli Daniel , Zubler Rudolf H. 
Published: March 2007

AbstractWe had previously found that a mutagenized subline of the mouse thymoma EL 4 very efficiently stimulates B cells via direct cell‐cell contact, thereby inducing the responsiveness of B cells to cytokines. In the present study, we investigated whether this effect could also be mediated by plasma membranes of EL 4 (and other) cells. By equilibrium centrifugation of cell homogenates, four cell membrane fractions of different densities were obtained. These were tested for (a) stimulation of B cell proliferation in conjunction with EL4 supernatant as source of cytokines, and (b) enhancement of B cell proliferation at suboptimal concentration of lipopolysaccharide. It turned out that all membrane fractions from a variety of T lineage cells (mutant EL4, parent EL4, BW5147, P198 thymomas, normal T cells) and B lineage cells (BCL1 lymphoma, X63Ag8 cytoplasma, normal B cells) exhibited similar B cell stimulating activity in both assays. Interleukin 1 activity was not detected in the membrane fractions. Heat treatment abolished all activity showing that protein at least was involved. Either protease treatment or extraction with detergent abolished the activity of subcellular fractions rich in intracellular membranes but not that of fractions most enriched in surface membranes. Finally, erythrocyte membranes also displayed B cell‐stimulating activity sensitive to protease and detergent extraction. In contrast, and in confirmation of a previous study, liver cell membrane was inhibitory in the B cell proliferation assay with lipopolysaccharide.In conclusion, the effects of cell membranes did not reflect the unique activity of intact mutant EL 4 cells. However, with respect to our data it is conceivable that membrane proteins with relatively nonspecific activity and wide distribution among lymphoid cells could play a role in T cell help together with molecules specialized in cell adhesion and cell triggering.