bluuebunny/crossref_metadata_2025_split huggingface dataset:
T90/44 (9.3 antigen). A cell surface molecule with a function in human T cell activation
Authors: Lesslauer Werner , Koning Frits , Ottenhoff Tom , Giphart Marius , Goulmy Els , Van Rood Jon J. 
Published: February 2007

AbstractT90/44 is a cell surface antigen which is present on human T cells of the helper and cytotoxic subsets and which binds the 9.3 monoclonal antibody (9.3 mAb). It is expressed in the form of 90‐kDa disulfide‐bonded dimers of a 44‐kDa polypeptide and of free 44‐kDa subunits. The function of T90/44 was investigated in a series of T cell function assays. 9.3 mAb was found to inhibit the activation of class II‐restricted cloned T helper cells derived from leprosy patients and reactive with M. leprae antigens. The inhibition was first found at 1–10 ng/ml 9.3 mAb and regularly increased with the antibody concentration. The extent of the inhibition varied among different T cell clones in proportion to the respective different levels of T90/44 expression at their cell surface. The proliferative responses of peripheral blood lymphocytes (PBL) to purified protein derivative of M. tuberculosis (PPD) and tetanus toxoid were enhanced by the 9.3 mAb resulting in up to 20–30‐fold increase of [3H]‐thymidine incorporation. After phytohemagglutinin‐induced activation of PBL, the number of T90/44 molecules per cell expressed at the cell surface rose from day 0 to day 7 by a factor of about 10. High concentrations of 9.3 mAb (5–10 μ/ml) at low cell densities and in the presence of monocytes in culture media supplemented by fetal calf serum were directly mitogenic for resting lymphocytes. The cytolytic effector functions of class I‐restricted cytotoxic T lymphocytes (CTL) were not modulated by 9.3 mAb. The mixed lymphocyte reactions of three class I‐restricted CTL to their specific target cells were found not to be significantly influenced bv 9.3 mAb. In conclusion it is proposed that an antigen‐independent T cell activation pathway can be entered at T90/44.
Purification of an antibody‐like protein from the sea star Asterias rubens (L.)
Authors: Delmotte Francis , Brillouet Claude , Leclerc Michel , Luquet Gilles , Kader Jean‐Claude 
Published: February 2007

AbstractCells from sea star (Asterias rubens) axial organs stimulated with trinitrophenyl (TNP) or fluoresceinyl‐haptened polyacrylamide beads and subsequently stimulated in vitro with the same antigen produced and released a specific antibody‐like protein which induced lysis of haptened sheep erythrocytes in the presence of serum complement. The anti‐TNP antibody‐like protein isolated by ammonium sulfate precipitation, gel filtration and affinity chromatography exhibited a single precipiting peak after crossed immunoelectrophoresis against rabbit antiserum to partially purified culture supernatant. The anti‐TNP antibody‐like protein gave a specific affinity precipitate in crossed affino‐electrophoresis using a p‐nitrobenzoyl‐substituted gel. The analysis by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis under both reducing and nonreducing conditions evidenced a unique 30‐kDa polypeptide chain. According to gel filtration experiments, the molecular weight of the major component isolated by affinity chromatography was about four times higher. Therefore, the antibody‐like molecule could be a tetrameric protein devoid of any disulfide bond.
Autoantibodies against gp140, the Epstein‐Barr virus and C3d receptor in sera from rheumatoid arthritis patients
Authors: Barel Monique , Kahan Alice , Charriaut‐Marlangue Christiane , Kahan André , Frade Raymond 
Published: February 2007

AbstractGp140 is the Epstein‐Barr virus receptor and the C3d receptor (EBVR/C3dR) of human B lymphocytes. Recently, we have shown that cross‐linking of EBVR/C3dR on cell surface by polyclonal anti‐gp140 induced B cell activation, in presence of T cell factors.Immunoregulatory abnormalities of EBV‐induced B cell activation have been demonstrated in rheumatoid arthritis (RA) patients. These data prompted us to analyze the putative presence of anti‐EBVR/C3dR autoantibodies in human sera. The IgG fractions from eleven RA and 10 normal sera were tested for their ability to: (a) bind to Raji cell surface; (b) inhibit the binding to cell surface of 3 anti‐EBVR/C3dR monoclonal antibodies (mAb), which recognized different epitopes on gp140; (c) inhibit the binding of particle‐bound C3d and (d) react with 1% Nonidet‐P40‐solubilized gp140 from Raji cell membranes, in immunoblotting assays. Three RA sera carry anti‐ EBVR/C3dR autoantibodies which react with gp140 expressed on Raji cell surface or its solubilized form. The purification of monomeric IgG fraction of selected RA sera ruled out involvement of immune complexes carrying C3 molecules, which could interfere in these assays. One of these 3 RA sera was able to inhibit the binding to cell surface of anti‐EBVR/C3dR mAb and particle‐bound C3d. However, the 2 other RA sera, found positive by immunoblotting, did not inhibit particle‐bound C3d and presented differences in their inhibitory effect on anti‐EBVR/C3dR mAb binding to Raji cell surface. These data allow us to demonstrate differences which exist in the properties of anti‐EBVR/C3dR autoantibodies. These autoantibodies were not detected in all the normal and other RA sera. Anti‐EBVR/C3dR autoantibodies could play a role “in vivo” in B lymphocyte activation of RA patients.
Evidence for a regulatory role of the T8 (CD8) antigen in antigen‐specific and anti‐T3‐(CD3)‐induced lytic activity of allospecific cytotoxic T lymphocyte clones
Authors: Van Seventer Gijs A. , Van Lier René A. W. , Spits Hergen , Ivanyi Pavol , Melief Cornells J. M. 
Published: February 2007

AbstractThe functional role of the T8 antigen of human T cells was studied by inhibition with anti‐T8 monoclonal antibodies (mAb) of the cytotoxic action of T8+ cytotoxic T lymphocyte clones (CTL). All clones were allospecific and directed against HLA‐B7. The ability of seven different anti‐T8 mAb to inhibit the cytotoxicity of these alloreactive CTL clones corresponded with their avidity for a particular target cell. The lysis of cross‐reactive antigen‐bearing target cells was more readily blocked by anti‐T8 mAb than lysis of the specific B7 target cell against which a clone was raised. The seven anti‐T8 mAb showed a spectrum of CTL blocking ability ranging from strong blocking with all five CTL clones tested to weak inhibition of only two out of five clones. mAb inhibition of CTL reactivity and cold target inhibition studies with one of the five CTL clones indicate a post‐binding role of the T8 molecule. Functional epitope mapping based on CTL blocking with the anti‐T8 mAb resulted in the definition of one nonfunctional epitope on the T8 molecule which is only expressed on mature T lymphocytes and a cluster of closely related functional epitopes expressed on both thymocytes and mature T lymphocytes.Not only allospecific cytotoxicity, but also nonspecific cytotoxicity induced by anti‐T3 mAb in these allospecific clones was inhibited by anti‐T8 mAb in the absence of HLA class I expression on the target cell (Daudi cell line). The hierarchy of blocking with anti‐T8 mAb and the classification of functional epitopes on T8 in anti‐T3‐induced nonspecific cytotoxicity were similar to those obtained in blocking of allospecific reactivity of the CTL clones. This analogy points to an identical function of the T8 antigen in both allospecific and anti‐T3‐induced nonspecific cytotoxicity. If HLA class I molecules are the counter structures of the T8 antigen, then these results argue against an adhesion‐like function of the T8 structure. The combined results show that the T8 molecule has a regulatory role in CTL activation. It is postulated that the T8 antigen might serve as a receptor that transduces a negative feedback signal for T cell activation which prevents T cell triggering by nonspecific interaction.
Antigen presentation by hapten‐specific B lymphocytes III. Analysis of the immunoglobulin‐dependent pathway of antigen presentation to interleukin 1‐dependent T lymphocytes
Authors: Rock Kenneth L. , Haber Susan I. , Liano Douglas , Benacerraf Baruj , Abbas Abul K. 
Published: February 2007

AbstractThe ability of antigen‐specific murine B lymphocytes to present antigen to a normal (nontransformed) antigen‐specific, interleukin (IL)1‐dependent T cell clone and to heterogeneous T lymphocytes was investigated. Hapten‐specific lymphocytes present protein antigens to both the D10G.4.1 T cell clone and heterogeneous immune T cells. When the antigen bears an epitope recognized by the specific B cell, the subsequent presentation of this antigen is 102–104‐fold more efficient, as compared to the same, but nonhaptenated protein. The requisite B lymphocyte binds hapten, is radiosensitive and is nonadherent to plastic. The hapten‐specific antigen presentation ‐ is blocked by antibodies to the surface Ig receptor, while the presentation of unmodified protein is unaffected. These observations are identical to our findings in studies of B cell antigen presentation to T‐T hybridomas and therefore demonstrate the generality of the immunoglobulin‐dependent pathway of presentation. However, in contrast to the results with T‐T hybridomas, the specific B lymphocytes are necessary, but not sufficient, to activate IL 1‐dependent T cells. A third cell is required for both B lymphocyte immunoglobulin‐dependent and nonspecific antigen‐presentation. This cell is radioresistant, plastic adherent and of low density. The requirement for this third cell can be circumvented by supplementing cultures with highly purified IL 1. These results demonstrate that the remarkably efficient ability of B lymphocytes to present antigen is operative with factor‐dependent T lymphocytes. Furthermore, conventional accessory cells also appear to play a role in this process, which is consistant with their known requirement in antigen‐specific T‐B interactions in the generation of antibody responses.
Two natural killer cell populations which belong to T cell lineage in nude mice
Authors: Habu Sonoko , Shimamura Kazuo , Tamaoki Norikazu , Kumagai Yoshihiro , Okumura Ko 
Published: February 2007

AbstractEnriched natural killer (NK) cell populations from BALB/c nude mice obtained by using nylon wool column (NWC) separation were stained with anti‐Thy‐1 and anti‐asialo GM1 (GA1), and then were fractioned by flow cytometry into 4 cell populations: Thy‐1+GA1+ cells, Thy‐1+GA1− cells, Thy‐1−GA1+ cells and Thy‐1−GA1− cells. These cell populations were sorted out by flow cytometry and were examined for NK activity. Of the sorted cells, high NK activity was found in the two populations, Thy‐1+GA1+ cells and Thy‐1−GA1+ cells. In the other populations expressing Thy‐1 antigen alone or expressing neither GM1 nor Thy‐1, NK activity was almost undetectable. The two cell populations with NK activity were lineaged with respect to rearrangement of the T cell receptor genes. Southern gel analysis using a cDNA probe containing the Dβ1, Jβ1.3 and Cβ1 genes of the T cell receptor showed a reduction of the germ‐line band of DNA in the 3 fractionated populations other than Thy‐1−GA1−cells. Since these observations were demonstrated in nude spleen cells, it is indicated that the cells with NK activity belong to T cell lineage even if they lack Thy‐1 expression and that they may develop out of the thymus, if they express Thy‐1 antigen.
Intracellular pathway of interleukin 2 following receptor‐mediated endocytosis
Authors: Lowenthal John W. , Robson MacDonald H. , Iacopetta Barry J. 
Published: February 2007

AbstractElectron microscope autoradiography was used to examine the intracellular pathway of radioiodinated interleukin 2 ([125I]IL2) following its receptor‐mediated endocytosis in CTLL cells. Direct measurement of the kinetics of endocytosis showed that 60–70% of surface‐bound [125I]IL2 was internalized after 1 h at 37°C. [125I]IL2 was observed to enter cells through invagination of coated pits at the cell surface and to concentrate into lysosomal multivesicular bodies as early as 5–10 min after endocytosis. These results provide ultrastructural information on the intracellular pathway of IL2 and on its probable site of degradation within the cell.
Functional role in self reactivity for Ia antigens on murine synovial cells
Authors: Fournier Catherine , Takenaka Yoshitaka , Michel‐Bechet Marc 
Published: February 2007

AbstractCultures of synovial cells from normal CBA mice were established after collagenase treatment of synovial tissue collected from the knee joint. Morphological studies using light and electron microscopy have shown that confluent monolayers are composed of 90% triangular or stellate dendritic cells with numerous microvilli and 5% secreting cells containing many dense granules. Less than 5% contaminating cells, such as fibroblasts or macrophages, are present. The class I and class II antigens of the major histocompatibility complex, detected by indirect immunofluorescence or complement‐dependent cytotoxicity, are expressed on the cell surface of normal CBA synovial monolayers. Functional Ia antigens borne by synoviocytes are evidenced by the proliferative responses they elicit from syngeneic (or allogeneic) spleen cells after a 3‐day co‐culture. Similarly, monolayers of Ia+ synovial cells were obtained from both MRL/1pr mice, which spontaneously develop an autoimmune syndrome, and the control MRL/n mice. Spleen cells from young MRL/1pr exhibited significantly higher levels of blastogenesis in syngeneic co‐cultures than those from MRL/n mice. Conversely, with advancing age the syngeneic proliferative responses declined minimally for MRL/1pr mice and were unchanged for MRL/n mice. These findings suggest that Ia+ synovial cells can effectively interact with syngeneic lymphocytes and may initiate autoimmune reactivity.
Different human B cell subsets respond to interleukin 2 and to a high molecular weight B cell growth factor (BCGF)
Authors: Vazquez Aime , Gerard Jean‐Philipe , Olive Daniel , Auffredou Marie‐Thérèse , Dugas Bernard , Karray Saoussen , Delfraissy Jean‐François , Galanaud Pierre 
Published: February 2007

AbstractAfter activation by anti‐μ antibody human B cells acquire the ability to proliferate in the presence of recombinant interleukin 2 (IL2), a 20‐kDa mol. mass B cell growth factor (BCGF) and a high mol. mass BCGF (50‐kDa BCGF). An anti‐IL2 receptor (IL 2R) monoclonal antibody inhibits the IL2‐dependent proliferation without affecting that induced by BCGF. B cells expressing the IL2R after anti‐μ antibody activation (IL2R+ cells) were separated from those not expressing IL2R (IL2R− cells). IL2 stimulated the proliferation of only IL2R+ cells whereas the 20‐kDa BCGF acted on both IL2R+ and IL2R− cells. Importantly, the 50‐kDa BCGF supported the proliferation of IL2R− cells whereas it was inactive on IL2R+ cells. Thus, the B cell subset responding to the 50‐kDa BCGF after anti‐μ antibody activation is distinct from that responding to IL2.
A surface molecule on guinea pig lymphocytes involved in adhesion and homing
Authors: Kraal Georg , Twisk Agaath , Tan Ben , Scheper Rik 
Published: February 2007

AbstractA monoclonal antibody, CT4, which recognizes an antigenic determinant on the majority of guinea pig lymphocytes, was tested for its ability to interfere with adherence and homing capacity of lymphocytes. Incubation with F(ab′)2 fragments of the antibody blocks the in vitro binding to high endothelial venules (HEV) of both peripheral lymph nodes and Peyer's patches. When tested in vivo using a short‐term homing assay with radiolabeled cells also a reduction of migration into the spleen was observed. Fluorescence‐activated cell sorter analysis of lymph node cells showed a separation into duller and brightly positive cells whereas in the thymus the bright population is absent. Thymus cells adhere less effectively to HEV and this binding can only marginally be blocked by CT4 incubation. The results suggest a role of CT4 in adhesion processes.
Suppression of the anti‐hapten IgE antibody response with hapten‐modified spleen cells
Authors: Weber Ernst A. , Blaser Kurt 
Published: February 2007

AbstractSpleen cells of BALB/c mice were chemically modified with phosphorylcholine or benzylpenicilloyl hapten. The i.v. administration of such cells into syngeneic animals suppressed the formation of specific IgE antibodies against the respective hapten. The IgE antibody response against ovalbumin, which was used as an immunogenic carrier for the haptens, was not affected and the anti‐hapten IgG or IgG1 response remained at the levels of the controls. The suppression could be transferred into X‐irradiated mice by T cells from tolerized animals. Moreover, it was demonstrated that not only the induction of IgE, but also an established anti‐hapten IgE antibody response is accessible to suppression by treatment with hapten‐modified spleen cells from syngeneic animals. The results indicate that the i.v. administration of antigen coupled to syngeneic spleen cells induces T cells which suppress the formation of specific IgE antibodies in the primary and the secondary response without significantly affecting the formation of IgG antibodies.
A specific serine proteinase is inducible in Lyt‐2+, L3T4− and Lyt‐2−, L3T4+ T cells in vitro but is mainly associated with Lyt‐2+, L3T4− effector cells in vivo
Authors: Simon Markus M. , Fruth Ulli , Simon Hans Georg , Kramer Michael D. 
Published: February 2007

AbstractRecently, we and others reported on the expression of a serine proteinase in long‐term cultured murine T lymphocyte cell lines. In an attempt to explore the distribution and possible regulation of this enzyme in T lymphocyte subsets, we performed the presented detailed study. We found that the proteinase is not expressed by thymocytes and resting T cells but can be induced by lectin or antigen in combination with lymphokine sources in vitro in macrophage‐depleted unselected T cells as well as in both T cell subsets (Lyt‐2+, L3T4−and Lyt‐2−, L3T4+) separated by flow cyto‐fluorometry. Furthermore, it appears that cell‐associated proteinase activity is increasing with prolonged culture period of sensitized T lymphocytes and that it is higher in antigen‐activated as compared to lectin‐activated T cells. When tested for substrate specificity the T cell‐associated proteinase was shown to preferentially cleave model peptide substrates carrying L‐arginine at position P1 in combination with nonpolar amino acids at position P2 and P3. As concluded from its sensitivity to proteinase inhibitors the enzyme can be classified as a serine proteinase and by molecular sieving at high ionic strength it was shown to have a mol. mass of ∼ 50–60 kDa.Analysis of in vivo activated T cells revealed that this particular proteinase was expressed in flow cytofluorometry sorted lymphocytic choriomeningitis virus‐specific Lyt‐2+, L3T4− cytolytic T lymphocytes but not in Lyt‐2−, L3T4+T cells presensitized with either Listeria monocytogenes or I‐A alloantigens.The data demonstrate that the two T cell subsets (Lyt‐2+, L3T4−; Lyt‐2−,L3T4+) have distinct in vitro induction requirements for the expression of proteinase and that after activation of T cells in vivo the enzyme is preferentially associated with Lyt‐2+, L3T4−effector cells.
Lymphoma models for B cell activation and tolerance IV. Growth inhibition by anti‐Ig of CH31 and CH33 B lymphoma cells
Authors: Pennell Christopher A. , Scott David W. 
Published: February 2007

AbstractCH31 and CH33 are B cell lymphomas whose growth in vitro is inhibited by anti‐Ig reagents, including both polyclonal and monoclonal anti‐μ antibodies, and an anti‐idiotype antiserum. Antibodies against class I or class II major histocompatibility complex antigens do not affect the growth of these cells. Inhibition is dependent on surface Ig cross‐linking and does not require ligand binding to Fc receptors. Interestingly, the inhibition of growth by anti‐μ, is reversed in CH31 (but not CH33) by E. coli lipopolysaccharide. These lymphomas should provide excellent models to study the mechanisms of growth inhibition mediated by surface Ig cross‐linking and the pathways of its reversal.
B cell receptors for interleukin 2: demonstration of IL 2 internalization and of complementary effects of lipopolysaccharide and phorbol diester on receptor expression
Authors: Lowenthal John W. , Link Ladislav , Hashimoto Noboru , Zubler Rudolf H. 
Published: February 2007

AbstractWe have previously shown (J. Exp. Med. 1984. 160: 1170) that murine B cells activated with lipopolysaccharide (LPS) and rabbit anti‐mouse Ig antibodies together (LPS‐RaMIg blasts) express high‐affinity interleukin 2 receptors (IL2R) and respond to IL2. This is not the case for B cells activated with either LPS alone (LPS blasts) or anti‐Ig alone. In the present study IL2R function and expression were further investigated by using this model. First, it was found that LPS‐RaMIg blasts internalize IL2 in a time‐ and temperature‐dependent manner very similar to that occurring in CTLL (T lineage) cells. LPS blasts, however, did not internalize IL2. LPS blasts were found to express 12 times less binding sites for anti‐IL2R monoclonal antibody (PC 61 monovalent Fab) as compared to LPS‐RaMIg blasts and at least 30 times less IL2 binding sites of high as well as of lower affinity. Second, with regard to the requirements for receptor expression, it was observed that either anti‐Ig or phorbol diester (phorbol‐12‐myristate 13‐acetate) can induce IL2R and IL2 responsiveness (proliferation assay) in LPS blasts but not in fresh B cells. Taken together these results (a) provide further evidence for the similarity of IL 2R function in activated B and T cells, (b) confirm that surface‐Ig cross‐linkage and phorbol‐12‐myristate 13‐acetate have similar effects on B cells and (c) suggest that LPS on the one hand, and phorbol‐12‐myristate 13‐acetate or anti‐Ig on the other provide complementary signals necessary for IL2R expression.
T cell nature of some lymphokine‐activated killer (LAK) cells. Frequency analysis of LAK precursors within human T cell populations and clonal analysis of LAK effector cells
Authors: Moretta Lorenzo , Pende Daniela , Cozzani Raffaella , Merli Annalisa , Bagnasco Marcello , Mingari Maria Cristina 
Published: February 2007

AbstractThe cell lineage of the lymphokine‐activated killer (LAK) cells has been reinvestigated. Both T and non‐T cells, isolated on the basis of rosette formation with sheep erythrocytes (E), generated LAK activity after 3–4 days of culture in recombinant interleukin 2 (rIL 2) in 8 different individuals tested. By applying a microculture technique which allows clonal expansion of virtually all E resetting T cells, we further analyzed the frequency of clonogenic LAK precursors within T cell populations. Approximately 1 of 25 T cells was found to be a LAK precursor. Moreover, microcultures with LAK activity lysed both the natural killer‐sensitive K562 cell line and the P815 target cells in the presence of phytohemagglutinin (PHA). Since cytolytic T lymphocytes capable of lysing P815 cells in the PHA‐dependent assay were approximately 1/3, it is evident that only a minor subset of cytolytic T lymphocyte precursors can acquire LAK activity even in the presence of large amounts of IL 2. Several LAK clones obtained by limiting dilution were further expanded and analyzed for their phenotypic and functional properties. Twelve out of 14 clones analyzed expressed the T3+ T11+ phenotype whereas 2 were T3− T11+. All had maintained their original cytolytic pattern; moreover, the large majority of the T3+ clones produced IL 2 and interferon‐γ following PHA stimulation.