bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cytotoxic T cell lysis of H‐2‐negative murine sarcoma cells
Authors: Noll Gabriele , Schmidt Wilhelm , Bauer Heinz 
Published: February 2007

AbstractThe DOH cell line was established from C3H.OH (H‐2Kd, Dk) embryonic fibroblasts transformed with Rous sarcoma virus (RSV) in vitro. When injected into syngeneic mice, DOH cells were very weakly tumorigenic and induced a cytotoxic immune response. Cytotoxic T lymphocytes (CTL) specifically lysed DOH cells but not other RSV‐induced sarcoma cells, which shared the H‐2Kd or H‐2Dk antigen, respectively, with DOH. Serological and immunochemical analysis of H‐2 antigens subsequently showed that DOH sarcoma cells did not express syngeneic H‐2K and H‐2D antigens. Surprisingly, a H‐2Kd‐specific monoclonal antibody (100‐5) bound to DOH cells and was inhibitory for syngeneic CTL specific for DOH. In addition, DOH cells were lysed by alloreactive H‐2Kk‐specific CTL. The demonstration of immunogenic H‐2‐negative sarcoma cells suggests that either the H‐2K antigens have been extensively altered or that hitherto unidentified major histocompatibility complex class I molecules are expresled on DOH sarcoma cells surfaces, acting as target antigens for tumor‐specific CTL.
Isotype restriction of idiotopes associated with human anti‐streptococcal A carbohydrate antibodies
Authors: Emmrich Frank , Zenke Gerhard , Eichmann Klaus 
Published: February 2007

AbstractSharing of idiotopes betwen IgG and IgM antibodies has been described with antibodies of various specificities in the literature. However, this does not seem to be the rule for human IgG and IgM antibodies with specificity to streptococcal A carbohydrate. Six idiotopes were described which are associated either with IgM or with IgG antibodies to one of the two major epitopes of streptococcal A carbohydrate: N‐acetyl‐D‐glucosamine or α(1,2), α(1,3)‐linked rhamnose oligomers. Some of the idiotopes are widely cross reactive with antibodies of the corresponding specificity in other individuals. They were constantly found to be restricted to either IgM or IgG in all individuals tested so far. We discuss several alternatives to explain this finding and conclude that switching from IgM to IgG is either a very rare event in human B cells of this specificity, or leads to loss and gain of idiotopes and/or specificity due to frequent somatic mutations. The phenomenon of idiotope restriction to certain isotypes might be important if anti‐idiotopic monoclonal antibodies are considered for use in therapeutical approaches aimed at the manipulation of antibody production.
CD2 and CD3 antigens mobilize Ca2+ independently
Authors: O'Flynn Kieran , Knott Lesley J. , Russul‐Saib Mahmood , Abdul‐Gaffar Rafiu , Morgan Gareth , Beverley Peter C. L. , Linch David C. 
Published: February 2007

AbstractAntigen‐induced stimulation of T cells is mediated via the CD3 antigen receptor (Ti) complex and monoclonal antibodies (mAb) reacting with CD3 and Ti result in rapid intracellular Ca2+ mobilization, followed by monocyte‐dependent proliferation. Combinations of mAb to CD2, the sheep red blood cell receptor, also mobilize calcium and induce mitogenesis and purified phytohemagglutinin (PHA) stimulates T cells predominantly by interaction with this molecule. It has been suggested that activation via CD2 requires the presence of CD3 and that the hydrophobic ϵ chain of CD3 is the T cell calcium channel. To investigate this further we have obtained large numbers of natural killer (NK) cells which express CD2 but not CD3 from a patient with a chronic expansion of this lymphocyte subpopulation. It is shown that calcium mobilization can be induced in these cells by mAb to CD2 and purified PHA but not by anti‐CD3 mAb. This indicates that calcium mobilization can be induced via the CD2 molecule in NK cells not expressing CD3 and that activation through CD2 is separate from the antigen receptor CD3 pathway.
Degeneracy of H‐2 recognition by cytotoxic T lymphocytes: 10% of the total repertoire is “specific” for a given haplotype and up to 1% is self‐H‐2 reactive
Authors: Beretta Alberto , Ermonval Myriam , Larsson Eva‐Lotta 
Published: February 2007

AbstractThe frequency of specific cytotoxic T lymphocytes (CTL) precursors in the total CTL pool was analyzed in a lectin‐driven limiting dilution system. We found that up to 10% of the expressed CTL repertoire in a normal mouse is “specific” for a given allogeneic H‐2 haplotype. Split‐well analysis under clonal conditions demonstrates that the antigens recognized by the effector CTL are H‐2 encoded. A high frequency of CTL “specific” for self‐H‐2 antigens was revealed in all the experiments, accounting for about 1% of the total inducible pool of CTL. These results suggest a high degree of degeneracy of H‐2 recognition by CTL and the immunocompetence of self‐H‐Zreactive CTL precursors in normal individuals.
Recognition of exon‐shuffled class II molecules by T helper cells
Authors: Wegmann Dale R. , Roeder William D. , Shutter John R. , Kop Joann , Chiller Jacques M. , Maki Richard A. 
Published: February 2007

AbstractExon shuffled I‐Aβ genes transfected into the B lymphoma cell line A20‐2J were used to localize the epitope recognized by the monoclonal antibody 10.2.16 to the carboxy terminal portion of the β1 domain. In addition, several T helper cell hybrids were tested against these novel I‐A molecules and the following observations were made: (a) the β1 domain of Aβ plays a dominant role in the restricted recognition by T helper cells; (b) there appear to be multiple restriction epitopes on the I‐A molecule; (c) these epitopes can consist of conformational epitopes created by specific α and β chains or consist of the polymorphic determinants encoded on the β chain alone, and (d) these novel I‐A molecules serve as restriction elements in the antigen‐specific recognition by T cells and in one case stimulate an alloreaction in the absence of antigen.
Cyclic tetramolecular complexes of monoclonal antibodies: A new type of cross‐linking reagent
Authors: Lansdorp Peter M. , Aalberse Rob C. , Bos Rogier , Schutter Wilma G. , Van Bruggen Ernst F. J. 
Published: February 2007

AbstractA simple and efficient procedure for the construction of bifunctional molecules is described and their use in a variety of applications documented. This procedure is based on our observation that mouse IgGl monoclonal antibodies, when mixed with equimolar amounts of a high‐affinity rat monoclonal antibody specific for mouse IgG1, yield uniform cyclic tetramolecular complexes each consisting of two mouse and two rat antibodies as shown by gel electrophoresis and electron microscopy. When solutions of two mouse antibodies (e.g. a and b) are mixed prior to the formation of complexes with the rat antibody, stable bispecific (a × b) complexes together with monospecific (a × a and b × b) complexes are obtained. Bispecific complexes prepared in this way were able to efficiently bind peroxidase to cell surface antigens, and to bind red blood cells to selected nucleated cell types present in heterogeneous populations. Tetrameric antibody complexes are more easily prepared than bispecific antibodies or bifunctional antibodies produced by transfection of myelomas with recombinant genes. They also have the advantage that the antigen‐binding properties of the bivalent monoclonal antibodies are not compromised. Tetrameric antibody complexes thus represent a powerful new type of cross‐linking reagent that may have a wide spectrum of applications in biology and medicine.
Role of IgE as a mast cell development co‐factor in the differentiation of murine gut‐associated mast cells in vitro
Authors: Kawanishi Hidenori 
Published: February 2007

AbstractA role of IgE in the differentiation of gut‐associated mast cells (MC) was determined in vitro in the presence of a T cell product, interleukin 3 (IL3). The presence of both IL3 and IgE induced MC with higher precursor frequency than that of IL3 alone, by up to nearly 4 times, while IgE alone failed to develop the clonal growth of MC. IgE, but not the other isotype‐specific immunoglobulins, augmented the proliferation of IL3‐induced MC in the presence of IL3. Thus, IgE acts as a cofactor in the growth and/or differentiation of MC.
Mouse monoclonal antibodies induced by anti‐allotype antibody display internal images of the rabbit VHa1 allotype: Direct visualization by immunoelectron microscopy
Authors: Van Cleave Victor H. , Murti Kuruganti G. , Metzger Dennis W. 
Published: February 2007

AbstractWe have previously shown that injection of adult rabbits with anti‐immunoglobulin (Ig) antibody (Ab) induces the expression of genetically unexpected Ig markers, i.e., a1 allotypic determinants. We now show that these rabbit Ig markers can also be induced in mice by a similar treatment; in the latter case the a1 determinants are located in the antigen‐combining site and thus represent “internal images”. Two monoclonal antibodies (mAb) were developed from mice treated with anti‐allotype Ab. These mAb (a) were reactive with all homologous and heterologous anti‐a1 Ab but not normal Ig; (b) efficiently inhibited the binding of rabbit a1 Ig to anti‐a1 Ab; and (c) elicited the production of anti‐allotype Ab when injected into normal mice. To determine whether the al‐like determinants on these mAb were located in the antigen‐combining site, immunoelectron microscopy was utilized to directly visualize Ab complexes. Complexes composed of intact Ab and anti‐a1 Fab fragments yielded uniform binding patterns which were identical to those produced by anti‐idiotypic reactions. In each case, an identical tip‐to‐tip binding configuration was observed with a single Fab fragment attached at an approximate 180° angle to the V region terminus of each Ab arm. In contrast, rabbit a1 Ig bound as many as two anti‐a1 fragments per Ig arm; these fragments were attached laterally and at right angles to the intact molecule. These mAb thus provide the first direct evidence that Ab2β determinants are located in, or near, the antigen‐combining site.
Triggering of the lethal hit in human cytotoxic T lymphocytes: a functional role for a 103‐kDa T cell‐ specific activation antigen
Authors: Fleischer Bernhard , Schendel Dolores J. , Von Steldern Dierk 
Published: February 2007

AbstractA monoclonal antibody (CB.1) is described that defines a new triggering signal for human cytotoxic T lymphocytes (CTL). The antibody precipitates a 103‐kDa surface antigen from activated normal human T cells. The antigen is undetectable or present in only low amounts on resting T lymphocytes but its expression increases strongly after activation and proliferation on T4+ and T8+ T lymphocytes. Binding of antibody CB.1 to CTL results in triggering of the lethal hit. This induction of cytotoxicity is dependent on cross‐linking of CTL and an Fc receptor‐bearing target cell with CB.1 and requires Ca2+ like antigen‐specific triggering. CB.1‐induced triggering can be specifically inhibited by binding of antibodies to the T8 or T4 molecules on T8+ or T4+ CTL.
Monoclonal antibodies against leucoagglutinin‐reactive human T lymphocyte surface components: Two antibodies which inhibit cell‐mediated cytotoxicity at a post‐binding stage
Authors: Vargas‐Cortes Mauricio , Hammarström Marie‐Louise , Hammarström Sten , Hellström Ulla , Perlmann Peter 
Published: February 2007

AbstractTwo out of 20 monoclonal antibodies (IgM,χ), mAb 3192 and mAb K3G, raised against leucoagglutinin‐reactive components on human T cells, effectively blocked lymphocyte‐mediated cytotoxicity in vitro. No antigenic polypeptide reactive with these antibodies has been identified thus far. However, they have previously been shown to react specifically with certain neutral glycolipids obtained from spleen. Both mAb inhibited the cytotoxicity of natural killer (NK) cells against K.562 cells, antibody‐dependent cellular cytotoxicity (ADCC) towards antibody‐coated bovine erythrocytes and cytotoxic T lymphocyte activity against allogeneic target cells. In both NK and ADCC, preincubation of the lymphocytes with different antibody concentrations resulted in a dose‐dependent reduction of cytotoxicity. In contrast, preincubation of the target cells had no effect indicating that the mAb inhibited cytotoxicity at the effector cell level. When studied at the single‐cell level, the mAb did not alter the number of lymphocytes forming conjugates with K562 but significantly reduced the frequency of conjugates containing dead target cells. Addition of the mAb to preformed conjugates resulted in a dose‐dependent reduction in the proportion of conjugates containing dead target cells. Furthermore, mAb 3192 did not reduce the number of lymphocytes forming rosettes with bovine erythrocytes, indicating that inhibition of ADCC was not due to blocking of the effector cell‐target cell interaction mediated by the Fc receptor of the effector cells. Taken together, these results suggest that the mAb inhibited cytotoxicity by interfering with a post‐binding step common for the different cytotoxicity systems.
Thymic nurse cells: a school for alloreactive and autoreactive cortical thymocytes?
Authors: Wick Georg , Oberhuber Georg 
Published: February 2007

AbstractThe possibilities for functional analysis of thymic nurse cells (TNC) have so far been hampered by the low yield of these cells by means of gradient centrifugation and their fragility preventing purification by a fluorescence‐activated cell sorter. Furthermore, they are extremely unstable in cell culture. Here we present functional data obtained by the analysis of single TNC in an avian system: the chicken with its extramaternal embryonic development prompted us to use the chorioallantoic membrane (CAM) pock formation assay to investigate the possible graft‐vs.‐host reactivity (GVHR) of TNC lymphocytes (TNC‐L). The CAM assay proved to be an optimal and unique “cell culture” system for the investigation of the functional characteristics of TNC. Our data show that TNC‐L, unexpectedly, are able to exert a GVHR on allogeneic CAM with the very high efficiency of 1/13 as compared to thymocytes of the same donors showing a GVHR efficiency of 1/350. TNC‐L are even able to induce GVH‐like reactions in syngeneic combinations, while thymocytes and peripheral blood lymphocytes from the same donors always remain negative.
myo‐Inositol reverses Li+‐induced inhibition of phosphoinositide turnover and ornithine decarboxylase induction during early lymphocyte activation
Authors: Mustelin Tomas , Pösö Hannu , Iivanainen Antti , Andersson Leif C. 
Published: February 2007

AbstractOne of the earliest detectable responses by T lymphocytes in vitro to various mitogenic ligands is the rapid induction of ornithine decarboxylase (ODC) activity (Scott et al., Eur. J. Immunol. 1985. 15: 783). This early activation is measurable within minutes after the addition of the mitogen. The T cell mitogen concanavalin A also induces rapid breakdown of phosphoinositides in T lymphocytes. The inositol phosphates formed are recycled and used in synthesis of new phosphoinositides. Li+interrupts this cycle by inhibiting the enzyme inositol‐1‐phosphatase, which produces the inositol needed for phosphoinositide synthesis.Here we report that when human blood lymphocytes are kept in an inositol‐deficient medium for 30 min in the presence of 1 mM Li+, the cells become unable to respond to mitogens by inositide breakdown and rapid induction of ODC activity. Addition of 1 mM myo‐inositol restores the inducibility of these responses within a few minutes. These findings represent a novel aspect of the activation of resting lymphocytes and implies a new role for the inositol turnover during signal transduction.
Co‐expression of different types of Fc receptors on murine peritoneal macrophages
Authors: Větvička Václav , Fornů Lubor , Kincade Paul W. , Kopeček Jindrich 
Published: February 2007

AbstractSimultaneous expression of particular immunoglobulin Fc receptors (FcR) was studied on the plasma membranes of murine peritoneal macrophages. This was facilitated by the use of sheep red blood cells (SRBC) and/or synthetic microspheres coated with monoclonal antibodies of different isotypes. It was concluded that a majority of macrophages bear more than one type of FcR; macrophages bearing at least three types of FcR were present in the peritoneal cavity; macrophages bearing FcμR did not bind IgE, IgA or IgG; all macrophages bearing FcαR also expressed Fcγ2bR, Fcγ3R, and FcεR; all macrophages bearing FcεR also expressed Fcγ2bR and FcαR. Except for FcαR, essentially equivalent numbers of FcR‐bearing macrophages were detected when antibody‐coated SRBC or polymeric microspheres were used. Simultaneous applications of these reagents permitted the most detailed and direct investigations yet performed of multiple FcR expression on individual cells.
Fine specificity of antibodies produced in rhesus monkeys following in vivo treatment with anti‐T cell murine monoclonal antibodies
Authors: Villemain Françcoise , Jonker Margreet , Bach Jean‐François , Chatenoud Lucienne 
Published: February 2007

AbstractThe immune response of 23 rhesus monkeys against different murine monoclonal antibodies (mAb) administered in vivo as immunosuppressive agents has been analyzed. Seven mAb specific for either helper‐inducer (CD4 molecules) or cytotoxic/suppressor (CD8 molecules) T cells, that cross‐react with monkey lymphocytes, were administered i.v. for 10 consecutive days in rhesus monkeys. Nineteen of the animals were recipients of a skin or renal allotransplant. Nineteen out of the 23 monkeys developed a significant immune response against the injected monoclonal. This response was restricted in its specificity since unrelated murine monoclonals were not recognized by the monkeys' anti‐monoclonal immunoglobulins. Fine analysis of the monkeys' sera revealed that the antibodies produced against the xenogeneic proteins selectively exhibited two major specificities i.e., anti‐isotypic and anti‐idiotypic. On practical basis, these results suggest that an animal already immunized against a given mAb should still be sensitive to the therapeutic effect of another monoclonal sharing the same specificity but different idiotype.
Suppression of specific IgM, IgA and IgG responses in mice treated with anti‐6 from birth
Authors: Wathen Patricia M. , Manning Dean D. 
Published: February 2007

AbstractIn contrast to previous studies, we report that heterologous anti‐δ antibodies can act as a powerful multi‐class humoral immunosuppressant. Primary direct plaque‐forming cell (IgM) responses of BALB/c mice injected from birth with a rabbit anti‐δ antiserum were reduced to 3% of control levels against a T‐dependent antigen (sheep red blood cells), and to 2% against a T‐independent antigen (dextran); IgA responses against 2 intraduodenal injections of cholera toxin were reduced to 7% of control levels. Other secondary immune responses of anti‐δ‐suppressed mice were suppressed to a lesser degree. IgM plaque responses generated by 2 injections of sheep red cells, for example, were reduced to 50% of control levels, with reduction of the corresponding IgG response to 42%.The multi‐class suppression observed indicates a clonal differentiation pathway in which the IgD+ cell develops into IgM‐, IgA‐ and IgG‐secreting cells. In light of reports that the IgD+ cell is antigen sensitive, our demonstration that IgD is capable of delivering the same sort of immunosuppressive signal in response to anti‐heavy chain antibodies that IgM delivers also suggests, though it does not establish, an antigen‐receptor role for IgD.
Evidence for distinct epitopes on human IgG with T cell proliferative and suppressor function
Authors: Baxevanis Constantin N. , Ioannides Constantin‐Demosthenes G. , Reclos George J. , Papamichail Michael 
Published: February 2007

AbstractThe Fc or pFc' fragments of the human IgG were demonstrated to exert different effects on murine T lymphocyte subsets. Thus, murine lymph node (LN) T cells were specifically induced to proliferate in vitro to pFc' after priming in vivo. This proliferation could be inhibited, either by depleting the responding LN population of macrophages, or by monoclonal antibodies specific for responder haplotype Ia antigenic determinants. Priming in vivo and subsequent restimulation in vitro with Fc resulted in the activation of a suppressor T cell subpopulation which, in an antigen‐specific manner, could highly suppress proliferative responses. T cell subset isolation showed that the pFc'‐specific proliferation was performed by Lyt‐l+2− cells whereas the suppressor Fc‐specific cells were of Lyt‐l−2+ phenotype. Our data demonstrate that distinct epitopes on the human γ chain induce either Ir gene‐restricted T cell proliferation (pFc' fragment) or T cell suppressor function (Fc fragment).
Ontogeny of priming of cytotoxic T cells to minor alloantigens: the development of direct priming precedes that of cross‐priming
Authors: Rafii‐Tabar Elahe , Czitrom Andrei A. 
Published: February 2007

AbstractCytotoxic T lymphocytes of heterozygous adult mice primed in vivo with minor alloantigens on cells of one parental H‐2 genotype can be boosted in vitro to respond to minor alloantigens on cells of both the immunizing parental H‐2 genotype (direct priming) and of the H‐2 genotype of the other parent (cross‐priming). We studied the ontogeny of this phenomenon and show that during early postnatal life the development of direct priming precedes that of cross‐priming. The delayed maturation of cross‐primed responses parallels the known development time sequence of functional antigen‐presenting cells and provides evidence for the explanation of cross‐priming in terms of antigen processing.
Composition of the lymphoid cell populations from omental milky spots during the immune response in C57BL/Ka mice
Authors: Paper Short , Dux Kazimir , Rouse Robert V. , Kyewski Bruno 
Published: February 2007

AbstractThe lymphoid cell composition of milky spots was analyzed in unprimed mice before and after i.p. immunization with sheep red blood cells. Milky spots contained surface immunoglobulin‐positive B lymphocytes, and T cells of the helper and cytotoxic phenotype. After secondary antigen challenge (a) the number of lymphocytes increased up to 40‐fold, (b) B and T cells were found to segregate into distinct areas in situ, and (c) lymphocytes were found to associate with I‐A‐negative stromal cells in vivo. These findings qualify milky spots as a peripheral lymphoid organ exhibiting a remarkable change in number and composition of lymphocytes in response to a local antigen stimulus.