bluuebunny/crossref_metadata_2025_split huggingface dataset:
Serological evidences for a membrane structure related to human β2‐microglobulin expressed by certain earthworm leukocytes
Authors: Roch Philippe , Cooper Edwin L. , Eskinazi Daniel P. 
Published: February 2007

AbstractIndirect immunofluorescence performed with 2 polyclonal and 4 monoclonal antibodies directed against human β2‐microglobulin (β2m) revealed the presence of a β2m‐like determinant on the membrane of a subpopulation of earthworm leukocytes classified as weakly adherent acidophils. Two out of the 4 monoclonal antibodies were found to bind to 15% of the earthworm leukocytes. Similar results were obtained with antibodies specific for β2m and isolated by affinity chromatography from either polyclonal antiserum or anti‐β2m hybridoma supernatant. Additional binding inhibition and competition experiments strengthened the results and suggested that the homology between the structure present on earthworm leukocytes and human β2m may be restricted to only one major determinant. The existence of a β2m‐like molecule in earthworms may provide important clues for understanding protein evolution and basic immune mechanisms.
The introduction of one or two 3β‐cholestanyl residues into benzylpenicilloyl‐eicosa‐L‐lysines greatly potentiates their tolerogenicity for anti‐benzylpenicillol IgE antibody formation
Authors: Lüscher Immanuel F. , Weber Ernst , de Weck Alain L. 
Published: February 2007

AbstractBALB/c mice were repeatedly immunized with microgram doses of benzylpenicilloylated Ascaris protein(s) (BPO9Asc) in alum. At different stages of the immune response, BPO21 eicosa‐L‐lysine or two analogs containing one or two hydrophobic p‐oxymethylbenzyl‐3β‐cholestanyl succinate (OSuco) groups were injected. When injected early in the immune response, the anti‐BPO IgE antibody formation was much more strongly and permanently suppressed by the lipophilic conjugates than by the hydrophilic BPO21 eicosa‐L‐lysine. A similar, but less marked, suppressive effect was observed on the anti‐BPO IgG1 response.By adoptive cell transfer experiments, it was found that the OSuco‐containing derivatives induce and act via suppressor T lymphocytes, since this cell‐mediated suppression was sensitive to cyclophosphamide or to treatment with anti‐Lyt‐2.2 antibody plus complement.When these compounds were injected into repeatedly immunized mice producing late ongoing antibody responses no differences in suppression between hydrophilic and hydrophobic derivatives were observed. In this case, the IgE response was suppressed by about 50%, while the IgG1 response was not affected.These results are compatible with the suggestion that early IgE responses are most sensitive to T cell‐mediated suppression and that T suppressor cells are better induced by lipophilic than by hydrophilic antigens. The late ongoing IgE response, on the other hand, is less amenable to T cell‐induced suppression and tolerogenic effects brought about by plurivalent BPO antigens operate directly on hapten‐specific IgE‐bearing B cells, regardless of their lipophilic character.
Influenza A hemagglutinin‐specific T cell clones strictly restricted by HLA‐DR1 or HLA‐DR7 molecules
Authors: Sterkers Ghislaine , Henin Yvette , Lepage Virginia , Fradelizzi Didier , Hannoun Claude , Levy Jean Paul 
Published: February 2007

AbstractThe antigenic specificities, major histocompatibility complex restrictions and functional properties of influenza virus‐specific proliferative cloned cell lines have been studied. These lines were specific for the H3 hemagglutinin subtype of influenza A viruses. By using a large panel of HLA‐phenotyped antigen‐presenting cells, it was found that the polymorphic structures, defined as DR1 and DR7 molecules, or closely associated structures, function as the restricting elements. We excluded for these lines a possible restricting role of supertypic specificities, known cross‐reacting elements on DR molecules, or products of other loci in known linkage disequilibrium with the HLA‐DR molecules. Such exquisitely restricted clones might be of great help in the class II typing of antigen‐presenting cells. Their specific activity was stable for several months. This has allowed the study of some functional properties of these long‐term‐cultured cloned cell lines: interleukin 2 sensitivity and production, helper function in specific antibody synthesis and ability to stimulate in mixed leukocyte reactions.
Pecking order among tumor‐specific antigens
Authors: Urban James L. , van Waes Carter , Schreiber Hans 
Published: February 2007

AbstractThe ultraviolet light‐induced fibrosarcoma 1591 is regularly rejected upon transplantation into young syngeneic mice; in rare instances, however, this tumor grows progressively and the tumors that develop are then heritably stable variant progressor tumors (1591‐PRO tumors). In this study, we have induced transplantation resistance to 1591‐PRO tumors and determined which antigens were recognized by mice that rejected these progressor tumors. We found that cytolytic T cells of such mice recognized a 1591‐specific antigen that was present not only on all the independently derived 1591‐PRO tumors but also on the parental regressor tumor (1591‐RE). However, the cytolytic immune response of mice that rejected 1591‐RE lysed 1591‐RE tumor cells but not 1591‐PRO tumor cells. Thus, the 1591‐RE tumor seemed to express two antigens that were specific for tumors of the 1591 lineage, one that was lost and a second that was retained by 1591‐PRO tumor cells. Mice challenged with 1591‐RE tumor cells mounted a response to only one of the tumor‐specific antigens which was therefore “immunodominant” over the other “immunorecessive” antigen. This immunorecessive antigen became the target of the immune response once the immunodominant antigen was lost. This “pecking order” interfered with the simultaneous recognition of two tumor‐specific antigens and this mechanism may favor immune escape.
Acetylcholinesterase of Schistosoma mansoni: antigenic cross‐reactivity with Electrophorus electricus and its functional implications
Authors: Tarrab‐Hazdai Rebecca , Levi‐Schaffer Francesca , Smolarsky Moshe , Arnon Ruth 
Published: February 2007

AbstractAcetylcholinesterase (AChE) of the parasite Schistosoma mansoni cross‐reacts with rabbit antibodies against AChE from the electric eel. Cross‐reactivity was demonstrated by radioimmunoassay with sonicate, as well as soluble, preparations from various stages of the parasite life cycle. On sucrose density gradient, the parasite enzyme migrates as an 7.5 S form, whereas an 9.5 S peak is observed with the enzyme‐antibody complex. Immunofluorescence microscopy shows specific staining of intact schistosomula as well as of adult worms. Moreover, the interaction of these antibodies resulted in a marked complement‐dependent cytotoxicity towards intact schistosomula, indicating that AChE is an antigen of significance on the surface of the parasite.
B lymphocyte activation upon exclusive recognition of major histocompatibility antigens by T helper cells
Authors: Pobor Grgur , Pettersson Sven , Bandeira Antonio , Martinez‐A. Carlos , Coutinho Antonio 
Published: February 2007

AbstractThis study has investigated whether exclusive recognition of I‐A or I‐E molecules on the B cell surface by T helper cells is sufficient to activate resting B cells. Lines and clones of long‐term‐cultured T helper cells with specificity for I‐A or I‐E antigens have been derived from mixed lymphocyte cultures between spleen cells from major histocompatibility complex (MHC)‐congenic mouse strains. These cells were tested for helper activity and proved competent to induce resting B lymphocytes expressing the specific MHC antigens to polyclonal expansion and maturation to Ig secretion. B cell activation was shown to require direct recognition of I‐A/E antigens by the helper cells on the responding B lymphocyte surface and it could not be achieved by soluble factors released by “third‐party” helper cell activity ongoing in the same cultures. Since B lymphocyte activation occurs in the absence of antigen recognition by the responding B cells, these observations suggest that I‐A and I‐E molecules expressed on the B cell surface participate in the functional reception of T helper cell‐derived induction signals.
Identification of an anti‐monocyte monoclonal antibody that is specific for membrane complement receptor type one (CR1)
Authors: Hogg Nancy , Ross Gordon D. , Jones David B. , Slusarenko Margaret , Walport Mark J. , Lachmann Peter J. 
Published: February 2007

AbstractA monoclonal antibody (E11) was produced by immunization of mice with intact human cells of monocyte lineage. Despite the finding that E11 did not inhibit rosettes with C3b‐coated sheep erythrocytes (EC3b), several lines of evidence indicated that E11 was specific for complement receptor type one (CR1). All monocytes, neutrophils, lymphocytes and erythrocytes that reacted with E11 formed EC3b rosettes. The E11 antigen on these cells was shown to be a molecule of 222 × 10 kDa. Treatment of lymphocytes, monocytes, and neutrophils with E11 followed by fluorescein‐coupled F(ab′)2 anti‐mouse‐IgG at 37 °C in buffer lacking sodium azide, led to capping or apparent endocytosis of the E11 antigen and a diminution in CR1 activity of 88%, 59% and 25%, respectively. This same treatment had no detectable effect on monocyte or neutrophil CR3 activity (EC3bi rosettes). Furthermore, with E11‐capped lymphocytes, the residual EC3b rosetting was capped directly over the E11‐fluorescence cap, whereas EC3d, g rosetting (CR2 specific) was undiminished and distributed evenly around the circumference of cells containing E11‐fluorescence caps. Finally, the binding of E11 to cells was inhibited by the prior treatment of these cells with a well characterized rabbit polyclonal anti‐CR1. These data indicated that E11 was specific for a site in CR1 that was distal from the C3b‐binding site, so that E11 was unable to block CR1 activity. E11 proved to be useful for identifying CR1 on various cells in tissue sections, and for quantitating CR1 on erythrocytes and neutrophils. Erythrocytes and neutrophils from normal individuals were found to bind an average of 610 and 4.6 × 104 125I‐labeled E11 molecules per cell. When E11 was visualized in tissues by immunoperoxidase staining, the cells that apparently contained the greatest amounts of CR1 were dendritic reticulum cells and kidney podocytes. The E11 reactive dentritic reticulum cells were characteristic of both follicular and diffuse follicular center cell tumors. Lymphocytes from patients with chronic lymphocytic leukemia (CLL) characteristically expressed little E11, confirming earlier studies that CLL cells lacked CR1 activity detected by EACI‐3b rosette formation. Because normal B cells have been shown to express CR1 at a very early stage of maturation, the absence of CR1 on CLL cells is discordant with the immature nature of CLL cells defined by immunoglobulin expression.
MRC OX‐19: A monoclonal antibody that labels rat T lymphocytes and augments in vitro proliferative responses
Authors: Dallman Margaret J. , Thomas Matthew L. , Green Jon R. 
Published: February 2007

AbstractA mouse monoclonal antibody, designated MRC OX‐19, has been prepared that binds to virtually all rat thymocytes, T lymphocytes and a maximum of 2% B lymphocytes. Immunoperoxidase studies on tissue sections showed no reactivity with nonlymphoid cells in intestine, thymus, spleen and lymph node. The antigen recognized by MRC OX‐19 antibody was identified by metabolic and cell surface labeling of thymocytes followed by immunoprecipitation and sodium dodecyl sulfate gel elec‐trophoresis. It is a surface glycoprotein of Mr = 69000. When included in in vitro assays for T cell functions, MRC OX‐19 increased proliferation stimulated by allogeneic spleen cells or the lectins phytohemagglutinin and concanavalin A. The antibody itself was not mitogenic and its stimulatory effect could be correlated with an increase in interleukin 2 production. Taken together the data suggest that MRC OX‐19 could be the equivalent of mouse Ly‐1 antigen and human T1 antigen.
Control of the immune complex‐complement interaction by protein H of the alternative complement pathway and the natural inhibitor heparin
Authors: Spycher Martin O. , Nydegger Urs E. 
Published: February 2007

AbstractThe potential of the negative regulatory protein H of the alternative complement pathway convertase and of heparin in modulating the complement‐dependent capacity of fresh serum to inhibit immune complex precipitation (CIICP) between bovine serum albumin (BSA) and rabbit anti‐BSA as well as tetanus toxoid (TT) and human anti‐TT was assessed. Additions of purified H to serum to increase the intrinsic concentration of this protein by 80% (BSA‐anti‐BSA system) and 190% (TT‐anti‐TT system) resulted in an inhibition of CIICP by 50% and 60%, respectively, whereas further increase of the amount of H lead to a decrease of its inhibitory activity. A similar effect was observed with heparin: at a concentration of 400 U/ml a 90% inhibition of CIICP in the TT‐anti‐TT system was obtained which diminished at higher heparin concentrations. The effect of H on C3 deposition to immune aggregates was assessed through its influence on C3b‐mediated immune adherence hemag‐glutination; factor H dose‐dependently suppressed such hemagglutination induced by aggregated human IgG or preformed TT‐anti‐TT complexes when added to the immune complex‐fresh serum mixture at the outset but not after 45 min of the 37 °C incubation period which means that H inhibited more likely decoration of immune complexes with C3b than it did inhibit the interaction of C3b‐coated immune complexes with erythrocytes. This suppressive effect of H was reversed by the simultaneous addition of the activating protein B. Complement‐mediated binding of tritiated C3 to latex‐bound human IgG was assessed and H was found to dose‐dependently inhibit such binding with a maximal inhibition of 37% at a H concentration of 7 μg/ml.
Binding of a murine monoclonal anti‐DNA antibody to Raji cells. Implications for the interpretation of the Raji cell assay for immune complexes
Authors: Tron François , Jacob Laurent , Bach Jean‐François 
Published: February 2007

AbstractA murine monoclonal anti‐DNA antibody binds to the plasma membrane of Raji cells at its antigen‐combining site. This result urges caution in the interpretation of a Raji positivity in human sera containing anti‐DNA antibodies.
The effect of T lymphocyte depletion on neonatal tolerance induction, graft‐vs.‐host disease and cellular chimerism
Authors: Rayfield Lee S. , Brent Leslie 
Published: February 2007

AbstractTreatment with a monoclonal anti‐Thy‐1 antibody and complement completely prevented C57BL spleen cells from causing graft‐vs.‐host disease following their inoculation into newborn CBA mice. The proportion of mice that became tolerant to C57BL antigens, as measured by skin grafting, was significantly less compared with mice given (CBA × C57BL)F1 hybrid cells. This was not due to the elimination of T cells, for antibody‐treated F1 cells induced tolerance as readily as complement‐treated control F1 cells.To investigate whether the apparent superiority of F1 cells over C57BL cells is attributable to differences in the mechanism inducing and maintaining unresponsiveness, two approaches were followed. First, the level of donor cell chimerism in the spleens of tolerant animals was studied. Though no difference between F1 and C57BL cells was uncovered, the presence of T cells in the donor inocula favored the establishment of chimerism. Second, the involvement of suppressor T cells was examined in adoptive transfer experiments. Splenic suppressor T cells were associated with tolerance regardless of how it was elicited. Preliminary results with F1 cells show that the tolerogenic property is not confined to any one cell type. It is proposed that the greater tolerogenicity of F1 cells is brought about by the presence of host‐type (self) antigens, which enable the tolerogenic signals to operate without recourse to antigen processing by host cells.
Mechanism of T lymphocyte activation by OKT3 antibodies. A general model for T cell induction
Authors: Landegren Ulf , Andersson Jan , Wigzell Hans 
Published: February 2007

AbstractThe OKT3 monoclonal antibody has unique reactivity for human T cells and induces a mitogenic response equal to that of concanavalin A (Con A). However, significant differences were found in activation requirements for the two T cell mitogens. Although both OKT3 and Con A required living accessory cells for stimulation of T cells, the OKT3 antibody was optimally mitogenic at a molar concentration 103 times less than Con A. Under such conditions, the two mitogens showed similar kinetics as well as magnitude or responses. Furthermore normal IgG blocked the OKT3‐induced proliferation selectively. The inhibition is most likely caused by the Fc portion of IgG competing for Fc receptors on accessory cells. The different requirements for activation are discussed in relation to the T cell receptor and its role in T cell activation.
Nucleotide sequence of a cDNA encoding the constant region of a rabbit immunoglobulin light chain of the λ type
Authors: Duvoisin Robert M. , Kocher Hans P. , Garcia Irène , Rougeon François , Jaton Jean‐Claude 
Published: February 2007

AbstractA cDNA library has been constructed in the plasmid pBR322 using as template 12 S poly(A)‐RNA isolated from spleen cells of a hyperimmunized Basilea rabbit. One of these cDNA‐containing clones was used to determine the nucleotide sequence coding for the λ light chain constant (C) region. The deduced amino acid sequence of this cDNA was found in good agreement with a Basilea rabbit Cλ region amino acid sequence previously determined. The nucleotide sequence of the rabbit Cλ‐coding region was compared with man, mouse and chicken Cλ sequences and showed 78%, 72% and 66% homology, respectively. Southern blot hybridization analyses of liver DNA from various rabbits were carried out. The comparison of the restriction patterns suggests that a few Cλ‐related genes occur in the rabbit genome. In addition, discrete differences in the restriction patterns may exist between rabbits of different genetic backgrounds.
Reactions among IgM antibodies derived from normal, neonatal mice
Authors: Holmberg Dan , Forsgren Stina , Ivars Fredrik , Coutinho Antonio 
Published: February 2007

AbstractAttempting to obtain a representative sample of the “natural antibody” repertoire in the developing immune system, we have derived IgM‐secreting hybridomas from 4 normal untreated BALB/c mice of the same litter on day 6 after birth. Partially purified IgM preparations obtained in the supernatants of 70 such clones were each screened in binding assays for reactivity with a panel of 9 IgM antibodies, randomly selected from the same collection. Five of these 9 IgM antibodies were found to react with a considerable number of other IgM in the collection, while the other 4 showed only sporadic reactivity. On the other hand, more than half of the 70 antibodies were found to bind specifically to at least one of these five. With a few exceptions, these reactions showed quantitative levels ranging from 5 to 20% of those observed between either of the two interacting IgM and monoclonal rat anti‐μ antibodies. The selectivity of these reactions indicated V‐region specificity, which was confirmed by analyzing in some detail the reaction between 2 IgM antibodies isolated from the same mouse.
Direct demonstration of multiple VH allotopes on rabbit Ig molecules: allotope characteristics and Fab arm rotational flexibility revealed by immunoelectron microscopy
Authors: Roux Kenneth H. 
Published: February 2007

AbstractImmune complexes composed of rabbit IgG and Fab fragments of antibody specific for the VH framework allotypes were analyzed by molecular immunoelectron microscopy. In this manner, the number of allotypic epitopes (allotopes) and their approximate topological location could be determined. A monoclonal anti‐allotype Fab was used to show that relatively fine details of allotope location and orientation are demonstrable with this technique. Each of the three VH allotypes (a1, a2 and a3) was found to express at least two spacially separated allotopes. The locations of the allotopes varied for each of the three allotypes. Some allotopes were observed near the VH‐CH1 switch region while others were in close proximity to the complementarity‐determining region or were at intermediate positions. In addition to the information concerning allotope topology, the variety of configurations resulting from the interaction of monoclonal antibody Fab with IgG suggest considerable rotational flexibility (twisting) of the Fab arm of IgG about its long axis.
Autoregulation of autoantibody synthesis in mercuric chloride nephritis in the Brown Norway rat II. Presence of antigen‐augmentable plaque‐forming cells in the spleen is associated with humoral factors behaving as auto‐anti‐idiotypic antibodies
Authors: Chalopin Jean Mark , Lockwood Christopher M. 
Published: February 2007

AbstractPlaque‐forming cell (PFC) assays were used to investigate in vitro the immunoregulatory mechanism operating in the self‐limiting anti‐glomerular basement membrane (GBM) autoantibody response of Brown Norway (BN) rats given HgCl2. The peak splenic PFC response occurred at day 9; thereafter the response fell sharply and was rarely detected after day 12. In specificity studies, incorporation of soluble GBM in the PFC assays of animals at day 9 had two distinct effects. In some animals the PFC response was inhibited in a dose‐dependent fashion; however, in others an augmented number of PFC was observed. Furthermore, addition of GBM to the PFC mixture from certain animals studied at day 12 (or after) revealed large numbers of GBM‐specific PFC when originally no GBM‐specific PFC had been observed in the standard PFC assay. Sera from such animals, with and without antigen‐augmentable PFC, were incorporated in the PFC mixture containing cells taken from day 9 animals. Sera from animals with revealed plaques could inhibit the GBM‐specific PFC response of day 9 animals, whereas sera from animals without revealed plaques could not. Thus sera, from BN rats whose own antibody levels were falling, could inhibit the GBM‐specific plaque‐forming capability of cells from animals at an earlier stage of the autoimmune response and showed the potential importance of humoral factors, putatively anti‐idiotypic antibodies, in effecting autoregulation of autoantibody formation in this model.
Monoclonal antibodies to stromal cell types of the mouse thymus
Authors: van Vliet Els , Melis Marleen , Van Ewijk Willem 
Published: February 2007

AbstractSeven hybridoma cell lines secreting monoclonal antibodies (mAb) to nonlymphoid cells of the mouse thymus have been prepared. These mAb clearly demonstrate the heterogeneity of the thymic stroma. Based on their anatomical distribution patterns observed with the immunoperoxidase technique on frozen tissue sections, they were subdivided into four groups. The first group of mAb, ER‐TR1, 2 and 3, detects antigens encoded for by the I region of the major histocompatibility complex. These antigens are expressed on both stromal and lymphoid cells in lymphoid organs. mAb of the second category, ER‐TR4, react with epithelial cells in the thymic cortex. mAb of the third group detect stromal cells of the thymic medulla. One antibody of this group, ER‐TR5, exclusively reacts with medullary epithelial cells. ER‐TR6, the other antibody of this group, reacts with medullary interdigitating cells and macrophages. The fourth type of antibodies, ER‐TR7, detects the reticular fibroblasts of the thymus. The possible role of the thymic cell types detected by the present antibodies in T cell differentiation is discussed.