bluuebunny/crossref_metadata_2025_split huggingface dataset:
B lymphocyte development in fetal liver
Authors: Melchers F. 
Published: February 2007

AbstractSingle cell suspensions of fetal liver cells, prepared from embryos at day 13 of gestation until birth, develop mitogen bacterial lipopolysaccharide (LPS)‐reactive B cells “in vitro” within the same time as they do “in vivo”. The development of these mitogen LPS‐reactive B cells in vitro is dependent on unknown components of fetal calf serum, found in some but not all batches. It does not require the presence of the corresponding B cell mitogens, i.e. LPS, in culture. Fetal liver cells, put in culture at different times of gestation, all acquire LPS reactivity at the equivalent of birth in vitro. When the cells have become LPS‐reactive, they are then stimulated by LPS to growth and maturation into clones of IgM‐secreting, IgA‐secreting and IgG‐secreting plaque‐forming cells (PFC). The development of these PFC responses is mitogen‐dependent: in the absence of LPS only 2‐5 % of the LPS‐stimulated PFC responses develop. Only the magnitude, but not the development in time, of LPS reactivity of fetal liver cells is different in vivo and in vitro. This may indicate either that an early precursor cell to LPS‐reactive B cells can only divide in vivo but not in vitro, or that early precursors continue to migrate with time of gestation into fetal liver. After birth B cells in liver are immediately reactive to LPS; however, they rapidly leave the liver.Few, if any, dextrans sulfate or lipoprotein‐reactive B cells, yielding a PFC response, develop in fetal liver cells either in vivo or in vitro. Neonatal spleen contains immediately mitogen‐reactive B cells. Comparable numbers of LPS, dextran sulfate and lipoprotein‐reactive cells are found.Development of fetal liver cells to Ig‐secreting PFC, occurs, therefore, in two stages. The first (pre‐B → B) is independent of externally added mitogen (such as LPS), the second (B → PFC) requires the addition of mitogen. The majority of spleen cells have already passed this first stage of development.
Genetic variation in antibody response and natural killer cell activity against a Moloney virus‐induced lymphoma (YAC)
Authors: Åsjö Birgitta , Kiessling R. , Klein G. , Povey Susan 
Published: February 2007

AbstractAntibody formation against the Moloney virus‐determined surface antigen (MCSA) was found to be under genetic control. In the (A × C57BL)F1 cross one dominant gene played a major role, resulting in bimodal distribution of the antibody response. This gene showed no linkage to H‐2, IgG heavy chain immunoglobulin allotype, the coat color markers B and C, and five different isozyme markers representing chromosome numbers 1,4,7,8 and 9. Antibody response to MCSA was not correlated with antibody titers against the virion proteins, confirming that MCSA was an independent entity. There was no relationship between the segregation of natural killer cell activity and antibody response in a [(A × C57BL) × A] backcross population.
Inhibition of lymphocyte proliferation by factor(s) produced by Schistosoma mansoni
Authors: Dessaint J.P. , Camus D. , Fischer E. , Capron A. 
Published: February 2007

AbstractNormal spleen cells of CBA mice or Fischer rats were cultured with mitogens or allogeneic cells, together with various substances of Schistosoma mansoni origin, and thymidine uptake was measured. The proliferation (DNA synthesis) of normal lymphocytes was inhibited by the incubation product of the parasite as well as by cell‐free supernatant of schistosome culture. Inhibition was obtained only when active materials were added at the beginning of the culture. Both T and B cell proliferation were inhibited. The inhibitory activity found in cell‐free supernatant suggested the release by the parasite of some factor(s) interfering with lymphocyte proliferation. Moreover, serum from rats infected by S. mansoni inhibited lymphocyte proliferation also. The inhibitor(s) appeared heat resistant, dialyzable and of low molecular weight (500–1000). Incubation of normal spleen cells with S. mansoni inhibitor(s) did not enhance the release of nonspecific suppressor cell factor. The inhibition product(s) released by the parasite could explain part of the immunosuppression status found in schistosomiasis.
Role of epitope density in the induction of immunity and tolerance with thymus‐independent antigens IV. Selective tolerance of IgE response by DNP‐levan conjugates
Authors: Desaymard Catherine 
Published: February 2007

AbstractTolerance induction of IgE antibody‐forming cells by dinitrophenylated levan (DNP‐LE) conjugates was investigated in CBA mice. Antibody production was measured by passive coutaneous anaphylaxis on rat skin. Specific antibody neutralization was obtained with conjugates of different substitution degrees. Specific inhibition of IgE antibody production was obtained only with highly substituted conjugates. However, the epitope density required for inducing tolerance to antibody synthesis of the IgE class was lower than for other classes of immunoglobulins. The tolerance induced by DNP‐LE was shown to affect only the anti‐DNP B cells of IgE class without T cell participation.These results demonstrate that B cell precursors of all Ig classes are susceptible to tolerance induction and not to triggering by T‐independent antigens.
Evidence for a similar or common mechanism for natural killer cell activity and resistance to hemopoietic grafts
Authors: Kiessling R. , Hochman Paula S. , Haller O. , Shearer G. M. , Wigzell H. , Cudkowicz G. 
Published: February 2007

AbstractTwo types of host reactivities not requiring immunization in the mouse and not mediated by T lymphocytes were compared: resistance of irradiated and nonirradiated F1 hybrids to accept parental grafts of normal or malignant hemopoietic cells (Hh system), and the natural killer cell activity against mouse lymphomas (NK system). The effects of six independent variables known to influence resistance to marrow grafts were investigated in the NK system using YAC‐1 lymphoma cells as targets. The following properties were shared: (a) maturation during the fourth week of life; (b) low sensitivity to acute total body irradiation; (c) dependence on the integrity of bone marrow as demonstrated by reduced reactivity in 89Sr‐treated mice; (d) suppression by a single injection of rabbit anti‐mouse bone marrow serum; (e) suppression by a single injection of the anti‐macrophage agents silica and i‐carrageenan; and (f) suppression by multiple injections of parental spleen cells into F1 mice. These positive correlations are particularly significant because most of the variables have either opposing or no effect on conventional immunity. F1 mice rendered specifically unresponsive to parental marrow grafts, could retain NK cell activity, and genetically susceptible mice could be rendered hyporeactive in terms of NK cells, indicating that the specificities of YAC‐1 and Hh‐1 incompatible targets were different.It is extremely unlikely that this remarkable parallelism is fortuitous. These results indicate that either a very similar, or more likely a common mechanism is operative in the two cell‐mediated natural reactivities: effector cells in the NK and Hh systems do not bear B or T lymphocyte markers but are nevertheless endowed with “specificity”. They are dependent for generation in vivo (presumably by maturation or by recruitment) on the interaction with nonlymphoid accessory cells not endowed with specificity, capable of also interacting in vitro with Thy‐1‐positive F1 hybrid prekiller cells specific for parental targets. Because of thymus independence in vivo and apparent restriction to target cells of the hemopoietic system, these reactivities should be effective in the regulation of hemopoiesis and surveillance over leukemogenesis.
A myeloma hybrid producing antibody specific for an allotypic determinant on “IgD‐like” molecules of the mouse
Authors: Pearson T. , Galfrè G. , Ziegler A. , Milstein C. 
Published: February 2007

AbstractA hybrid cell line was produced by fusing a mouse myeloma line with spleen cells from BALB/c mice immunized with B10 cells. The hybrid line grew in tissue culture and in syngeneic mice and produced IgM antibody specific for “IgD‐like” molecules of mice with the Igb haplotype. The concentration of monoclonal antibody in the serum of tumor‐bearing animals reached about 2 mg/ml and gave cytotoxic titers of up to 1:800 000. The derivation of the line, some properties of the antibody secreted and the nature of its antigenic target aredescribed.
Immunosuppressive factor(s) specific for L‐glutamic acid50‐L‐tyrosine50 IV. In vitro activity and immunochemical properties
Authors: Thèze J. , Waltenbaugh C. , Germain R.N. , Benacerraf B. 
Published: February 2007

AbstractThe responsiveness of BALB/c spleen cells to the terpolymer L‐glutamic acid60‐L‐alanine30‐L‐tyrosine10(GAT), the copolymer of L‐glutamic acid50‐L‐tyrosine50 (GT) and the corresponding complexes with methylated bovine serum albumin (MBSA) has been studied in vitro in a modified Mishell‐Dutton culture system, Cultures of BALB/c spleen cells respond to GAT, GAT‐MBSA and GT‐MBSA over a wide dose range. Contrary to in vivo findings BALB/c spleen cell cultures respond to GT in vitro although in a much narrower dose range. Lymphoid extracts from GT‐primed BALB/c or B10.BR mice (GT‐TSF) specifically suppress the GT‐MBS A response in vitro. This culture system has allowed us to further investigate immunochemical properties of both BALB/c and B10.BR GT‐TSF. GT‐TSF from both strains display affinity for GT‐Sepharose and bear determinants encoded by the I region of the H‐2 complex. Moreover, we demonstrate that the suppressive activity from B10.BR mice is a molecule or a molecular complex which displays affinity for GT and bears determinants of the I‐J subregion of the H‐2k haplotype.
B cell antigens on effectors for natural cell‐mediated cytotoxicity
Authors: Koide Y. , Takasugi M. , Billing R. 
Published: February 2007

AbstractCell suspensions enriched for N cells, the effector cell for human natural cell‐mediated Cytotoxicity, were observed t o react strongly with a rabbit antiserum directed against an antigen associated with B cells. Treatment of the effector suspension with the antiserum resulted in inhibition of natural cell‐mediated cytotoxicity. The blocking occurred, however, only with the intact antibody indicating that inhibition was caused through the formation of antigen‐antibody complexes. The antiserum was then employed t o arm natural effector cells to react specifically with B cell lines. Specific arming was achieved after the formation of antigen‐antibody complexes was prevented by initially reacting the effector suspension with F(ab′)2 of the anti‐B cell antibody. This study also supports the identity of the subset of cells responsible for antibodydependent and natural cell‐mediated cytotoxicit y and the similarity in their mechanisms.
Derivation of hybrids between a thymoma line and spleen cells activated in a mixed leukocyte reaction
Authors: Köhler G. , Lefkovits I. , Elliott B. , Coutinho A. 
Published: February 2007

AbstractWe have established 16 independent hybrid lines derived from a fusion between an AKR thyrnoma and mixed leukocyte reaction‐stimulated C57BL/6 spleen cells. The hybrids express both parental H‐2 alleles and show hybrid glucose‐6‐phosphate isomerase activity. Two of the lines showed Fc receptor activity not expressed in the parental thymoma. The AKR Thy‐1.1 allele was expressed in all hybrid lines, but no Thy‐1.2 could be detected. No killing activity was retained in the hybrid cells, probably because Sendai virus‐mediated fusion of killer cells resulted in the lysis of the thymoma fusion partner.
Idiotype‐bearing and antigen‐binding receptors produced by blood T lymphocytes in a case of human myeloma
Authors: Preud'Homme J.L. , Klein M. , Labaume Sylvaine , Seligmann M. 
Published: February 2007

AbstractTwenty‐five to 30 % of blood lymphocytes from a myeloma patient with an IgGl(k) protein with antibody activity to horse α2‐macroglobulin (α2M) reacted with purified IgG from a rabbit antiserum to the idiotypic determinants of this protein. A small proportion of these idiotype‐bearing lymphocytes were IgG‐bearing B cells, but most of them were T cells. Several experiments demonstrated the actual synthesis of the idiotypic structures carried by the T lymphocytes. All idiotype‐bearing lymphocytes bound horse α2M, and the structures that bore the idiotype and bound the antigen were shown to completely cocap. After biosynthetic labeling with 14C‐labeled amino acids, immunoprecipitation and sodium dodecyl sulfate gel electrophoresis, the anti‐idiotypic serum and the α2M antigen were found to react with the same molecules. Preliminary data on the size of these antigen‐binding T lymphocyte‐derived molecules are in accord with those of Binz and Wigzell (Scand. J. Immunol. 1976. 5: 559) in the rat. The finding in this patient with multiple myeloma of a homogeneous and possibly malignant population of T lymphocytes, synthesizing identical antigen receptors which share idiotypic (but not isotypic) determinants of the immunoglobulin molecule produced by the malignant B cell clone, therefore confirms in man the results of several recent studies in other mammalian species.
Idiotype‐specific neonatal suppression of phosphorylcholine‐responsive B cells
Authors: Accolla R. S. , Gearhart Patricia J. , Sigal N. H. , Cancro M. P. , Klinman N. R. 
Published: February 2007

AbstractThe effect of neonatal anti‐idiotypic suppression on the expression of B cells of the T15 clonotype has been investigated at the level of individual clonal precursor cells. The results indicate that B cells of the T15 clonotype are almost completely eliminated from the repertoire for four months after neonatal injection of allogeneic anti‐idiotypic serum. The degree of this suppression is dependent on the amount of anti‐idiotypic antibody administered and is less profound if anti‐idiotypic antibody is given after the first week of life. No suppression was observed when anti‐idiotypic antisera were administered to mice 30 days of age or older, which may indicate that immature B cells are the population most susceptible to suppression. However, since suppression could be reversed by administration of T15 myeloma protein several days after injection of anti‐idiotype, the inability to suppress adult BALB/c mice may have been due to the high level of T15 idiotype normally present in their serum. Finally, phosphorylcholine‐responsive B cells of identifiable clonotypes other than T15, even a clonotype sharing antigen‐combining site determinants with T15, appear unaffected by anti‐T15 suppression.
Evolution of the lymphoid system II. Evidence for immunoglobulin determinants on all rainbow trout lymphocytes and demonstration of mixed leukocyte reaction
Authors: Etlinger H. M. , Hodgins H. O. , Chiller J. M. 
Published: February 2007

AbstractIndirect fluorescent antibody analyses utilizing antiserum specifc for rainbow trout serum immunoglobulin (Ig) demonstrated that essentially all rainbow trout lymphocytes from thymus, spleen, anterior kidney and peripheral blood possess either Ig determinants or structures which cross‐react with those determinants found on serum Ig.Peripheral blood leukocytes from rainbow trout were found to be capable of participating in a mixed leukocyte reaction. This observation is discussed in terms of the evolution of T cell function.
Conformational flexibility of an antibody combining site composed of two identical V regions
Authors: Gavish M. , Dwek R. A. , Givol D. 
Published: February 2007

AbstractThe variable portion of the light chain (VL) of protein 315 was studied as a model for antibody composed of two “like” chains. VL exists as a dimer which contains the binding subsite for the dinitrophenyl (Dnp) ring of Dnp ligands. Circular dichroism analysis of hapten‐protein complex demonstrated that the geometry of the Dnp hapten in the (VL)2 binding site is different from that in the Fv (composed of VL–VH) site. The VL dimer was found to be present in two distinct, pH‐dependent conformations which differ markedly in their binding properties. At pH 8.0 VL dimer binds two Dnp‐lysine per dimer, whereas at pH 6.0 only one ligand is bound per (VL)2. The association constant of (VL)2 for Dnp‐L‐lysine at pH 6.0 is 3–4‐fold higher than that at pH 8.0. The geometry of the hapten in the combining site is also different in the two conformers of (VL)2 as can be judged from the disappearance at pH 6 of the 480 nm and 390 nm absorbance bands in the difference spectrum of VL‐bound Dnp‐caproate. The pH‐dependent changes in the difference spectra between bound and free ligands were used to follow the transition between the two conformers of VL dimer. It was concluded that the pKa of this transition is at pH 6.9. The change in VL conformation is also expressed in a 2–3‐fold enhancement of VL fluorescence between pH 6 and pH 8, suggesting that the conformation at pH 8 which binds two ligands is more open, whereas at pH 6 a more tight conformation exists, binding one ligand with higher affinity. Such changes were not observed with Fv which is composed of both VL and VH‐These data suggest that an antibody site composed of two like chains (VL–VL) can undergo marked conformational changes at physiological pH values. The relevance of this finding to problems of receptors on thymus‐derived lymphocytes is discussed.
Human B cell differentiation. I. Immunoglobulin synthesis induced by Nocardia mitogen
Authors: Lêthibichthuy  , Ciorbaru Rita , Brochier J. 
Published: February 2007

AbstractNocardia water‐soluble mitogen (NWSM) is a mitogen which activates human B lymphocytes even in the absence of T cells. Tonsil and peripheral blood lymphocytes cultured in the presence of NWSM gave rise to large numbers of cells containing cytoplasmic immunoglobulins of IgM, IgA or IgG classes. The number of plasma cells appeared to be elevated as early as day 3 of culture and peaked on day 5 or 7. The IgM response preceded the development of cells containing other Ig classes, and was found to remain predominant on days 5 and 7. A similar number of plasma cells were generated in T‐deprived suspensions; however, a quantitative regulation by T cells cannot yet be excluded. The response to pokeweed mitogen appeared to be similar, except that it was often less intense and not observed in the absence of T cells. Very few or no IgD‐containing cells were found to be differentiated with both mitogens.
Rapid disappearance from serum of intravenously injected rat myeloma IgA and its secretion into bile
Authors: Jackson G. D. F. , Lemaǐtre‐Coelho Isabel , Vaerman J.‐P. , Bazin H. , Beckers A. 
Published: February 2007

AbstractIntravenously injected monoclonal rat IgA is first removed from rat serum at a very fast rate (93% in 4 h), then at a much slower rate (t/2 = 24 h). The rapid initial disappearance is thought to be due in part to secretion into rat bile. This was demonstrated by rat liver perfusions with semisynthetic medium containing diluted (1:200) IgA myeloma serum. During perfusion, the cannulated bile displayed increasingly high levels of this IgA, with a bile to medium ratio of 38 after 1 h of perfusion; at the same time, there was a 40% drop of the rat monoclonal IgA concentration in the medium, which was not observed for rat IgG2a and albumin. All of the monoclonal biliary IgA was bound to secretory component. The rat liver is thus able to actively secrete a monoclonal IgA from the circulation into bile against a strong concentration gradient.
Eosinophil‐dependent cytotoxicity in rat schistosomiasis. Involvement of IgG2a antibody and role of mast cells
Authors: Capron Monique , Capron A. , Torpier G. , Bazin H. , Bout D. , Joseph M. 
Published: February 2007

AbstractUsing Schistoma mansoni schistosomula collected in vitro and sensitized with 42‐day‐infected rat serum, normal rat peritoneal cells enriched in eosinophils were proven to subsequently adhere to and kill the schistosomula within 24 to 48 h. The cell‐dependent, heat‐stable antibody in infected rat serum reached a peak between 30 and 42 days after infection. Inhibition experiments with aggregated immunoglobulins indicated the role of IgG2a antibody in the adherence of eosinophils to sensitized schistosomula. The immune absorption technique showed that IgG2a antibody was involved in the mechanism of cytotoxicity of effector to target cells, whereas the role of IgE antibody could be excluded.Ultrastructural studies revealed the constant presence of eosinophils and mast cells in contact with schistosomula. The use of purified cell populations showed that the cytotoxic effect of the original cell population was significantly decreased after depletion of mast cells and partially restored after addition of mast cells. These observations, together with those concerning the role of IgE immune complexes in macrophage cytotoxicity, suggest the possible participation of anaphylactic antibodies in immunity to schistosomes in the rat.
Suiciding of lymphocytic precursor cells by tritiated nucleosides, in vitro
Authors: Uyeki E. M. , Nishimura T. , Bisel Teresa U. 
Published: February 2007

AbstractDifferences in suiciding by various tritiated nucleosides were observed between two functional assays for in vitro lymphocytic precursor cell development, the hemolysin plaque‐forming cell (PFC) assay and the B lymphocytic colony‐forming cell (CFC‐L) assay, using BDF1 mouse spleen cells. PFC growth was markedly reduced by an early (days 0–1) pulse of tritiated deoxyadenosine ([3H]dAdo), but relatively unaffected by a pulse of tritiated thymidine ([3H]dThd) during the same interval. In contrast, CFC‐L formation significantly dropped after an early (day 0) [3H]dThd pulse, as well as after pulses of [3H]dAdo and the corresponding tritiated ribosides, uridine and adenosine. This implied a cycling state in an early lymphocytic precursor cell, as opposed to the PFC insensitivity to an early [3H]dThd pulse. The response pattern of colonies and clusters to [3H]dThd supported our notion of a delayed suiciding of CFC contributing to the increase in cluster numbers.
The role of complement factors in acute antibody‐mediated rejection of mouse skin allografts
Authors: Berden J. H. M. , Capel P. J. A. , Koene R. A. P. 
Published: February 2007

AbstractEstablished, H‐2 incompatible, mouse skin allografts are destroyed in 24–48 h by a single intravenous injection of specific alloantibody and heterologous complement (C) from rabbits (RC), guinea pigs (GpC) or humans (HC). Mouse complement (MC) itself is inefficient in this respect since grafts are not destroyed by the injection of antibody alone. This is in keeping with the low efficiency of MC in in vitro cytolysis.We have studied the role of different C factors in this model. Two patterns were observed. (a) Three C‐deficient sera (GpC‐R4, GpC‐R3, RC‐R6) showed neither activity in vitro (C‐mediated lymphocytotoxicity in a trypan blue assay) nor did they induce graft destruction. Activity in vitro and in vivo could be completely reconstituted with the appropriate C component. (b) Two C‐deficient sera (GpC‐R1 and HC‐R9) were inactive in in vitro cytotoxicity but, nevertheless, induced destruction of the skin grafts if injected with antibody. Thus, in vivo, the mouse seemed to provide the deficient factor, and this was confirmed by the observation that in vitro cytotoxicity could be reconstituted not only with the appropriate C component, but also with normal mouse serum. The results show that the inefficiency of MC in vitro and in vivo does not reside in the factors C1 or C9. Furthermore, in our model C is activated via the classical pathway, and at least exogenous C4, C3 and C6 are required to induce acute antibody‐mediated graft destruction.From the experiments with C6‐deficient serum which has normal chemotactic properties, it is concluded that activation of chemotactic factors with attraction of granulocytes is not sufficient to induce rejection, but that the activation of the membrane attack unit is required.