bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cell‐free media of mixed lymphocyte cultures augmenting sensitization in vitro of mouse T lymphocytes against allogeneic fibroblasts
Authors: Altman A. , Cohen I. R. 
Published: February 2007

AbstractUsing an in vitro mouse lymphocyte anti‐fibroblast reaction (AFR), we recently reported that the addition of allogeneic stimulator lymphocytes to the sensitization phase of the AFR enhanced sensitization to fibroblast antigens as evidenced by a marked increase in the cytolytic activity of the sensitized lymphocyte population. In the present report we studied the mechanism of this helper effect by testing the capacity of cell‐free media derived from 48‐h mixed spleen cultures to enhance anti‐fibroblast sensitization. We found that such cell‐free media could produce a marked helper effect when applied to the sensitization phase of the AFR, but not when added to the cytolytic effector phase. The stimulator cells in the mixed lymphocyte culture (MLC) did not have to be syngeneic with the sensitizing fibroblasts in the AFR in order for the helper effect to be demonstrated. Lymphocytes sensitized to fibroblast antigens in the presence of MLC medium retained their specificity of the effector phase. Our data suggest that the MLC medium acts by enhancing differentiation processes of antigen‐triggered lymphocytes. Generation of helper activity by the MLC was abolished by 1000 r irradiation of the responder cells. By using nu/nu and normal spleens, both from two different strains, as cell sources for the MLC, we found that the generation of helper activity depended on T cells capable of proliferation. Furthermore, stimulator lymphocytes differing from responder lymphocytes by non‐H‐2 alloantigens as well as by point mutation within the H‐2 complex were capable of eliciting helper factor(s). Thus, soluble factor(s) produced in a MLC, which are dependent on T lymphocyte proliferation, have the capacity to enhance the sensitization of mouse lymphocytes against antigens present on allogeneic fibroblasts.
Ontogeny of the antibody‐forming cell line in mice. I. Kinetics of appearance of mature B cells
Authors: Rosenberg Yvonne J. , Cunningham A. J. 
Published: February 2007

AbstractThe development of functionally mature B cells in the liver and spleen of fetal and neonatal CBA mice has been followed. A mature B cell is defined as one giving rise to antibody‐producing progeny within 2 days in culture. Very few such B cells are found during fetal life. After birth there is a rapid rise in the numbers reaching 1/3 of adult levels in the 7‐day‐old spleen.
Independent expression of the two HL‐A antigen polypeptide chains
Authors: Ostberg L. , Rask L. , Nilsson K. , Peterson P. A. 
Published: February 2007

AbstractIt is now well established that β2‐microglobulin constitutes one of the two HL‐A antigen subunits. In this study support was obtained for the previous notion that the human lymphoma Daudi does not produce β2‐microglobulin (β2m). Papain‐solubilized as well as nonidet P‐40‐solubilized Daudi HL‐A antigens do not contain any β2m or any detectable structural analogue of this protein. The chemical and physico‐chemical characteristics of highly purified HL‐A antigens derived from Daudi cells are indistinguishable from those of the HL‐A antigen‐carrying polypeptide chain isolated from the P3HRIK cell line. Like P3HRIK‐derived HL‐A antigens, the HL‐A antigens derived from Daudi cells are composed of two identical, heavy, alloantigenic polypeptide chains with a molecular weight of about 50000 each, which are held together by disulfide bridge(s). The HL‐A antigens of P3HRIK cells contain, in contrast to Daudi HL‐A antigens, two molecules of β2m. Although no evidence was obtained suggesting any β2m synthesis in Daudi cells it was apparent that these cells express the HL‐A alloantigenic polypeptide chain in amounts similar to those of other cell lines which produce β2mThe present data suggest [1] that β2m and the alloantigenic HL‐A polypeptide chain are under separate genetic regulation [2], that the cell surface integration of the HL‐A antigen‐carrying polypeptide chain is independent of the presence of β2m and [3] that β2m does not constitute a membrane component absolutely necessary to the integrity of the cell membrane.
Studies on the generation of B lymphocytes in the mouse embryo
Authors: Owen J. J. T. , Raff M. C. , Cooper M. D. 
Published: February 2007

AbstractUsing an organ culture technique, the development of B lymphocytes has been studied in a number of isolated embryonic hemopoietic tissues. Developing B lymphocytes were identified by cytoplasmic and surface immunofluorescence using purified class‐specific antibodies and a Fab antiimmunoglobulin reagent. In fetal liver cultures these cells were further characterized for Fc and complement receptors and for the presence of mousespecific B lymphocyte antigen. The results indicate that B lymphocytes develop independently in fetal liver and in fetal spleen; they do not develop in cultures of yolk sac and thymus. In conclusion, it is likely that B lymphocyte maturation in mammals is multifocal and is not dependent upon gastrointestinal influences as suggested previously.
Characteristics of the effector cells mediating cytotoxicity against antibody‐coated target cells. II. The mouse nonadherent K cell
Authors: Greenberg A. H. , Shen L. , Walker L. , Arnaiz‐Villena A. , Roitt I. M. 
Published: February 2007

AbstractA cell of lymphoid morphology capable of killing antibody‐coated chicken erythrocytes was isolated from nonimmune mouse spleen using a combination of carbonyl iron treatment and glass bead column passage. This nonphagocytic effector cell, which is referred to as the nonadherent K (killer) cell, is distinguished from the non‐phagocytic myeloid K cell described earlier (Greenberg, A.H., Shen, L. and Roitt, I.M., Clin. Exp. Immunol. 1973. 15: 251) by its relatively weak surface adherence properties and low concentration within the mouse spleen. The cell is further characterized by its relatively large size, lack of theta or immunoglobulin determinants, the presence of Mg++‐independent complement receptors, affinity for aggregated IgG2 myeloma proteins, inhibition by cytochalasin B and good survival in cell culture. The possible lineage of the cell is discussed.
Persisting T cells in rats tolerant of human serum albumin. The significance of tolerant and nonimmune T cells which preferentially restrict high affinity antibody synthesis
Authors: Bell E. B. , Shand F. L. 
Published: February 2007

AbstractThe adoptive response of primed rat thoracic duct lymphocytes (′TDL) following specific antigen challenge (soluble human serum albumin, s‐HSA) was restricted when cells were transferred into syngeneic, adult (AS2 × AS) F1 hybrid recipients in comparison with irradiated hosts. This adoptive memory response was also inhibited in irradiated recipients by transferring nonimmune TDL along with ′TDL. Recirculating B cells (B‐TDL) did not inhibit the ′TDL response, indicating that the adoptive secondary response was regulated by T cells. Antibody synthesis was preferentially restricted in the high affinity memory cell precursor population, demonstrating a role for T cells in regulating the maturation of antibody affinity. The adoptive memory response was liberated from this T regulatory effect in adult recipients when hosts were challenged with the alum‐precipitated adjuvant form (HSA‐adj) rather than the soluble form of HSA.Since the adoptive memory response was sensitive to the presence or absence of T cells, this experimental model was used to determine whether or not T cells were eliminated from HSA‐tolerant rats. Antibody synthesis by ′TDL was reduced approximatel 10‐fold compared with controls when transferred into tolerant recipients and challenged with either s‐HSA or HSA‐adj; a similar reduction was not observed by substituting bovine serum albumin (BSA) ′TDL and challenging with s‐BSA. The tolerance‐induced inhibition of HSA ′TDL was destroyed by irradiation and TDL from HSA‐tolerant donors were more effective than normal nonimmune TDL in reducing the adoptive HSA ′TDL response. HSA‐tolerant TDL did not inhibit the BSA ′TDL response significantly.The results indicate that T cells are not eliminated by tolerance induction in this model and after interaction with tolerogen may exert an activ (or competitive) role in restricting antibody synthesis by high affinity B memory cell prcursors. However, the fact that tolerant T cells are not able to prevent a primary response suggests that unresponsiveness to HSA in the T compartment represents a functional deficiency and not an active suppression at this level. Nevertheless, the presence of these tolerant cells probably accounts for the failure of antibody affinity to mature in partially tolerant rats.
Immune response to phosphorylcholine. I. Characterization of the epitope‐specific antibody
Authors: Kluskens L. , Lee W. , Köhler H. 
Published: February 2007

AbstractThe antibodies to phosphorylcholine induced in BALB/c mice were isolated and studied with a variety of biochemical and immunochemical methods. Analysis of the idiotype and the hapten‐binding specificities showed no differences to the phosphorylcholine‐binding myeloma protein TEPC 15, indicating a high degree of homogeneity. However, disc electrophoresis, isoelectric focusing and amino acid composition data indicated large differences in the structure of anti‐phosphorylcholine antibody and TEPC 15. By these criteria the anti‐phosphorylcholine anti‐bodies from BALB/c mice are of oligoclonal origin.
Close linkage between genes coding for allotypic markers on chicken IgG and IgM
Authors: Pink J. R. L. , Ivanyi J. 
Published: February 2007

AbstractThe allotypic markers Gla and Gld (present on chicken IgG molecules) and Mla and Mlc (present on IgM) have previously been defined. The inheritance of these markers was studied in the F2 progeny of a cross between birds of the inbred lines CB (Gla+,d−, Mla+, c−) and WA (Gla−, d+, Mla‐, c+). The results suggest that antigens Gla and Gld, and Mla and Mlc, are genetically controlled by alleles at two loci (Gl and Ml, respectively) and also show that these loci are closely linked.
Correlation of “sneaking through” of tumor cells with specific immunological impairment of the host
Authors: Mengersen R. , Schick R. , Kölsch E. 
Published: February 2007

AbstractThe preferential take of tumors after small‐size inocula of transplantable tumor cells has been described for many systems. The phenomenon has been named “sneaking through” or “dilution escape”. Using a BALB/c mastocytoma, we have analyzed the immunological parameters accompanying sneaking through that can be observed upon injection of 101 to 103 living cells. Mice can also be conditioned by injection of low, subimmunogenic numbers of irradiated cells to show increased tumor incidences upon injection of living cells in doses two orders of magnitude above the sneaking through dose. The general immune reactivity of the animals is not impaired under these conditions. However, determinant‐specific unresponsiveness is found which can be transferred by spleen cells and therefore seems to be actively maintained. It is concluded that sneaking through of tumor cells is the result of specific immunological impairment of the host's immune system by subimmunogenic small‐size inocula of tumor cells.
Role of epitope density in the induction of immunity and tolerance with thymus‐independent antigens. II. Studies with 2,4‐dinitrophenyl conjugates in vivo
Authors: Desaymard Catherine , Howard J. G. 
Published: February 2007

AbstractThe immunogenicity and tolerogenicity of 2,4‐dinitrophenyl (DNP) conjugates of levan, type 3 pneumococcal polysaccharide (SIII), dextran B512 and dextran B 1299 with different levels of substitution were assessed in vivo. It was confirmed that, as in vitro, conjugates with low epitope density are solely immunogenic for Bμ cells, whereas higher density conjugates are both immunogenic and tolerogenic according to dosage. The maximal anti‐DNP plaque‐forming cell responses attainable varied by 2 log10 according to the carrier, being greatest with dextrans and least with SIII. The effect of the carrier on immunogenicity was not attributable to B cells responding to it, as concurrent tolerization by either free polysaccharide or the conjugate itself was without effect. Optimal immunization was succeeded by varying degrees of responsiveness (“exhaustion”) which was greatest with the more immunogenic conjugates. In contrast, reduction of tolerizing dose by cyclophosphamide suppression was only a feature of more highly substituted conjugates.
T cell proliferation in the mixed lymphocyte culture does not necessarily result in the generation of cytotoxic T effector cells
Authors: Röllinghoff M. , Pfizenmeier K. , Trostmann H. , Wagner H. 
Published: February 2007

AbstractIt was tested whether T lymphocytes, when stimulated in vitro by M locus‐coded lymphocyte activating determinants (LAD), are able to mediate cytotoxic effector functions. The assay for cytotoxicity included both the use of purified appropriate target cells (i.e. purified lipopolysaccharide blasts) as well as the use of phytohemagglutinin dependent cytolysis as a model for detecting cytotoxic T lymphocytes (CTL). Although strong proliferative responses were obtained in the mixed lymphocyte culture, the T cell blast generated did not display any detectable cytotoxic effector function. Thus, it is concluded that LAD, at least in the M locus‐dependenet system, do have the capacity to induce T cell proliferation but do not induce CTL.
I‐region‐associated determinants: expression on mitogen‐stimulated lymphocytes and detection by cytotoxic T cells
Authors: Nabholz M. , Young H. , Rynbeek A. , Boccardo R. , David C. S. , Meo T. , Miggiano V. , Shreffler D. C. 
Published: February 2007

AbstractWe have studied the expression of Ia‐antigens, controlled by genes in the I‐region of the H‐2 complex, on phytohemagglutinin (PHA)‐stimulated lymph node cells and on lipopolysaccharide (LPS)‐stimulated spleen cells, and have compared these two types of cell populations as targets for killer cells in the cell mediated lympholysis (CML) assay. PHA targets are almost completely insensitive to complement‐mediated lysis by anti‐Ia sera while the majority of LPS targets are killed. T cell‐mediated lysis against I‐region determinants was also detected, and these determinants, in contrast to H‐2K and H‐2D CML determinants, seem to be much more strongly expressed on LPS‐stimulated cells. No differences in the kinetics of the response to K‐or I‐region CML determinants were observed. Lysis by killer cells can also be obtained against incompatibilities which do not give rise to strong skin graft rejection and against determinants which are most probably controlled by genes outside the K‐D interval.
Inhibition of mixed leukocyte culture by anti‐idiotypic antibodies
Authors: Binz H. , Askonas Brigitte A. 
Published: February 2007

Abstract(CBA × C57BL/6)F1 antisera prepared by injecting F1 mice with CBA T lymphocytes or CBA anti‐C57BL/6 alloantibodies were tested for their ability to inhibit the mixed leukocyte culture (MLC) response. Presence of antiserum throughout the culture period in the absence of complement did not have any effect on the MLC response. Treatment of CBA responder cells with F1 antiserum and complement prior to the culture specifically inhibited the MLC response. Specificity of the suppression was ascertained; absorption of the F1 sera with F1 or C57BL/6 spleen cells did not remove the suppressive factor, whereas absorption with CBA spleen cells did so. F1 antiserum treatment left intact the response to third party alloantigens (DBA/2).Immunabsorbent columns with alloantibody of corresponding specificity removed the suppressive factor from anti‐T cell sera as well as from antisera to alloantibody. The data suggest that the circulating alloantibody population contains molecules which share idiotypic determinants with surface receptors on T cells recognizing the same alloantigens.
Separation of antigen‐specific lymphocytes. A new general method of releasing cells bound to nylon mesh
Authors: Kiefer H. 
Published: February 2007

AbstractInserting a disulfide bridge between nylon and hapten or antigen allows the release of fiber bound cells by cleaving the disulfide bond with 10−4 M 2‐mercaptoethanol at 4°C. Four to 12‐fold enrichments in specific precursor cells could be obtained. The method is compared with the thermal release previously used. The T and B cell content of the specific fraction was determined.It is suggested that the low enrichment in plaque‐forming cells of the hapten‐specific fraction found after stimulation with antigen in vitro might be due to the fact that there is also enrichment for suppressor cells in the specific fraction.
Permissiveness of athymic (“nude”) mice towards congenic memory cells
Authors: Kobow Ursula , Weiler E. 
Published: February 2007

AbstractSpleen cells from BALB/c or BALB‐Igb mice immunized against the determinant oligo‐D‐alanine were transferred to the following recipients: normal BALB/c; lethally irradiated BALB/c; and congenitally athymic BALB/c‐nu. Irradiated as well as nude recipients permitted the development of a strong adoptive antibody response, while the response in normal BALB/c recipients was very low (“isogeneic barrier”). Using allotypically marked spleen cells from BALB‐Igb donors it was shown that the antibodies in irradiated as well as in nude recipients were produced by donor cells. The same conclusion was drawn by assessing isoelectric focusing spectra, which in each transfer displayed the individually characteristic pattern of the donor. In addition to specific antibodies, the donor cells produced considerable levels of IgG, as characterized by allotype, but again only in nude and in irradiated recipients.The ready permissiveness of nude recipients towards congenic memory cells could be abolished when prospective recipients were restored, some time prior to transfer, by BALB/c thymus or BABL/c spleen cells.The results are interpreted to suggest that the isogeneic barrier in normal recipients is due to a thymus‐dependent suppression or rejection of memory cells by the recipients.
Energy requirements of the binding and lytic steps of T lymphocyte‐mediated cytolysis of leukemic cells in vitro
Authors: Berke G. , Gabison D. 
Published: February 2007

AbstractThe process of T lymphocyte‐mediated destruction of target cells in vitro is temperature dependent and is suppressed by inhibitors of energy metabolism, but the energy requirements for the conjugation and lytic steps of the process are different. The conjugation step of lymphocytes and target cells is prevented by metabolic inhibitors and is dependent on temperature, increasing in the range from 2°C to 22°C. However, after lymphocyte‐target cell conjugates are formed, they are stable at low temperatures (0°C) and in the presence of metabolic inhibitors. Thus, the formation but not the maintenance of lymphocyte‐target cell conjugates is an energy‐dependent process. In contrast to the conjugation step, which is influenced both by metabolic inhibitors and by temperature, the lytic step, which occurs only between 22°C and 37°C, is not affected by inhibitors of energy metabolism. The sigmoidal behavior of lysis as a function of temperature, showing a sharp inflection around 20°C, can be explamed in terms of the alteration of the viscosity of the membrane matrix of the target cells rather than as a general metabolic effect on the killer and target cells.
Specific B lymphocyte suppression by infectious bursal agent (Gumboro disease virus) in chickens
Authors: Hudson L. , Pattison M. , Thantrey N. 
Published: February 2007

AbstractChickens infected experimentally with infectious bursal agent (IBA) during embryonation or early after hatching show a severe depression of bursa‐dependent lymphoid components, and associated immune functions. Data presented here and elsewhere show that the degree of B cell suppression correlates with the time of infection. This would be compatible with a virus‐induced block in B lymphocyte differentation. Accordingly, the virus may be cytopathic for early (bursal) but not late (circulating) B lymphocytes or, more likely, the virus inactivates those non‐lymphoid bursal cells mediating lymphocyte differentiation.
B cell tolerance induced by polymeric antigens. III. Dissociation of antibody formation and memory generation in tolerant mice
Authors: Klaus G. G. B. , Willcox H. N. A. 
Published: February 2007

AbstractHapten (2,4‐dinitrophenyl (DNP))‐substituted type 3 pneumococcal polysaccharide (DNP‐lys‐S3) effectively suppresses both primary and secondary anti‐DNP antibody responses to DNP‐proteins. The present experiments show that tolerizing doses of DNP‐lys‐S3 have much less effect on B cell memory (re)generation in three distinct situations: (i) in serial transfers of DNP‐protein‐primed cells, (ii) in virgin mice tolerized before priming with DNP‐hemocyanin, and (iii) in tolerized, hemocyanin‐primed mice boosted with DNP‐hemocyanin. Under some conditions tolerized mice developed 10–50% of normal memory in the absence of significant antibody formation.Isoelectric focusing analyses revealed that many B cell clones proliferate in tolerant mice, but produce very little antibody until transferred to further hosts. Clones that escape suppression in partially tolerant mice do not appear to be resistant to DNP‐lys‐S3, when retested.Since there is independent evidence that the generation of B memory cells is less T cell‐dependent than the development of antibody‐forming cells, these data are best explained by assuming that DNP‐lys‐S3 blocks lymphocyte cooperation. This would be expected to preferentially suppress antibody formation, and to spare memory generation.
Surface immunoglobulins on the lymphocytes of the skate Raja naevus
Authors: Ellis A. E. , Parkhouse R. M. E. 
Published: February 2007

AbstractLiving lymphocytes of the Elasmobranch fish, Raja naevus, have been examined for surface immunoglobulin (Ig) by treatment with a fluorescent anti‐Ig system. Large numbers of Ig‐positive cells (60–80%) were found in peripheral blood, spleen and thymus. Following modulation of the surface Ig with anti‐Ig, resynthesis occurred, showing that the surface Ig is a product of the individual lymphocytes rather than material passively absorbed from the serum. Formation of caps was independent of temperature, occurring as readily at 4°C as at 20°C, a finding which presumably reflects the environmental conditions normally experienced by the skate. The presence of Ig‐bearing lymphocytes in the adult skate thymus suggests a similarity to the amphibian larval thymus, which may be a primary lymphoid organ for the production of both T and B lymphocyte analogues.
Genetics of mouse antibodies. I. Linkage of the dextran response locus, VH‐DEX, to allotype
Authors: Riblet R. , Blomberg Bonnie , Weigert M. , Lieberman Rose , Taylor B. A. , Potter M. 
Published: February 2007

AbstractThe antibody response of mice to α‐1,3 linked dextran is shown to be controlled by a heavy chain variable region gene, VH‐DEX. The map distance between this gene and the heavy chain allotype locus is estimated to be 0.3 recombination units.