bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unique lectin‐binding characteristics of cytotoxic T lymphocytes allowing their distinction from natural killer cells and “K” cells
Authors: Kimura Arthur , Örn Anders , Holmquist Göran , Wigzell Hans , Ersson Bo 
Published: February 2007

AbstractCytotoxic T lymphocytes (CTL) can be selectively depleted from in vitro or in vivo alloactivated populations of T cells on Vicia villosa lectin adsorbents through the lectin‐specific interaction with the CTLassociated surface glycoprotein T 145 (Kimura, A, Wigzell, H. and Holmquist, G., J. Exp. Med. 1979. 149: 473). Results from these and other experiments have demonstrated the general applicability of this fractionation procedure in which no constraints related to antigenic specificitiy of the CTL have been observed.When this fractionation procedure was applied to other compartments of cytolytic cells (natural killer cells and “K” cells), no detectable impact could be seen. This differential lectin binding would appear to offer a means of dissecting the activities of CTL from other compartments of cytolytic lymphoid cells.
Composite activities on B cells of products released by T cells activated by concanavalin A
Authors: Primi Daniele , Lewis George K. , Goodman Joel W. 
Published: February 2007

AbstractSupernatants from murine spleen cells cultured for 48 h in the presence of 1.0 μg of concanavalin A (Con A) induced polyclonal antibody synthesis in cultures of spleen cells from both normal and athymic mice in the absence of exogeneous antigen. Moreover, the Con A‐induced supernatant rescued B cells which had been rendered unresponsive by a tolerogen [haptenated poly(DGlu,DLys)]. The capacity of the supernatant to induce cell proliferation was studied under both high and low‐density culture conditions. In contrast to antibody secretion, proliferation was only detectable in low‐density cultures.The Con A‐induced supernatant also contained suppressive components, since the primary anti‐sheep red blood cell (SRBC) response was markedly suppressed when the antigen added to cultures consisted of SRBC which had previously been used for absorbing the supernatants. Absorbed supernatants displayed enhanced helper activity indicating that only the suppressor component was removable by antigen. The suppressive component was eluted from erythrocytes with ammonium thiocyanate and was itself strongly suppressive when added to cultures with fresh erythrocytes. Furthermore, the suppressive component proved to be highly antigen‐specific, as the SRBC‐absorbed factor did not affect the response to horse RBC.The results indicate that supernatants from Con A‐activated spleen cells contain both helper and suppressor factors, the latter having easily demonstrable antigen specificity. They further suggest that a nonantigen‐derived signal is sufficient to trigger both proliferation and antibody synthesis by B cells.
The production of fibrinolysis inhibitors as a parameter of the activation state in murine macrophages
Authors: Klimetzek Volker , Sorg Clemens 
Published: February 2007

AbstractMacrophages from peritoneal exudates which had been induced by various irritants were cultured, and the supernatants were tested for inhibitors of fibrinolysis using the plasmin‐dependent lysis of 125I‐labeled fibrinogen as assay. Washout macrophages and casein or proteose peptone‐elicited macrophages were found to release fibrinolysis inhibitors in contrast to lipopolysaccharide or thioglycollate‐induced macrophages. The molecular weight of inhibitors was determined at 60 000, 45 000 and 15 000 by Sephadex chromatography. Whereas the inhibitors at 15 000 and 45 000 could be detected in all experiments, the inhibitor at mol. wt. 60 000 was not present in all preparations. The isoelectric point of inhibitor I (mol. wt. 15 000) and inhibitor II (mol. wt. 45 000) was determined at 4.15. The proteolytic and esterolytic activity of trypsin and chymotrypsin were both inhibited by each of the two inhibitors. On the other hand, only the proteolytic activity of plasmin could be inhibited. Evidence for the active synthesis of inhibitors by macrophages came from several experiments. Macrophages in serum‐free cultures continued to release inhibitors for at least 48 h; normal mouse serum did not contain inhibitors of the same molecular size, and [3H]leucine was incorporated into the inhibitors which were specifically detected by the absorption of plasmin inhibitor complexes to lysyl‐Sepharose. Since inhibitors and plasminogen activator could not be detected in the same macrophage culture supernatants, it appears that the production of inhibitors and plasminogen activator by the same macrophage population is mutually exclusive.
Some limits to post‐antigen generation of diversity: Failure to detect variants in clones of hapten‐specific antibody‐forming cells (AFC) developing in culture from direct AFC‐progenitor B cells
Authors: Shortman Ken , Howard Maureen , Pike Beverley L. , Marbrook John , Baker Julie 
Published: February 2007

AbstractA search was made for variants in clones of hapten‐specific antibody‐forming cells (AFC) arising by stimulation of mature B cells with either thymus‐independent hapten‐POL (polymerized bacterial flagellin) conjugates, or the polyclonal activator lipopolysaccharide. Enriched, hapten‐binding B cells or unfractionated spleen cells were cultivated for 3–4 days at limiting dilution in the presence of thymus filler cells, and the AFC in each microculture well were then assayed for plaque formation on various hapten‐sheep red cell monolayers. No variants were found from (4‐hydroxy‐3‐iodo‐5‐nitrophenyl) acetyl (NIP) to 2,4‐dinitrophenyl specificity, nor from fluorescein (FLU) to NIP specificity. No variants were found in avidity for FLU hapten. All 374 clones examined, including clones of up to 300 AFC, appeared to be homogeneous in antibody specificity and plaque morphology under our conditions. These results differ from published findings using erythrocytes as antigens. Reasons for this discrepancy are discussed, including differences in sensitivity differences in immunological similarity between the test antigens, and in the particular B cell subsets involved.
Antigen‐specific stimulation and trans‐stimulation of T cells in long‐term culture
Authors: Augustin Andrei A. , Julius Michael H. , Cosenza Humberto 
Published: February 2007

AbstractWhen T cells from antigen‐primed lymph nodes are stimulated in vitro with antigen, they give rise to a proliferative response as high as that elicited by the polyclonal T cell activator concanavalin A. It is likely that in these conditions not only antigen‐specific T cells proliferate. We have established an experimental system which demonstrates that large numbers of nonantigen‐specific T cells are induced to proliferate as a result of antigen‐specific T cells' confrontation with antigen. This phenomenon, which we call trans‐stimulation is antigen‐dependent and antigen‐specific. Although the presence of antigen‐specific T cells is required, these cells do not have to proliferate in order to induce trans‐stimulation.In an attempt to enrich for antigen‐specific T cells in vitro, we established conditions for culturing T cells in the presence of antigen for long periods of time (up to 6 weeks). High levels of antigen reactivity were observed upon antigen restimulation of “directly” stimulated T cells from long‐term cultures. In contrast, long‐term cultures of trans‐stimulated cells were depleted of antigen reactivity. Neither type of long‐term culture contained detectable alloreactive cells indicating that trans‐stimulation is not reflected randomly upon bystander T cells.
Non‐T cell nature of the naturally occurring, spleen‐associated suppressor cells present in the newborn mouse
Authors: Rodriguez George , Andersson Gunilla , Wigzell Hans , Peck Ammon B. 
Published: February 2007

AbstractSpleens from newborn mice less than 6‐7 days of age contain a “naturally occurring” suppressor cell which possesses the capacity to inhibit not only expression of alloreactivity in the newborn spleen per se, but also T‐dependent and T‐independent immune responses of third‐party adult spleen cells. Similar suppressor activity is not detectable in the newborn thymus. The effector cell of this suppressor activity is not a classical T cell: suppression is resistant to treatment with anti‐T cell reagents, is absent from purified spleen T cell populations, is present in the spleens of T‐deficient (nu/nu) mice, is Helix pomatia A hemagglutinin‐nonbinding. Furthermore, this cell appears to be distinct from classical B cells, natural killer (NK) cells and macrophages. Instead, this naturally occurring, newborn spleen‐associated suppressor cell has similar characteristics to the non‐T suppressor cell detectable during old‐age immunological senescence, described by Singhal et al. (Fed. Proc. 1978. 37: 1245). When this suppressor cell is removed from newborn spleen cell populations, the resulting T cells exhibit strong alloreactivity. Thus, these data indicate, first, that the nonresponsive state of the newborn spleen is not due to a lack of functional T cells or macrophages, and second, that the suppressor activity in the newborn spleen is not effected by a thymus‐ dependent cell as is currently hypothesized.
Are VH framework antigenic determinants expressed on both rabbit B and T lymphocytes?
Authors: Wllder Ronald L. , Yuen Catherine C. , Scher Irwin , Mage Rose G. 
Published: February 2007

AbstractThe extent to which VH framework determinants are represented on T cell receptors is unresolved and controversial. We have studied this question in the rabbit using antia (VH framework) allotype antisera and a goat anti‐rabbit VH antiserum. Flow micro‐ fluorometric analysis of spleen lymphocytes from hyperimmune animals (Freund's adjuvant plus picryl chloride) demonstrated closely similar frequencies of cells stained with the anti‐VH framework antisera compared to anti‐light chain antisera. To search for potentially hidden molecules, additional studies were performed with radioiodinated, detergent‐solubilized plasma membranes derived from immune spleen and lymph node cells. The membranes were analyzed by standard immunoprecipitation techniques. Absorption with anti‐Ig constant region immunoabsorbents removed all radioactivity precipitable by specific anti‐VH framework antisera compared to controls, whereas after absorption with control (normal goat globulin) immunosorbents, VH‐bearing surface IgM and putative surface IgD (presumably of B cell origin) were readily demonstrated by immunoprecipitation. Thus, no evidence for a population of cells or a class of molecule(s) bearing VH in the absence of light or heavy chain constant region determinants was obtained. Although these studies do not support the concept of similar VH framework determinants on T and B cell receptors, they do not exclude a much more limited sharing of determinants or a very minor T cell subpopulation which expresses VH framework that would not be detectable by the methods used in these studies.
The detection of membrane‐associated complement components (C 3 and C 4) on circulating human normal and leukemic leukocytes and on cultured cells with monkey erythrocytes
Authors: Burns Gordon F. , Cawley John C. 
Published: February 2007

AbstractMonkey erythrocyte (Mk) rosette formation is described as an exquisitely sensitive method for the detection of complement (C) components on the membrane of human leukocytes. Blocking of the immune adherence receptor on Mk blocked subsequent rosette formation as did pretreatment of leukocytes with antiserum to the C components C3 and C4. In vitro C deposition by immune complex formation with normal human lymphocytes enhanced Mk rosette formation, and this could be inhibited with antiserum to C3. The use of Mk rosette formation revealed that cells from a wide variety of human lymphoid and myeloid leukemias carry membrane‐bound C. It was also shown that several lymphoblastoid cell lines, including a T cell line, probably synthesize both C3 and C4. Mk rosette formation is not dependent on metabolic activity of the resetting leukocyte, and it is suggested that this technique will be of value in detecting C deposition in a variety of situations.
Isolated hapten‐binding receptors of sensitized lymphocytes: V. Cellular origin of receptor molecules
Authors: Krawinkel Ulrich , Cramer Matthias , Kindred Berenice , Rajewsky Klaus 
Published: February 2007

AbstractChimeric mice were constructed by injection of thymus cells into nu/nu mice. The thymus cells carried a different immunoglobulin (Ig) heavy chain linkage group than the cells of the recipients. The chimeric animals were then immunized with the hapten (4‐hydroxy‐3‐nitro‐phenyl)acetyl (NP) on an appropriate carrier, and NP‐binding receptor molecules were isolated from the spleen cells of the animals. Receptor molecules and antibodies were analyzed for the presence of two Ig heavy chain variable region (VH) markers which are specific for the anti‐NP response of mice carrying the Igb allogroup, namely the NPb idiotpye and the heteroclitic fine specificity of hapten binding. Two types of receptor molecules are obtained by our method, those carrying determinants of Ig constant domains (anti‐Ig+ receptors) and others lacking such determinants (anti‐Ig− receptors). The two VH region markers were found on anti‐Ig− receptors but not on anti‐Ig+ receptors and humoral antibodies when the T cells in the chimeric mice carried the Igb allogroup, whereas the B cells were Iga/a. Conversely, anti‐Ig+ receptors and humoral antibodies but not anti‐Ig−receptors, expressed the two markers when the B cells of the chimeras carried the Igband the T cells the Iga allogroup. From these results and previous data showing that anti‐Ig− receptors are enriched together with T lymphocytes and anti‐Ig+ receptors together with B cells, we conclude that the VH‐bearing anti‐Ig− receptors are not only present on T cells, but are indeed synthesized by these cells.
Deficient production of anti‐red cell autoantibodies by mice with an X‐linked B lymphocyte defect
Authors: Marshall‐Clarke Stuart , Cooke Anne , Hutchings Patricia R. 
Published: February 2007

AbstractThe production of anti‐self red cell antibodies has been studied in mice bearing the CBA/N X‐linked B lymphocyte defect and their phenotypically normal littermates. Defective mice produced anti‐self red blood cell (RBC) antibodies at markedly reduced levels after multiple injections of rat RBC. They also failed to show significant numbers of plaque‐forming cells against enzyme‐treated isologous RBC. These findings are discussed in terms of the nature of the CBA/N defect and the acquisition of a complete specificity repertoire.
The presence of Thy‐1 on the surface of rat lymphoid stem cells and colony‐forming units
Authors: Hunt Simon V. 
Published: February 2007

AbstractBy labeling Thy‐1‐positive cells of rats with xenoanti‐Thy‐1 or mouse alloanti‐Thy‐1 antibody and separating them from Thy‐1‐negative cells on a fluorescence‐activated cell sorter, it was shown that early lymphopoietic stem cells all carry Thy‐1‐antigen. This was so for both young, adult bone marrow and near‐term fetal liver cells. Two kinds of assay were used: long‐term radiation chimeras employing B and T cell alloantigens to mark cells of donor origin, and in vivo colony‐forming units in the spleens of irradiated recipients (bone marrow only). Thy‐1‐negative cells gave essentially no B or T progeny, even 6 to 12 months after reconstitution of the chimeras. The kinetics of appearance of Thy‐1‐positive cells in rat marrow, which peaked at 6‐8 weeks of age, were also studied. In rats, Thy‐1 is on the surface of pluripotent stem cells and on early progenitors of both B and T lymphocytes.
Production and characterization of cytotoxic Thy‐1 antibody‐secreting hybrid cell lines Detection of T cell subsets
Authors: Lake Phil , Clark Edward A. , Khorshidi Manoocher , Sunshine Geoffrey H. 
Published: February 2007

AbstractResponses to Thy‐1 were used as a model system to examine parameters which affect the production of antibody‐secreting lines derived from somatic cell hybridization. Experiments with the Thy‐1.1 response revealed that the frequency of clones producing Thy‐1.1 antibodies is a constant of 4 to 6% for each 10000 plaque‐forming cells (PFC) input in the fusion cell mixture, regardless of the maturational stage of the response. Therefore, PFC responses to Thy‐1 were optimized by studying variables in the choice and dose of antigen, the response kinetics and in the fusion procedures. Thus, to produce Thy‐1.1 antibody‐secreting cell lines, we used (a) spleen cells at the peak of the PFC response, (b) xenogeneic (rat) rather than allogeneic donors, (c) secondary rather than primary responses and (d) high ratios of NS‐1 to spleen cells.For the reproducible production of Thy‐1.2 antibody‐secreting hybridomas, PFC responses to Thy‐1.2 were similarly optimized in AKR mice. Response kinetics and antigen dose were shown to be very critical parameters. By varying the number of cells used for priming, it was revealed that doses only slightly higher than optimal produced a dramatic hyporesponsiveness in the subsequent secondary response. Using the above information, hybrid lines secreting antibody to Thy‐1.2 were obtained reproducibly and one line, F7D 5, which secretes a cytotoxic IgM antibody was characterized in detail since a monoclonal antibody may differ from conventional antisera for immunochemical and genetic reasons.Serologically, F7D 5 Thy‐1.2 antibody was found to behave as a conventional Thy 1.2 alloantiserum, At high dilutions however, the antibody can be used to discriminate long‐lived T cells (adult thymectomized mice) from newly produced T cells (antilymphocyte antiserum‐treated mice). Functionally, in numerous T cell‐dependent assays both in vivo and in vitro, including helper, suppressor and cytotoxic T cell functions as well as responses to mitogens and antigens, the F7 D 5 antibody behaved as a potent and absolute T cell‐depleting agent. This cell line and some anti‐Thy‐l.1 producing lines are available for research purposes.
Genetic control of the immune response to the terpolymer L‐glutamic acid 60‐L‐alanine 30‐L‐tyrosine10(GAT). III. Restricted heterogeneity of the anti‐GAT response from BALB/c responder mice
Authors: Petit Christine , Joskowicz Mireille , Stanislawski Marc , Thèze Jacques 
Published: February 2007

AbstractThe heterogeneity of the anti‐GAT [terpolymer poly(Glu60, Ala30, Tyr10)] response of GAT responder mice has been analyzed. Purified anti‐GAT antibodies from BALB/c mice belong only to the γ1χ subclass. The isoelectric focusing pattern obtained indicates that the anti‐GAT antibodies are particularly basic and restricted. These results have been confirmed by two‐dimensional polyacrylamide gel electrophoresis; by this technique, we have shown that the γ1 chain and the corresponding χchain of anti‐ GAT antibodies are restricted. All the anti‐GAT antibodies from 10 BALB/c mice bear the cross‐reactive GAT idiotype previously defined (J. Thèze and G. Sommé, Eur. J. Immunol. 1979, 9: 294). The present results indicate that the anti‐GAT repertoire expressed in BALB/c mice is very limited.
Demonstration of a murine cell surface component with affinity for exogenous β2‐microglobulin
Authors: Sege Karin , Östberg Lars , Peterson Per A. 
Published: February 2007

AbstractMurine and human β2‐microglobulin (β2m) bind to various types of mouse cells. The binding is saturable and displays a single association constant of about 1 × 109 liter/mol. The binding of β2m to splenocytes was not affected by a variety of metabolic inhibitors but was temperature‐dependent. It is suggested that the β2m “receptor” exhibits a temperature‐dependent conformational change since the “receptor”, whether integrated into the membrane or solubilized by the detergent Triton X‐100, binds β2m poorly at low temperatures. Spleen T and B lymphocytes display more binding sites than thymocytes, kidney, liver and brain cells. The relative amounts of the β2m‐binding “receptor” on these cell types are strongly correlated to the relative amounts of H‐2 antigens. This correlation is also obvious for the teratocarcinoma cell line F9, which lacks both β2m “receptor” and H‐2 antigens, but spermatozoa, which express very small amounts of H‐2 antigens, have an appreciable amount of the β2m “receptor”. The latter observation, together with the fact that alloantisera directed against H‐2 K and D antigens do not measurably affect the binding of β2m to the “receptor”, may argue against the notion that the β2m “receptor” represents H‐2 antigens which have lost their endogeneous β2m. Normal mouse serum contains a component which inhibits the binding of β2m to splenocytes. It is likely that this serum protein is identical to a newly discovered H‐2 antigen‐like glycoprotein. The β2m “receptor” appears to be under the control of the major histocompatibility complex as splenocytes of the H‐2f haplotype bind considerably more β2m than splenocytes of other haplotypes.
Analysis of the repertoire of anti‐(4‐hydroxy‐3‐nitro‐phenyl)acetyl (NP) antibodies in C 57 BL/6 mice by cell fusion. II. Characterization of idiotopes by monoclonal anti‐idiotope antibodies
Authors: Reth Michael , Imanishi‐Kari Thereza , Rajewsky Klaus 
Published: February 2007

AbstractCBA and SJL mice were immunized against the hybrid cell antibody Bl‐8 (μ,λ1) which we have previously isolated from the primary response of C57BL/6 mice against the hapten (4‐hydroxy‐3‐nitro‐phenyl)acetyl (NP) (Eur. J. Immunol. 1978. 8: 393). Cell lines secreting monoclonal antibodies against B1–8 idiotopes were isolated, and the anti‐idiotope antibodies were used to characterize the variable portion of B1–8 and of other anti‐NP antibodies all belonging to an antibody family which carries a major idiotypic marker, namely the NPb idiotype.Three groups of idiotopes were defined by the monoclonal anti‐idiotope antibodies on the B1–8 protein; a first, in the NP binding site so that the corresponding anti‐ idiotopes compete with the NP hapten for binding to B1–8 (group 1); a second, presumably further apart from the binding site so that there is competition of the corresponding anti‐idiotopes with a polyvalent NP‐protein conjugate but not the free hapten for binding to B1–8 (group 2); and a third (group 3), specific for a determinant constructed by B1–8 μ chains and MOPC 21 χ chains which are still present in the B1–8 preparation as the product of the X63‐Ag8 parent cell line. Group 1 idiotopes were expressed on 1–10% of χ1‐bearing primary anti‐NP antibodies of C57BL/6 origin and group 2 idiotopes on 10–100% of these antibodies. Group 3 idiotopes were not detected in anti‐NP antisera. The analysis of a set of monoclonal hybrid cell anti‐NP antibodies from C57BL/6 confirmed that group 2 idiotopes are more abundantly expressed in the primary anti‐NP response than any given group 1 idiotope. Group 2 idiotopes can thus be expressed independently of group 1 idiotopes. In addition, group 1 idiotopes appear to exhibit a higher degree of diversity than idiotopes of group 2.The present analysis dissects the NPb idiotype into a large set of idiotopes which can be grouped in terms of localization on the antibody molecule and of variability and which are combined in various ways on a large number of χ chain‐bearing antibody species. At least some of the idiotopes recognized by the monoclonal antibodies are under the control of the heavy chain linkage group, as shown by the idiotope analysis of serum antibodies from Igh‐congenic mice.In the course of the fusion experiments, also cell lines secreting antibodies of SJL origin with specificity for the constant region of χ1 chains were isolated, and we also describe the preparation of an Fv fragment from B1–8, an IgM antibody.