bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Suppressive Immunoglobulin-Binding Factor (IBF)
Authors: Joskowicz Mireille , Rabourdin-Combe Chantal , Neauport-Sautes Catherine , Fridman Wolf Herman
Published: December 2022

The biochemical characteristics of immunoglobulin binding factor produced by activated cells (ATC) were investigated. For this purpose, supernatants of ATC were purified by affinity chromatography on insolubilized IgG and the eluted material was iodinated (125I), treated with mercaptoethanol; and run on SDS polyacrylamide gels. The radioactivity was found in two peaks corresponding to m.w. of 38,000 d and 18,000 d. This result extends and confirms our previous findings that IBF produced by ATC is identical of IBF produced by L-5178-Y internally labeled thymoma cells.

The effect of various pH, temperatures, and proteolytic and glycolytic enzymes on the binding properties of 3H-leucine-or H-fucose-labeled IBF to IgG and on the poly-acrylamide gel profiles was also studied. By all these criteria, IBF appeared to be a glycoprotein in which the presence of the 38,000 to 40,000 d chain is necessary for the binding to IgG.

In the attempt to study the relationships between IBF and I-region products, purified IBF produced by ATC was incubated with anti-Ia immunoadsorbent, and the eluted material was iodinated and run on gels. The 38,000 d and 18,000 d chains characteristic of IBF were found to be specifically retained on the relevant immunoadsorbent. These data favor the hypothesis that IBF bears or is associated with Ia determinants.
Relationship Between Trinitrophenol and H-2 Antigens on Trinitrophenyl-Modified Spleen Cells
Authors: Forman James , Vitetta Ellen S.
Published: December 2022

Con A lymphoblasts were treated with 2 mM TNBS and then cultured for 24 hr. At the time of treatment, approximately half of the cell membrane H-2 molecules were derivatized with TNP, whereas after culture less than 10% of the H-2 molecules were TNP derivatized. When the TNBS-treated and cultured cells were tested in a cold target competition assay for antigenic activity by using anti-TNP cytotoxic effector cells, it was found that these cells were greatly reduced in their ability to inhibit activity. This lack of activity could be overcome by retreatment of the inhibitor cells with 2 mM TNBS such that these cells now displayed TNP-H-2 molecules and blocking activity in the TNP-CML assay. Although the cultured cells shed 50% of their TNP molecules, it is unlikely that the failure of these cells to block in the TNP-CML assay was due to loss, since cells treated with 0.5 mM TNBS but used without culturing were able to efficiently block in the competition assay. The 0.5 mM TNBS-treated cells displayed an equivalent amount of TNP molecules bound per cell as the cells treated with 2 mM TNBS and cultured for 24 hr.

Thus, the data indicate that after 24 hr of culture of TNBS treated cells, H-2 molecules turnover rapidly so that the TNP-H-2 molecules are replaced. These cells fail to express antigenic activity that can be recognized by cytotoxic anti-TNP effector cells.
Binding of Desoxycholate, Phosphatidylcholine Vesicles, Lipoprotein and of the S-Protein to Complexes of Terminal Complement Components
Authors: Podack Eckhard R. , Müller-Eberhard Hans J.
Published: December 2022

Quantitative measurements of sodium desoxycholate (DOC) binding to intermediate complexes of the terminal components showed increasing binding ability with the progression of complex assembly. C5b-6 and C5b-7 bound, respectively, 24 and 27 moles DOC/mole complex, C5b-8 and C5b-9 bound 63 and 86 moles, DOC/mole complex, respectively. All four complexes behaved as amphiphilic proteins upon charge shift electrophoresis. DOC above the critical micellar concentration prevented aggregation of nascent C5b-7 (C5b-7*), dissociated the S-protein from SC5b-9, and efficiently extracted C5b-9 from complement-treated sheep erythrocyte membranes without dissociating the complex. Nonionic detergents did not bind to the four complexes, were incapable of preventing aggregation of C5b-7*, and of dissociating the S-protein from SC5b-9.

The forming C5b-9 complex, depending on the experimental conditions, was found to combine with either DOC, S-protein, lipoprotein, or lipid vesicles. In absence of either of these substances it aggregated with itself. The binding and aggregation phenomena are considered expressions of the same underlying molecular reaction, which is also considered responsible for the membranolytic function of the complex.

Efficiency of binding of C5b-7* varies 1000-fold depending on the properties of the acceptor. Reversible ionic interaction of C5b-6 with the acceptor before the reaction with C7 may be responsible for this observation. Reversible ionic interaction of C5b-6 with DOC micelles before hydrophobic binding of the detergent may also explain the differential binding of ionic and nonionic detergents. It is proposed that the C5b-7 complex overcomes the charge barrier of the membrane by ionic interactions and associates itself with the membrane by secondary hydrophobic interactions. Subsequent binding of C8 and C9 leads to increased hydrophobicity of the complex, causing a perturbation of the membrane by transmembrane channel formation or by the generation of protein-phospholipid micelles.
Idiotypic Analysis of Anti-GAT Antibodies
Authors: Ju Shyr-Te , Kipps Thomas J. , Theze Jacques , Benacerraf Baruj , Dorf Martin E.
Published: December 2022

The synthetic terpolymer of L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT) induced anti-GAT antibodies in D1.LP mice. Some of these antibodies shared common idiotypic specificities. The interaction between idiotypic antibody and anti-idiotypic antiserum was specifically inhibited by GAT and the closely related polymer of L-glutamic acid and L-tyrosine (GT) but not by the copolymer of L-glutamic acid and L-alanine (GA). The binding of labeled GAT by the anti-GAT antibodies was also specifically inhibited by the anti-idiotypic antiserum. These results indicated a close association of idiotypic determinants with the antibody-combining sites. Furthermore, such active site-related common idiotypic specificities were found in individual sera of both responder mice (D1.LP) and nonresponder mice (DBA/1) immunized with GAT and GAt-MBSA, respectively, indicating that both responder and nonresponder mice carry B cells with common clonotypes.
Inosiplex, A Stimulating Agent for Normal Human T Cells and Human Leukocytes
Authors: Wybran Joseph , Govaerts Andre , Appelboom Thierry
Published: December 2022

The influence of inosiplex upon various in vitro leucocyte assays was studied in normal individuals. It was found that the drug increases the response of bidirectional and unidirectional mixed lymphocyte cultures at concentrations of 200, 300, and 500 µg/ml. It also significantly increases the percentage of active T rosettes (concentration range: 50 to 500 µg/ml) and the percentage of autologous red cell T rosettes (concentration: 100 µg/ml). In contrast, inosiplex did not modify the percentage of total T rosettes and EAC rosettes. Inosiplex increases the number of nonadherent leucocytes in the leucocyte adherence inhibition test at a concentration range between 100 and 300 µg/ml. Finally, inosiplex also increases the percentage of monocytes phagocytizing yeast at a concentration between 50 and 500 µg/ml. These data indicate that inosiplex enhances the function of normal human T cells, monocytes, and possibly neutrophils. Therefore inosiplex appears to have immunostimulant properties.
Testosterone Control of Serum Levels of C4-Binding Protein in Mice
Authors: Ferreira Arturo , Weisz-Carrington Paul , Nussenzweig Victor
Published: December 2022

Sex hormones control variations in the serum levels of C4-binding protein (C4-bp) in mice. The levels of C4-bp in castrated males are decreased as compared to the sham-operated controls. Castrated females injected with testosterone have higher levels of C4-bp than those injected with the vehicle alone. Effective “masculinization” of castrated females, with respect to C4-bp levels, was achieved by periodic inoculations of testosterone, and “feminization” of males was obtained by orchidectomy. In this regard, C4-bp behaves like other C components (C4, C5, C6) whose serum levels are strongly influenced by sex hormones.
Potentiation of Lymphocyte Activation by Colchicine
Authors: Stenzel Kurt H. , Schwartz Racheline , Rubin Albert L. , Novogrodsky Abraham
Published: December 2022

Proliferation of human lymphocytes induced by IO4- is potentiated by 30 min exposure to colchicine (10-6 M), whereas the response to Con A is inhibited. Treatment with colchicine before or after IO4- modification has similar enhancing effects. Lumicolchicine does not alter proliferative responses. In addition to the proliferation of IO4--oxidized cells, irradiated IO4--modified lymphocytes induce proliferation when mixed with untreated lymphocytes. Enhancement occurs in both these conditions only when IO4--modified cells are treated with colchicine. Preliminary data indicate that proliferation in mixed lymphocyte cultures is also potentiated when either stimulating or responding cells are pretreated with colchicine. These findings suggest a selective stimulatory effect of colchicine on lymphocyte responses induced by cell-cell contact. Agents that modify microtubular assemblies might regulate the induction of immune responses that involve cellular interactions.
Cell-Mediated Cytotoxicity and Serum-Mediated Blocking: Evidence that Their Associated Determinants on Human Tumor Cells are Different
Authors: Levy Nelson L.
Published: December 2022

The preceding paper showed that patients with gliomas may have lymphocyte-mediated cytotoxic activity (LMC) directed against at least two determinants on the glioma cell surface. The present study showed that serum from patients with gliomas could block this LMC. The blocking activity, however, was specific for different determinants on the glioma cell than those to which the LMC was directed.

Blocking activity was specific for tumor cells homotypic to those of the serum donor. It was effective, however, in blocking the cytotoxic activity against these cells of lymphocytes from patients with tumors either homotypic or heterotypic to that of the serum donor. Likewise, although patients with glioblastomas or melanomas had LMC against fetal glial cells, sera from such patients were unable to block the LMC against these fetal glial targets.

The specificity of the blocking activity was confirmed by absorption of the sera with various normal and neoplastic cells. These studies have thus shown an immunologic functional dichotomy among different determinants on the glioma cell surface.
Apparent Lack of H-2 Restriction of Allograft Rejection
Authors: Murasko Donna Marie
Published: December 2022

BALB/c ByJ (H-2d) mice immunized with tail skin grafts of either B10.D2 (H-2d) or B10 (H-2b) demonstrated similar second set rejection of B10.D2 tail skin. This apparent lack of H-2 restriction was not due to the induction of a new population of cytotoxic T lymphocytes (Tc) since 450R given 24 hr before the challenge graft did not abrogate the second set reactivity. Host macrophage processing or anti-Qa-2 reactivity was also not the explanation for the lack of H-2 restriction since immunization of BALB/c Li mice with either B10.D2 or B10 tail skin grafts resulted in second set rejection of B10 tail skin. Shared public H-2 specificities of H-2d and H-2b may result in cross-reactive Tc, thus causing the apparent lack of H-2 restriction. However, no H-2 restriction of allograft rejection is observed when only one public H-2 specificity is shared between the recipient and the allogeneic challenge graft (H-2f and H-2k combination). These results suggest that H-2 restriction of T cell cytotoxicity has little relevance in allograft rejection because 1) one public H-2 specificity is sufficient to cause crossreactivity or 2) Tc are not the major effectors of allograft rejection.
Qa-2 and Qa-3 Antigens on Lymphocyte Subpopulations
Authors: Flaherty Lorraine , Zimmerman Debra , Sullivan Karen A.
Published: December 2022

The effects of anti-Qa-2 plus C and anti-Qa-3 plus C on mitogen-induced proliferation were studied. Both of these antisera in the presence of C markedly reduced both Con A- and PHA-induced proliferation while having little or no effect on LPS-induced proliferation. LPS, Con A, and PHA cultures and cultures containing media alone, examined at 72 hr, contained high proportions of Qa-2+ and Qa-3+ cells.
Idiotype-Specific Suppression of MOPC-315 IgA Secretion in vivo: Reversible Blockade of Secretory Myeloma Cells by Soluble Mediators
Authors: Rohrer James W. , Odermatt Bernhard , Lynch Richard G.
Published: December 2022

MOPC-315 cells grown in peritoneal diffusion chambers (DC) in Id315-immunized BALB/c mice exhibit a marked alteration in expression of the TNP-binding IgAλ2 protein (M315). The sera from such mice do not have detectable M315, whereas sera from Id460-immunized or nonimmune mice implanted with DC-enclosed MOPC-315 cells contain as much as 2.5 mg M315/ml. The failure to detect serum M315 is not due to the formation of M315-a-Id315 immune complexes.

When M315 secretion by individual MOPC-315 cells was quantitated in an indirect Jerne plaque assay, less than 2% of MOPC-315 cells recovered from Id315-immune mice 10 days after DC implantation formed plasques with TNP-SRBC. In contrast, about 45% of MOPC-315 cells recovered at 10 days from Id460-immunized and nonimmune mice formed plaques with TNP-SRBC. When MOPC-315 cells recovered from Id315-immune mice were treated with pronase before the Jerne assay, about 45% of the cells formed indirect plaques with TNP-SRBC, whereas pronase treatment of MOPC-315 cells recovered from Id460-immunized or nonimmune mice did not influence the frequency of plaque formation.

These findings suggest that M315 production and release by MOPC-315 cells are suppressed in Id315-immunized mice. The inhibition of M315 release: a) is idiotype-specific; b) is effected at the level of the actual secretory MOPC-315 cells; c) is mediated by Id315-specific soluble factors; d) is rapidly reversible in vitro; and e) occurs independently of any effect on the growth of MOPC-315 cells or their morphologic differentiation from lymphocytoid to plasmacytoid forms.

These observations: a) provide another instance of the susceptibility of myeloma cells to specific immunoregulatory signals induced in the myeloma-bearing host; b) provide further insight into the mechanism of idiotype-specific myeloma transplantation resistance; and c) identify a highly characterized, monoclonal B cell model with which to analyze the cellular and molecular basis of idiotype suppression.
In Vitro Growth of Murine T Cells
Authors: Rosenberg Steven A. , Schwarz Susan , Spiess Paul J.
Published: December 2022

Growth factors (GM), produced by murine lymphoid cells incubated with Concanavalin A, have been used to grow cytotoxic lymphoid cells in culture. C57BL/6 and DBA/2 lymphoid cells were sensitized against each other in primary, secondary, and tertiary in vitro cultures. These sensitized cells were grown in vitro in GM and retained their cytotoxic properties. Cells grew in culture about 10-fold every 5 to 7 days for over 2 months. Initial growth of cytotoxic cells in GM resulted in marked enhancement of specific cytotoxicity that returned to original levels after subsequent subcultures. After five 10-fold cell culture generations some nonspecific cytotoxicity directed against the responding target cell strain appeared in continuous cultures. This technique for growing large numbers of cytotoxic cells may be of value in the development of adoptive immunotherapies.
Demonstration of the in Vitro Phagocytosis of Treponema Pallidum by Rabbit Peritoneal Macrophages
Authors: Lukehart Sheila A. , Miller James N.
Published: December 2022

Evidence has been provided for the in vitro phagocytosis of virulent Treponema pallidum by stimulant-induced peritoneal macrophages. After the 4-hr incubation of macrophages with T. pallidum, treponemal antigens associated with the macrophages are specifically stained using indirect immunofluorescent techniques. Phagocytized treponemes appear within the cytoplasm of macrophages as round, brightly fluorescent “bodies” observable in increasing numbers as the duration of the treponeme-phagocyte interaction increases. Their presence is significantly reduced in the cytoplasm of macrophages that have been treated with cytochalasin B, a known inhibitor of phagocytosis, and in nonphagocytic fibroblasts. Additionally, supportive evidence for T. pallidum phagocytosis in vitro has been provided by electron microscopic examination in which treponemes have been demonstrated within typical phagocytic vacuoles. This study also provides evidence that immune serum factor(s) significantly promote the phagocytosis of T. pallidum, although a contribution by heat-labile serum factors has not been demonstrated. The possible mechanisms of immune serum contribution and the implications of the demonstration of T. pallidum phagocytosis are discussed.
Subpopulations of Human T Lymphocytes
Authors: Gupta Sudhir , Good Robert A.
Published: December 2022

Peripheral blood from 120 healthy subjects, of whom 59 were young (33.5 ± 9.6 years) and 61 aging (69.2 ± 4.2 years), was examined for the proportions and numbers of lymphocyte populations, with a battery of surface markers. Absolute lymphocyte count and T, B, and third population cells were comparable in both groups. Tγ cell proportions were significantly (p <0.001) increased in aging subjects when compared with the young subjects. However, this difference was more significant (p <0.001) when aged females were compared with the young females as compared to aged males vs young males (p <0.05). When data were analyzed for absolute numbers of Tµ and Tγ cells, a similar significant decrease in Tµ and increase in Tγ cells were observed. Interestingly, when these data were analyzed according to gender, significant differences in Tµ and Tγ cell numbers were observed between young and old females but not between young and old men. Implications of these results are discussed.
Activation of Human Complement by Liposomes: A Model for Membrane Activation of the Alternative Pathway
Authors: Cunningham Carolyn M. , Kingzette Mae , Richards Roberta L. , Alving Carl R. , Lint Thomas F. , Gewurz Henry
Published: December 2022

Liposomal model membranes were found to activate the alternative pathway of human complement. Activation was measured by C3 conversion and component consumption in serum that had been incubated with liposomes. C3 conversion did not require C1 or C2 of the classical pathway, since it was observed in serum from a C1r-deficient patient, serum from a C2-deficient patient, and normal serum in buffer containing EGTA and MgCl2. The incubation of liposomes with C2-deficient serum resulted in consumption of components C3 through C9 with no consumption of C1 or C4 in a profile typical of alternative pathway activation. The reaction was further shown to require alternative pathway factor D, and to be independent of antibody.

Activation of the alternative pathway was dependent on the membrane composition of the liposomes. A positive charge was required for liposomes to produce C3 conversion. Liposomal cholesterol concentration and phospholipid fatty acyl chain length and unsaturation all influenced activation, suggesting the importance of membrane fluidity. Positively charged liposomes containing dimyristoyl phosphatidylcholine and cholesterol required the presence of certain glycolipids for C3 conversion. The activation of the alternative complement pathway by liposomes of defined membrane composition may provide a suitable model for the study of alternative pathway activation by cellular membranes.
Lipid Synthesis: An Indicator of Antigen-Induced Signal Transduction in Antigen-Binding Cells
Authors: Kenny James J. , Martínez-Maza Otoniel , Fehniger Thomas , Ashman Robert F.
Published: December 2022

A biochemical parameter of lymphocyte activation, lipid synthesis, has been measured in a purified specific antigen-binding cell population (ABC). ABC isolated from immune and nonimmune animals by sequential centrifugation on buoyant density and sedimentation velocity gradients have a 2- to 7-fold higher rate of 14C-choline incorporation into phospholipid than either unfractionated spleen cells or cells depleted of ABC. Also ABC from immune animals were shown to have a 4- to 7-fold higher rate of 14C-acetate incorporation into their neutral lipids than nonbinding controls.

The elevated lipid synthesis seen in both nonimmune SRBC-ABC and TNP-SRBC ABC indicates that antigenic contact via the B cell immunoglobulin receptor results in signal transduction and activation of the specific receptor-bearing lymphocyte population. Binding of the same particle (SRBC) to B cells via their Fc receptors did not regularly result in activation of lipid synthesis. The magnitude of the increased lipid synthesis in ABC populations approached that seen in LPS-stimulated spleen cells. We propose that the measurement of early activation events in purified ABC may be a more appropriate criterion for antigen-induced signals than later events such as thymidine incorporation or antibody secretion.
Cross-Reactions between Tryptic Polypeptides of Staphylococcal Enterotoxins B and C
Authors: Spero Leonard , Morlock Beverly A.
Published: December 2022

The strong cross-reactions demonstrated for staphylococcal enterotoxins B (SEB) and C1 (SEC1) by measurement of antigen-binding capacity were reflected in well defined polypeptides obtained by limited tryptic digestion from SEB and SEC1. Two antigenic determinants on each enterotoxin were capable of reacting with heterologous antibody, one on the first 57 amino acids and one on the last 150 residues of the polypeptide backbone. The larger, carboxyl terminal polypeptides bound efficiently to homologous antiserum but about two orders of magnitude less efficiently to heterologous antibody. The amino terminal peptides showed only weak homologous binding but nearly comparable heterologous binding. It is proposed that the determinant on the amino terminal polypeptides is largely responsible for the strong reciprocal binding of the intact enterotoxins and that their low antigen-binding capacity is due to a random or a structurally distorted conformation in solution.
Ontogeny of B Lymphocyte Function
Authors: Szewczuk Myron R. , Sherr David H. , Cornacchia Anthony , Kim Young T. , Siskind Gregory W.
Published: December 2022

The responses to one or to two injections of antigen (referred to as “primary” and “secondary” responses, respectively) by lethally irradiated LAF1 mice reconstituted with syngeneic neonatal liver cells plus adult thymus cells are compared with the responses of irradiated mice reconstituted with adult spleen and thymus cells. In every case the primary response by mice reconstituted with neonatal B cells is of restricted heterogeneity of affinity and low average affinity as compared with the response of animals reconstituted with adult spleen as the source of B cells. The secondary responses by mice reconstituted with adult spleen cells are all highly heterogeneous and of high affinity. The secondary responses to Ova, BSA, DNP-BGG, and the F(ab′)2 fragment of HGG by mice reconstituted with neonatal liver are highly heterogeneous and of high affinity, like those of animals reconstituted with adult spleen. In contrast, the secondary responses to HGG and BGG by mice reconstituted with neonatal liver are of low affinity and restricted heterogeneity as compared with the secondary responses of mice reconstituted with adult spleen cells. Thus, the immune responses of immature B cells to heterologous immunoglobulins differ from their responses to other T-dependent antigens. This difference may be related to some property of the Fc portion of the heterologous immunoglobulin. In addition, the data indicate that with most of the antigens studied a high affinity memory B cell population can be selectively expanded in lethally irradiated mice reconstituted with neonatal liver despite the fact that their primary responses lack detectable high affinity PFC. This suggests that the failure of mice reconstituted with neonatal or fetal B cells to produce a high affinity primary PFC response may reflect an inability of the immature B cells to differentiate into antibody-secreting cells.
Cytolytic T Lymphocytes Recognize Alloantigens on Schistosomula of Schistosoma Mansoni, but Fail to Induce Damage
Authors: Butterworth Anthony E. , Vadas Mathew A. , Martz Eric , Sher Alan
Published: December 2022

Murine peritoneal exudate cells rich in cytolytic T lymphocytes (CTL) with specificity for alloantigens were found to adhere specifically to schistosomula, recovered from the lungs of mice, which bear alloantigens on their surface as a result of passive acquisition from the host. The presence of CTL in the adherent cell population was confirmed by a mixed killing reaction, in which it was shown that most of the cells that had adhered to the schistosomula were subsequently able to kill an appropriate tumor target cell. These CTL, however, failed to damage the schistosomula even after prolonged periods of culture (up to 66 hr) at high effector to target ratios. The same organisms were at least partially susceptible to complement-dependent damage by antibody with specificity for the same alloantigens. Furthermore, the same CTL preparations could artificially be induced to adhere to skin-stage schistosomula, which do not bear alloantigens on their surface, by using concanavalin A as a nonspecific binding agent to overcome the requirement for specific recognition of target antigens by the CTL. Such organisms were also insusceptible to CTL-mediated damage, even though they have previously been shown to be damaged by both eosinophils and neutrophils. Reasons for the lack of CTL damage are discussed, and it is emphasized that the adherence reaction provides a new model for examining the early stages of the interaction of CTL with their targets, and for studying the recognition by CTL of antigens that have been passively inserted into a target membrane.
Mast Cell Granule Peroxidase: Location, Secretion, and SRS-A Inactivation
Authors: Henderson William R. , Kaliner Michael
Published: December 2022

Rat peritoneal mast cells contain peroxidase as demonstrated both histochemically and enzymatically. This enzyme is localized to the mast cell granule where it is concentrated along with histamine and superoxide dismutase (SOD). Rat mast cell degranulation initiated by 48/80 produced a significantly larger percentage of net histamine release than of either peroxidase or SOD. Examination of isolated mast cell granule preparations revealed that histamine was readily displaced from the granule upon exposure to physiologic NaCl solutions and that NaCl solutions of sufficient molarity to dissolve the granular matrix were required to solubilize the bulk of peroxidase and SOD. Therefore, we washed 48/80 treated mast cells with hypertonic NaCl solutions in order to partly dissolve the extracellular granules. A 3.9-fold increase in supernatant peroxidase was produced by this washing without an accompanying commensurate increase in histamine or loss of the capacity of the cells to exclude trypan blue. Based upon these observations, there appeared to be three distinct sources of biologically active mediators generated as a consequence of mast cell degranulation: preformed, readily displaced molecules such as histamine and serotonin; newly generated molecules such as slow-reacting substance of anaphylaxis (SRS-A), and the prostaglandins; and granule matrix associated activities such as peroxidase, SOD, heparin, chymotrypsin, and others. Assessment of the molecules released into the supernatant of degranulated mast cells may therefore indicate only a portion of the mediators actually discharged from the mast cell. The granule matrix-associated activities may be transposed more slowly and cause more subtle and delayed responses. Among the potential activities relevant to immediate hypersensitivity is the capacity of the granule to inactivate SRS-A as well as superoxide .
Con A-Inducible Suppression of MLC: Evidence for Mediation by the TH2+ T Cell Subset in Man
Authors: Reinherz Ellis L. , Schlossman Stuart F.
Published: December 2022

Human peripheral lymphoid cells pretreated with Concanavalin A for 48 hr can markedly suppress the proliferative response of untreated autologous lymphoid cells in MLC. Isolation studies with Sephadex G-200 anti-F(ab′)2 affinity chromatography, nylon adherence, and E rosetting indicate that the Con A-induced suppressor cell is a T cell. Further fractionation into TH2+ and TH2- cell subsets with an equine-anti TH2 serum show that both subsets can be activated by Con A to an equivalent degree. After activation only the TH2+ subset can suppress autologous responder cells in MLC. The TH2- subset, which comprises 80% of peripheral human T cells, although induced by Con A to proliferate, cannot itself suppress the MLC response. Nevertheless, the TH2- subset can be shown to modulate the generation of suppressor TH2+ cells at 24 hr but not at 48 hr. These studies support the notion that the Con A-induced suppressor cell is confined to a distinct T cell subset in man and that T-T interactions are important in the overall expression of the immune response.
Regulatory T Cell Subpopulations in Pregnancy
Authors: Chaouat Gérard , André Voisin Guy
Published: December 2022

Previous in vivo experiments have provided evidence of suppressive activity induced by multiple allogeneic pregnancies. The reactivity of maternal spleen cells toward paternal strain alloantigens was investigated by use of MLR microculture technique. A study of the kinetics of the MLR showed an early peak of reactivity (48-hr culture) followed by a decline leading to a decreased reactivity by 96 hr when spleen cells from allogeneically pregnant mice were compared to those of virgin or even isogeneically pregnant mice, suggesting the possible action of MLR regulatory cells. A strong suppression of a H-2k (CBA) anti-H-2a (A/J) or anti-H-2d (C57BL/Ks) MLR was observed when mitomycin-treated spleen cells from CBA mice multiparous by A/J or C57BL/Ks (but not CBA) males were added to the culture. This suppression was abolished by treating the regulatory cell population with anti-ϑ serum plus complement or replacing the 1% normal mouse serum in the medium by a proper anti-idiotypic mouse serum.
Antigenic Properties and Molecular Weights of Murine Leukemia Virus-Binding Proteins
Authors: Baird Stephen M.
Published: December 2022

A murine T lymphoma cell line, WEHI-22, has been studied for the presence of murine leukemia virus-binding proteins and for the presence of cell surface molecules that share antigens with mouse immunoglobulins. With surface radioiodination, detergent disruption, and immunoprecipitation, a 60 to 70,000-dalton molecule has been described that is recognized by chicken anti-mouse immunoglobulin serum. In competition experiments this molecule cross-reacts with highly purified mouse IgM myeloma proteins. A cell surface molecule of similar size can be shown to bind to mouse leukemia viruses. Preprecipitation of the WEHI-22 cell surface material with chicken anti-mouse immunoglobulin removes the material binding to leukemia viruses.
Structural Evidence for a Polymorphic or Allelic form of the Heavy Chain Variable Region
Authors: Latham Claflin J. , Rudikoff Stuart
Published: December 2022

The heavy (H) chains of anti-phosphocholine (PC) antibodies from C57BL/6J and CBA/J were sequenced through the N-terminal 36 residues and compared with previously published sequences of A/J anti-PC antibody and BALB/c PC-binding myeloma proteins T15, M603, and M511. Each of these antibody preparations contained molecules having light (L) chains and idiotypic determinants of T15, M511, and M603 indicating the presence of at least three different anti-PC antibodies in each pool. The structures of the C57BL/6J and CBA/J H chains each revealed a single sequence from positions 1 to 36 (which includes the first complementarity determining region (CDR)), and they were identical. The first CDR was identical to that previously found for BALB/c and A/J indicating that this portion of these antibody molecules is highly conserved throughout inbred mice and is probably critical to PC-binding. A surprising finding was that both C57BL/6 and CBA sequences differed from the BALB/c and A/J sequences at two positions, residue 14 and 16. Since each of these strains differs at the allotype locus, the data indicates that the evolution of allotypy in mice occurred after variable region diversity for these particular genes.
Immune Responses During Human Schistosomiasis Mansoni
Authors: Todd Charles W. , Goodgame Richard W. , Colley Daniel G.
Published: December 2022

Peripheral blood mononuclear cells (PBMN) from chronically infected schistosomiasis mansoni patients responded poorly in vitro to a soluble schistosomal egg antigen preparation (SEA) and moderately well to either soluble worm (SWAP) or soluble cercarial (CAP) antigenic preparations. The responses induced by SWAP or CAP were dramatically increased, in 84 and 92%, respectively, of the 24 chronically infected patients tested, upon removal of adherent/phagocytic (A/P) cells from the original cell populations. In contrast, removal of A/P cells from the PBMN of treated patients, transiently infected patients, and uninfected control subjects did not result in enhanced reactivity to these antigens. Overall, SEA-induced responsiveness of chronically infected patients' cells remained low in spite of A/P cell removal. Lymphocyte transformation induced by phytohemagglutinin-P and Candida albicans extract was not significantly altered by removal of A/P cells in any of the groups tested. The expression of another regulatory system concerned with a nonspecific suppressive influence exerted by SEA was also unaffected by the presence or absence of A/P cells. The previously reported, in vitro, schistosome antigen-specific, serosuppression mediated by sera from most chronically infected patients was effective in the presence or absence of A/P cells. However, serosuppression and A/P cells combined to exert maximum suppression of both the SWAP- and CAP-induced responses of chronically infected patients' cells. The enhanced responses observed after A/P cell depletion represented actual increases in blastogenesis, as determined morphologically, as well as increased incorporation of tritiated thymidine. These studies have demonstrated the presence of immunoregulatory A/P cells in the PBMN cells of chronically infected schistosomiasis mansoni patients which have the capability to suppress lymphocyte blastogenesis induced by the antigenic preparations derived from adult worms and the infectious, cercarial, larval stage of the parasite Schistosoma mansoni.
Hybrid Resistance to BALB/c Plasmacytomas
Authors: Clare Walker Mary , Phillips-Quagliata Julia M.
Published: December 2022

Resistance to the BALB/c plasmacytoma MPC-11 by F1 hybrids between BALB/c and four C57BL/10 congenic resistant strains was abrogated or reduced by 450 rads total body irradiation but was unaffected by intravenous injection of 3 to 4 mg of silica. These results are consistent with the idea that hybrid resistance to MPC-11 depends on an active immune response and is different from Hh-1 controlled hybrid resistance.
Effect of Inhibitors of Arachidonic Acid Metabolism on Mitogenesis in Human Lymphocytes: Possible Role of Thromboxanes and Products of the Lipoxygenase Pathway
Authors: Kelly James P. , Johnson Mary C. , Parker Charles W.
Published: December 2022

Although it is already known that prostaglandins inhibit lymphocyte responses to mitogens the role of other products of arachidonic acid (AA) metabolism has not previously been investigated. Various inhibitors of AA metabolism were studied for their effects on mitogenesis in human lymphocytes, including imidazole, benzylimidazole, N-0164, L-8027, 5, 8, 11, 14 eicosatetraynoic acid, nordihydroguaiaretic acid, indomethacin, and aspirin. Selective or partially selective inhibitors of thromboxane synthesis, such as imidazole, benzylimidazole, N-0164, and L-8027 inhibited the mitogenic response at concentrations that also substantially affect thromboxane B2 synthesis in platelet-free lymphocyte preparations. Since indomethacin failed to reverse the inhibition by imidazole or N-0164, it is probably due to decreased thromboxane synthesis per se rather than secondary increases in prostaglandin synthesis. Eicosatetraynoic acid and nordihydroguaiaretic acid were more effective inhibitors of mitogenesis than of thromboxane synthesis. Since these agents also affect the lipoxygenase pathway, it is possible that part of their action is at this level. Thus, in addition to the inhibitory effects of prostaglandins on mitogenesis, other products of AA metabolism may promote the response.
Interferon-Induced Enhancement of IgE-Mediated Histamine Release from Human Basophils Requires RNA Synthesis
Authors: Hernandez-Asensio Mercedes , Hooks John J. , Ida Shiroh , Siraganian Ruben P. , Louis Notkins Abner
Published: December 2022

Incubation of human leukocytes with certain viruses results in the enhancement of IgE-mediated release of histamine. This enhancement is produced by interferon. The present experiments show that an induction period of 6 to 9 hr and new RNA synthesis are required for interferon to enhance histamine release. This points to the possibility that interferon may exert its antiviral and histamine-release enhancing activities by acting through a common pathway.
Regulation of T Cell Mitogen Activity of Anti-Lymphocyte Serum by a B-Helper Cell
Authors: Norcross Michael A. , Smith Richard T.
Published: December 2022

Rabbit anti-mouse brain antiserum (RaMB) was found to be mitogenic for mouse lymphocytes by using a 3H-thymidine incorporation assay. The mitogenic activity was maximal at 48 hr incubation and was absorbable with brain and T lymphocytes. Specificity was directed toward a Thy-1 like molecule without Thy-1 allotypic restrictions. Mixed populations of lymphocytes from spleen and lymph node were highly responsive to low concentrations of RaMB at which purified subpopulations of T or B lymphocytes were unresponsive. T cell responses could be reconstituted by addition of B-enriched cell subpopulations. Macrophages had no helper effect; rather they inhibited the response even at very low numbers of cells. Proliferative responses in mixed populations involved both T and B cell subpopulations in which the T cell component accounted for 80 to 90%, and the B cell subpopulation about 10 to 20% of net thymidine incorporation. B cell proliferation was not required for the regulatory effect. No B cell helper activity was detectable if F(ab′)2 fragments prepared from RaMB-Ig were used as mitogen. The data suggest that T cell activation by anti-T cell serum first involved ligand-antibody interaction. This is a necessary but insufficient cell surface event to trigger proliferation. A second interaction appears to be required to initiate proliferation. The data suggest that the Fc region of the bound antibody molecule supplies this impetus by engaging the Fc receptor of the B-helper cell.
Regulation of Lymphocyte-Activating Factor (LAF) Production and Secretion in P388D1 Cells: Identification of High Molecular Weight Precursors of LAF
Authors: Mizel Steven B. , Rosenstreich David L.
Published: December 2022

Phorbol myristic acetate (PMA) markedly enhanced the production and secretion of lymphocyte-activating factor (LAF) by the murine macrophage cell line, P388D1. The stimulatory effect of PMA proceeded, in part, via activation of an existing intracellular precursor pool of LAF. This conclusion is based on the observations that 1) the initial stimulatory effect of PMA on LAF production and secretion occurred for at least 4 hr in the presence of two inhibitors of protein synthesis, cycloheximide and puromycin, and 2) higher m.w. aggregate forms of LAF, possessing differing levels of activity, were present in the sonicates of P388D1 cells. Five species of intracellular LAF with approximate m.w. of 220,000, 50,000 to 70,000, 39,000, 26,000, and 13,000 daltons were resolved on a Sephacryl S200 column. The 50,000 and 13,000 m.w. forms exhibited the most LAF activity, the 39,000 and 26,000 m.w. species were significantly less active, and the 220,000 m.w. form was only weakly active. The 13,000 m.w. intracellular LAF exhibited the same charge heterogeneity on DEAE cellulose as the LAF obtained from the culture supernatants of PMA-stimulated cells, suggesting that the charge heterogeneity of LAF is probably not the result of extracellular modification but a characteristic of the intracellular factor. The 50,000 m.w. species could be completely converted to the 26,000 and 13,000 m.w. forms of intracellular LAF at 37°C. The conversion reaction was not mediated by a trypsin or chymotrypsin-like enzyme nor was the reaction inhibited or enhanced by sodium dodecyl sulfate. The reaction was, however, strongly temperature dependent, proceeding with low efficiency at 4° or 25°C. We propose that during the initial stage of macrophage activation (“priming”), the inactive precursor form(s) of LAF is synthesized and stored. Upon exposure of the primed cells to a secondary stimulus such as PMA, the LAF precursor is converted to an active low m.w. form and secreted. This precursor activation process would thus provide a rapid and efficient mechanism for the mobilization and release of relatively large quantities of LAF by primed or activated macrophages.
Specific Inhibition of Human Lymphocyte Responses by Primed Autologous Lymphocytes
Authors: Sheehy Michael J. , Mawas Claude , Charmot Dominique
Published: December 2022

Human lymphocytes from person A, primed for 10 to 14 days in MLC against lymphocytes from person B, inhibit specifically the proliferative response to B by fresh (i.e., unprimed) lymphocytes of A. Gamma-irradiated (2000 R) primed lymphocytes likewise inhibit specifically, although less strongly. Cells of A, primed with cells of B and then irradiated, usually can inhibit the response of A to cells of any individual sharing HLA-D antigens with B, and the effect tends to be independent of the number of stimulating cells. We also often see inhibition of responses to cells sharing HLA-A and -B antigens with person B, but this effect tends to be lost when the number of stimulating cells is increased. Similarly, at low doses, cells primed for HLA-D antigen a appear not to inhibit the response to an irrelevant HLA-D antigen b on the same stimulating cell. At higher doses of primed cells, even the response to the irrelevant antigen is inhibited. These data suggest to us that at least two mechanisms may be involved: one directed at the stimulating cell (most likely cell-mediated cytolysis), and predominant at high ratios of primed cells to stimulating cells; the other directed at specific clones of responding cells, and predominant at low ratios.
Inhibition of Specific Immune Responses by Feeding Protein Antigens
Authors: Hanson Donald G. , Vaz Nelson M. , Rawlings Linda A. , Lynch James M.
Published: December 2022

Feeding of 20 mg of ovalbumin (OVA) to normal, high-responder BDF1 mice produced virtually complete unresponsiveness to subsequent parenteral immunization with OVA in A1(OH)3 adjuvant. In previously immunized animals, a single intragastric feeding of 1 to 20 mg of OVA resulted in secondary antibody responses. Primary antigen-binding titers (Farr assay) showed graded increases that were directly proportional to oral dose of antigen. The time course of responses was parallel to responses in mice boosted i.p. with soluble antigen. IgE antibody titers also increased significantly in response to feeding of OVA, but were not dose dependent in the range tested. Despite effective boosting of ongoing antibody responses by feeding, subsequent responsiveness to parenteral immunization with OVA in adjuvant was significantly reduced in mice fed larger doses of antigen.

In normal mice, when feeding was preceded on the same day by parenteral injection of 20 µg of purified anti-OVA antibodies, the degree of tolerance associated with feeding was substantially reduced, suggesting that specific antibodies may contribute importantly to differences between normal and immune mice in response to feeding. In addition, subcutaneous priming with 10 µg of soluble OVA at the time of feeding produced an intermediate level of responsiveness to later immunization in relation to an exposure to OVA by either route alone. The pattern of results suggests that antigen-derived material absorbed from gut has a dual immunogenic and tolerogenic potential, such that the net effect of feeding can be strongly influenced by responses to past and concurrent contacts with specific antigen.
Immunoregulation in Experimental Schistosomiasis: in Vitro Induction and Assay of Spleen Cell Suppressor Activity
Authors: Kayes Stephen G. , Colley Daniel G.
Published: December 2022

Spleen cells from normal CBA/J mice or mice infected with Schistosoma mansoni were exposed for 48 to 72 hr to either concanavalin A (Con A), soluble egg antigen (SEA), or soluble worm antigenic preparation (SWAP), treated with mitomycin C to prevent further DNA synthesis, and admixed with either normal or sensitized syngeneic spleen cells exposed to a concentration gradient of phytohemagglutinin (PHA) or SEA, respectively. Both nonspecific (by Con A) and “antigen-specific” (by SEA and SWAP in infected mice only) induction of suppression was observed when using PHA-induced blastogenesis as the final assay. The number of mice with inducible splenic suppressive activity and the degree of PHA suppression induced by exposure to SEA appeared to decline between 8 and 20 weeks of infection. In contrast, when the response of spleen cells from mice infected for 8 weeks to SEA served as the final assay, strong suppressive activity was induced from the spleen cells of all chronically infected mice (20 weeks of infection). This model permits parallel analysis of the induction of suppressor activity by nonspecific and schistosome antigen-specific signals during the course of this chronic, immunoregulated condition, schistosomiasis mansoni.
Role of the Myeloperoxidase-H2O2-Halide System in Concanavalin A-Induced Tumor Cell Killing by Human Neutrophils
Authors: Clark Robert A. , Klebanoff Seymour J.
Published: December 2022

Human blood neutrophils in the presence of the lectin, concanavalin A, exhibited potent cytotoxic activity against murine lymphoma cells (LSTRA) as assessed by 51Cr release from labeled target cells. Tumor cell killing was rapid, with significant 51Cr release observed at 30 min and maximal release at 2 hr. Cytotoxicity showed a linear relationship to the log of the effector cell:target cell ratio, with significant killing detected at ratios as low as one neutrophil to 20 LSTRA cells. Under the conditions employed, human blood mononuclear leukocytes (lymphocytes plus monocytes) were not effective killer cells.

Cytotoxicity required halides (chloride, iodide) for maximal activity and was markedly reduced by agents that inhibit heme enzymes (azide, cyanide) or degrade H2O2 (catalase). Neutrophils deficient in myeloperoxidase or the respiratory burst had impaired cytotoxic activity, and these defects were corrected by the addition of purified myeloperoxidase or an H2O2-generating enzyme system, respectively. Concanavalin A also initiated protein iodination by neutrophils, a process that requires myeloperoxidase and H2O2. Both cytotoxicity and iodination were inhibited in a dose-related fashion by α-methyl-D-mannoside, a carbohydrate that blocks concanavalin A binding to mammalian cell membranes.

These data demonstrate that concanavalin A-induced neutrophil-mediated tumor cell cytotoxicity occurs as a consequence of lectin-binding to the effector cell. Furthermore, this surface stimulation results in the secretion of the lysosomal enzyme, myeloperoxidase, and the metabolic product H2O2. These agents combine with extracellular halides to form a system that is cytotoxic to mammalian tumor cells.