bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional analysis of GAT-specific T cell clones: H-2-restricted monoclonal T helper cells do not regulate expression of antibody isotypes.
Authors: Seman M , Zilberfarb V , Gougeon M L , Theze J 
Published: December 2022

Abstract
We obtained T cell clones specific for poly (Glu60, Ala30, Tyr10) (GAT) from GAT-primed lymph node cells of BALB/c mice. The clones consisted of helper cells that were carrier-specific and H-2-restricted and required a hapten-carrier bridge to activate B cells. They may be considered TH1 cells. They could all induce antibody responses of various isotypes in adoptive transfer in vitro. Isotypic patterns of the responses obtained with the clones were identical to those obtained with polyclonal T cells and were not dependent on the number of T helper cells added to the culture. Therefore, our observations demonstrate that classic TH1 cells do not regulate isotype expression on secondary responses. The expression of idiotype-like determinants on the GAT-specific clones was assayed. A syngeneic anti-idiotypic serum (B658), prepared in BALB/c mice against BALB/c anti-GAT antibodies previously characterized, was shown to block specifically the helper activity of GAT-specific T cell lines from BALB/c mice. Under the same experimental conditions the activity of none of the BALB/c clones was affected by serum B658.
Characterization of H-2Db antigens implies haplotype differences in the number of H-2 molecules expressed.
Authors: Melino M R , Nichols E A , Strausser H R , Hansen T H 
Published: December 2022

Abstract
Investigation of the molecular heterogeneity of H-2Db region antigens by using monoclonal antibodies and complex alloantisera has yielded evidence for the existence of only one gene product in this region. Sequential immunoprecipitation and isoelectric focusing analysis suggest that the private H-2.m2 and public H-2.m64 specificities defined by monoclonal or alloantibodies are present on the same molecule. Blocking studies with these reagents indicate these specificities represent two determinants spatially separated on the H-2Db molecule. Functional studies suggest that effector T cells may be generated against both of these determinants or closely associated epitopes, but the majority of the T cells recognize an epitope associated with or identical to the private specificity H-2.m2. Studies of the D region-encoded products of haplotypes besides H-2b have shown two or more distinct molecules can be detected by anti-H-2.m64 in both the H-2d and H-2q haplotypes. The presence of H-2.m64 on a single Db molecule is unique and gives further evidence for the lack of other gene products encoded in this region. Speculations based on the molecular heterogeneity of the D region gene products are made concerning the evolution and genetic organization of H-2 genes.
Role of the major histocompatibility complex in T cell activation of B cell subpopulations: antigen-specific and H-2-restricted monoclonal TH cells activate Lyb-5+ B cells through an antigen-nonspecific and H-2-unrestricted effector pathway.
Authors: Hodes R J , Shigeta M , Hathcock K S , Fathman C G , Singer A 
Published: December 2022

Abstract
Monoclonal T helper (TH) cell populations were employed to study the mechanism of activation of the Lyb-5+ B cell subpopulation in T cell-dependent antibody responses in vitro. It was demonstrated that monoclonal T cell populations were sufficient to help rigorously T-depleted unprimed (B + accessory) cells for direct plaque-forming cell responses to trinitrophenyl- (TNP) conjugated keyhole limpet hemocyanin (KLH). The activation of several lines of cloned (H-2b X H-2k)F1 TH cells was antigen (KLH) specific and H-2 restricted. Individual clones were restricted to H -2b, H-2k, or unique (H-2b X H-2k)F1 encoded determinants. Under the experimental conditions employed, responses mediated by cloned TH cells were found to result in the activation of the Lyb-5+ B cell subpopulation. The activation of Lyb-5+ B cells by cloned TH cells did not require covalent linkage of carrier and hapten, and responses could be stimulated in the presence of free KLH plus TNP conjugated to an irrelevant carrier. The H-2 restriction of TH cell function was shown to reflect a requirement for T cell recognition of determinants expressed by accessory cells, whereas no requirement existed for restricted T cell recognition of B cells. These findings suggest that the help provided by monoclonal TH cells, once activated, was both antigen nonspecific and H-2 unrestricted. Consistent with this interpretation, it was found that the supernatant of antigen-stimulated TH cells provided antigen-nonspecific help to T-depleted spleen cells. Thus, these results demonstrate that the activation of Lyb-5+ B cells by antigen-specific and H-2-restricted monoclonal TH cell populations is itself antigen nonspecific and H-2 unrestricted.
Stimulation of the intracellular killing of Staphylococcus aureus by monocytes: regulation by immunoglobulin G and complement components C3/C3b and B/Bb.
Authors: Leijh P C , van den Barselaar M T , Daha M R , van Furth R 
Published: December 2022

Abstract
The intracellular killing of Staphylococcus aureus by human monocytes requires continuous stimulation by extracellular serum factors interacting with the cells via membrane binding sites. At least 75% of the intracellular killing in the presence of fresh serum was accounted for by the combined stimulatory activities of IgG, C3/C3b, and B/Bb. C3b is a more potent stimulator than C3, and Bb stimulates the killing to the same degree as B. The stimulation of intracellular killing by C3 and C3b occurs by interaction of the stable binding site of this molecule with the C3b receptor in the monocyte membrane. The stimulation of intracellular killing by B and Bb is most probably mediated via a binding site on these proteins interacting with a receptor site in the monocyte membrane. Both complement receptors, i.e., for C3b and B, are pronase sensitive. However, only the C3b receptor can be inhibited by (Fab')2 fragments of anti-C3 receptor antibodies, indicating that the binding sites for C3/C3b and B/bb are different.
The immune response in aged C57BL/6 mice. II. Characterization and reversal of a defect in the ability of aged spleen cells to respond to the adjuvant properties of Fc fragments.
Authors: Morgan E L , Weigle W O 
Published: December 2022

Abstract
Fc fragments derived from papain cleavage of human Ig were found to be unable to enhance the in vitro anti-SRBC response of aged mice. The inability of aged spleen cells to respond to the adjuvant properties of Fc fragments is localized to the aged T cell population. The addition of Fc fragments to cultures of aged B cells and young adult T cells, but not young adult B cells and aged T cells, resulted in an enhanced anti-SRBC response. The Fc fragment adjuvant defect in spleen cells from aged mice can be reversed by the addition of IL 2 to culture. The addition of either Fc fragments alone or IL 2 alone with antigen to intact aged spleen cell populations did not result in an enhanced anti-SRBC response. When aged spleen cell cultures receive both Fc and IL 2, however, a marked enhancement is observed. These data indicate that IL 2 action on aged spleen cells results in the acquisition of reactivity to Fc adjuvant action by aged mice.
Suppression of anti-hapten antibody responses by hapten-specific cytolytic T lymphocytes: role of I-A-associated antigen on target B lymphocytes.
Authors: Moser G , Burakoff S J , Abbas A K 
Published: December 2022

Abstract
Cytolytic T lymphocytes (CTL) specific for 2,4,6-trinitrophenyl (TNP) determinants suppress the effector phase of a secondary anti-TNP antibody responses of murine syngeneic spleen cells in vitro. The cells mediating this suppression are hapten-specific, H-2-restricted, and possess properties typical of CTL. Moreover, the targets of the suppression appear to be antigen-primed B lymphocytes that are recognized by CTL via soluble antigen bound noncovalently to their Ig receptors. The effect of the CTL can be blocked by the addition of monoclonal antibodies directed against I-A molecules but not I-E or H-EK-encoded molecules on the target B cells, even in strain combinations in which the CTL-B cell interaction is restricted only by the H-2K and I regions of the MHC. This result suggests that B lymphocyte-bound antigen tends to associate preferentially with I-A rather than H-2K/D-encoded determinants, and that the suppressive effect of the CTL population is attributable to the minor subset that recognizes hapten-modified Ia antigens. These findings are also discussed in terms of the possible immunoregulatory function of Ia-restricted CTL.
Gamma interferon (IFN gamma) and IFN alpha/beta suppress murine myeloid colony formation (CFU-C)N: magnitude of suppression is dependent upon level of colony-stimulating factor (CSF).
Authors: Klimpel G R , Fleischmann W R , Klimpel K D 
Published: December 2022

Abstract
The effect of different types of interferon (IFN) on macrophage and granulocyte colony formation (CFU-C) in vitro was studied using bone marrow cells from C57BL/6 mice. CFU-C formation was measured at 7 days using a standard methylcellulose culture system with L-cell conditioned medium (LCCM) as a source of colony-stimulating factor activity (CSF), IFN gamma was obtained from staphylococcal enterotoxin A- (SEA) stimulated mouse spleen cells and was partially purified (50-fold) using affinity chromatography. IFN alpha/beta was obtained from Newcastle disease virus-infected mouse L-cells and was partially purified (286-fold) using an AcA 202 column. IFN gamma inhibited CFU-C formation in a dose-dependent manner and was 100 times more inhibitory than IFN alpha/beta. IFN gamma completely suppressed CFU-C formation with as little as 15 units of antiviral activity. In contrast, 1000 to 2000 units of antiviral activity of IFN alpha/beta was required for complete suppression of CFU-C formation. The ability of IFN gamma to inhibit CFU-C formation was completely abolished after pH 2 treatment (24 hr), heat treatment (60 degrees C, 2 hr), or treatment with a specific antiserum against IFN gamma, which indicated that IFN gamma was the mediator of CFU-C inhibition. When IFN gamma and IFN alpha/beta were mixed together and added to bone marrow cells, they had a synergistic effect on the suppression of CFU-C formation. The level of inhibition mediated by both IFN gamma and IFN alpha/beta was totally dependent upon the amount of CSF present in the culture system; increasing the level of CSF could completely overcome the IFN suppressive effect. These results suggest that IFN gamma and IFN alpha/beta may have regulatory roles in hematopoiesis.
Characterization of a suppressive factor produced by a human T hybridoma.
Authors: Grillot-Courvalin C , Dellagi K , Chevalier A , Brouet J C 
Published: December 2022

Abstract
The mode of action and the target cell of a suppressive factor continuously and spontaneously produced by a human hybrid T cell line constructed recently are reported. This factor was shown to suppress pokeweed mitogen-induced B cell differentiation when added within the first 48 hr of culture. It does not suppress B cell differentiation induced by Nocardia extracts, a relatively T-independent mitogen. The target cell for this factor seems to be a T lymphocyte in that it can be absorbed by E-rosetting cells but not by B lymphocytes or monocytes. This factor does not impair mitogen or allogeneic-induced lymphocyte proliferation and has an apparent m.w. of approximately 45,000 as estimated by Sephacryl S200 gel chromatography.
Effect of recent antigen exposure on the functional expression of B cell subpopulations.
Authors: Pillai P S , Scott D W , Piper M , Corley R B 
Published: December 2022

Abstract
We investigated whether the definition of functional B cell subpopulations changes after the exposure of B cells to specific antigen. Recent in vivo priming with fluorescein- (FL) coupled T-independent (TI) antigens leads to an augmentation of the subsequent in vitro responses of B cells to FL-coupled TI antigens, including FL-polymerized flagellin, FL-lipopolysaccharide, and FL-Brucella abortus, as well as a FL-coupled T-dependent (TD) antigen, FL-keyhole limpet hemocyanin (KLH). This effect, which is evident 7 days after priming, is of short duration in that B cells from FL-Ficoll injected mice display normal responsiveness 3 wk after priming. When mice are primed with FL-KLH, the TD antigen, B cells responsive to a subsequent FL-KLH challenge are expanded, but not short-term cross-priming for any of the TI antigen challenges is observed. Limiting dilution precursor analysis shows that B cell populations responding to different FL-coupled TD and TI antigens overlap in unimmunized animals. FL-TI antigen priming induces not only quantitative changes in the responding B cells (increased precursor frequencies) but also results in functional changes in FL-specific B cells. The primed B cells now respond to FL-hapten in a carrier-restricted manner and behave as independent (non-overlapping) subpopulations. We suggest that B cell responses to different forms of the same hapten are influenced in part by their recent "history" of antigenic exposure.
Cellular origin of interleukin 2 (IL 2) in man: evidence for stimulus-restricted IL 2 production by T4+ and T8+ T lymphocytes.
Authors: Meuer S C , Hussey R E , Penta A C , Fitzgerald K A , Stadler B M , Schlossman S F , Reinherz E L 
Published: December 2022

Abstract
The human T cell subset(s) responsible for production of interleukin 2 (IL 2) was investigated in the present study. For this purpose, highly purified T4+ and T8+ T lymphocytes were stimulated with mitogens and alloantigens. Subsequently, culture supernatants were analyzed for IL 2 activity in each of two assay systems: 1) proliferation of long-term T cell lines and 2) induction of cytotoxic effector cells from a resting T8+ population incubated in MLC. Mitogen stimulation led to secretion of equivalent amounts of IL 2 from both the major T cell subsets; in contrast, after allogeneic activation, IL 2 was produced predominantly from the T4+ subset. The stimulus dependency of IL 2 production suggests that the individual functional repertoires of T4+ and T8+ T cell subsets may be linked to unique surface receptors and/or interaction molecules involved in cell triggering rather than a restricted capacity to produce lymphokine.
Antigen-specific human T lymphocyte clones: mechanisms of inhibition of proliferative responses by xenoantiserum to human nonpolymorphic HLA-DR antigens.
Authors: Lamb J R , Eckels D D , Ketterer E A , Sell T W , Woody J N 
Published: December 2022

Abstract
We studied the effects of xenoantiserum to human nonpolymorphic Ia-like antigens upon in vitro antigen-specific T cell proliferative responses in unfractionated PBL populations and at the monoclonal level. Our findings suggest that the xenoantiserum, although it inhibits the antigen-specific response of unfractionated PBL and allospecific T cell clones, does not inhibit the proliferative response to cloned influenza virus immune human T lymphocytes, and therefore may be mediating inhibition by dual mechanisms: direct inhibition of alloantigen recognition and induction of nonspecific suppression. Kinetic differences may explain these phenomena. In cocultivation experiments with a virus-specific clone, the RaIa antiserum appears to induce an OKT3+,8+,4-, radiosensitive regulatory subset of lymphocytes. When adoptively transferred, these induced cells inhibit the TLC response in an antigen-nonspecific and genetically nonrestricted manner. We discuss the various modes and levels of inhibition of antigen-specific proliferation by anti-Ia antisera and their multiple activities.
Interferon-mediated inhibition of human polyclonal immunoglobulin synthesis.
Authors: Fleisher T A , Attallah A M , Tosato G , Blaese R M , Greene W C 
Published: December 2022

Abstract
Human lymphoblastoid IFN suppressed human polyclonal Ig synthesis in a dose-related manner, with 71% mean inhibition of antibody production found when 1000 units of IFN were added to the cultures. This suppression was demonstrated to be mediated by an electrophoretically pure preparation of IFN. Furthermore, IFN inhibition of both the T-dependent and the T-independent polyclonal activators was not the result of direct cellular cytotoxicity. IFN-mediated suppression of human polyclonal Ig production does not result from induction of T suppressor cells, and in a T helper cell-independent system this inhibition appears to result from either a direct action on the B cells or an indirect effect via monocytes.
Monoclonal antibodies coupled to LPS specifically induce synthesis of immunoglobulins with complementary variable region determinants.
Authors: Primi D , Cazenave P A 
Published: December 2022

Abstract
The aim of this work was to investigate whether LPS coupled to monoclonal immunoglobulins would, at certain critical doses, specifically trigger B cells carrying immunoglobulins with V region complementary to that of the immunogen. Thus sera of BALB/c mice injected with 5 micrograms of LPS-M-460 contained immunoglobulins that specifically reacted with the M-460 protein. Similarly, injection of LPS coupled to a monoclonal anti-M-460 immunoglobulin F6(51) resulted in the selective production of antibodies specific for F6(51). In addition, radioimmunoassay studies clearly showed that the induced immunoglobulins reacted with F6(51) through idiotypic interactions. This immune response is independent from T cells because nu/nu responded as well as their heterologous littermates. Kinetic studies showed that the titer of F6(51) complementary antibodies in mice injected with F6(51)-LPS remained elevated for more than 1 mo, and that the majority of these immunoglobulins belong to the IgM class. Surprisingly, F6(51)-LPS induced F6(51)-specific antibodies only in mice with the Igh-a allotypic haplotype, indicating that although thymus-independent, the response is under regulation. Finally, addition of small amounts of F6(51)-LPS to cultures of B cells from BALB/c mice resulted in the secretion of antibodies capable of reacting with F6(51). These low concentrations failed to activate nonspecific cells. Consequently our data offer the possibility of selectively inducing in vivo or in vitro idiotype-positive immune responses in the complete absence of the antigen recognized by the induced immunoglobulins.
The quantitative relationship between clearance rate constants and number of C1-fixing sites.
Authors: Meryhew N L , Marsden K , Runquist O A 
Published: December 2022

Abstract
The rate equation correlating kinetic data for immune-mediated clearance of RBC in guinea pigs was extended to human studies. Rate constants were evaluated for clearance of IgG, IgM, and cold agglutinin-sensitized RBC in normal human volunteers as well as for clearance of IgM-sensitized cells from a small group of patients with primary biliary cirrhosis. All rate constants evaluated in the clearance of sensitized RBC were found to correlate with the number of C1-fixing sites. These correlations not only provide additional support for the mechanism from which the rate of equation was derived, but also allow a quantitative prediction of rate constants and clearance patterns based on the level of sensitization. In addition, the analysis of data from abnormal clearance studies produced rate constants that provided both identification and quantification of the specific defective reaction(s).
Arachidonic acid metabolism of the murine eosinophil. II. Involvement of the lipoxygenase pathway in the response to the lymphokine eosinophil stimulation promoter.
Authors: Rand T H , Turk J , Maas R L , Colley D G 
Published: December 2022

Abstract
Eosinophil stimulation promoter (ESP) is a murine lymphokine that enhances the migration of eosinophils. Exogenous arachidonic acid between 0.5 and 2 micrograms/ml potentiated the activity of ESP on murine eosinophil migration, whereas such concentrations did not affect migration in the absence of ESP. Among the lipoxygenase products identified from an enriched population of murine eosinophils, leukotriene B4 (optimal activity at 100 ng/ml) and 12-HETE (optimal activity at 2 micrograms/ml) stimulated migration of these cells. Another lipoxygenase product from these cells 15-HETE inhibited ESP-induced migration; between 5 and 10 micrograms/ml 15-HETE decreased by one-half both stimulated migration and 12-HETE biosynthesis. Structurally diverse drugs at concentrations that inhibited HETE biosynthesis inhibited ESP-induced migration. The concentrations that decreased migration activity by one-half were 5 microM NDGA, 10 microM ETYA, and 150 microM BW755C. Aspirin and indomethacin at concentrations reported to inhibit prostaglandin biosynthesis did not substantially inhibit ESP activity, but concentrations of indomethacin above 20 microM caused concentration-dependent inhibition of migration. The selective lipoxygenases inhibitor 134,7,10,13-eicosatetraynoic acid was more potent than ETYA in inhibition of ESP-induced migration, and the selective cyclooxygenase inhibitor 6,9,12-octadecatriynoic acid did not effect inhibition. These results are consistent with the hypothesis that stimulation of eosinophils by the lymphokine ESP involves the generation of lipoxygenase products from arachidonic acid, which positively and negatively regulate the migratory activities of these cells.
Functional activity in vivo of effector T cell populations. I. Antitumor activity exhibited by allogeneic mixed leukocyte culture cells.
Authors: Engers H D , Sorenson G D , Terres G , Horvath C , Brunner K T 
Published: December 2022

Abstract
The in vivo activity of murine cytolytic T lymphocyte-containing effector cell populations generated in vitro was studied in a tumor allograft model system by monitoring the elimination of 131I-IUdR-labeled tumor cells with whole-body counting techniques. Mice were irradiated sublethally and 16 hr later 131I-labeled tumor cells were injected either subcutaneously or i.p. Simultaneously, graded doses of various effector cell populations were injected i.v. and the mice were counted daily to assess the potential elimination of the radiolabeled tumor cells. Thus, allogeneic 2 degrees mixed leukocyte culture cells were observed to eliminate allogeneic but not syngeneic tumor cells in a dose-dependent manner, with as few as 0.2 x 10(6) effector cells causing significant destruction of 2 x 10(6) allogeneic tumor cells. The protective effect of the mixed leukocyte culture cells was considerably reduced when Lyt-2+-bearing lymphocytes were eliminated by treatment with monoclonal antibody plus complement. In additional experiments, Lyt-2+ lymphocytes positively selected by enrichment on antibody-coated petri dishes gave efficient protection, in the absence of Lyt-2- cells. Surprisingly, when several different cloned, specific, long-term allogeneic cytolytic T cells lines were injected either i.p. of i.v., tumor cell destruction was observed only after i.p. injection.