bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ligand-induced association of surface immunoglobulin with the detergent-insoluble cytoskeletal matrix of the B lymphocyte.
Authors: Braun J , Hochman P S , Unanue E R 
Published: December 2022

Abstract
Ligand binding is believed to induce surface immunoglobulin (Ig) to form a physical association with the underlying cell cytoskeleton. We investigated this interaction by use of nonionic detergents, which are known to dissolve membrane proteins but preserve a detergent-insoluble cytoskeletal residue. In the absence of ligand treatment, surface Ig in the B cell plasma membrane was fully dissolved by nonionic detergent; however, interaction with a ligand converted the receptor to a novel, detergent-insoluble state. The conversion of surface Ig to a detergent-insoluble form required receptor cross-linking but occurred independently of capping. Several types of experiments demonstrated that this form of Ig was not due to the size insolubility of immune complexes and involved a stable, noncovalent association of the receptor with the detergent-insoluble, cytoskeletal residue. Incubation of ligand-bound cells at 37 degrees C promoted the degradation of surface Ig and the appearance of new, lower m.w. species, including a major soluble protein (50,000 daltons) that was antigenically related to surface Ig. These events corresponded to receptor endocytosis by several criteria (time course, temperature sensitivity, and energy dependence). Taken together, these results were consistent with the ligand-induced transmembrane attachment of receptors to the underlying cytoskeletal matrix followed by receptor internalization and catabolism.
A ganglioside-dependent cellular binding mechanism in rat macrophages.
Authors: Riedl M , Forster O , Rumpold H , Bernheimer H 
Published: December 2022

Abstract
A rosetting assay was performed with rat alveolar and peritoneal macrophages and sheep red blood cells (SRBC) treated with gangliosides. SRBC incubated with GM2, GD1a, and a mixture of bovine brain gangliosides (BBG) showed binding to rat macrophages. The extent of binding was dependent on the concentration of gangliosides. Binding induced by GM2 was stronger than that induced GD1a and BBG. GM1 and GA2 did not induce rosette formation. Inhibition studies with gangliosides, sialyllactose, lactose, and neuraminic acid suggested that the macrophage binding site recognizes neuraminic acid in conjunction with neighboring carbohydrates showing highest affinity for GM2. Sodium azide, sodium fluoride, ethylenediaminetetraacetate, cytochalasin B, and colchicine did not inhibit rosette formation. The percentage of peritoneal macrophages binding ganglioside-treated SRBC was lower than that of alveolar macrophages. Proteose-peptone-stimulated peritoneal macrophages, however, showed an increase of rosette formation. Around 30% of adherent spleen cells also had binding activity for GM2-treated SRBC. Peripheral blood mononuclear cells did not bind ganglioside-treated SRBC. Phagocytosis of GM2-treated SRBC attached to alveolar macrophages could not be observed. It is suggested that macrophages may express recognition sites for certain gangliosides that might be important in cell-cell interaction.
Restoration of T cell depression and suppression of blood pressure in spontaneously hypertensive rats (SHR) by thymus grafts or thymus extracts.
Authors: Ba D , Takeichi N , Kodama T , Kobayashi H 
Published: December 2022

Abstract
Spontaneously hypertensive rats (SHR) that develop hypertension and arterial lesions resembling human periarteritis nodosa were found to possess a selective depression of T cell functions with an appearance of natural thymocytotoxic autoantibody (NTA). The relationship between T cell depression and hypertension in these animals was investigated. The immune responsiveness of T cell-depressed SHR was completely recovered by histocompatible thymus grafts and was partially restored by histoincompatible allogeneic or xenogeneic thymus grafts or by injection of thymus extracts. Transplantation of compatible thymus tissues into neonatal SHR produced long-lasting recovery of immune functions. When complete immunologic restoration was achieved, significant suppression of high blood pressure was obtained. The SHR that showed high blood pressure were always accompanied with high NTA titers and arterial lesions. Thymus grafts or thymus extracts significantly decreased the titers of NTA. The development and dissemination of arterial lesions, which may cause increased blood flow resistance, were completely prevented by compatible thymus grafts into neonatal SHR. These results suggest that thymus grafts and thymus extracts may suppress the development of hypertension by preventing or curing the periarteritis nodosa in SHR.
Switch from NP-specific IgG3 to IgG1 in the mouse hybridoma cell line S24/63/63.
Authors: Baumhäckel H , Liesegang B , Radbruch A , Rajewsky K , Sablitzky F 
Published: December 2022

Abstract
We have isolated by fluorescence-activated cell sorting an IgG1 expressing class switch variant (S24-1/47) from the IgG3-producing mouse hybridoma cell line S24/63/63. Both Ig bind the hapten 4-hydroxy-3-nitro-phenylacetyl (NP) with approximately the same affinity and fine specificity and are idiotypically indistinguishable. The apparent m.w. is 50,000 for the gamma 1 and 51,000 for the gamma 3 chain. The genomic DNA of IgG3-producing S24/63/63 cells contains a 14-kb Eco RI restriction fragment with C gamma 3 sequences representing a rearranged C gamma 3 gene. In the class switch variant S24-1/47 the C gamma 3 gene is deleted.
A new complement-dependent bactericidal factor found in nonimmune mouse sera: specific binding to polysaccharide of Ra chemotype Salmonella.
Authors: Ihara I , Harada Y , Ihara S , Kawakami M 
Published: December 2022

Abstract
It has been shown that nonimmune mouse sera contain a complement-dependent bactericidal factor that reacts specifically with Ra chemotype Salmonella. In this study we investigate a specific determinant to which this factor binds. This factor bound to Ra chemotype lipopolysaccharide (LPS) but not to S or Re chemotype LPS. The binding was markedly inhibited by N-acetyl-D-glucosamine (GlcNAc), which was the nonreducing terminal of the Ra polysaccharide chain and by certain monosaccharides structurally relating to L-glycero-D-mannoheptose, a terminal component of a side branch of Ra polysaccharide. The factor bound to the Ra bacteria could be eluted with a medium containing GlcNAc. These results indicate that the specific determinant is the polysaccharide region of LPS characteristic of Ra chemotype Salmonella. Ca2+ but not Mg2+ was required for the specific binding of the factor to cells of Ra bacteria. A molecule composed of a polypeptide of 28,000 m.w. was found in the active fraction obtained by the monosaccharide elution. However, no polypeptides corresponding to light and heavy chains of mouse immunoglobins were detected from the active fraction.
Human host response to Giardia lamblia. I. Spontaneous killing by mononuclear leukocytes in vitro.
Authors: Smith P D , Elson C O , Keister D B , Nash T E 
Published: December 2022

Abstract
To understand host resistance to Giardia lamblia infection, we investigated the capacity of human peripheral blood effector cells to kill G. lamblia trophozoites. Peripheral blood was obtained from 12 healthy, uninfected individuals without detectable IgG anti-G. lamblia antibody or known exposure to G. lamblia. Isolated mononuclear leukocytes (MNL), granulocytes, lymphocytes, and monocytes were cultured 16 hr with G. lamblia that had been pulsed with (3H)TdR while in log growth. MNL from all 12 individuals were spontaneously cytotoxic for G. lamblia. Specific cytotoxicity ranged from 13% at an E:T of 3:1 to 56% at an E:T of 100:1. Release of 3H directly correlated with a decrease in viable G. lamblia. In contrast to the uniform cytotoxicity by mononuclear cells, granulocytes and lymphocytes had no spontaneous cytotoxic activity for G. lamblia. MNL depleted of phagocytic or adherent cells lost all cytotoxic activity. Also, G. lamblia induced nonspecific MNL cytotoxicity to unrelated target cells. Finally, cytotoxicity against G. lamblia could be inhibited by adding unlabeled Trichomonas vaginalis, suggesting that this may be a more general mechanism of host defense against extracellular protozoa. We conclude that human peripheral blood monocytes-macrophages are spontaneously cytotoxic for G. lamblia and that this may be a major mechanism of host defense against this parasite.
Functional analysis of human T cell subsets defined by monoclonal antibodies. V. Suppressor cells within the activated OKT4+ population belong to a distinct subset.
Authors: Thomas Y , Rogozinski L , Irigoyen O H , Shen H H , Talle M A , Goldstein G , Chess L 
Published: December 2022

Abstract
In the present report, we characterize a monoclonal antibody directed at a surface differentiation antigen on human T cells. The monoclonal antibody, OKT17, recognizes a cell surface antigen present on the majority of resting normal peripheral T cells. In contrast, OKT17 is unreactive with normal B cells, B cell lines, T cell lines, or SIg+ CLL. Interestingly, after activation, the antigen recognized by OKT17 is lost from a subset of OKT4+ cells. We took advantage of this finding to explore further the functional heterogeneity within activated OKT4+ cells. Evidence was obtained that the PWM-activated OKT4+ subset remaining after depletion of OKT17-reactive T cells (OKT4+ 17-) contains radiosensitive helperr cells but is devoid of suppressor cells. In contrast, the activated OKT4+ 17+ population contains potent radiosensitive suppressor cells as well as radioresistant helpe cells. Taken together, these studies suggest that the OKT17 monoclonal antibody can differentiate two functionally mature, activated OKT4+ human T cells: OKT4+ OKT17+ radiosensitive suppressor cells and OKT4+ 17- radiosensitive helper cells.
Conformational changes in complement component C4 induced by activation, treatment with amines, chaotropes, or freezing-thawing, detectable by radioiodination using lactoperoxidase.
Authors: von Zabern I , Gigli I 
Published: December 2022

Abstract
Conversion of C4 to C4b by enzymic cleavage or generation of a C4b-like form by treatment with amines, chaotropes, or freezing and thawing is accompanied by conformational alterations in the molecule. The nature of the changes is the same whether C4 is converted to a C4b-like form or to C4b. Evidence for structural changes at the surface of the C4 molecule was obtained by peripheral labeling with 125I by the lactoperoxidase method: there are residues, probably tyrosines, that are inaccessible for radioiodination in C4b and C4b-like C4, but exposed in native C4. The residues concerned are located in two separated parts of the alpha-chain at a distance of approximately 9000-34,000 m.w. from the N-terminus and in a 16,000 m.w. portion at the C-terminus. It is so far unknown whether the observed changes are involved in the uncovering of new binding sites, or whether they are the mere reflection of alterations elsewhere in the molecule that are of greater functional significance.
Control of macrophage Ia expression in neonatal mice--role of a splenic suppressor cell.
Authors: Snyder D S , Lu C Y , Unanue E R 
Published: December 2022

Abstract
The control of macrophage expression of I region-associated antigens (Ia) in neonatal mice was studied by comparing responses of neonatal and adult mice to immune vs nonimmune stimuli. Adults generated peritoneal exudates rich in Ia-bearing macrophages in response to i.p. injection of live Listeria monocytogenes, Listeria-immune T cells, and heat-killed Listeria, or a soluble mediator termed macrophage Ia-recruiting factor (MIRF). Neonates failed to respond to these stimuli. In contrast, both neonates and adults generated Ia-negative peritoneal exudates when stimulated with thioglycollate. A neonatal spleen cell that blocked the response of adults both to immune T cells and heat-killed Listeria and to MIRF was identified and characterized. Some of the suppressor cells appeared to be early precursors of the phagocytic lineage that develop into mature monocyte-macrophages. Suppression was apparently mediated by metabolites of arachidonic acid since indomethacin and aspirin in vivo blocked the effect. Similar suppressor activity was found in adult bone marrow and in adult resident peritoneal exudate cells. Thus, the phagocytic line autoregulates its surface expression of Ia in both neonatal and adult mice. This mechanism becomes particularly pointed during early development and could contribute to the lack of immunity during ontogeny.
Lymphokine modulation of fibroblast proliferation.
Authors: Nielson E G , Phillips S M , Jimenez S 
Published: December 2022

Abstract
In an experimental model of interstitial nephritis resulting in fibrosis, lymphokines secreted by a common population of antigen-reactive T lymphocytes have been shown to exert a bidirectional influence on fibroblast proliferation and collagen synthesis. We report that these lymphokines can be chromatographically separated into two fractions. The larger m.w. fraction stimulated fibroblast proliferation whereas the smaller m.w. fraction was inhibitory. These results further clarify potentially important immune regulators of fibrogenesis.
Prolonged suppression of experimental allergic encephalomyelitis in the Lewis rats: the effect of lipopolysaccharides.
Authors: Raziuddin S , Morrison D C 
Published: December 2022

Abstract
The current investigations have revealed that Lewis rats preimmunized with BP in CFA, and after recovery from the first episode of EAE, developed a second mild attack of EAE after challenge with BP/CFA at specified times. However, preimmunization of Lewis rats with BP complexed to LPS in CFA protects animals for a longer time from a second attack induced by BP/CFA challenge.
A monoclonal antibody detecting unusual Thy-1 determinants.
Authors: Auchincloss H , Ozato K , Sachs D H 
Published: December 2022

Abstract
20-10-5S is a monoclonal antibody produced by the fusion of C3H anti-C3H.SW splenocytes with the SP2/0 cell line. The antibody appears to react with Thy-1 determinants by several criteria including cytotoxicity patterns, functional assays, genetic analyses, and competitive binding experiments. However, the antibody and the determinants it detects are unusual in that: 1) 20-10-5S is autoreactive; 2) the antibody shows allospecificity for Thy-1.2 vs Thy-1.1 antigens only on peripheral lymphocytes and not on thymocytes; and 3) the antibody reacts only with determinants on murine T cells and not with antigens on brain tissue or on rat thymocytes. It therefore seems that 20-10-5S reacts with murine T cell-specific Thy-1 determinants that are lost or modified during maturation of the cells on which they are expressed.
In vitro and in vivo allogeneic effects: differential modulation of B cell subpopulations.
Authors: Golding H , Rittenberg M B 
Published: December 2022

Abstract
We examined the sensitivity of primary TD and TI responses to allogeneic effects and found that primary TD responsive B cells were very sensitive to negative allogeneic effects elicited in vitro. The primary TI-2 responses, on the other hand, were not suppressed but rather enhanced twofold to threefold under the same culture conditions. Thus, primary B cell subsets resemble their IgG memory counterparts (1) in their differential sensitivity to allogeneic T cells. The ability of in vivo induced allogeneic effects of modulate antibody responses was studied using chronic graft-vs-host reaction (GVH) as a model. F1 mice immunized with TD (TNP-KLH, TNP-sheep-gamma-globulin) antigens shortly after GVH induction had reduced IgM and IgG primary responses. In contrast, the primary response to TNP-Ficoll was enhanced and included a large number of primary IgG PFC. Furthermore, mice undergoing chronic GVH were incapable of developing long-term memory after immunization with a TD antigen (TNP-KLH), as determined by secondary in vitro challenges with either TD or TI antigens. These mice retained helper T cells, indicating a failure of memory development in the B cell compartment. These studies suggest that the secondary TD- and TI-responding precursors (B2 gamma and B1 gamma, respectively) are probably both derived from primary B2 precursors (which are very sensitive to negative allogeneic effects). The maturation of the B1 memory population may thus be linked to increased resistance to allosuppression.
Regulation of macrophage populations. IV. Modulation of Ia expression in bone marrow-derived macrophages.
Authors: Calamai E G , Beller D I , Unanue E R 
Published: December 2022

Abstract
The expression of I region-associated (Ia) antigens was studied in macrophages derived from bone marrow cell precursors cultured in L cell-conditioned medium (LCM) as a selective growth stimulator. Very few macrophages expressed Ia either while growing actively in LCM or when quiescent, after the removal of LCM from the culture. The addition of T cell lymphokines, however, stimulated the biosynthesis and membrane expression of Ia. Uptake of bacteria by the macrophage during exposure to the lymphokines produced a synergistic increase in Ia expression. The lymphokine-induced stimulation of Ia was reduced by the simultaneous presence of LCM, suggesting that growth and differentiative stimuli have opposing effects on Ia induction. All macrophage colonies derived from single precursors contained cells that could be induced to express Ia.
Identification and molecular characterization of macrophage-associated antigens of the rat.
Authors: Veit B C , Hamilton T A , Kotb M 
Published: December 2022

Abstract
Rabbit antiserum to rat peritoneal exudate (PE) macrophage (M phi) antigens was prepared and its reactivity with cell surface proteins of M phi, granulocytes, and lymphocytes was studied by one- and two-dimensional polyacrylamide gel electrophoresis (PAGE). A total of 14 membrane antigens were identified of which three were found to be expressed only by M phi and granulocytes. By one-dimensional analysis, a protein with an approximate m.w. of 105,000 was present on splenic and PE M phi and on splenic lymphocytes. Two-dimensional analysis revealed that this band was heterogeneous and contained at least three species, one of which was restricted to expression on M phi and granulocytes. A second protein of 150,000 daltons was resolved into two species by two-dimensional analysis. Both of these species were present on M phi and granulocytes but not on lymphocytes. Both the 105,000- and 150,000-dalton proteins were glycosylated. Because the 105,000- and 150-000-dalton proteins expressed by M phi were also expressed by granulocytes, is is likely that these are differentiation antigens whose expression is a characteristic property of cells within both monocytoid and myeloid lineages. All three 105,000-dalton species and one of the two 150,000-dalton species were detected on mouse M phi, indicating their expression is not unique to the rat.
Structural analysis of thymus-leukemia (TL) antigens in the mouse.
Authors: McIntyre K R , Hämmerling U , Uhr J W , Vitetta E S 
Published: December 2022

Abstract
Thymus-leukemia (TL) antigens have been sequentially immunoprecipitated from glycoprotein pools prepared from lysates of biosynthetically labeled ASL-1w leukemia cells with a monoclonal antibody and a standard alloantiserum. Results suggest that on leukemia cells from Tlaa mice, as previously reported for thymocytes from these mice, all the alloantiserum-defined TL specificities (TL.1, 2, 3, 5, 6) as well as the specificity defined by the monoclonal antibody (TL.m3) are carried by a single molecular species. The degree of structural homology between the 45,000-m.w. heavy chains of TL and H-2 was investigated by the technique of comparative tryptic peptide mapping. Results indicate that TL is more distantly related at the primary structural level to H-2 than H-2 antigens are to one another.
Studies on the mechanism of NK cell lysis.
Authors: Quan P C , Ishizaka T , Bloom B R 
Published: December 2022

Abstract
The mechanism of cytolysis by murine NK cells was analyzed using a variety of metabolic inhibitors that have proven informative in studying the lytic mechanism of CTL and the mechanism of histamine release by mast cells. Target cell binding occurred in the absence of calcium and was inhibited by only one of the agents studied, cytochalasin B. Lysis was initiated by addition of Ca2+ ions, as in the case of CTL. Subsequent to target cell binding, but prior to programming for lysis by Ca2+, NK cell lytic activity could be suppressed by inhibitors of chymotrypsin-like, but not trypsin-like proteases, in contrast to CTL. In addition, 3-deaza-SIBA, an inhibitor of transmethylation reactions and quinacrine, an inhibitor of phospholipase A2, appear to act before the Ca2+-dependent programming for lysis. Sr2+ ions blocked the lytic function, as did trifluoperazine (stelazine), the former presumably competing for ionic calcium, the latter known to block binding of Ca2+ to calmodulin. 8Br-cAMP and colchicine blocked later steps required for lysis. With the possible exception of trifluoperazine, all of the agents that blocked NK cell lysis are known to inhibit histamine release from mast cells. These results lend support to the stimulus-secretion model, originally proposed to explain the mechanism of CTL cytolysis, as relevant to the mechanism of lysis by NK cells.
Monocyte aggregation and superoxide anion release in response to formyl-methionyl-leucyl-phenylalanine (FMLP) and platelet-activating factor (PAF).
Authors: Yasaka T , Boxer L A , Baehner R L 
Published: December 2022

Abstract
Like the PMN, human peripheral blood monocytes were capable of aggregating in response to FMLP and PAF. Monocyte aggregation was dependent on glycolysis and the presence of divalent cations. Unlike the PMN, monocyte aggregation in response to FMLP was not accompanied by degranulation, nor was it potentiated by cytochalasin B. Furthermore, cytochalasin B and its cogenitor, dihydrocytochalasin B, inhibited aggregation in response to PAF. PAF and FMLP appeared to react with the monocyte at separate receptors because sequential challenge of the monocyte with the same agents failed to elicit further aggregation, whereas rechallenge with the alternative agent induced further aggregation. Because the monocyte will aggregate to chemotactic agents in vitro, it is likely that the cell will be affected by these agents in vivo, which could lead to leukoembolization of circulating monocytes.
Effect of mouse anti-I region antiserum and complement on human mononuclear cell response to concanavalin A.
Authors: Campbell D A , Oehler J R , Tsai C T , LoBuglio A F , Niederhuber J E 
Published: December 2022

Abstract
Pretreatment of human peripheral blood mononuclear cells with mouse anti-Ia serum and complement was found to inhibit the subsequent T cell proliferative response to Con A. The cells from each individual tested were inhibited, regardless of DR allospecificity. Inhibition of Con A response by mouse anti-Ia antibodies and C was found to be due to elimination of adherent accessory cells (monocytes) rather than T cells. Anti-Ia serum appeared to recognize an essential subpopulation of human monocytes bearing cross-reactive antigens, since not all monocytes treated with anti-Ia serum and C were lysed. The use of highly restricted mouse anti-Ia serum demonstrated that the required monocyte population expressed antigens recognized by antibodies with activity to I-Ek products (Ia specificities Ia.7 and Ia.22). The required monocyte subpopulation was also recognized by a monoclonal antibody specific for Ia.7. Mouse anti-I-Ek alloantiserum or monoclonal anti-Ia.7 antibodies may be important tools with which to study human monocytes, and for further characterization of DR determinant requirements for monocyte-antigen presentation and monocyte-T cell interactions.