bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immune lysis of reconstituted myelin basic protein--lipid vesicles and myelin vesicles.
Authors: Boggs J M , Samji N , Moscarello M A , Hashim G A , Day E D 
Published: December 2022

Abstract
Complement-mediated lysis of reconstituted lipid-myelin basic protein (BP) vesicles and myelin vesicles due to antibody raised against BP and isolated myelin is measured by determination of the amount of a water-soluble spin label, tempocholine chloride, released from the vesicles. The response is shown to be antigen-specific, antibody-dependent, and complement mediated. The relative response to different anti-BP antibody samples is similar to that determined by radioimmunoassay procedures. In contrast to immunoassays with BP in aqueous solution, this method measures immune recognition of the protein in either a synthetic or a natural membranous environment. This is important because this protein has been shown to have a different conformation when bound to lipid bilayers than in aqueous solution and its conformation depends on lipid composition. It is also a more rapid method because no separation of spin label still trapped in the vesicles and that released due to immune lysis is required. In synthetic membranes consisting of sphingomyelin, cholesterol, and an acidic lipid, either phosphatidylglycerol, phosphatidic acid, or phosphatidylserine, the response was greatest when the acidic lipid was phosphatidic acid. The response did not depend significantly on the antigen concentration expressed as molar ratio of BP to sphingomyelin, over the range 0.15:600 to 2:600, although it decreased at molar ratios less than 0.15:600. The antigen density required for immune lysis of vesicles containing this protein antigen is similar to that reported elsewhere for lipid antigens, although the time required for maximal lysis was greater. Both anti-BP and anti-myelin antibodies caused a greater specific complement-mediated response with synthetic vesicles than with myelin vesicles, which may be due to the different lipid and/or protein composition of myelin. Response was also obtained with the myelin vesicles, however, indicating that some determinants of BP can be recognized on the surface of the bilayer in isolated myelin by anti-BP.
Interleukin 2-mediated immune interferon (IFN-gamma) production by human T cells and T cell subsets.
Authors: Kasahara T , Hooks J J , Dougherty S F , Oppenheim J J 
Published: December 2022

Abstract
Human interleukin 2 (IL 2, or T cell growth factor), which was free of lectin and interferon activity (IFN), induced human peripheral T lymphocytes to produce immune IFN (IFN-gamma). In contrast, non-T cells and macrophages did not produce IFN-gamma in response to IL 2. IL 2 acted directly on unstimulated T cells to induce IFN-gamma production, and also acted in synergy with a suboptimal dose (2 micrograms/ml) of concanavalin A (Con A) to enhance IFN-gamma production. The IFN-gamma-inducing activity of partially purified IL 2 was absorbed along with the IL 2 activity by murine IL 2-dependent CT-6 cell line cells. This further supports the view that IFN-gamma-inducing activity is identical to IL 2. When T cells were separated further into helper/inducer T4+ and suppressor/cytotoxic T8+ subsets by negative selection with monoclonal antibody and complement, both T4+ and T8+-enriched cells produced significant levels of IFN-gamma in response to IL 2. Complete removal of macrophages from purified T lymphocyte populations by treatment of OKM1 plus complement consistently reduced IFN-gamma production in response to IL 2 to a limited degree; readdition of macrophages restored IFN-gamma production by both T cell subsets. This observation that IL 2 contributes to the production of IFN-gamma by human lymphocytes suggests that a cascade of lymphocyte-cell interactions participates in human immune responses.
Mechanisms of suppression of mouse mesangial cell proliferation by macrophage supernatants.
Authors: Ooi Y M , Weiss M A , Hsu A , Ooi B S 
Published: December 2022

Abstract
The monocyte/macrophage has been identified as an effector cell infiltrating the glomerulus in human and experimental nephritis. To clarify the role of the macrophage in this context, an in vitro system was developed in which mouse mesangial cell cultures were maintained. Macrophage supernatants were obtained from peritoneal macrophages harvested from either resident or endotoxin-stimulated C57BL/6J male mice cultured for 24 hr. Incubation of mesangial cell cultures with macrophage supernatants resulted in depression of mesangial cell metabolism as indicated by incorporation of (3H)-thymidine; the effect was more marked when supernatants of endotoxin-treated mice were used. The molecular mechanisms by which suppression was obtained was clarified by experiments fractionating macrophage supernatants by G-100 column chromatography. By this means, two fractions were obtained with different molecular and physiologic properties. One fraction, a molecular size of 14,600 to 29,000 daltons, was shown to mediate the suppressive effect by stimulating endogenous mesangial cell PGE synthesis; additionally, a novel molecular species was identified, which was biologically active at higher concentrations of macrophage supernatants, had a larger molecular size (29,000 to 68,000 daltons), exerted its suppressive effect by an independent mechanism, and accounted for the inability of indomethacin pretreatment of mesangial cells to abrogate completely the suppressive effect of macrophage supernatant at higher concentrations.
Clearance kinetics and fate of mouse IgA immune complexes prepared with monomeric or dimeric IgA.
Authors: Rifai A , Mannik M 
Published: December 2022

Abstract
To determine the pathophysiologic mechanism(s) involved in experimental IgA nephropathy, the clearance kinetics and tissue distribution of soluble IgA immune complexes in mice were investigated. Purified radiolabeled dimeric (dIgA) and monomeric (mIgA) IgA antidinitrophenyl, obtained from MOPC-315, were covalently cross-linked with a bivalent affinity-labeling antigen, bis-2,4-dinitrophenyl pimelic ester. After i.v. injection, heavy polymers (greater than 1.2 X 10(6) m.w.) were rapidly removed from circulation. Analysis of circulating intermediate-latticed complexes by gradient polyacrylamide gel electrophoresis indicated that polymers with a minimal composition of four dIgA or eight mIgA were required for rapid elimination. The dIgA and mIgA complexes with lattices smaller than this critical size were removed at slower rates (yielding a t1/2 of 35 min for complexes with dIgA and a t1/2 of 60 min for complexes with mIgA). Tissue distribution of both dIgA and mIgA immune complexes was similar. The liver was the major organ involved in uptake of IgA immune complexes with an insignificant amount in the bile. Heavy polymers of dIgA or mIgA were predominantly localized in the hepatic nonparenchymal cells.
Expression of a bone marrow-associated Ly-6 determinant on the T cell population expanding in the lymph nodes of the autoimmune mouse strain MRL/Mp-lpr/lpr.
Authors: Melino M R , Dumont F J , Habbersett R C , Hansen T H 
Published: December 2022

Abstract
In this report we describe the reactivity patterns of two monoclonal anti-Ly-6.2 antibodies toward lymph node (LN) cells of the autoimmune MRL/Mp-lpr/lpr (lpr) and the normal congenic MRL/Mp-+/+ (+/+) mouse strains. The monoclonal antibody 34-11-3, which has previously been found to detect a LN-associated Ly-6.2 antigen, reacted with both lpr and +/+ LN cells. Another monoclonal antibody, 34-10-7, which has been demonstrated to detect a bone marrow- (BM) associated determinant, was found to react with a small proportion of +/+ LN cells and unexpectedly with a high percentage of lpr LN cells. The expression of this BM determinant found in the LN of lpr mice was age dependent, and its presence on Thy-1.2+ cells increased with the expansion of a subset of Lyt-1+2- cells. In contrast, dual labeling experiments showed that in +/+ and young lpr mice a small subset of Lyt-1+2+ cells express this BM-associated Ly6.2 determinant. Therefore these findings demonstrate that the lpr gene-dependent T cell expansion in the LN results in both aberrant expression and association of lymphocyte cell surface markers.
Functional studies on B cell hybridomas with B cell surface antigens. I. Effects of anti-immunoglobulin antibodies on proliferation and differentiation.
Authors: Hamano T , Asofsky R 
Published: December 2022

Abstract
B cell hybridomas with Ia and IgM molecules on the cell membrane were treated with either purified goat anti-mouse mu antibody (anti-mu) or monoclonal rat anti-mouse IgM antibody (anti-IgM). The spontaneous uptake of [3H] thymidine by these cells was markedly inhibited by both reagents. These hybrid cells could be induced to differentiate into IgM-secreting cells in the presence of these reagents at high frequency. Furthermore, the induction of IgM secretion by B cell hybridomas treated with these antibodies was completely T cell independent, and cell division was not required for the differentiative response to anti-mu. In addition, F(ab')2 fragments of anti-mu showed more effects on proliferation and differentiation of these cells than intact anti-mu. Interestingly, TH2.54, a subline of B cell hybridomas, could generate IgG2a production as well as IgM when incubated with anti-mu. These findings suggest very strongly that the interaction of either goat anti-mu or monoclonal rat anti-IgM with surface IgM molecules on the cell membrane of the B cell hybridomas inhibits in vitro spontaneous proliferation, and results in providing signals for differentiation into Ig-secreting cells without T cell factors.
Heterologous antisera to Lyt-1+, 2- -derived antigen-binding factor detect a subfactor of an antigen-specific suppressor factor and cell surface proteins on Lyt-1+, 2- and Lyt-1-, 2+ T cells.
Authors: Cone R E , Rosenstein R W , Tite J , Ptak W , Gershon R K 
Published: December 2022

Abstract
Rabbits were immunized with TNP-specific Lyt-1+, 2- T cell-derived, antigen-binding proteins (PCI-F) released by T cells sensitized by skin painting with picrylchloride. The resulting antiserum (anti-PCI-F) bound to PCI-F and TNP-specific factors that suppressed delayed hypersensitivity (TSF) known to be comprised of PCI-F and Lyt-2+ -derived polypeptides released by cells sensitized by injection of trinitrobenzenesulfonic acid (TNBSF). Anti-PCI-F bound to T lymphocytes and 68,000 to 72,000 m.w. T cell surface proteins but not B cells on their surface proteins. Anti-PCI-F bound to both Lyt-1+ and Lyt-2+ T cells and surface proteins. A comparison of anti-PCI-F with anti-TSF indicates that anti-TSF contains specificity for Ly-2+ T cell-derived components of TSF and T cells not present in anti-PCI-F. The possibility of multiple isotypes of T cell receptors and antigen-binding molecules is discussed.
Sensitization of circulating basophils in guinea pig recipients of passive transfer of cutaneous basophil hypersensitivity (CBH) with immune serum: antigen-specific histamine release in vitro.
Authors: Lett-Brown M A , Mitchell E B , Askenase P W 
Published: December 2022

Abstract
An in vitro histamine release assay was used to test the hypothesis that passive sensitization of circulating basophils is associated with the activity of immune serum that transfer the ability to elicit cutaneous basophil hypersensitivity (CBH) reactions. Systemic i.v. transfer of several types of immune sera that mediate CBH also led to passive sensitization of circulating basophils for antigen-specific release of histamine in vitro. In addition, we found that immune serum passively sensitizes basophils in vitro. Thus immune sera had three activities that are probably interconnected: sera will 1) passively transfer CBH in vivo, 2) passively sensitize basophils in vivo, and 3) passively sensitize basophils in vitro. These results suggest that passive sensitization of circulating basophils by immune serum contributes to the mechanism by which antibodies transfer the ability to elicit CBH reactions.
Human natural killer cells analyzed by B73.1, a monoclonal antibody blocking Fc receptor functions. II. Studies of B73.1 antibody-antigen interaction on the lymphocyte membrane.
Authors: Perussia B , Acuto O , Terhorst C , Faust J , Lazarus R , Fanning V , Trinchieri G 
Published: December 2022

Abstract
In this paper, we characterize the antigen recognized by the monoclonal antibody B73.1 and the modification occurring at the membrane of the positive cells after interaction with the antibody. The B73.1-defined antigen is a protein of 50,000 to 72,000 daltons that is sensitive to pronase but not to trypsin treatment. B73.1 antibody, and its F(ab')2 fragment, directly block, at high concentrations, the binding of IgG antibody-sensitized erythrocytes to the Fc receptors (FcR) of a subpopulation of lymphocytes and neutrophils. B73.1 antibody dissociates rapidly from the positive cells, but concomitant modulation of both B73.1 antigen and FcR is induced when cells are incubated in the continuous presence of antibody or when B73.1 antibody is cross-linked at the cell membrane with an anti-mouse immunoglobulin antiserum. Reaction of lymphocytes with immune complexes also induces modulation of both FcR and B73.1 antigen, without affecting the expression of other antigens on the positive cells. The possibility that the antigen is internalized and digested by the cell after reaction with the antibody is discussed. B73.1 antibody inhibits antibody-dependent cytotoxicity mediated by lymphocytes (K cells) and neutrophils, whereas it does not affect spontaneous cytotoxicity of NK cells. These results suggest the B73.1-defined antigen might be the FcR or a structure closely related to it on K/NK cells.
Epitopes of peptide 43-88 of guinea pig myelin basic protein: localization with monoclonal antibodies.
Authors: Fritz R B , Chou C H 
Published: December 2022

Abstract
Two monoclonal antibodies, one raised by immunization with mouse myelin basic protein (MBP) and the second raised by immunization with peptide 68-88 of guinea pig MBP, were compared with respect to specificity. The former antibody (15.32) cross-reacted completely with rat, guinea pig, human, and bovine MBP. It also reacted with peptide 43-88 from each MBP. The latter antibody (22.17) was nonreactive with MBP, but cross-reacted with peptide 43-88 from rat, human, guinea pig, and bovine MBP. When tested with small peptides derived from peptide 43-88, antibody 22.17 reacted with an epitope in the C-terminal region. Antibody 15.32 reacted with an epitope in the N-terminal half of the peptide. The data show that 22.17 reacted with a unique epitope associated only with free peptide, whereas 15.32 recognized an epitope common to both peptide 43-88 and MBP.
Encephalitogenic activity of the small form of mouse myelin basic protein in the SJL/J mouse.
Authors: Chou C H , Shapira R , Fritz R B 
Published: December 2022

Abstract
Mouse myelin basic proteins (MBP) were prepared by ion-exchange chromatography of an acid extract of homogenized, delipidated mouse brain. The use of a linear salt gradient during ion-exchange chromatography gave three peaks, 1, 2, and 3, of MBP. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of these peaks showed that peaks 2 and 3 were a mixture of the large and small forms of mouse MBP, whereas peak 1 was solely the small form. Tryptic peptides of mouse and rat small form MBP were compared by high-performance liquid chromatography. The elution times and absorbances at 210 nm were identical for 16 of 21 peaks derived from small form MBP of the two species. Amino acid analysis showed that 10 corresponding peaks from the small form of mouse and rat MBP had identical amino acid composition. When tested for encephalitogenicity in SJL/J mice, both the mixture of large and small forms of mouse MBP and the small form mouse MBP were highly encephalitogenic.
Soluble factors involved in B cell differentiation: identification of two distinct T cell-replacing factors (TRF).
Authors: Nakanishi K , Howard M , Muraguchi A , Farrar J , Takatsu K , Hamaoka T , Paul W E 
Published: December 2022

Abstract
Highly purified B lymphocytes cultured with affinity-purified goat anti-mouse IgM antibodies and B cell growth factor (BCGF) proliferate but fail to differentiate into immunoglobulin-synthesizing cells during 4-day cultures. Induction of immunoglobulin (Ig) synthesis depends on the presence of two additional T cell-derived factors (T cell-replacing factors [TRF]). One TRF, designated B15 1K 12-TRF, is found in the supernatant of B15 1K 12 T hybridoma cells. It is required relatively early in these cultures and appears to cause an increase in cell yield as well as Ig synthesis. The second factor, designated EL-TRF, is found in PMA-induced EL-4 supernatant. It appears to be different from both BCGF and IL 2 in that it can be separated from the former by isoelectric focusing and from the latter by phenyl-Sepharose chromatography. EL-TRF is still active if added on the last day of a 4-day culture. A model for the action of anti-IgM and these three T cell-derived factors in B cell activation and differentiation is proposed.
In vitro analysis of allogeneic lymphocyte interaction. VI. I-J-restricted self-reactive and alloreactive components of allogeneic effect factor (AEF) are distinct I-J- molecules that interact with I-J+ T cells and antigen-presenting cells.
Authors: Delovitch T L , Kaufman K , Gorczynski R M 
Published: December 2022

Abstract
An allogeneic effect factor (AEF) generated across an I-J incompatibility was derived from MLR cultures of alloactivated B10.A(3R) responder T cells and irradiated T cell-depleted B10.A(5R) stimulator spleen cells. This AEF consists of two soluble, secreted I-J-restricted helper components. One helper component, TH-I, recognizes self-I-J determinants on an I-J+ B10.A(3R) antigen-presenting cell (APC), whereas the other helper component, TH-II, recognizes allo-I-J determinants on an I-J+ B10.A(5R) APC. TH-I-B10.A(3R) APC interaction and TH-II-B10.A(5R) APC interaction each induce an in vitro primary anti-SRBC PFC response of either B10.A(3R) or B10.A(5R) B cells. Thus, I-J determinants serve as restricting elements during a TH-APC and not an APC-B interaction. TH-II mediates the I-J-restricted allogeneic effect required to activate T suppressor (TS) cells during a contact sensitivity or delayed-type hypersensitivity response to hapten-conjugated syngeneic lymphoid cells. This indicates that TH-II is also involved in a TH-pre-TS type interaction. TH-I and TH-II are I-J-, 68,000 m.w. molecules that differ by about 0.10 units in their pl values. Their charge difference is not due to an altered amount of sialylation or phosphorylation, but may result either from another form of altered glycosylation and/or from a difference in their primary structure. Peptide mapping analyses reveal that TH-I and TH-II possess at least 80% shared peptides and may be structurally homologous but nonidentical molecules; however, the possibility that TH-I and TH-II are structurally identical cannot be eliminated. Papain cleaves TH-I and TH-II into a 40,000 m.w. fragment. No subunit structure of TH-I and TH-II is apparent. It is suggested that TH-I and TH-II are I-J- -activated responder T cell-derived receptors for self-I-J and allo-I-J determinants, respectively.
Human soluble Fc gamma-binding material. I. Immunochemical properties of the material produced by the T cell line KE37.
Authors: Caraux J , Chichehian B , Serrou B , Weigle W O 
Published: December 2022

Abstract
A soluble Fc gamma-binding material (S-Fc gamma BM) is produced by the Fc gamma receptor-bearing human T cell line KE37 but not by the two Fc receptor-negative cell lines Molt 4 and Reh 6. The S-Fc gamma BM has specific affinity for the Fc fragment of IgG and none for the Fab fragments. It can be obtained in radioactive form after internal labeling with radioactive amino acids. It can then be isolated from the supernatant of the KE37 cell line by affinity chromatography, gel filtration and isoelectric focusing. The subunit components of S-Fc gamma BM are 23,000-dalton polypeptide chains. The soluble form is a dimer (42,000 to 45,000 m.w., pl 6.2), which retains Fc gamma-binding activity after isolation. Higher m.w. polymers of the 23,000-dalton subunits are also present in the supernatant of the KE37 cell line. These polymers are relatively insoluble in aqueous solvents but possess Fc gamma-binding activity. The S-Fc gamma BM molecules might be derived from a membrane-inserted form by restricted proteolytic cleavage at connecting regions of a larger polypeptide chain folded into 23,000-dalton subunits.
Studies of antigen binding on human basophils. I. Antigen binding and functional consequences.
Authors: MacGlashan D , Lichtenstein L M 
Published: December 2022

Abstract
We developed an assay to study simultaneously antigen binding and its functional consequences on human basophils. Using a 125iodine-labeled penicillin-human serum albumin conjugate, we were able to detect as few as 100 molecules of antigen bound to purified basophils. We found that histamine release could be initiated with fewer than 100 molecules of antigen and that the optimum for histamine release occurred at a concentration at which 10 to 15% of the available antibody-binding sites were occupied. Analysis of the binding kinetics in the presence of monovalent hapten allowed a calculation of the affinity constant for the antibody:hapten association; the value of 2 to 3 X 10(6)/Msec confirmed an earlier independent calculation. Binding data also suggested a 25% fraction of the bound antigen was binding in monogamous bivalent form. It is anticipated that studies of this kind will delineate the nature of the antibody-antigen reaction on cell surfaces.
Identification and in situ localization of the "thymic nurse cell" in man.
Authors: van de Wijngaert F P , Rademakers L H , Schuurman H J , de Weger R A , Kater L 
Published: December 2022

Abstract
The observation of the "thymic nurse cell" (TNC), a reticuloepithelial cell with intracytoplasmic lymphocytes, in suspension of murine thymic tissue prompted us to investigate the existence of this cell in cell suspension, as well as in tissue sections of the human thymus. TNC-like cells were enriched in suspension by enzymatic disintegration of thymic tissue and 1 X G sedimentation over 50% fetal calf serum gradients. TNC-like cells were negative for lysosomal enzymes: in this respect, as well as in light microscopic morphology, the cells were different from tissue macrophages with intracytoplasmic lymphocytes. In electron microscopy, TNC-like cells showed reticuloepithelial characteristics. In 1-micron tissue sections, clusters of lymphocytes with a possible reticuloepithelial nucleus were observed close to blood capillaries in the cortical area. Ultrastructural analysis confirmed the epithelial nature of this cell, as well as its location adjacent to blood capillaries. We concluded that there is in situ existence of TNC in man. This observation enables studies on the role of TNC in intrathymic T cell maturation.