bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heterogeneity in cellular antigen retention structures.
Authors: Betancourt S V , Solvay M J , Irani D N , Thomas D W , Nairn R 
Published: December 2022

Abstract
The mechanism of presentation of foreign antigens to helper T lymphocytes and the nature of the structures involved in this process are not totally understood. It is well documented that this event is carried out by antigen-presenting cells (APC) (e.g., macrophages, dendritic cells, and B lymphocytes) that internalize the antigen, process it, reexpress it on their membrane surface, and present it to the T cell in the context of major histocompatibility complex class II (Ia) molecules. Recent evidence supports the hypothesis that peptide antigens associate directly with Ia molecules on the APC surface membrane. However, the characteristics of other APC membrane structures potentially involved in antigen presentation are not entirely clear. Previous studies in our laboratories identified a guinea pig macrophage membrane-bound, non-Ia-containing antigenic complex (peak A) formed upon incubation of APC with the octapeptide antigen angiotensin (AII). This complex was capable of stimulating AII-immune guinea pig T cells and thus appeared to contain the immunologically relevant form of the antigen. For this reason it was important to establish whether such complex formation with peptides occurs with other cell types and with other peptide antigens. In the present study we found that other types of cells are also capable of forming such a membrane complex with antigen (peak A) and that this event is not unique to AII. Two other peptides, alpha-melanocyte-stimulating hormone and human fibrinopeptide B, both of which are antigenic in mice, were found to form peak A with a number of murine cell lines. As in our earlier studies with guinea pig macrophages, there was no evidence from these experiments for a role for major histocompatibility complex Ia antigens in the peptide binding observed. Differences in both the amount of peak A formation and the pattern of peptide antigen degradation were found from cell line to cell line for a given peptide, and from peptide to peptide for a given cell line, suggesting cellular heterogeneity in peptide processing and retention. In addition, cross-inhibition studies indicated that there was peptide specificity in the formation of peak A perhaps suggestive of molecular heterogeneity in the structure of peak A. These results indicate that there may be several types of cell surface molecules that specifically bind and retain peptide antigens.(ABSTRACT TRUNCATED AT 400 WORDS)
Quantitative analyses of the binding of soluble complement-fixing antibody/dsDNA immune complexes to CR1 on human red blood cells.
Authors: Edberg J C , Wright E , Taylor R P 
Published: December 2022

Abstract
We have used direct binding isotherm analyses to measure the association constant (Ka) and number of binding sites for the binding of prepared complement-fixing antibody (Ab)/dsDNA immune complexes (IC) to human red blood cells (RBC). In order to generalize this study we have examined the binding reaction for a number of different anti-dsDNA Ab (from systemic lupus erythematosus plasmas), complement sources, RBC donors, and dsDNA sizes. The affinity of the IC for the RBC is quite high, and the Ka values fall within a narrow range (5 to 14 X 10(10) liter/mol). Similarly, the limiting stoichiometries for the number of IC bound per RBC were between 40 and 91. The very high affinity and limiting stoichiometries both suggest that the IC bind to the RBC via multiple contacts with clusters of complement receptor type 1 (CR1). Furthermore, we have used three specific monoclonal AB (mAb) to quantitate CR1 on human RBC in the presence and absence of bound IC. One of these Ab, mAb 1B4, is blocked from binding to the RBC if IC are previously bound, and we have used this observation to verify the multivalent nature of the interaction of complement-fixing IC with CR1 on human RBC.
T lymphocyte control of human eosinophilic granulopoiesis. Clonal analysis in an idiopathic hypereosinophilic syndrome.
Authors: Raghavachar A , Fleischer S , Frickhofen N , Heimpel H , Fleischer B 
Published: December 2022

Abstract
The idiopathic hypereosinophilic syndrome (HES) comprises a heterogeneous group of disorders with unknown pathogenesis characterized by persistent peripheral blood and bone marrow eosinophilia and eosinophilic infiltrates of multiple organs leading to severe organ dysfunction. In the present study, T lymphocyte clones were randomly established from the blood of a patient with HES and propagated in culture with mitogen and interleukin 2. Whereas 28 of 29 clones were able to stimulate myeloid colony formation when co-cultured with normal bone marrow cells in a double-layer micro-agar culture system, one third of these clones preferentially stimulated pure eosinophil colonies (up to 98% of all colonies). This pattern differed markedly (p less than 0.001) from the pattern of release of hemopoietic factors by 126 T cell clones established from four other individuals. Eosinophil colony stimulation was due to the release of a lineage-specific eosinophilic colony-stimulating factor (Eo-CSF) by these clones after appropriate stimulation. Production of Eo-CSF in vitro was inhibited by hydrocortisone or cyclosporin A. All Eo-CSF-producing clones had the T4+8-phenotype and were capable of producing in addition interleukin 2 and interferon-gamma. Southern blot analysis of the T cell receptor beta-chain rearrangement of the Eo-CSF-producing clones showed a different rearrangement pattern for each clone. These studies suggest a reactive T cell-mediated eosinophilia as the pathogenetic mechanism in this case of HES and, for the first time, point to a biologic relevance of a lymphokine-induced stimulation of hemopoiesis.
Protective monoclonal antibodies from mice vaccinated or chronically infected with Schistosoma mansoni that recognize the same antigens.
Authors: Gregoire R J , Shi M H , Rekosh D M , Loverde P T 
Published: December 2022

Abstract
An IgM monoclonal antibody, designated mAb 1.G1, has been generated from spleen cells of mice immunized with irradiated Schistosoma mansoni cercariae. As determined by indirect immunofluorescence, mAb 1.G1 binds to the surface membrane of schistosomula and to the ciliated plates of miracidia. mAb 1.G1 also binds to the protonephridial systems of live adult worms and denuded, acetone-fixed schistosomula. Western blot analysis shows that the target epitope of this mAb is found on Nonidet P-40-solubilized schistosomular antigens ranging in molecular size from 85 to 130 kDa and ciliated plate antigens of miracidia at 92, 95, and 102 kDa. The recognized epitope in an 8 M urea adult worm extract is found on a 97-kDa molecule. In addition, mAb 1.G1 mediates a high level of complement-dependent cytotoxic activity against schistosomula when used in an in vitro assay. In passive immunization experiments, approximately 40% protection was provided mice when mAb 1.G1 was administered either at the time of challenge or when given 8 days postchallenge. However, when administered 15 days postchallenge, mAb 1.G1 failed to mediate passive protection. The ability of mAb 1.G1 to mediate protection in vivo correlates with its recognition of epitopes on the surfaces of live schistosomula up to 8 days but not at 15 days. Western blot analysis showed that the antigens were contained within Nonidet P-40 extracts of schistosomula during the same time period. Furthermore, a second monoclonal antibody (mAb 4.4B) derived from mice chronically infected with S. mansoni exhibits the identical properties as described for mAb 1.G1.
Interleukin 2 and concanavalin A stimulate interferon-gamma production in a murine cytolytic T cell clone by different pathways.
Authors: Dunn D E , Herold K C , Otten G R , Lancki D W , Gajewski T , Vogel S N , Fitch F W 
Published: December 2022

Abstract
We identified a variant murine cytolytic T lymphocyte (CTL) clone which, in contrast to the parent clone and all other murine T cell populations tested, was found to have acquired spontaneously the ability to produce interferon-gamma (IFN-gamma) in response to recombinant interleukin 2 (rIL-2). IFN-gamma production in response to concanavalin A (Con A), which was characteristic of all T cell populations tested, was preserved in this variant. The IFN produced by the variant in response to either stimulus was active in both a macrophage-activating factor assay and an anti-viral assay. Both activities induced by either stimulus could be blocked by monoclonal anti-IFN-gamma antibodies. Upon Northern blot analysis using an IFN-gamma-specific cDNA probe, the IFN-gamma RNA isolated from variant cells stimulated with Con A or IL-2 were found to migrate equivalently. The unusual pattern of responsiveness in this variant CTL was exploited to compare the mechanisms involved in induction of IFN-gamma production by Con A or IL-2. Striking differences were observed. Unlike IFN-gamma production induced by Con A, IFN-gamma production induced by IL-2 was not accompanied by an elevation of intracellular Ca2+ levels, did not require physiologic extracellular Ca2+ levels, and was not inhibited by the immunosuppressive agent cyclosporin A. Thus, in this variant CTL clone, conditions that have ordinarily been associated in an obligate manner with lymphokine gene expression were found instead to be related to the specific mode of stimulation.
Sequential appearance of thymocyte subpopulations and T cell antigen receptor gene messages in the mouse thymus after sublethal irradiation.
Authors: Tomooka S , Matsuzaki G , Kishihara K , Tanaka K , Yoshikai Y , Taniguchi K , Himeno K , Nomoto K 
Published: December 2022

Abstract
The sequential differentiation patterns of thymocyte were observed with cell surface phenotypes and the expression of T cell antigen receptor in 800 rad irradiated adult mice. Thymus was severely reduced in size and cell number by day 5 after whole body irradiation and rapidly recovered from day 7 to day 14. Surface marker analysis on day 5 after irradiation showed thymocytes with Thy-1low L3T4+/Lyt-2- dominantly existed and suggested that these cells were radioresistant-survived cells. On the other hand, thymocytes on day 7 were composed of a large number of Thy-1high L3T4+/Lyt-2+ blast-like cells and a relatively high proportion of Thy-1high L3T4-/Lyt-2- cells which expressed a large amount of gamma-chain gene messages but scarcely any alpha- and beta-chain gene messages similar to the fetal thymocytes. On day 14, thymocytes were composed mostly of Thy-1high H-2low L3T4+/Lyt-2+ subpopulation which expressed a remarkably low level of gamma-chain gene messages, and high levels of alpha- and beta-chain transcripts analogous to those of normal adult thymus. Taken together, intrathymic radioresistent stem cells for T thymocytes seem to proliferate and differentiate after irradiation with the same pattern as was seen in a fetal thymus development.
A limited number of B cell lineages generates the heterogeneity of a secondary immune response.
Authors: Blier P R , Bothwell A 
Published: December 2022

Abstract
We have studied the cellular basis for heterogeneity in the secondary immune response by creating a large set of B cell hybridomas from a single C57BL/6 mouse immunized with the hapten (4-hydroxy-3-nitrophenyl)acetyl coupled to chicken gamma-globulin, and searching among the cells for all possible sets of clonally related lines. Among 28 independent cell lines from a single animal we find that 21 of them fall into seven small families of from two to five members; only seven lines have no matches among the set. A statistical analysis determines that the number of genetically distinct B cell precursors whose progeny were isolated during this secondary response is 18, with 95% confidence limits of 14 and 26. The distribution of family sizes implies that each activated clone has proliferated to approximately the same extent. Complete sequencing of the variable region of immunoglobulin heavy chain mRNA from 19 of the cell lines reveals many shared somatic mutations among related lines, implying a pronounced founder effect has occurred to eliminate most of the progeny of each precursor B cell. This may be the result either of a high frequency of debilitating somatic mutation or from selection against cells still expressing the idiotype of primary anti-(4-hydroxy-3-nitrophenyl)acetyl antibodies.
Properties of a second epitope of the murine Fc receptor for aggregated IgG.
Authors: Puré E , Witmer M D , Lum J B , Mellman I , Unkeless J C 
Published: December 2022

Abstract
The murine macrophage and lymphocyte Fc receptor for aggregated IgG (Fc gamma R) has previously been characterized by using the anti-Fc gamma R monoclonal antibody (mAb), 2.4G2. In the studies presented here, we describe a new mAb, 6B7C, that defines a second epitope of the Fc gamma R. The tissue distribution of the 6B7C epitope is coincident with the 2.4G2 epitope. However, only the 2.4G2 epitope is accessible to mAb binding on intact primary macrophages or lymphocytes. The 6B7C epitope is not detectable on primary macrophages or lymphocytes but is exposed on a portion of B lymphocyte Fc gamma R after activation by lipopolysaccharide and on some tumor cell lines. The expression of the 6B7C epitope on the surface of B lymphoblasts and tumor cell lines seems to correlate with their ability to release soluble Fc gamma R. The 6B7C mAb has the advantage that it reacts with native as well as denatured receptor and therefore can be used for techniques such as immunoblotting.
Prostaglandin E1 inhibits N-formyl-methionyl-leucyl-phenylalanine-mediated depolarization responses by decreasing the proportion of responsive cells without affecting chemotaxin-induced forward light scatter changes.
Authors: Fletcher M P 
Published: December 2022

Abstract
Hypaque-Ficoll-purified human polymorphonuclear neutrophils (PMN) equilibrated with the membrane potential-sensitive probe 3,3'dipentyloxacarbocyanine [di-O-C(5)(3)] were incubated with buffer or cytochalasin B (cyto B) followed by incubation with prostaglandin E1 (PGE1) (0 to 10(-5) M) for 5 min at 37 degrees C. The cells were then stimulated with N-formyl-methionyl-leucyl-phenylalanine (FMLP) (0 to 10(-5) M). Changes in forward light scatter (FWD-SC), 90 degrees scatter (90 degrees -SC), and fluorescence intensity were measured by flow cytometry to determine the effects of PGE1 on FMLP-induced shape change, secretion, and membrane potential responses, respectively. In other experiments, the effects of PGE1 preincubation on FMLP +/- cyto B and phorbol myristate acetate-induced (O2) production were measured by superoxide dismutase-inhibitable cyto c reduction. PGE1 had no direct effects on the FWD-SC, 90 degrees-SC, or resting potential fluorescence of unstimulated or cyto B-pretreated PMN. PGE1 produced a dose-dependent inhibition of the proportion of depolarizing PMN in response to FMLP, which was maximal at 10(-6) M (42.1 +/- 6.9% inhibition, p less than 0.005), but was apparent at 10(-8) M. The PGE1-induced inhibition was maximal after 30 sec of incubation at 37 degrees C and was caused by a decrease in the maximal percentage of depolarizing PMN without a significant change in the FMLP dose-response curve (Km = 2.43 vs 3.62 X 10(-8) M, control vs PGE1-treated) or an inhibition in the degree of depolarization by the responding subpopulation. PGE1 also inhibited the loss of 90 degrees-SC induced by FMLP in cyto B-pretreated cells (secretion response) (46.2 +/- 16.5% inhibition of the maximal 90 degrees-SC loss, n = 5, p less than 0.005), but did not affect the increase in FWD-SC seen with FMLP-induced PMN activation or the ability of cyto B to recruit more PMN to depolarize. PGE1 also inhibited FMLP +/- cyto B-induced O2 production in a dose-dependent fashion; phorbol myristate acetate-induced O2 production was also slightly inhibited, but only at high PGE1 concentrations. The data indicate that PGE1 inhibits FMLP-induced cell activation by a mechanism that involves a step distal to the recruitment of unresponsive PMN by cyto B, and that PGE1 is capable of inhibiting depolarization responses without affecting FMLP-induced shape change, providing more support for a dissociation between the two activation pathways.
Frequency of herpes simplex virus-specific murine cytotoxic T lymphocyte precursors in mitogen- and antigen-driven primary in vitro T cell responses.
Authors: Hengel H , Lindner M , Wagner H , Heeg K 
Published: December 2022

Abstract
The aim of this study was to assess and to compare the frequencies and specificities of herpes simplex virus (HSV)-specific cytotoxic T lymphocyte precursors (CTL-p) in mitogen (concanavalin A)-activated splenic T cells, as well as in antigen-activated splenic T cells of normal nonimmunized mice. In the mitogen-driven system one of 130 T cell blasts developed clonal progenies able to lyse specifically HSV-infected syngeneic targets. In the antigen-driven system HSV-specific CTL-p could be detected in normal lymphocytes provided the stimulator cells used were enriched for dendritic cells and pulsed with high concentrations of heat-inactivated HSV. Depending on the mouse strain used, the frequencies of HSV-specific CTL-p ranged from 1/500 to 1/10,000 in normal mice. Upon antigen priming within local lymph node cells, an increase of frequencies from 1/500 to 1/170 was observed in CBA/Ca mice.
Cyclosporine-induced tolerance in experimental organ transplantation. Evidence of diminished donor-specific cytotoxicity relative to donor-specific proliferative response.
Authors: Norin A J , Kamholz S L , Pinsker K L , Emeson E E , Veith F J 
Published: December 2022

Abstract
Alloreactivity of intragraft and peripheral blood lymphocytes from tolerant canine lung allograft recipients was examined. Tolerance was induced by variable periods of treatment with cyclosporine. Analysis of effector cells from lung allografts (obtained by bronchoalveolar lavage) revealed the absence of specific cytolytic T lymphocyte (CTL) activity and the presence of a low level of cytolytic activity detected in a lectin-dependent cell-mediated cytotoxicity assay. In contrast, high levels of specific CTL activity and lectin-dependent activity were detected in cell preparations from lung allografts undergoing rejection. Tolerant recipients retained normal ability to generate specific CTL activity to third party alloantigens in mixed lymphocyte cultures (MLC) but had diminished ability to generate CTL to donor alloantigens in recipient X donor MLC. Addition of exogenous interleukin 2 to these MLC was unable to restore donor-specific CTL activity. Lymphocytes from tolerant recipients were, however, capable of generating proliferative responses and lectin-dependent cytotoxicity on exposure to donor alloantigens in MLC. Evidence presented in this report suggests that the lectin-dependent cytolytic activity generated in these MLC is mediated by lymphokine-activated killer cells. Such cells are likely to be activated by interleukin 2 released in the proliferative response. The results support the proposal that the cyclosporine-induced tolerant state is characterized by the relative inability to respond against major histocompatibility complex class I antigens in contrast to class II antigens and/or minor histocompatibility antigens since MLC-induced CTL are directed, for the most part, against class I molecules.
Population kinetics of precursors of IL 2-producing peripheral T lymphocytes: evidence for short life expectancy, continuous renewal, and post-thymic expansion.
Authors: Rocha B B 
Published: December 2022

Abstract
The fate of spleen T cell populations able to produce IL 2 after stimulation with Con A (IL 2p) was evaluated at different times after injection into IL 2p-deficient, syngeneic nude recipients. Precise enumeration of transferred cell populations in recipient organs was performed by limiting dilution analysis. The results obtained confirm previous findings on the short life-span of IL 2p cells. They also demonstrate that: the transferred populations containing IL 2p were capable of continuous renewal and expansion in the host; IL 2p cell expansion, a transient event that takes place predominantly in lymph nodes, is much reduced when injected cells are depleted of recent thymus migrants; in steady-state conditions, IL 2p T cells do not lose their self-renewal ability and maintain population sizes by continuous cell production and death in peripheral pools. The self-renewal capacity, the expansion potential of peripheral IL 2p T cells and, in particular, of recent thymus migrants may allow extensive post-thymic modulation of peripheral T cell specificities, suggesting that post-thymic selection may have a major role in the establishment of the available and actual mature IL 2p T cell repertoire.
Epidermal lesions of the GVHR: evaluation of the role of different MHC and non MHC loci and of the Ly-2+ and L3T4+ T lymphocytes.
Authors: Piguet P F , Janin-Mercier A , Vassalli P , Saurat J H 
Published: December 2022

Abstract
Irradiated mice (750 rad) were injected with T-depleted bone marrow cells (BMC) and T lymphocytes in various combinations of T/host incompatibility. The epidermis was examined histologically and the incidence of two basic epidermal lesions of graft-vs-host disease (GVHD), the epidermal cell necrosis (ECN) and the lichenoid hyperplastic reaction (LR), were evaluated by a semi-quantitative evaluation. During the acute phase of GVH reaction (GVHR) (days 15 to 25), there was an obvious increase in ECN in reactions elicited by minor loci, whole major histocompatability complex (MHC) differences, or a MHC class I or II difference only. Allogeneic effect without T lymphocyte/epidermis incompatibility did not induce a significant incidence of ECN. Neither depletion of the Ly-2+ nor that of the L3T4+ T lymphocyte subset by treatment with monoclonal antibody (performed in vitro, before injection or also by treatment of the recipient) did prevent the occurrence of ECN, indicating that both T lymphocyte subsets are capable of initiating the epidermal cell damage. The LR was due mainly to the T lymphocytes of the L3T4+, Ly-2- helper phenotype. During chronic GVHR (after 35 days) elicited by either Ly-2+ or L3T4+ lymphocytes, ECN and LR were no longer evident, but the number of epidermal cells and especially the number of replicating cells among the epidermal cells were markedly reduced.
Functional characterization of cloned intrahepatic, hepatitis B virus nucleoprotein-specific helper T cell lines.
Authors: Ferrari C , Mondelli M U , Penna A , Fiaccadori F , Chisari F V 
Published: December 2022

Abstract
We have previously reported the establishment and preliminary characterization of polyclonal hepatitis B virus (HBV) nucleoprotein (HBcAg)-specific CD4+ and CD8+ T cell lines derived from the hepatic lymphomononuclear cell infiltrate of several patients with chronic active hepatitis B. The isolated subsets from these lines were specifically activated by HBcAg and displayed antigen-specific help and suppression with respect to proliferation of the alternate subset. One of these lines was recently cloned by limiting dilution, and four HBcAg-specific CD3+ CD4+ CD8-DR+ T cell lines were produced that had a 95.3% likelihood of monoclonality. Antigenic specificity was confirmed by dose-dependent, HLA class II (DR)-restricted proliferation in response to recombinant and human serum-derived HBcAg and the lack of proliferation to HBV envelope antigens (HBsAg and pre-S(2)Ag). All cloned lines were interleukin 2 dependent, produced interferon-gamma in an antigen-specific manner, and provided antigen-specific help to autologous B cells with respect to anti-HBc production. We conclude that HBcAg-specific, HLA-class II restricted helper T cells capable of inducing antigen-specific functional responses by autologous B lymphocytes and T lymphocytes are present at the site of viral antigen synthesis and hepatocellular injury in HBV infection.