bluuebunny/crossref_metadata_2025_split huggingface dataset:
A murine IgM monoclonal antibody binds an antigenic determinant in outer surface protein A, an immunodominant basic protein of the Lyme disease spirochete.
Authors: Benach J L , Coleman J L , Golightly M G 
Published: December 2022

Abstract
A hybridoma cell line formed by the fusion of the P3x63-Ag8.653 myeloma cell line with splenocytes from BALB/c mice immunized with Borrelia burgdorferi produced an IgM monoclonal antibody (mAb-11G1) with kappa-light chains which detected an antigenic determinant in a major spirochetal protein of m.w. approximately 31,000, also known as outer surface protein A (OSP-A). Apparent saturation was reached in approximately 35 min with 34 ng of mAb-11G1 binding to 5 X 10(7) spirochetes giving an estimated 4.8 X 10(2) IgM molecules per spirochete and thus a minimum of 480 binding sites per organism. Enzymatic digestion studies suggest that the antigenic determinant to mAb-11G1 is contained within the peptide chain of OSP-A as binding could be eliminated by treatment of the spirochetes with proteinase K, Pronase and pepsin (100 to 200 micrograms/ml of enzyme) but not by trypsin or bromelain treatment. Periodate oxidation as well as mixed and endoglycosidase treatment of the spirochetes did not alter the binding of mAb-11G1. Two-dimensional gel electrophoresis of whole spirochetal cell lysates disclosed that OSP-A is a heterogeneously charged basic protein with an apparent isoelectric point range from 8.5 to 9.0. Amino acid analysis of OSP-A showed a 10% lysine component which could provide the basic nature to the protein. OSP-A with the intact antigenic determinant for mAb-11G1 can be found in the urine of hamsters experimentally infected with B. burgdorferi.
Recombinant interleukin 2 as an adjuvant for vaccine-induced protection. Immunization of guinea pigs with herpes simplex virus subunit vaccines.
Authors: Weinberg A , Merigan T C 
Published: December 2022

Abstract
We determined that recombinant interleukin 2 (rIL-2) administered in conjunction with herpes simplex virus (HSV) crude extract or recombinant glycoprotein D subunit vaccine enhances the protective effect of either antigen preparation against HSV type 2 genital infection in guinea pigs. Animals that received the vaccine accompanied by rIL-2 had an incidence of infection, assessed by detection of clinical lesions and/or viral shedding, that varied between 0 and 43% significantly lower than the incidence of 63 to 100% in guinea pigs submitted to the same immunization schedule without rIL-2. Animals that escaped acute infection failed to develop recurrent disease. In addition, severity of acute infection was decreased by rIL-2 co-administration as well as by increasing the number of vaccine doses. We also studied the immune response of the guinea pigs to vaccination and the mechanism of protection. Both enzyme-linked immunosorbent assay titers of antibodies to HSV type 2 and specific antigen stimulation of lymphocytes measured by proliferation and interferon production did not significantly differ among the immunization groups. However, specific cellular cytotoxicity was enhanced by rIL-2 co-administration and was positively correlated with protection. This suggests that rIL-2 may become an important adjuvant in active immunization programs using subunit vaccines, particularly against diseases in which cellular cytotoxicity is a major defense mechanism.
Increased in vitro bone resorption by monocytes in the hyper-immunoglobulin E syndrome.
Authors: Leung D Y , Key L , Steinberg J J , Young M C , Von Deck M , Wilkinson R , Geha R S 
Published: December 2022

Abstract
Children with the hyper-immunoglobulinemia E syndrome are prone to bone fractures. We determined bone density in six patients with hyper-IgE syndrome using photon absorptiometry. All six patients had significantly reduced bone density compared with age- and sex-matched controls. The capacity of peripheral blood monocytes to degrade 45Ca-labeled bone in vitro was studied. The mean percent 45Ca release in four hyper-IgE patients (40.8 +/- 8.6) was significantly higher (p less than 0.01) than in ten age-matched healthy control subjects (7.1 +/- 2.6), seven age-matched patients with recurrent infections (7.9 +/- 1.6), or nine patients with severe atopic dermatitis and elevated serum IgE levels (5.8 +/- 1.3). Monocytes from four of four patients studied spontaneously released abnormally high levels of prostaglandin E2. Bone degradation by these monocytes was significantly reduced in the presence of 10(-6) M indomethacin in vitro. Administration of aspirin in vivo to two hyper-IgE patients reduced boned degradation by their monocytes to normal levels. These results suggest that monocytes from patients with hyper-IgE syndrome are activated to resorb bone via products of the prostaglandin synthase (cyclooxygenase) pathway. The activation of cells in the monocyte/macrophage family to resorb bone may contribute to the osteopenia observed in hyper-IgE syndrome.
Expression of the functional erythropoietin receptors on interleukin 3-dependent murine cell lines.
Authors: Tsao C J , Tojo A , Fukamachi H , Kitamura T , Saito T , Urabe A , Takaku F 
Published: December 2022

Abstract
Two distinct hemopoietic growth factors, interleukin 3 (IL-3) and erythropoietin (EPO), support the growth and development of erythroid cells in a sequential manner in vitro. Stimulation of multipotential stem cells by IL-3 appears to develop committed erythroid progenitor cells that respond to EPO. When several murine IL-3-dependent cell lines were assayed for their ability to respond to EPO, the growth and survival of the three cell lines showing the profiles of either myeloid or mast cell lineage (IC-2, DA-1, FDC-P2) were stimulated by EPO in a dose-dependent fashion. To determine whether the biologic effects were mediated through the specific receptors for EPO, we performed binding experiments on these cells with radioiodinated EPO. All of these cells displayed significant levels of specific binding for EPO. Among a family of hemopoietic growth factors, only unlabeled EPO was able to compete for the binding of radioiodinated EPO to the cells. Analysis of the binding data revealed the existence of a single case of binding sites in extremely low abundance. IC-2 cells were used to study the effects of IL-3 on the regulation of expression of EPO receptors. It was demonstrated that a decrease in IL-3 concentration in the culture medium increased the responsiveness to EPO and the amount in specific binding of EPO as well. These results suggest that some IL-3-dependent cell lines have functional EPO receptors and their expression may be modulated by IL-3.
Peptide and protein antigens require distinct antigen-presenting cell subsets for the priming of CD4+ T cells.
Authors: Constant S , Sant'Angelo D , Pasqualini T , Taylor T , Levin D , Flavell R , Bottomly K 
Published: December 2022

Abstract
Priming of naive CD4+ T cells to Ag requires an antigen-presenting cell (APC) that can take up the Ag and present peptide bound to MHC class II molecules. We have used both in vivo and in vitro approaches to demonstrate that the APC used to prime naive CD4+ T cells depends on the initial form in which an Ag is administered. Although Ag delivered as a peptide was presented most efficiently to CD4+ T cells by DC, these APC were poor at priming to a protein form of the same Ag. In contrast, the presence of B cells was a requisite for priming to protein Ag.
IL-12 directly enhances in vitro murine erythropoiesis in combination with IL-4 and stem cell factor.
Authors: Dybedal I , Larsen S , Jacobsen S E 
Published: December 2022

Abstract
It has been demonstrated recently that in vivo administration of murine IL-12 to mice enhances the activity of cytotoxic NK cells and lymphocyte-activated killer cells, and that it has antitumor and antimetastatic activity. However, one side effect observed in response to systemic IL-12 treatment is anemia. In the present study, we examined for the first time the ability of IL-12 to affect directly the growth of murine erythroid progenitor cells in vitro. Whereas IL-12 alone or in combination with Erythropoietin (Epo) showed no stimulatory effect on erythroid progenitors, IL-12 potently enhanced the number of erythroid burst-forming unit (BFU-E) colonies formed in response to Epo+IL-4 by 63% and Epo+stem cell factor by 80%. The stimulatory effect of IL-12 occurred in a concentration-dependent fashion, with maximum enhancing effect observed at 50 ng/ml. Furthermore, single cell experiments suggested that the stimulatory effect of IL-12 on erythroid colony formation was directly mediated. Thus, IL-12 can directly enhance murine erythropoiesis in vitro, suggesting that IL-12-induced anemia is mediated through an indirect mechanism.
Colony-stimulating factor-1 secreted by fibroblasts promotes the growth of dendritic cell lines (XS series) derived from murine epidermis.
Authors: Takashima A , Edelbaum D , Kitajima T , Shadduck R K , Gilmore G L , Xu S , Taylor R S , Bergstresser P R , Ariizumi K 
Published: December 2022

Abstract
We have established recently from mouse epidermis long-term dendritic cell lines (XS series) that resemble epidermal Langerhans cells (LC) by their surface phenotype, Ag-presenting profile and cytokine mRNA profile. The growth of XS lines was promoted maximally by granulocyte-macrophage-CSF or by a factor secreted by NS lines, which are fibroblastic cell lines established from dispase-separated specimens of mouse epidermis. The purpose of this study was to determine the identity of XS cell growth factor secreted by NS cells. We report the following: 1) NS cells express constitutively mRNA for CSF-1; 2) XS cells express the CSF-1R at mRNA and protein levels; 3) rCSF-1 mimics NS culture supernatant in its ability to promote XS cell growth; 4) NS supernatant-dependent XS cell growth is blocked completely by each of two Abs against the CSF-1R. We conclude that CSF-1 is responsible for the XS growth-promoting activity secreted by NS lines. We also report the following: 5) LC freshly isolated from skin express CSF-1R mRNA; and 6) fibroblasts derived from specimens of dermis also express mRNA and secrete large amounts (50-100 ng/ml) of CSF-1. These observations give rise to a new concept that dermal fibroblasts may support the survival and growth of LC (and their precursors) through the paracrine effect of elaborated CSF-1.
Dissociation of beta 2-microglobulin from HLA class I heavy chains correlates with acquisition of epitopes in the cytoplasmic tail.
Authors: Little A M , Nössner E , Parham P 
Published: December 2022

Abstract
A rabbit antiserum "ABR2" was raised against a peptide with sequence identity to 10 amino acids of the cytoplasmic tail of HLA class I heavy chains. Western blotting and immunoprecipitation analyses demonstrate that ABR2 reacts with HLA class I heavy chains. The antiserum reacts poorly with beta 2-microglobulin (beta 2-m)-associated heavy chains and reacts strongly with free heavy chains. ABR2 reacts with immature heavy chains from the endoplasmic reticulum that have yet to bind beta 2-m and mature heavy chains that have dissociated from beta 2-m at the plasma membrane. Comparison with HC10, a mAb that recognizes an epitope defined by polymorphism at residue 62 of the alpha 1 helix of free HLA class I heavy chains, shows that ABR2 reacts with overlapping populations of free heavy chains (for those allotypes that react with both Abs), but it also identifies populations that bind to one Ab and not the other. ABR2 induces dissociation of beta 2-m from HLA-B38 molecules expressed by the human B cell line "TEM," a phenomenon not detected with other allotypes or with the same allotype in a different cell line. This study shows that association of beta 2-m with the extracellular domains of HLA class I heavy chains can cause a change in the cytoplasmic tail that prevents binding of Abs present in the ABR2 antiserum. Similar findings have been made for mouse H-2 class I molecules, which suggests that this is a general property of class I MHC molecules.
Development of antimalaria immunity in mice lacking IFN-gamma receptor.
Authors: Tsuji M , Miyahira Y , Nussenzweig R S , Aguet M , Reichel M , Zavala F 
Published: December 2022

Abstract
IFN-gamma receptor deficient (IFN-gamma R-/-) mice, immunized with different developmental stages of malaria parasites, were used to define the mechanisms of protection against the various stages of this infection. IFN-gamma R-/- mice failed to develop protective immunity against Plasmodium yoelii sporozoites or liver stages, upon immunization with a single dose of irradiated sporozoites, whereas in immunized wild-type mice, parasite development was strongly inhibited. Immunized wild-type mice expressed high levels of inducible nitric oxide synthase (iNOS) mRNA in their liver, upon challenge with viable sporozoites, whereas only background levels of iNOS were detected in immunized IFN-gamma R-/- mice. In contrast, after immunization with multiple doses of irradiated sporozoites, both IFN-gamma R-/- and wild-type mice mounted an immune response, which strongly inhibited the development of liver stage parasites. In both types of mice, protection occurred in the absence of appreciable expression of liver iNOS mRNA. As for the course of the erythrocytic phase of infection by nonlethal malaria species, P. yoelii yoelii and P. chabaudi adami, we observed only a moderately prolonged parasitemia in IFN-gamma R-/- mice compared with wild-type mice, indicating that IFN-gamma may only play a modest role in immunity against erythrocytic stages. These results indicate that IFN-gamma is the main mediator of the protective mechanism that develops first upon immunization with sporozoites. However, the nature of the anti-parasite mechanism(s) changes in the course of immunization, so that multiple immunizing doses elicit additional protective mechanisms, which are independent of IFN-gamma and its receptor.
Neutrophil accumulation and activation by homologous IL-8 in rabbits. IL-8 induces destruction of cartilage and production of IL-1 and IL-1 receptor antagonist in vivo.
Authors: Matsukawa A , Yoshimura T , Maeda T , Ohkawara S , Takagi K , Yoshinaga M 
Published: December 2022

Abstract
Whether or not IL-8 attracts T lymphocytes and activates neutrophils in vivo remains unclear. Most studies on function of IL-8 in vivo have been done on human IL-8 in heterologous animals. To elucidate the role of IL-8 in vivo, we injected homologous IL-8 into rabbit knee joints and investigated the inflammatory response. Injection of 10 micrograms of rabbit IL-8 induced a massive accumulation of neutrophils. IL-8 attracts T lymphocytes in vitro; however, rabbit IL-8 induced no appreciable lymphocyte accumulation in rabbits. Although human IL-8 was reported not to induce cartilage destruction when injected into heterologous animals, we observed that rabbit IL-8 did provoke a release of neutrophil elastase, leading to cartilage destruction, when injected into rabbits. An inhibitor against neutrophil elastase (ONO-5046) prevented destruction of the cartilage. Injection of rabbit IL-8 induced bioactive and immunoreactive IL-1 beta and IL-1 receptor antagonist (IL-1Ra) in the joint cavity. Immunohistochemistry showed that IL-1 beta and IL-1Ra positive cells were infiltrating leukocytes. In neutrophil-depleted rabbits, rabbit IL-8 induced far lesser concentrations of IL-1 beta and IL-1Ra and no cartilage destruction compared with findings in normal rabbits. Thus, the infiltrating neutrophils are the main producers of these cytokines and are responsible for the cartilage destruction. In addition to neutrophil chemotactic activity, IL-8 proved to have a neutrophil-activating capability in vivo, with respect to release of neutrophil elastase and induction of IL-1 beta and IL-1Ra.
Dexamethasone up-regulates A3 adenosine receptors in rat basophilic leukemia (RBL-2H3) cells.
Authors: Ramkumar V , Wilson M , Dhanraj D N , Gettys T W , Ali H 
Published: December 2022

Abstract
The cross-linking of surface IgE receptors by multi-functional Ags promotes the degranulation of mast cells. Previous studies have indicated that the nucleoside adenosine potentiates this response by activating putative A3 adenosine receptors (AR) coupled to phospholipase C in mast cells or their cultured analogues, rat basophilic leukemia (RBL-2H3) cells. Moreover, it has been shown that exposure of RBL-2H3 cells to dexamethasone attenuated antigen-mediated mast cell degranulation, but potentiated the response elicited by adenosine. To determine whether the A3AR is a potential site of action of dexamethasone, we have assessed the status of these receptors in RBL-2H3 cells treated with and without dexamethasone. Treatment with dexamethasone (100 nM) for 24 h resulted in an increase in the number of A3AR to 217 +/- 50% of control. The increased receptor expression was both time- and concentration-dependent, with optimal increases observed following 16 h of treatment and using 100 nM of dexamethasone. No increase in the level of the A2aAR was detectable following dexamethasone treatment. Northern blotting studies indicated a 2.7 +/- 0.3-fold increase in A3AR mRNA in RBL-2H3 cells treated with dexamethasone for 24 h. Dexamethasone also increased the expression of G protein alpha i2, alpha i3, alpha s, and beta subunits by two- to threefold. Activation of the A3AR by aminophenylethyladenosine (APNEA) following dexamethasone treatment enhanced the production of inositol phosphates and the mobilization of intracellular Ca2+. From these data, it is concluded that dexamethasone increases the expression of both A3AR and G proteins in RBL-2H3 cells which contributes to the enhanced response to adenosine.
IL-8 is expressed by human peripheral blood eosinophils. Evidence for increased secretion in asthma.
Authors: Yousefi S , Hemmann S , Weber M , Hölzer C , Hartung K , Blaser K , Simon H U 
Published: December 2022

Abstract
Eosinophils possess the capacity to synthesize various cytokines. We demonstrate that IL-8 mRNA and protein are constitutively expressed by freshly isolated resting human eosinophils. Most of the patients with bronchial asthma or atopic dermatitis show evidence for up-regulated IL-8 protein expression in eosinophils but not in neutrophils, suggesting that an eosinophil-specific cytokine may act in these patients. To investigate whether the intracellular IL-8 can be released, eosinophils were stimulated by different cytokines and platelet-activating factor. Priming with granulocyte-macrophage CSF and a subsequent 25-min stimulation with RANTES or platelet-activating factor resulted in release of IL-8 from highly purified human eosinophils in vitro. As the eosinophil is the predominant cell in asthmatic inflammation, we determined IL-8 concentrations in bronchoalveolar lavage fluids from normal individuals and asthmatic patients. Bronchoalveolar lavage fluids from patients with bronchial asthma consistently demonstrated high IL-8 concentration compared with the controls. This suggests that IL-8 is released in vivo by inflammatory bronchial cells in asthma.
Role of TCR specificity in CD4 versus CD8 lineage commitment.
Authors: Kersh G J , Hedrick S M 
Published: December 2022

Abstract
We have examined the role that TCR-alpha beta specificity plays in lineage commitment of thymocytes. Thymocytes in the process of selection have been distinguished by the expression of high levels of CD69 and CD5. The phenotype of most of these selected thymocytes is either CD4highCD8low or CD4lowCD8high, but some are CD4lowCD8low, a phenotype referred to as double-positive dull. Analysis of the phenotype of apoptotic thymocytes shows that double-positive dull cells make up many of the cells undergoing negative selection. Thymocytes from MHC class I- or class II-deficient mice and from MHC class I- and class II-restricted TCR transgenic mice have been analyzed for cells undergoing positive and negative selection. This analysis shows that the TCR specificity is a critical factor in the lineage determination of thymocytes, and any stochastic component to lineage commitment is minor.
MHC class I signaling in T cells leads to tyrosine kinase activity and PLC-gamma 1 phosphorylation.
Authors: Skov S , Odum N , Claesson M H 
Published: December 2022

Abstract
We have studied the biochemical signal pathway leading to a rise in intracellular free calcium concentration ([Ca2+]i) following cross-linking of MHC class I (MHC-I) molecules on human T leukemic Jurkat cells. Evidence is presented that MHC-I signaling is dependent on tyrosine kinase activity before the observed increase in [Ca2+]i. Thus, tyrosine phosphorylation was detected within 5 s after MHC-I cross-linking, whereas an increase in [Ca2+]i was observed after a lag period of 30 s. Moreover, an inhibitor of tyrosine kinases, herbimycin A, almost completely blocked MHC-I-induced tyrosine phosphorylation and the subsequent calcium response. The early tyrosine kinase activity was found to be dependent on expression of the TCR/CD3 complex and the CD45 molecule on the surface of the T cells. Furthermore, MHC-I cross-linking was shown to tyrosine phosphorylate PLC-gamma 1 (phospholipase C-gamma 1). Collectively, these results indicate that the MHC-I signaling pathway is linked to activation of tyrosine kinase(s) in Jurkat cells.
Multivalent, but not divalent, antigen receptor cross-linkers synergize with CD40 ligand for induction of Ig synthesis and class switching in normal murine B cells. A redefinition of the TI-2 vs T cell-dependent antigen dichotomy.
Authors: Snapper C M , Kehry M R , Castle B E , Mond J J 
Published: December 2022

Abstract
A number of previous studies have suggested that cross-linkage of the B cell Ag receptor may be critical for induction of humoral immune responses to T cell-dependent (TD) Ags in vivo. Previous work also indicated a critical role, in these responses, for CD40-mediated signaling mediated by binding of the inducible T cell membrane protein, CD40 ligand (CD40L). Data in this manuscript demonstrate that concentrations of bivalent anti-IgD or anti-IgM Ab as high as 30 micrograms/ml induced little if any enhancement of CD40-dependent Ig secretion by resting murine B cells. In contrast, concentrations as low as 3 pg/ml of multivalent, dextran-conjugated, anti-IgD (alpha delta-dex) or anti-IgM (alpha mu-dex) were strongly synergistic with CD40L for induction of B cell proliferation, viable cell outgrowth, Ig isotype switching, and maturation to Ig secretion. As many as 30% of the B cells became membrane IgG1+ after stimulation with CD40L, anti-Ig-dextran, and IL-4 + IL-5, with a concomitant three- to fivefold increase in numbers of viable cells as compared with control cultures. High Ig secretory responses were obtained in response to the combined actions of CD40L and alpha delta-dex or alpha mu-dex, utilizing concentrations of B cell activator that when acting alone induced only modest Ig secretion. Surprisingly, although we previously demonstrated that alpha delta-dex selectively and strongly suppressed IgE production by T cell-activated B cells, it strikingly augmented IgE expression by CD40L-activated B cells. These data suggest 1) a key role for Ag receptor cross-linkage in CD40-dependent induction of humoral immune responses, 2) that to achieve a membrane Ig-dependent enhancing effect in the presence of activated T cells, TD Ags must be displayed to the B cell as a multivalent array of epitopes, 3) that picomolar concentrations of Ag can mediate this effect, and 4) that at least for induction of IgE responses, B cell stimulation via CD40L or via activated T cells may lead to a qualitatively different pathway of activation.