bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitation of L-selectin and CD18 expression on rabbit neutrophils during CD18-independent and CD18-dependent emigration in the lung.
Authors: Burns A R , Doerschuk C M 
Published: December 2022

Abstract
In the systemic circulation, the leukocyte adhesion molecule, L-selectin facilitates the initial adhesion of the neutrophil to the inflamed endothelium, whereas CD11/CD18 is essential to transendothelial migration. Previous work from our laboratory showed that neutrophil emigration in the lung occurs through either a CD18-independent or CD18-dependent mechanism, depending on the inflammatory stimulus. This study quantitated and compared the surface expression of L-selectin and CD18 on neutrophils in the lungs of rabbits during emigration toward Streptococcus pneumoniae (a CD18-independent stimulus) and Escherichia coli endotoxin (a CD18-dependent stimulus). Ultrathin frozen lung tissue sections were immunogold labeled for 1-selectin and CD18, and gold particles were quantitated on intravascular, interstitial, and airspace neutrophils by transmission electron microscopy. The results show that CD18-independent neutrophil emigration was associated with L-selectin down-modulation (78%) and CD18 up-modulation (260%) on intravascular neutrophils, before emigration. A similar alteration in the expression of L-selectin and CD18 was observed during CD18-dependent neutrophil emigration, but only on neutrophils that emigrated into the interstitium and airspace. In emigration induced by either stimulus, alterations in L-selectin and CD18 expression were restricted to the inflammatory focus and emigrated airspace neutrophils consistently expressed greater levels of CD18 than intravascular and interstitial neutrophils. We conclude that before emigration, L-selectin and CD18 expression on intravascular neutrophils is altered only during CD18-independent emigration and only on those neutrophils within the inflammatory focus. The increased CD18 expression on airspace neutrophils may facilitate bacterial phagocytosis.
Antibodies specific for human thyrotropin receptor induce MHC antigen expression in thyroid cells.
Authors: Ropars A , Marion S , Takorabet L , Braun J , Charreire J 
Published: December 2022

Abstract
Autoantibodies (AAbs) to hormone receptors are found in autoimmune diseases such as Graves' disease (GD) or myasthenia gravis. A structural link between hormone receptor and MHC genes has been documented, suggesting a possible co-regulation of MHC and hormone receptor genes. Thus, in vitro experiments were designed to search for a pathologic role for AAbs. In a model study, we investigated whether adding murine anti-human thyrotropin receptor mAbs would affect MHC gene expression in either cloned human thyroid epithelial cell or primary murine thyroid epithelial cell cultures. We found that two anti-human thyrotropin receptor monoclonal AAbs, 11E7 and 34A, induced, with an intensity comparable to that of IFN-gamma, transcription and expression of class I and class II/Ii chain proteins in human and murine thyroid epithelial cells. Two other anti-human thyrotropin receptor mAbs, 12E3 and 243-3, were ineffective. These data suggest a new role for autoantibodies in the pathology of autoimmune endocrinopathies.
Prevention of anti-CD3 monoclonal antibody-induced thymic apoptosis by protein tyrosine kinase inhibitors.
Authors: Migita K , Eguchi K , Kawabe Y , Mizokami A , Tsukada T , Nagataki S 
Published: December 2022

Abstract
The thymus gland is crucial for the formation of thymocytes of diverse TCR specificity. Recent studies have demonstrated that deletion (negative selection) of autoreactive thymocytes occurs through the process of apoptosis in which TCR activates cell death by DNA fragmentation. In addition, in vitro stimulation of thymocytes with anti-CD3 mAb, calcium ionophore, or glucocorticoids results in DNA fragmentation followed by cell death. The availability of various substances capable of inhibiting activation-induced programmed cell death of thymocytes may be used as a tool to help identify several important events occurring during the process of apoptosis. We investigated the effect of protein tyrosine kinase (PTK) inhibitors, herbimycin A and genistein, on thymocyte apoptosis induced by stimulation of anti-CD3 mAb or glucocorticoid. Anti-CD3 mAb stimulation resulted in removal of CD4+CD8+ thymocytes by DNA fragmentation. However, in PTK inhibitor-pretreated thymocytes, there was a minimal deletion of double positive thymocytes. In contrast, PTK inhibitors did not prevent glucocorticoid-induced thymic apoptosis. Our results suggest that anti-CD3 mAb-induced thymic apoptosis depends on PTK activation via TCR, and that glucocorticoid-induced thymic apoptosis is PTK-independent.
Single IL-2-secreting precursor CD4 T cell can develop into either Th1 or Th2 cytokine secretion phenotype.
Authors: Sad S , Mosmann T R 
Published: December 2022

Abstract
Immunocompetent T lymphocytes in peripheral tissues mainly secrete IL-2 when first stimulated, whereas effector T lymphocytes generated during an immune response secrete different cytokine patterns, such as the Th1, Th2, or other phenotypes displayed by in vitro T cell clones. In this paper, we have examined whether the cell populations that have distinctive cytokine-producing capabilities represent different cell lineages or whether they are derived from the same uncommitted precursor T cell. During allostimulation of CD4+ spleen T cells, TGF-beta inhibited the development of T cells that could produce the Th2 cytokines IL-4 and IL-5. Anti-IFN-gamma inhibited the development of Th1-like IFN-gamma-secreting cells, and the combination of TGF-beta and anti-IFN-gamma resulted in the proliferation of a cell population that produced IL-2, but not IFN-gamma, IL-4, or IL-5, on restimulation. These IL-2-producing T cells expressed low levels of CD45RB and MEL14 and high levels of CD44. Clones of IL-2-producing T cells were isolated, and either bulk culture or clonal IL-2-producing populations acquired the ability to secrete Th1 or Th2 cytokine patterns when restimulated in the presence of TGF-beta or IL-4, respectively. These results demonstrate that both Th1- and Th2-like cells can be derived from a bipotential IL-2-producing precursor CD4+ T cell.
Functional analysis of the serpin domain of C1 inhibitor.
Authors: Coutinho M , Aulak K S , Davis A E 
Published: December 2022

Abstract
To analyze the role of the heavily glycosylated amino-terminal domain of C1 inhibitor in protease inhibitory activity, two truncated C1 inhibitor molecules were constructed. The abilities of the recombinant truncated inhibitors to complex with target proteases were compared with that of the wild-type recombinant protein. One recombinant truncated molecule consisted of amino acid residues 76 to 478 (C-serp(76)) and the other of residues 98 to 478 (C-serp(98)). The recombinant proteins were each expressed in similar quantities. The thermal denaturation profiles of the two truncated proteins were similar to that of the wild-type protein. Identical binding of C1s, C1r, kallikrein, and beta factor XIIa was observed with the three molecules. Furthermore, the truncated molecules also effectively inhibited C1 activity in hemolytic assays. These studies therefore clearly demonstrate that the amino-terminal domain of C1 inhibitor does not influence complex formation with target proteases.
Selective inhibitory effects of the anticoagulant activated protein C on the responses of human mononuclear phagocytes to LPS, IFN-gamma, or phorbol ester.
Authors: Grey S T , Tsuchida A , Hau H , Orthner C L , Salem H H , Hancock W W 
Published: December 2022

Abstract
Recent studies have shown that infusion of the anticoagulant protein, activated protein C (APC), can ameliorate many of the systemic effects of endotoxemia in experimental animals, although the mechanisms in this action are unknown. We investigated the effects of APC on the responses of blood monocytes, alveolar macrophages, and cells of the monocyte line, THP-1, to stimulation in vitro by LPS, IFN-gamma, or PMA. Mononuclear phagocyte (MO) activation was associated with rapid production of TNF-alpha, down-regulation of the glycophosphatidylinositol-linked protein CD14 (the key MO receptor for complexes of LPS and LPS-binding protein responsible for intracellular signaling), and down-regulation of the related LPS-binding proteins CD11b and CD18. Addition of APC, but not the zymogen, PC, or active site-blocked APC, inhibited selected MO responses involving the CD14-dependent LPS-induced pathway of MO activation, or activation induced by IFN-gamma or PMA. Thus, APC inhibited the production of TNF-alpha and prevented down-regulation of membrane CD11b, CD14, and CD18, but had no effect on up-regulation of MHC class II, ICAM-1, or IL-2R, down-regulation of MO expression of another glycophosphatidylinositol-linked protein, CD59, or production of reactive oxygen intermediates. These data show that APC inhibits host cytokine production but maintains MO responses associated with adhesion, phagocytosis, and killing of Gram-negative bacteria, such that use of APC may be a logical and potent adjunctive therapy in select inflammatory diseases involving MO activation and damaging host cytokine overproduction.
Relationship of TSG-14 protein to the pentraxin family of major acute phase proteins.
Authors: Lee G W , Goodman A R , Lee T H , Vilcek J 
Published: December 2022

Abstract
TNF-stimulated gene-14 (TSG-14) encodes a secreted glycoprotein with significant sequence homology to C-reactive protein (CRP) and serum amyloid P component (SAP), members of the pentraxin family of acute phase proteins. TSG-14 mRNA was elevated in human FS-4 fibroblasts by treatment with TNF, IL-1, or bacterial LPS, and weakly by dexamethasone. Abs to recombinant TSG-14 immunoprecipitated a 42-kDa protein from the culture supernatants of TNF- or IL-1-stimulated FS-4 cells. TSG-14 protein was also inducible in the Hep3B human hepatoma cell line by TNF, IL-1, IL-6, or dexamethasone. CRP protein, identified by immunoprecipitation of a 25-kDa band with Abs to CRP, was induced in Hep3B cells by IL-1, IL-6, or dexamethasone. Immunoprecipitations with polyclonal Abs to TSG-14 and CRP suggested that the two proteins are immunologically cross-reactive. Appearance of TSG-14 protein was demonstrated in the serum of mice after injection with LPS. No TSG-14 mRNA was detected in the liver of LPS-injected mice, suggesting that hepatocytes are not the major site of TSG-14 synthesis. Thus, in the intact organism the main cellular sources of TSG-14 and classical acute phase proteins appear to be different.
Stem cell factor is a chemotactic factor for human mast cells.
Authors: Nilsson G , Butterfield J H , Nilsson K , Siegbahn A 
Published: December 2022

Abstract
The mast cell is one of the major effector cells in inflammatory reactions and can be found in most tissues throughout the body. During inflammation, an increase in the number of mast cells can be seen, e.g., in the intraepithelial cell layer after a provoked allergic reaction. Such accumulation probably requires directed migration of mature mast cells or their precursors. To study the migration of human mast cells we used as a model the human mast cell line, HMC-1, and stem cell factor-dependent (also referred to as mast cell growth factor or Kit ligand) cord blood-derived mast cells. The results show that stem cell factor is a potent chemotactic factor for human mast cells in vitro. The chemotactic response to SCF was found to be dose dependent, reaching a maximum at 50 ng/ml. The activity of SCF could be blocked by anti-SCF Abs. We also tested the effect of different intercrines, i.e., IL-8, MIP-1 alpha, MIP-1 beta, RANTES, and MCAF (also referred to as monocyte chemotactic protein 1), on human mast cell migration. Only RANTES was chemotactic for in vitro-developed mast cells. None of the tested intercrines induced migration of HMC-1 cells. For migration, the mast cells were dependent on binding to an extracellular matrix protein. Thus, coating of the filters with fibronectin was required, whereas collagen or laminin did not promote migration. Adhesion of HMC-1 cells to fibronectin could also be shown in an adhesion assay. In addition, expression of receptors for fibronectin could be detected on the surface of the mast cells. These results show that SCF is not only a growth and differentiation factor for human mast cells in vitro but also a potent chemoattractant for such cells.
Expression of a novel autoantibody defined by the VH3-15 gene in inflammatory bowel disease and Campylobacter jejuni enterocolitis.
Authors: Berberian L S , Valles-Ayoub Y , Gordon L K , Targan S R , Braun J 
Published: December 2022

Abstract
This study newly introduces anti-VH mAbs to assess the role of clonal B cell activity in inflammatory bowel disease. Immunohistochemistry of colonic biopsies in ulcerative colitis (UC) and Crohn's disease (CD), but not unaffected individuals, demonstrated uniform staining of intravascular erythrocytes with BK2, a monoclonal specific for the VH3-15 Ig heavy chain gene product. Staining was caused by erythrocytes opsinized in vivo by anti-erythrocyte Abs present in patient sera and by using the VH3-15 gene product. The erythrocyte Ag was identified by immunoprecipitation as 22- and 28-kDa membrane proteins. A direct flow cytometric assay was developed to measure this serum autoantibody and was tested in 101 individuals with UC, CD, other acute or chronic colitis, and healthy controls. Compared with normal subjects, BK2+ anti-erythrocyte Abs were elevated in most sera from patients with CD and UC (including postcolectomy). BK2+ anti-erythrocyte Abs also were elevated in 10 of 38 noninflammatory bowel disease patients, all of whom had Campylobacter jejuni enterocolitis. These findings suggest that a common immunopathogenetic factor, manifested by VH3-15 B cell activation may be shared in UC, CD, and Campylobacter jejuni enterocolitis.
TAT-mediated transcellular activation of HIV-1 long terminal repeat directed gene expression by HIV-1-infected peripheral blood mononuclear cells.
Authors: Thomas C A , Dobkin J , Weinberger O K 
Published: December 2022

Abstract
We have previously shown evidence of Tat-mediated transcellular activation of the HIV-1 long terminal repeat (LTR) in vitro by using a laboratory-adapted strain of HIV-1. To examine the biologic significance of this observation, we asked whether primary PBMCs from HIV-1-infected individuals will transactivate the HIV-1 LTR transcellularly in suitable indicator cells. In cultures of PBMCs isolated from HIV-1-infected patients at various clinical stages, with either HIV-1 LTR-transfected Jurkat T cells or nonfusigenic HIV-1 LTR-transfected murine fibroblasts, transcellular activation was readily detected. Transactivation of the LTR in cocultured cells with HIV-1-infected PBMCs is detectable 1 to 2 wk before the onset of significant virus production and at ratios as low as 1 infected cell to 10(6) surrounding cells. Addition of the Tat inhibitor RO5-3335 substantially decreases transcellular activation, even at low concentrations (0.01 microM) that do not affect virus levels. In contrast, addition of the antiretroviral agent zidovudine has no effect on transcellular activation. These data suggest that Tat-mediated transcellular activation of the HIV-1 LTR occurs independently of cellular infection, and provides a mechanism that can promote the spread of HIV-1 in susceptible cell populations.
Formation of high affinity IL-2 receptors is dependent on a nonligand binding region of the alpha subunit.
Authors: Gutgsell N S , Malek T R 
Published: December 2022

Abstract
The IL-2R is composed of three subunits, alpha, beta, and gamma, each of which individually contributes to binding IL-2 in the high affinity IL-2R. The molecular mechanism by which the high affinity IL-2R assembles has not been established. Previous studies have shown that human IL-2R subunits form high affinity hybrid IL-2R when mixed with appropriate mouse IL-2R subunits, but the efficiency of this process is not known. In this study, we produced stable cell lines that expressed hybrid human/mouse IL-2R, comprised of heterologous alpha- and beta-chains, to determine the contribution of individual receptor subunits in stabilizing the high affinity IL-2R. Quantitative ligand binding studies and FACS analysis were performed for EL4J cells that expressed hybrid mouse/human IL-2R, and these data were compared with those of cells that expressed homologous mouse IL-2R subunits. EL4J cells that expressed human beta/mouse alpha formed high affinity IL-2R, comparable with cells that express homologous mouse alpha and beta subunits. In contrast, EL4J cells that expressed homologous mouse IL-2R contained an approximately 10-fold higher level of high affinity IL-2R than did EL4J cells that expressed heterologous human alpha/mouse beta IL-2R. This difference was not accounted for by lower levels of human alpha-chains in these cell lines or lower expression of the mouse IL-2R beta or gamma subunits. These results suggest that amino acid sequences within the alpha subunit, distinct from the IL-2 binding site, are important in the assembly and stabilization of the high affinity IL-2R.
In vivo CD4+ lymph node T cells from lpr mice generate CD4-CD8-B220+TCR-beta low cells.
Authors: Laouar Y , Ezine S 
Published: December 2022

Abstract
Double-negative CD4-CD8-T cells (DNT) have been shown to be the major population of T cells responsible for the massive lymphadenopathy associated with the early onset of the lupus-like syndrome in mice bearing the lpr gene. Previously, we demonstrated that these cells do not proliferate in the peripheral lymphoid organs that they invade; furthermore, we showed that a wide range of CD4 Ag expression was observed on lymph node CD4+ T cells. In this study, we used an in vivo transfer system to analyze the progeny of CD4+ T cells from B6-lpr/lpr mice. Purified CD4+ T cells injected into B6 nude mice are able to generate DNT cells; furthermore, phenotypic and functional characterizations of the DNT cells generated in vivo show that they share the same properties as DNT cells from B6-lpr/lpr mice. We also show that, after in vitro bromodeoxyuridine incorporation, only CD4+ cells cycle. From these studies, we conclude that the lymphoproliferation occurs at the CD4+ stage and that down-regulation of this Ag probably is followed by arrest of the cell cycle.
CD7 is associated with CD3 and CD45 on human T cells.
Authors: Lazarovits A I , Osman N , Le Feuvre C E , Ley S C , Crumpton M J 
Published: December 2022

Abstract
The CD7 cluster of mAb identifies a 40-kDa glycopolypeptide that is present on a major subset of human T cells. CD7 Ag mediates an accessory pathway of T cell activation in that cross-linked CD7 mAb are mitogenic, and signals delivered via CD7 Ag stimulate integrin-mediated adhesion. We have found that the CD7 molecule is associated with a tyrosine kinase whose major substrate is CD45. In vitro phosphorylation of CD7, CD3, or CD45 immunoprecipitates prepared from lysates of human T cells showed a similar pattern of multiple phosphorylated polypeptides; in addition, these immunoprecipitates phosphorylated a tyrosine kinase-specific peptide. Surface-iodinated T cells were lysed and immunoprecipitated with CD7, CD3, and CD45 mAb. Bands characteristic of CD45 and CD3 were identified in CD7 immunoprecipitates. Confirmation of an association of CD7 with CD3 and CD45 was obtained from Western blotting and fluorescence resonance energy transfer experiments. Furthermore, we provide evidence using immunoprecipitation and Western blotting that CD7 exists as a homodimer. These data support the hypothesis that CD7 exists in an oligomeric complex with CD3/TCR, the protein tyrosine phosphatase CD45, and a tyrosine kinase, thereby providing a physical basis for the accessory role of the CD7 molecule in T cell activation.
Systemic cytokine profiles in BALB/c mice immunized with trivalent influenza vaccine containing MF59 oil emulsion and other advanced adjuvants.
Authors: Valensi J P , Carlson J R , Van Nest G A 
Published: December 2022

Abstract
We have studied serum cytokine profiles in BALB/c mice after immunization with influenza vaccine alone or combined with the following adjuvants: alum; MF59 emulsion; MF59 containing the muramyl peptide N-acetyl-muramyl-L-alanyl-D-isoglutaminyl-L-alanine-2-(1,2- dipalmitoyl-sn-glycero-3-(hydroxyphosphoryloxy)) ethylamide (MTP-PE); MF59 plus the lipid A analogue monophosphoryl lipid A; MF59 plus the Quil A saponin fraction LTC; or LTC alone. Pooled mouse sera were analyzed by ELISA at various times after immunization for IL-1 alpha, IL-2, IL-3, IL-4, IL-5, IL-6, IL-10, IFN-gamma, and TNF-alpha. In naive mice, vaccine alone induced low levels of IL-3 and IL-5 only; vaccine plus alum induced a low IL-6 response as well. The MF59-based adjuvants significantly increased the IL-5 and IL-6 levels, whereas Quil A LTC induced strong IFN-gamma and measurable IL-2 responses, in addition to moderate IL-5 and IL-6. In previously infected mice, MF59 and MF59/MTP-PE were capable of generating IFN-gamma responses, as well as IL-5 and IL-6. All of the cytokine responses were rapid (peaking 3 to 12 h postimmunization) and short lived. In naive mice, the MF59 adjuvants induced serum cytokine profiles that are consistent with a primarily Th2-type response, whereas the Quil A LTC induced cytokines associated with both Th1 and Th2 responses. Ab analyses indicated that, although the adjuvants strongly affected the magnitude of the humoral response, there was no obvious correlation between the cytokine profile observed and the subclasses of Ab induced.
Human vascular smooth muscle cells poorly co-stimulate and actively inhibit allogeneic CD4+ T cell proliferation in vitro.
Authors: Murray A G , Libby P , Pober J S 
Published: December 2022

Abstract
We compared immunologic functions of human vascular smooth muscle cells (VSMC) with those of endothelial cells (EC) cultured from saphenous vein. Both cell types can express comparable levels of MHC class II molecules. However, class II-positive VSMCs, unlike ECs, do not stimulate resting CD4+ T cell proliferation. Limiting dilution analyses revealed IL-2-producing cells alloreactive to class II-positive ECs but not VSMCs. Class II molecules on VSMCs are functional, inducing CD25 expression on resting CD4+ T cells and stimulating proliferation of CD4+ T cells that have been pre-activated by ECs. VSMC expression of the co-stimulator molecules CD44, CD54, CD58, and CD59 is comparable to EC expression, and neither VCAM-1 nor B7 are expressed on either cell. However, VSMCs are less efficient than ECs at co-stimulating IL-2 production by PHA-stimulated PBL. VSMCs but not ECs cultured across a Transwell inhibit CD4+ T cell proliferation to allogeneic ECs and, to a lesser extent, IL-2 production in the same assay. Inhibition of proliferation cannot be transferred by VSMC-conditioned media, nor reversed by inhibitors of prostaglandin synthesis, TGF-beta 1, or nitric oxide synthesis. CD4+ T cells cocultured with class II-positive VSMCs proliferate to a subsequent challenge with ECs from the same donor as well as freshly isolated T cells. We conclude that VSMCs express functional MHC class II molecules and stimulate pre-activated T cells. However, VSMCs lack adequate costimulators to fully stimulate resting T cells, and VSMCs inhibit T cell proliferation.