bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neutrophils as a source of putative restriction proteases: degradation of mammalian and yeast proteins monitored by two-dimensional gel electrophoresis.
Authors: Lefkovits I , Frey J R , Kuhn L , Sadovnikov V B , Pleshakova O V , Sukharev S A 
Published: December 2022

Abstract
We have compared the ability of intact neutrophils to degrade a complex substrate of proteins from mammalian and yeast origin. The substrate was obtained by biosynthetic labeling, and subsequent lysis of K562 cells (leukemic cell line) and of yeast culture. The mammalian substrate consisted of 619 and the yeast substrate of 185 different polypeptides, as visualized and represented on two-dimensional gel patterns. Upon incubation of the mammalian substrate with neutrophils, the bulk of spots disappeared so rapidly that after 240 min of incubation only 21 spots were detectable. Just one spot remained unaltered in its intensity throughout the whole period of incubation. About 440 spots reveal a t1/2 shorter than 8 min. Yeast substrate is represented by a smaller number of the starting polypeptides (185) from which 55 spots "survive" the neutrophil treatment. About 30 spots have a t1/2 shorter than 8 min. We conclude that neutrophils are equipped with a potent proteolytic apparatus, and this is capable of eliminating various proteins in a highly efficient manner. The system is much less effective in eliminating proteins from distant species, like yeast. Although the cells governing and regulating the immune system are clearly of lymphoid origin, it might well be that the preimmune task of eliminating self antigens in a manner as predicted in the restriction protease hypothesis is performed by neutrophils.
Effects of extracellular ATP and adenosine on different thymocyte subsets: possible role of ATP-gated channels and G protein-coupled purinergic receptor.
Authors: Apasov S G , Koshiba M , Chused T M , Sitkovsky M V 
Published: December 2022

Abstract
To explore the possible role of purinergic receptors in thymocyte development and in pathogenesis of adenosine deaminase SCID, we studied effects of extracellular adenosine triphosphate (ATP(ext)) and adenosine on TCR- and steroid hormone-triggered processes in mouse thymocytes. Reverse transcriptase-PCR analysis confirms the mRNA expression of several types of purinergic receptors, while the functioning of ATP receptors in thymocytes is reflected by ATP(ext)-induced intracellular calcium increases and by thymocyte subset-specific sensitivity to the effects of ATP(ext) and adenosine. Only ATP(ext), but not the ATP catabolites, adenosine, dexamethasone, or TCR cross-linking, was efficient in triggering rapid protein synthesis independent lysis of CD4+8- thymocytes and peripheral CD4+ T cells. In contrast, extracellular adenosine specifically induced the apoptosis of CD4+8+ thymocytes. ATP(ext) also induced a slower process of DNA fragmentation and protein synthesis-dependent apoptosis in all thymocyte subsets. ATP(ext) had an additive effect with TCR cross-linking in the induction of thymocyte death, but, unexpectedly, the effects of ATP(ext) at high concentration were antagonistic to steroid-induced apoptosis. Described here, the properties of ATP(ext) and adenosine are consistent with their involvement in the regulation of T cell development due to differential expression and signaling through purinergic receptors in different thymocyte subsets. The possible role of purinergic receptor signaling in T cell differentiation and adenosine deaminase SCID is discussed.
N-acetylcysteine and alpha-tocopherol reverse the inflammatory response in activated rat Kupffer cells.
Authors: Fox E S , Brower J S , Bellezzo J M , Leingang K A 
Published: December 2022

Abstract
Activation of the resident macrophage populations of the reticuloendothelial system is a key component of the complex pathophysiology of sepsis. Macrophage activation leads to production and secretion of inflammatory mediators such as cytokines, vasoactive substances, free radicals, and chemokines, which have been associated with high morbidity and mortality in the septic patient. The goal of the present study was to determine whether antioxidants could suppress Kupffer cell activation at points beyond the initiation of activation. Kupffer cells were studied since they are central to the clearance of bacteria and endotoxins, and have been associated with hepatocellular dysfunction in sepsis. Cells were activated with 10 ng/ml LPS for various times whereupon N-acetylcysteine (30 mM) and alpha-tocopherol (50 microM) were added. Steady state levels of cytokine mRNA, activation of nuclear factor-kappaB, and TNF-alpha secretion were determined when expression was maximal in control cells. The results of this study show that antioxidants can be used to suppress Kupffer cell activation at points beyond the initiation of activation. Furthermore, we show that N-acetylcysteine-mediated inhibition of activation requires secondary protein synthesis, but does not modulate IkappaB-alpha mRNA expression. The inhibitory effect of these drugs occurs at the very earliest steps of the LPS signal transduction cascade as it is currently understood. The results of the present study suggest that the inflammatory response to sepsis may be controlled through appropriate antioxidant therapy.
Up-regulation of cytokine mRNA, adhesion molecule proteins, and MHC class II proteins in salivary glands of TGF-beta1 knockout mice: MHC class II is a factor in the pathogenesis of TGF-beta1 knockout mice.
Authors: Nakabayashi T , Letterio J J , Geiser A G , Kong L , Ogawa N , Zhao W , Koike T , Fernandes G , Dang H , Talal N 
Published: December 2022

Abstract
Mice homozygous for a disrupted TGF-beta1 allele develop multiple lymphoproliferative disorders similar to those seen in the pseudolymphoma of Sjögren's syndrome. At 2 wk of age, these TGF-beta1 mutant mice begin to develop wasting syndrome and die at around 4 to 5 wk of age. We studied salivary glands from symptomatic mutant mice &gt;14 days of age. Reverse transcriptase-PCR analysis showed up-regulation of proinflammatory cytokine genes such as IL-1alpha, IL-1beta, IL-2, IL-4, IL-6, IL-10, and IFN-gamma in these mutant mice. Enhanced expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM-1), and MHC class II as well as CD4-positive T lymphocyte infiltration was detected by immunostaining. To elucidate the role of MHC class II, salivary glands from TGF-beta1/MHC class II double knockout mice were used to investigate the expression of adhesion molecules and MHC class II. In spite of the existence of basal intercellular adhesion molecule-1 expression on vessels, there was neither MHC class II expression, enhanced vascular cell adhesion molecule-1 expression, nor lymphocytic infiltration in the salivary glands. These results suggest that MHC class II plays a significant role in the pathogenesis of TGF-beta1 mutant mice. Although the mechanism that initiates multiple inflammatory diseases in these mice remains unclear, the context reported here would provide insight into the immunopathology of Sjögren's syndrome.
Molecular cloning, chromosomal localization, expression, and functional characterization of the mouse analogue of human CD59.
Authors: Powell M B , Marchbank K J , Rushmere N K , van den Berg C W , Morgan B P 
Published: December 2022

Abstract
We have previously described the isolation and cloning of the rat analogue of the human complement inhibitor CD59 (hCD59). Using the rat CD59 (rCD59) coding region as probe, we have isolated positive cDNAs from a mouse kidney cDNA library. Sequence analysis of these clones indicated that they contained an open reading frame encoding a 124 amino acid protein. Comparisons with the known sequences of hCD59 and rCD59 suggested that the clones contained a full-length cDNA encoding the mouse analogue of CD59 (mCD59). The cDNA encoded a 81-bp 5'-flanking region, a 23 amino acid NH2-signal peptide, a 101 amino acid coding region including putative N-glycosylation sites and a glycosyl phosphatidylinositol (GPI) anchoring signal, and approximately 0.8 kb 3'-untranslated flanking region. Reverse transcriptase PCR revealed the presence of mCD59 mRNA in all mouse tissues examined. The gene for mCD59 was mapped by fluorescence in situ hybridization to the E2-E4 region of mouse chromosome 2, a region that includes areas syntenous with the location of the human CD59 gene on chromosome 11p13. Expression of mCD59 in a CD59-negative human cell line conferred protection against lysis by complement from rodent, human, and several other species, confirming that mCD59 was the functional analogue of hCD59 and that function was not species restricted. The expressed protein was glycosyl phosphatidylinositol anchored as demonstrated by its partial removal from U937 cells on treatment with phosphatidylinositol-specific phospholipase C. Abs raised against the expressed protein demonstrated the presence of mCD59 on all mouse blood cell types and on several mouse cell lines and neutralized function of mCD59 on mouse E and expressed on U937. Western blot analysis revealed that both expressed and endogenous mCD59 had a molecular mass of 22 to 24 kDa.
Response to local inflammation of IL-1 beta-converting enzyme- deficient mice.
Authors: Fantuzzi G , Ku G , Harding M W , Livingston D J , Sipe J D , Kuida K , Flavell R A , Dinarello C A 
Published: December 2022

Abstract
IL-1 beta-converting enzyme (ICE) cleaves pro-IL-1 beta to the mature, released form. Although other proteases can process pro-IL-1 beta, ICE-deficient (ICE -/-) mice do not release mature IL-1 beta in response to endotoxin. The purpose of our study was to investigate the response of ICE -/- mice in two models of local inflammation, turpentine-induced tissue damage and zymosan-induced peritonitis. No differences were observed in the development of the systemic acute phase response after turpentine administration between wild-type and ICE -/- mice, but this response was completely impaired in IL-1 beta -/- mice. Accordingly, the levels of mature IL-1 beta produced in response to turpentine did not differ between wild-type and ICE -/- mice. In contrast, following zymosan-induced peritonitis, the levels of mature IL-1 beta were significantly lower in ICE -/- mice. This was associated with a 50% decrease in cellular infiltrate in ICE -/- mice compared with that in wild-type controls. The reduced production of zymosan-induced mature IL-1 beta in ICE -/- mice was also observed from cultured peritoneal or spleen cells. Our results demonstrate that in turpentine-induced tissue necrosis, precursor IL-1 beta is processed by non-ICE proteases, but in complement-mediated inflammation, ICE participates in the processing of the IL-1 beta precursor.
Regulation of IFN-alpha/beta, MxA, 2',5'-oligoadenylate synthetase, and HLA gene expression in influenza A-infected human lung epithelial cells.
Authors: Ronni T , Matikainen S , Sareneva T , Melén K , Pirhonen J , Keskinen P , Julkunen I 
Published: December 2022

Abstract
The epithelial cells of the respiratory tract are the primary sites of virus replication in influenza A virus infections. We infected human alveolar epithelium-like A549 cells and fibroblast-like human fetal lung (HFL1) cells with a pathogenic influenza A virus (A/Beijing/353/89), and studied the kinetics of infection and the expression of host IFN-alpha/beta, MxA, OAS (2',5'-oligoadenylate synthetase), and HLA class I and II genes. Viral mRNA and protein synthesis was clearly seen in virus-infected lung cells. A549 and HFL1 cells produced only small amounts of IFN-alpha/beta, whereas virus-infected macrophages produced type I IFN very efficiently. The kinetics of IFN-beta gene expression in A549 cells was rapid, as shown by reverse-transcriptase PCR, and IFN-beta mRNA expression levels correlated well to the kinetics of nuclear factor-kappa B transcription factor activation. In influenza A virus-infected A549 and HFL1 cells, MxA gene induction was mediated by IFN-alpha/beta released into the cell culture supernatant, and was prevented by anti-type I IFN Abs. HLA class I Ag expression, which could be activated by IFN in noninfected A549 and HFL1 cells, was not induced in these cells by virus infection. The results suggest that type I IFN are essential for the activation of the antiviral response in lung epithelial cells.
A novel role for B cells in early protective immunity to an intracellular pathogen, Francisella tularensis strain LVS.
Authors: Culkin S J , Rhinehart-Jones T , Elkins K L 
Published: December 2022

Abstract
Normal BALB/cByJ mice given a sublethal infection of Francisella tularensis strain LVS survived 10(6) LD50s of lethal challenge given only 3 days later. Here, we determine the cell types responsible for this very strong early protective immunity. Early protection is observed in athymic nu/nu mice but not fully immunodeficient scid mice, implicating a lymphocyte in this response. Using scid mice that are reconstituted with various purified cell subpopulations, as well as mice with genetically targeted disruptions in lymphocyte subpopulations (knockout mice), we demonstrate that strong early protection is highly dependent on B cells. This protective mechanism, which limits bacterial growth in the organs of the reticuloendothelial system very quickly after infection, requires IFN-gamma but is unlikely to involve specific Ab.
Calpain, an upstream regulator of thymocyte apoptosis.
Authors: Squier M K , Cohen J J 
Published: December 2022

Abstract
Apoptosis is the common phenotype of programmed or physiologic cell death, the process used to remove excess or defunct cells during normal tissue maintenance. One of the most studied cell types with respect to apoptosis is the immature T cell from the thymus, which activates its death program in response to an enormous variety of agents. Previously, our group implicated the calcium-dependent cytosolic protease calpain as a participant in thymocyte apoptosis initiated by glucocorticoids or irradiation. We found that the calpain inhibitors N-acetyl-leu-leu-norleucinal (calpain inhibitor I) and carbenzoxy-val-phe-H (MDL 28,170) prevented dexamethasone-induced apoptosis of thymocytes; in this study, we show that two additional calpain active site inhibitors, L-3-carboxy-trans-2,3-epoxypropionyl-leu-amido-(4-guanidinio )butane ethyl ester (E64d) and carbenzoxy-leu-leu-tyr-CHN2 (ZLLY-CHN2), also prevent apoptosis in this model. Three compounds that inhibit lysosomal cysteine proteases, carbenzoxy-tyr-ala-CHN2 (ZYA-CHN2), ammonium chloride, and chloroquine, do not block apoptosis, indicating that the effect of the calpain inhibitors is not due to cross-inhibition of lysosomal proteases. In addition, I-benzyl-CH=C(SH)COOH (PD150606), a calpain inhibitor directed toward the calcium binding sites of calpain, also prevents apoptosis. Calpain is necessary for other models of programmed cell death that require new gene expression (induction models), those following treatment of thymocytes with the calcium ionophore A23187, ionomycin, or forskolin. However, two models of thymocyte apoptosis that do not require new gene expression (transduction models), those triggered by heat shock and by valinomycin, are calpain independent, as is calcium-triggered DNA fragmentation in isolated thymocyte nuclei. These experiments suggest an upstream regulatory role for calpain in a pathway to thymocyte apoptosis common to several inducers.
Mast cell Fc epsilonRI expression in the rat intestinal mucosa and tongue is enhanced during Nippostrongylus brasiliensis infection and can be up-regulated by in vivo administration of IgE.
Authors: Shaikh N , Rivera J , Hewlett B R , Stead R H , Zhu F G , Marshall J S 
Published: December 2022

Abstract
The activation of rodent and human mast cells can occur through the cross-linking of tetrameric IgE receptors each containing single alpha- and beta- and two gamma-subunits. However, the factors that regulate the in vivo expression of Fc epsilonRI are poorly understood. We have examined the expression of the Fc epsilonRI beta-subunit in the Nippostrongylus brasiliensis (Nb)-induced mode l of rat intestinal inflammation. We developed a double-staining technique for mast cell granules (Alcian blue) and the beta-subunit of Fc epsilonRI. The intensity of immunohistochemical staining per mast cell was quantified using an image analysis system. Jejunal and tongue mast cells of Lewis rats were visible by Alcian blue staining before Nb infection, but they expressed very low levels of beta-subunit as assessed by immunohistochemical staining. These levels were increased by day 11 postinfection and reached a maximum at day 14. Since serum IgE levels correlated well with the degree of beta-subunit expression, we investigated whether the observed enhancement of receptor expression might occur through the stabilization of receptor complexes by IgE. Therefore, Lewis rats were treated with myeloma IgE, and beta-subunit expression was examined. In both tongue and jejunal tissue, a significant rise in beta-subunit expression was observed in response to IgE injection, although levels of beta-subunit expression were not as high as those observed in Nb-infected animals. The increase in beta-subunit expression was accompanied by an increase in the amount of mast cell-associated IgE. These observations may have important implications for the regulation of IgE receptor expression during disease.
Cytokine-in-adjuvant steering of the immune response phenotype to HIV-1 vaccine constructs: granulocyte-macrophage colony-stimulating factor and TNF-alpha synergize with IL-12 to enhance induction of cytotoxic T lymphocytes.
Authors: Ahlers J D , Dunlop N , Alling D W , Nara P L , Berzofsky J A 
Published: December 2022

Abstract
To enhance and steer immune responses to synthetic peptide vaccines toward selected functional types and to understand the cooperative action of cytokines in fine-tuning the immune response, we attempted to influence the in vivo cytokine environment by delivering cytokines directly to the microenvironment in which the immune response is initiated. Here we study the effects of IL-2, IL-4, IL-7, IL-1beta, IL-12, IFN-gamma, TNF-alpha, and granulocyte-macrophage CSF (GM-CSF) incorporated with peptide in adjuvant on a variety of responses elicited: CTL, T cell proliferation, cytokine production and message, and Ab isotype. We show GM-CSF to be the single most effective cytokine for enhancing both cellular and humoral immunity to two previously characterized HIV-1 MN vaccine constructs. Novel synergies were also detected. GM-CSF synergized with IL-12 for CTL induction in BALB/c mice concomitant with suppression of Th2 cytokines IL-4 and IL-10. TNF-alpha also synergized with IL-12, but by a different mechanism, inducing IFN-gamma production in BALB/c mice and thus shifting the response to a Th1 phenotype. The results presented here suggest that in addition to IL-2, optimum induction of CD8+ CTL in vivo requires a combination of cytokines, including GM-CSF (probably acting to enhance Ag presentation and CD4+ cell help) and IL-12 (steering the Th response toward Th1 cytokines).
Presence of B cell progenitors in the thymus.
Authors: Mori S , Inaba M , Sugihara A , Taketani S , Doi H , Fukuba Y , Yamamoto Y , Adachi Y , Inaba K , Fukuhara S , Ikehara S 
Published: December 2022

Abstract
We characterize B cell progenitors in the thymus. Although mature thymic B cells are surface Ig+, B220(high), but CD43-, B cell progenitors in the thymus were found to be slg-, B220(med), and CD43+. Most progenitors showed rearranged Ig D-J and V-D-J patterns when DNA from sorted B cell progenitors was amplified by PCR, blotted, and probed. When B cell progenitors were purified from the thymus and injected intrathymically into Ig heavy chain (Igh) allotype-disparate recipients, B cells bearing donor-type Igh6 were detected in the thymus but not in the periphery. Thymic B cells generated from these progenitors were CD5+ cells, although there was a broad range of expression of CD5 molecules. Furthermore, B cells purified from thymus that had been inoculated with B cell progenitors were able to differentiate into Ab-forming cells under the influence of CD40 ligand plus IL-10, and secreted IgM with donor Igh6 allotype. We thus clarified the existence of B cell progenitors in the thymus and also characterized the surface markers and their developmental functions.
Kinase-independent potentiation of B cell antigen receptor-mediated signal transduction by the protein tyrosine kinase Src.
Authors: Lin J , Tao J , Dyer R B , Herzog N K , Justement L B 
Published: December 2022

Abstract
Signal transduction mediated by the B cell Ag receptor involves the activation of multiple protein tyrosine kinases that are members of the Src family (i.e., Fyn, Lyn, Blk, Lck). To determine whether members of the Src family possess common physical and/or enzymatic properties that enable them to potentiate signal transduction via the B cell Ag receptor, we expressed the protein tyrosine kinase Src in the B lymphoma cell line K46-17 mu m lambda. Based on coprecipitation analysis and two-color immunofluorescence, this heterologous Src family kinase was observed to physically associate with the B cell Ag receptor. Additional experiments demonstrated that B cell Ag receptor cross-linking results in increased tyrosine phosphorylation and activation of Src. Several parameters of B cell activation, including tyrosine phosphorylation of intracellular substrates, calcium mobilization, and transcription factor activation, were potentiated in cells that expressed Src when compared with control cells. To determine whether potentiation of Ag receptor-mediated signaling by Src was dependent on its catalytic activity, a kinase-deficient form of Src was expressed in K46-17 mu m lambda cells. Transfectants expressing kinase-deficient Src exhibited an enhanced responsiveness to stimulation through the B cell Ag receptor that was comparable with transfectants expressing wild-type Src. Additionally, kinase-deficient Src was observed to associate with the endogenous kinase Lyn in an activation-dependent manner. These findings indicate that members of the Src family may potentiate Ag receptor-mediated signaling via a kinase-independent mechanism(s) that involves amplification of kinase recruitment to the Ag receptor activation complex.
A family of human lymphoid and myeloid Ig-like receptors, some of which bind to MHC class I molecules.
Authors: Borges L , Hsu M L , Fanger N , Kubin M , Cosman D 
Published: December 2022

Abstract
Leukocyte Ig-like receptors (LIRs) are a newly discovered family of immunoreceptors expressed on monocytes and B cells and at lower levels on dendritic cells and NK cells. The amino acid sequences in the extracellular regions of eight of these receptors show between 63 and 84% identity to the prototypic LIR-1 sequence. LIRs contain either two or four Ig domains and fall into three classes: those with cytoplasmic domains containing two, three, or four immunoreceptor tyrosine-based inhibitory motif-like motifs; those with a short cytoplasmic domain and no immunoreceptor tyrosine-based inhibitory motif-like motifs; and those with no transmembrane domain represented by a single LIR molecule that is presumably secreted. The LIRs are structurally related to the human Fc(alpha)R and the killer inhibitory receptors and map to the same region of chromosome 19 as these genes. Like killer inhibitory receptors, at least two LIRs bind to MHC class I Ags, but their different cellular distribution suggests a distinct role in immune system modulation.