bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modulation of monocyte signaling and pore formation in response to agonists of the nucleotide receptor P2X7
Authors: Aga Mini , Johnson Christopher J , Hart Arlene P , Guadarrama Arturo G , Suresh M , Svaren John , Bertics Paul J , Darien Benjamin J 
Published: September 2022

AbstractPrevious reports about the nucleotide receptor P2X7, which exhibits ion channel and pore-forming activity and is known to promote IL-1β processing, have centered largely on its role in macrophage function, whereas its participation in monocyte activity has been unclear. However, because extracellular ATP has been shown to affect monocytes with respect to IL-1β release, we hypothesized that the P2X7 receptor is also present and functional in a subpopulation of blood monocytes. Flow cytometric analysis revealed that about 70% of monocytes isolated from normal human donors expressed the P2X7 receptor. Activation of P2X7 receptor-associated pore formation by the agonist BzATP resulted in a 9- to 15-fold increase in the uptake of the membrane-impermeant fluorescent dye YO-PRO, and this dye uptake is markedly inhibited by the P2X7 receptor antagonists KN-62 and oATP. Evidence supporting the presence of the functional P2X7 receptor in monocytes also includes the observation that BzATP exposure results in a dose-dependent increase in the activation of mitogen-activated 2protein kinases and the nuclear translocation of the transcription factor NF-κB in human monocytes and in THP-1 human monocytic cells. Furthermore, treatment of monocytes with BzATP induced the expression of cyclooxygenase-2 (COX-2) and tissue factor, which are two important endpoints that have not been previously shown to be regulated by nucleotide receptor action in monocytes. Together, these data indicate that a subpopulation of human monocytes express P2X7 receptors that are functional with respect to pore formation, signal transduction, and mediator production, further supporting a key role for this nucleotide receptor in host immune responses.
Concanavalin-A-induced liver injury is severely impaired in mice deficient in P-selectin
Authors: Massaguer Anna , Perez-del-Pulgar Sofía , Engel Pablo , Serratosa Joan , Bosch Jaime , Pizcueta Pilar 
Published: September 2022

AbstractP-selectin (CD62P) is an adhesion molecule that mediates the initial attachment of leukocytes to activated platelets and endothelial cells in damaged tissues. We evaluated the role of P-selectin in concanavalin A (Con A)-induced hepatitis, a model characterized by CD4+ T cell activation and infiltration of the liver. Con A injection induced transient P-selectin expression on hepatic venules and platelets. Mice lacking P-selectin showed impaired lymphocyte adhesion to liver venules and sinusoids, a striking reduction in intrasinusoidal occlusion, and decreased lymphocyte infiltration of liver parenchyma. The reduction in transaminase levels and the almost complete abolition of necrotic injury demonstrated that liver damage was lower in P-selectin-deficient mice. In wild-type mice, pretreatment with the P-selectin-blocking monoclonal antibody attenuated the sinusoidal occlusion and reduced the rise in transaminases after Con A treatment. These results implicate P-selectin in the development of Con A-induced liver injury and reveal the protective effect of blocking P-selectin in this hepatitis.
Proteoglycans guide SDF-1-induced migration of hematopoietic progenitor cells
Authors: Netelenbos Tanja , Zuijderduijn Suzanne , van den Born Jacob , Kessler Floortje L , Zweegman Sonja , Huijgens Peter C , Dräger Angelika M 
Published: September 2022

AbstractStromal cell-derived factor-1 (SDF-1) is a chemoattractant involved in hematopoietic progenitor cell (HPC) trafficking to the bone marrow. We studied the role of bone marrow endothelial proteoglycans (PGs) in SDF-1-mediated migration of HPC using a transwell assay. A subclone of progenitor cell line KG-1 (KG-1v) was used, displaying CXCR4-dependent transmigration. Cell surface PGs on bone marrow endothelial cell line 4LHBMEC did not mediate SDF-1-induced transendothelial migration. In contrast, transwell filters precoated with various glycosaminoglycans (GAGs) enhanced migration toward SDF-1. SDF-1-induced migration was reduced by degradation of heparan sulfate in subendothelial matrix produced by 4LHBMEC. The stimulating effect of GAGs was caused by the formation of a stable haptotactic SDF-1 gradient, as SDF-1 bound to immobilized GAGs and triggered migration. Soluble heparan sulfate enhanced SDF-1-induced migration dose-dependently, suggesting that SDF-1-heparan sulfate complexes optimized SDF-1 presentation. In conclusion, we provide evidence that PGs in the subendothelial matrix establish an SDF-1 gradient guiding migrating HPC into the bone marrow.
Population analysis of CD4+ T cell chemokine receptor transcript expression during in vivo type-1 (mycobacterial) and type-2 (schistosomal) immune responses
Authors: Chiu Bo-Chin , Shang Xiao-Zhou , Stolberg Valerie R , Komuniecki Eric , Chensue Stephen W 
Published: September 2022

AbstractChemokine receptor transcripts were defined among CD4+ T cells in lymph nodes of mice with type-1 and type-2 inflammation, respectively, elicited by mycobacterial and schistosomal Ag. CXCR3 and CCR6 transcripts were biased to type-1, and CCR4 transcripts increased in type-1 and type-2 populations. CCR3 and CCR5 signals were too weak to establish differences. CCR8 transcripts were not increased among unstimulated populations. Compared to naïve, type-1 and type-2 populations had reduced CCR7 and enhanced CXCR5 transcripts, consistent with a shift to memory cells. Subset depletion revealed that transcript expression was induced among CD44+ memory T cells. Surprisingly, CCR3 transcripts were enriched among CD44lo fractions. Ag stimulation augmented CXCR3, CCR4, and CCR8 but down-regulated CCR6 and CXCR5. CCR4 showed association with IFN-γ- and IL-4-producing cells, but other receptor transcripts were expressed among IFN-γ/IL-4 negative memory T cells. These studies provide several novel findings regarding Th cell chemokine receptor expression in vivo.
Identification of human cysteine-rich secretory protein 3 (CRISP-3) as a matrix protein in a subset of peroxidase-negative granules of neutrophils and in the granules of eosinophils
Authors: Udby Lene , Calafat Jero , Sørensen Ole E , Borregaard Niels , Kjeldsen Lars 
Published: September 2022

AbstractCysteine-rich secretory protein 3 (CRISP-3; also known as SGP28) was originally discovered in human neutrophilic granulocytes. We have recently developed a sensitive sandwich enzyme-linked immunosorbent assay for CRISP-3 and demonstrated the presence of CRISP-3 in exocrine secretions. To investigate the subcellular localization and mobilization of CRISP-3 in human neutrophils, we performed subcellular fractionation of resting and activated neutrophils on thee-layer Percoll density gradients, release-studies of granule proteins in response to different secretagogues, and double-labeling immunogold electron microscopy. CRISP-3 was found to be localized in a subset of granules with overlapping characteristics of specific and gelatinase granules and mobilized accordingly, thus confirming the hypothesis that peroxidase-negative granules exist as a continuum from specific to gelatinase granules regarding protein content and mobilization. CRISP-3 was found to be a matrix protein, which is stored in granules as glycosylated and as unglycosylated protein. The subcellular distribution of the two forms of CRISP-3 was identical. In addition, CRISP-3 was found as a granule protein in eosinophilic granulocytes. The presence of CRISP-3 in peroxidase-negative granules of neutrophils, in granules of eosinophils, and in exocrine secretions indicates a role in the innate host defense.
Human eosinophils express and release IL-13 following CD28-dependent activation
Authors: Woerly Gaetane , Lacy Paige , Ben Younes Amena , Roger Nadine , Loiseau Sylvie , Moqbel Redwan , Capron Monique 
Published: September 2022

AbstractHuman eosinophils produce a large number of cytokines, including immunoregulatory cytokines. Given that eosinophils store and release interleukin (IL)-4, a key cytokine in the pathogenesis of allergic inflammation, and that IL-4 and IL-13 share common biological functions, we investigated the possibility that IL-13 may be synthesized by these cells. Using flow cytometry and immunocytochemistry, we show that eosinophils synthesize and store IL-13. Granule localization was demonstrated after subcellular fractionation, and IL-13 immunoreactivity was localized to crystalloid, granule-enriched fractions. Furthermore, electron microscopic analyses specifically localized IL-13 to the dense cores of bicompartmental secondary granules. Upon CD28 ligation, IL-13 was released by eosinophils, whereas a combination of CD28 and immunoglobulin A complexes resulted in decreased IL-13 secretion. Furthermore, eosinophil-derived IL-13 exerts a biological effect, inducing CD23 expression on B cells. By having the capacity to synthesize and release IL-13, eosinophils may participate in the development and maintenance of the T helper cell type 2 response, a prominent feature of allergic diseases.
Dissociated ROS production and ceramide generation in sulfasalazine-induced cell death in Raw 264.7 cells
Authors: Salh B , Assi K , Huang S , O'Brien L , Steinbrecher U , Gómez-Muñoz A 
Published: September 2022

AbstractSulfasalazine (SSZ) is a drug used in inflammatory bowel disease, whose precise mechanism of action remains to be clarified. Here, we report that incubation of Raw 264.7 cells with SSZ but not salicylates [acetylsalicylic acid (ASA), 4-aminosalicylic acid (4-ASA), and 5-ASA] causes a mixed apoptotic and necrotic form of cell death. In contrast to its metabolites, sulfapyridine and 5-ASA, SSZ exposure in Raw 264.7 cells resulted in a threefold increase in ceramide generation, as well as a robust production of reactive oxygen species (ROS). However, inhibition of ceramide production by fumonisin B1 failed to attenuate cell death. Preincubation with catalase, cyclosporin A (CsA), and bongkrekic acid attenuated ROS production. When dead cells were quantified for apoptotic versus necrotic cell death, catalase and N-acetylcysteine reproducibly attenuated apoptosis, whereas CsA, in addition to reducing apoptosis, was observed to dramatically enhance necrosis. In conclusion, the cell-death response induced by SSZ in Raw 264.7 cells involves ROS in the apoptotic limb but is independent of ceramide formation.
Interleukin-2 family cytokines stimulate phosphorylation of the Pro-Ser-Pro motif of Stat5 transcription factors in human T cells: resistance to suppression of multiple serine kinase pathways
Authors: Nagy Zsuzsanna S , Wang Yuling , Erwin-Cohen Rebecca A , Aradi János , Monia Brett , Wang Li Hua , Stepkowski Stanislaw M , Rui Hallgeir , Kirken Robert A 
Published: September 2022

AbstractSignal transducer and activator of transcription (Stat)5a and Stat5b are critical for normal immune function. Progression of T cells through G1-S phase of cell cycle requires T cell receptor (TCR)- and/or cytokine-inducible tyrosine phosphorylation of Stat5a/b. Stat5a/b may also, in a cell-dependent manner, be constitutively or cytokine-inducibly phosphorylated on a Pro-Ser-Pro (PSP) motif located within the transcriptional activation domain. Phosphorylation of the PSP motif is needed for maximal transcriptional activation by Stat5, at least in certain promoter contexts. The basal and cytokine-inducible serine phosphorylation state of Stat5a/b has not been determined in T cells. Using primary human T cells and T lymphocytic cell lines coupled with novel phospho-specific antibodies to this conserved phosphoserine motif in Stat5a or Stat5b, we report that: Stat5a and Stat5b were unphosphorylated on the PSP motif under basal conditions and became markedly phosphorylated in response to several T cell growth factor stimuli, including interleukin (IL)-2, -7, -9, and -15 and phorbol ester 12-myristate 13-acetate but not TCR engagement; inducible Stat5a/b serine phosphorylation differed quantitatively and temporally; and Stat5a/b serine phosphorylation was, in contrast to inducible Stat3 serine phosphorylation, insensitive to inhibitors of mitogen-activated protein kinase, phosphatidylinositol-3 kinase, and mammalian target of rapamycin or deletion of Raf-A, -B, or -C by antisense oligonucleotides. We conclude that IL-2 family cytokines tightly control Stat5 serine phosphorylation through a kinase distinct from the Stat3 serine kinase.
Inducible expression of an antimicrobial peptide of the innate immunity in polymorphonuclear leukocytes
Authors: Tomasinsig Linda , Scocchi Marco , Di Loreto Carla , Artico Daria , Zanetti Margherita 
Published: September 2022

AbstractEpithelia- and leukocyte-associated antimicrobial peptides provide immediate protection against microbial infections by rapidly inactivating potential pathogens. Bac5 is a member of the cathelicidin family of antimicrobial peptides and is stored in the cytoplasmic granules of bovine neutrophils. We investigated the expression of this gene in airway and intestine, and although the gene was not found to be locally expressed in these tissues, a strong Bac5 induction signal was detected by in situ hybridization in neutrophils infiltrating infected lung, consistent with expression of this gene in activated neutrophils. The Bac5 gene was also induced in bovine peripheral neutrophils stimulated with Escherichia coli or purified lipopolysaccharide (LPS) but not in other blood cells and in resting neutrophils. The levels of Bac5 mRNA increased at 12–24 h post-stimulation, and a dose-dependent increase in Bac5 expression was determined in the presence of increasing amounts of LPS. A metabolically labeled product with a molecular weight compatible with that of proBac5 was immunoprecipitated from cell-free media of stimulated neutrophils, suggesting that the newly synthesized polypeptide is released extracellularly. Collectively, these results provide the first evidence that fully differentiated neutrophils are capable of de novo synthesis and secretion of a granule-associated antimicrobial peptide.
Granulocyte macrophage-colony stimulating factor delays neutrophil apoptosis and primes its function through Ia-type phosphoinositide 3-kinase
Authors: Yasui Kozo , Sekiguchi Yukio , Ichikawa Motoki , Nagumo Haruo , Yamazaki Takashi , Komiyama Atsushi , Suzuki Harumi 
Published: September 2022

AbstractPhosphoinositide 3-kinases (PI3Ks) constitute a family of lipid kinases that regulate an array of fundamental cellular responses by neutrophils [polymorphonuclear leukocytes (PMN)]. p85α Gene-disrupted mice were used to help accurately identify the physiological role of the PI3K isoform in PMN activation in the presence of granulocyte macrophage-colony stimulating factor (GM-CSF). PMN from the p85α−/− mice showed normal cellular motility, and the quantity of superoxide anion (O2−) produced by PMN upon stimulation with formyl-Met-Leu-Phe did not significantly differ between p85α−/− and wild-type mice under controlled conditions. In p85α−/− mice, the O2− production by PMN was enhanced (primed) by GM-CSF when stimulated with the chemotactic peptide but to a significantly lesser extent than in wild-type mice. In addition, no major GM-CSF-dependent delay in apoptosis or activation of Akt protein phosphorylation by GM-CSF was observed in the p85α−/− mice. In terms of targeting strategy, however, the mutation actually expressed a small amount of Ia-type (p85α-regulated) PI3K activity (partially abrogated) in the mice. These results demonstrate that Ia-type PI3K plays a critical role in the enhancement of the GM-CSF-modulated function of PMN and in the PI3K/Akt pathway-dependent delay of PMN apoptosis.
Molecular profiling of the role of the NF-κB family of transcription factors during alloimmunity
Authors: Finn Patricia W , He Hongzhen , Ma Chunyan , Mueller Thomas , Stone James R , Liou Hsiou-Chi , Boothby Mark R , Perkins David L 
Published: September 2022

AbstractAllograft rejection involves a complex network of multiple immune regulators and effector mechanisms. In the current study, we focused on the role of nuclear factor (NF)-κB/Rel. Previous studies had established that deficiency of the p50 NF-κB family member prolonged allograft survival only modestly. However, because of its crucial role in signal transduction in inflammatory and immune responses, we hypothesized that other NF-κB/Rel family members may produce more profound effects on alloimmunity. Therefore, in addition to p50, we analyzed the role of c-Rel, which is expressed predominantly in lymphocytes. Also, to investigate NF-κB activation in T cells, we examined transgenic mice that express a transdominant inhibitor of NF-κB [IκB(ΔN)] regulated by a T cell-restricted promoter. Allograft survival was prolonged indefinitely in the c-Rel-deficient and IκB(ΔN)-transgenic recipients. To determine the molecular basis of NF-κB modulation of rejection, we analyzed a panel of 58 parameters including effector molecules, chemokines, cytokines, receptors, and cellular markers using hierarchical clustering algorithms and self-organizing maps in p50−/−, c-Rel−/−, and IκB(ΔN)-transgenic, experimental groups plus allogeneic-, syngeneic-, and lymphocyte-deficient (alymphoid) control groups. Surprisingly, profiles of gene expression in the c-Rel recipients (which have indefinite graft survival) were similar to the p50−/− and allogeneic recipients (which rapidly reject grafts). As expected, gene expression in the IκB(ΔN) recipients (which also have indefinite graft survival) was similar to profiles of nonrejecting syngeneic and alymphoid recipients. Importantly, self-organizing maps identified a small subset of genes including several chemokine receptors and cytokines with expression profiles that correlate with graft survival. Thus, our results demonstrate a crucial role for NF-κB in acute allograft rejection, identify different molecular mechanisms of rejection by distinct NF-κB family members, and identify a small subset of inducible genes whose inhibition is linked to graft acceptance.
Dendritic cell maturation and IL-12 synthesis induced by the synthetic immune-response modifier S-28463
Authors: Fogel Mirjana , Long Julie A , Thompson Philip J , Upham John W 
Published: September 2022

AbstractDendritic cells (DC) play a prominent role in the development of T cell-immune responses to antigens and have a key influence over the differentiation of naive T cells into T helper cell type 1 (Th1) or Th2 effector cells. Consequently, there is considerable interest in pharmacological agents that might alter DC function and thereby modulate allergic inflammation. We examined the effects of the imidazoquinoline S-28463 on human monocyte-derived DC (Mo-DC) cultured in granuloctye macrophage-colony stimulating factor and interleukin (IL)-4 to determine whether this agent might be useful in augmenting Th1 immunity. We determined that S-28463 acts directly on Mo-DC, inducing their maturation and enhancing their capacity to present antigen. Importantly, S-28463 strongly induces synthesis of bioactive IL-12 p70, a key Th1-polarizing cytokine. We also examined the ability of S-28463 to modulate DC function in the context of transforming growth factor-β (TGF-β), a negative, immunoregulatory cytokine released from the epithelium of nonlymphoid organs. S-28463 was able to induce IL-12 synthesis even in the presence of TGF-β, whereas lipopolysaccharide (LPS) + interferon-γ-stimulated DC did not produce IL-12 in the presence of TGF-β. Taken together, our findings suggest that S-28463 and LPS are exerting their effects via distinctly different pathways and indicate that S-28463 may be beneficial in polarizing immune responses toward a Th1 response.
Pertussis toxin and the adenylate cyclase toxin fromBordetella pertussisactivate human monocyte-derived dendritic cells and dominantly inhibit cytokine production through a cAMP-dependent pathway
Authors: Bagley Kenneth C , Abdelwahab Sayed F , Tuskan Robert G , Fouts Timothy R , Lewis George K 
Published: September 2022

AbstractPertussis toxin (PT) and adenylate cyclase toxin (AT) are AB enterotoxins produced by Bordetella pertussis. PT is a powerful mucosal adjuvant whose cellular target and mechanism of action are unknown; however, emerging evidence suggests that dendritic cells (DC) may be a principal adjuvant target of PT. Here, we investigate the mechanism underlying the effects of these toxins on human monocyte-derived DC (MDDC) in vitro. We found that the effects of PT and AT on MDDC, including maturation, are mediated by cyclic adenosine monophosphate (cAMP). In this regard, adenosine 5′-diphosphate-ribosylation-defective derivatives of PT failed to induce maturation of MDDC, whereas dibutyryl-cAMP (d-cAMP) and Forskolin mimic the maturation of MDDC and dominant inhibition of cytokine production induced by these toxins. Also, cAMP-dependent kinase inhibitors blocked the ability of PT, AT, d-cAMP, and Forskolin to activate MDDC. Taken together, these results show that the effects of PT and AT on MDDC are mediated strictly by cAMP.
HMGB1 as a DNA-binding cytokine
Authors: Andersson Ulf , Erlandsson-Harris Helena , Yang Huan , Tracey Kevin J 
Published: September 2022

AbstractHMGB1 (high mobility group box chromosomal protein 1), historically known as an abundant, nonhistone architectural chromosomal protein, is extremely conserved across species. As a nuclear protein, HMGB1 stabilizes nucleosomes and allows bending of DNA that facilitates gene transcription. Unexpectedly, recent studies identified extracellular HMGB1 as a potent macrophage-activating factor, signaling via the receptor for advanced glycation end-products to induce inflammatory responses. It is released as a late mediator during inflammation and participates in the pathogenesis of systemic inflammation after the early mediator response has resolved. HMGB1 occupies a critical role as a proinflammatory mediator passively released by necrotic but not apoptotic cells. Necrotic Hmgb1−/− cells mediate minimal inflammatory responses. Stimulated macrophages actively secrete HMGB1 to promote inflammation and in turn, stimulate production of multiple, proinflammatory cytokines. HMGB1 mediates endotoxin lethality, acute lung injury, arthritis induction, activation of macrophages, smooth muscle cell chemotaxis, and epithelial cell barrier dysfunction. HMGB1 is structurally composed of three different domains: two homologous DNA-binding sequences entitled box A and box B and a highly, negatively charged C terminus. The B box domain contains the proinflammatory cytokine functionality of the molecule, whereas the A box region has an antagonistic, anti-inflammatory effect with therapeutic potential. Administration of highly purified, recombinant A box protein or neutralizing antibodies against HMGB1 rescued mice from lethal sepsis, even when initial treatment was delayed for 24 h after the onset of infection, establishing a clinically relevant therapeutic window that is significantly wider than for other known cytokines.