bluuebunny/crossref_metadata_2025_split huggingface dataset:
IL-2Rβ/IL-7Rα Doubly Deficient Mice Recapitulate the Thymic and Intraepithelial Lymphocyte (IEL) Developmental Defects of γc−/− Mice: Roles for Both IL-2 and IL-15 in CD8αα IEL Development
Authors: Porter Brian O. , Malek Thomas R. 
Published: January 2023

AbstractIL-7Rα-chain-deficient (IL-7Rα−/−) and common γ chain-deficient (γc−/−) mice both exhibit abnormal thymic and intestinal intraepithelial lymphocyte (IEL) development, but the developmental inhibition is not equivalent. In this report, we assessed whether the defects in T cell development associated with γc−/− mice were due to currently defined γc-dependent cytokines by cross-breeding IL-7Rα−/− mice to mice lacking either IL-2, IL-4, or IL-2Rβ. IL-2/IL-7Rα and IL-4/IL-7Rα double knockout (DKO) mice demonstrated equivalent thymic development to IL-7Rα−/− mice, whereas IL-2Rβ/IL-7Rα DKO mice, which lack IL-2, IL-7, and IL-15 signaling, displayed thymic T cell defects identical to γc−/− mice. Collectively, these data indicate that of the γc-dependent cytokines, only IL-7 and IL-15 contribute to the progression and production of thymic T cells. In the IEL, IL-7Rα−/− mice selectively lack CD8αα TCRγδ cells, whereas IL-2Rβ−/− mice show a significant reduction in all CD8αα cells. IL-2−/− and IL-2/IL-7Rα DKO mice demonstrated a reduction in CD8αα IELs to nearly the same extent as IL-2Rβ−/− mice, indicating that IL-2 functions in CD8αα IEL development. Moreover, IL-2Rβ/IL-7Rα DKO mice lacked nearly all TCR-bearing IEL, again recapitulating the phenotype of γc−/− mice. Thus, these data point to the importance of IL-2, IL-7, and IL-15 as the γc-dependent cytokines essential for IEL development.
The Differentiated State of Intestinal Lamina Propria CD4+ T Cells Results in Altered Cytokine Production, Activation Threshold, and Costimulatory Requirements
Authors: Hurst Stephen D. , Cooper Cristine J. , Sitterding Stephanie M. , Choi Jung-hee , Jump Robin L. , Levine Alan D. , Barrett Terrence A. 
Published: January 2023

Abstract
Intestinal lamina propria (LP) CD4+ T cells are memory-like effector cells that proliferate at relatively low levels and require high levels of TCR signaling and costimulation for full activation in vitro. To study LP CD4+ T cell functional potential we used DO11.10 TCR transgenic (Tg) mice specific for the class II MHC-restricted OVA323–339 peptide and nontransgenic BALB/c mice. Activation of LP Tg+ T cells with Ag using mucosal explants induced high levels of IL-2, IL-4, and IFN-γ. Culturing isolated LP cells with IL-12 enhanced IFN-γ production and down-regulated IL-4 and IL-2, whereas addition of IL-4 maintained IL-4 production without inhibiting IFN-γ production. Systemic administration of relatively high dose (HD; 100 nM) OVA323–339 peptide induced similar levels of bromodeoxyuridine (BrdU) incorporation by LP and splenic Tg+ T cells in vivo, whereas low dose (LD; 4.5 nM) peptide injections induced 4-fold greater levels of BrdU incorporation for LP compared with splenic Tg+ T cells. Coadministration of CTLA-4Ig reduced BrdU incorporation for splenic cells by 70% with HD and LD stimulation, but had little effect on LP responses to HD stimulation. Results of in vivo studies were confirmed in nontransgenic BALB/c mice using HD (200 μg) and LD (10 μg) anti-CD3 mAb+/− CTLA-4Ig. These results suggest that LP T cells are differentiated effector cells that respond at high levels when activated with relatively low levels of Ag- and B7-mediated costimulation in vivo. The reduced activation threshold of LP T cells may facilitate responses to low levels of Ag derived from mucosal pathogens.
Possible Involvement of Matrix Metalloproteinase-9 in Langerhans Cell Migration and Maturation
Authors: Kobayashi Yasunobu , Matsumoto Motonobu , Kotani Mayumi , Makino Taketoshi 
Published: January 2023

AbstractEpidermal Langerhans cells (LC) are potent dendritic cells in the induction of primary T cell-mediated immune responses in the skin. They capture foreign Ags and migrate to regional lymph nodes to carry and present these Ags to naive T cells. We investigated the role of matrix metalloproteinase-9 (MMP-9) in LC migration using an anti-MMP-9 mAb. Intradermal injection of anti-MMP-9 mAb before rhodamine B or oxazolone painting markedly inhibited these hapten-induced decreases in LC number in the epidermis and the accumulation of dendritic cells in the regional lymph nodes, indicating that MMP-9 plays some important roles in LC migration in the induction phase of contact sensitization. Treatment with anti-MMP-9 mAb also blocked the increase in cell size, dendrite development, and the enhanced expression of MHC class II Ags in LC induced by hapten painting. In addition, intradermal injection of purified MMP-9 induced marked increases in cell size, dendrite extension, and enhanced expression of MHC class II Ags in LC. These results strongly suggested that MMP-9 is involved not only in LC migration, but also in their morphological and phenotypic maturation in the skin.
Differential Impact of Substitution of Amino Acids 9–13 and 91–101 of Human CD14 on Soluble CD14-Dependent Activation of Cells by Lipopolysaccharide
Authors: Stelter Felix , Loppnow Harald , Menzel René , Grunwald Uwe , Bernheiden Martin , Jack Robert S. , Ulmer Artur J. , Schütt Christine 
Published: January 2023

AbstractThe soluble form of the endotoxin receptor CD14 is required for the LPS-induced activation of cells lacking membrane-bound CD14. It has been shown that a deletion mutant of human CD14 consisting of the N-terminal 152 amino acids has the capacity to mediate the stimulation of different cell types by LPS. To identify the structural domains of the molecule related to this functional property, we screened a set of alanine substitution mutants using CD14-negative U373 astrocytoma cells. We show that 3 of 18 soluble mutants of human CD14 failed to mediate the LPS-induced IL-6 production in U373 cells. These mutants were located in two regions of the molecule (aa 9–13 and 91–101) that are not essential for LPS binding. In addition, the mutants had a reduced capacity to mediate LPS-stimulated IL-6 production in human vascular endothelial and SMC. In contrast, the potential of sCD14(91–94,96)A, and sCD14(97–101)A to signal LPS-induced activation of human PBMC was not significantly reduced. These results show that the regions 9–13 and 91–101 are involved in the sCD14-dependent stimulation of cells by LPS but that the mechanisms by which different cell types are activated may not be identical.
Reduction of the Nonspecific Animal Toxicity of Anti-Tac(Fv)-PE38 by Mutations in the Framework Regions of the Fv Which Lower the Isoelectric Point
Authors: Onda Masanori , Kreitman Robert J. , Vasmatzis George , Lee Byungkook , Pastan Ira 
Published: January 2023

Abstract
Anti-Tac(Fv)-PE38, also called LMB-2, is a very active recombinant immunotoxin that has produced eight responses, including a durable clinical complete remission in a recently completed phase I trial of leukemias and lymphomas. Dose escalation was limited by liver toxicity. We have noted that the Fv of anti-Tac has an isoelectric point (pI) of 10.2. We hypothesize that the overall positive charge on the Fv portion of anti-Tac(Fv)-PE38 contributes to nonspecific binding to liver cells and results in dose-limiting liver toxicity. We have used a mouse model to investigate the basis of this toxicity and found that lowering the pI of the Fv of anti-Tac from 10.2 to 6.82 by selective mutation of surface residues causes a 3-fold decrease in animal toxicity and hepatic necrosis. This change in pI did not significantly alter the CD25 binding affinity, the cytotoxic activity toward target cells, or antitumor activity, resulting in a 3-fold improvement in the therapeutic index. If this decreased toxicity occurs in humans, it should greatly increase the clinical utility of this immunotoxin.
Subversion of Monocyte Functions byCoxiella burnetii: Impairment of the Cross-Talk Between αvβ3 Integrin and CR3
Authors: Capo Christian , Lindberg Frederik P. , Meconi Sonia , Zaffran Yona , Tardei Gratiela , Brown Eric J. , Raoult Didier , Mege Jean-Louis 
Published: January 2023

AbstractSeveral intracellular pathogens exploit macrophages as a niche for survival and replication. The success of this strategy requires the subversion or the avoidance of microbicidal functions of macrophages. Coxiella burnetii, the agent of Q fever, is a strictly intracellular bacterium that multiplies in myeloid cells. The survival of C. burnetii may depend on the selective use of macrophage receptors. Virulent C. burnetii organisms were poorly internalized but survived successfully in human monocytes, whereas avirulent variants were efficiently phagocytosed but were also rapidly eliminated. The uptake of avirulent organisms was mediated by leukocyte response integrin (αvβ3 integrin) and CR3 (αMβ2 integrin), as demonstrated by using specific Abs and RGD sequence-containing peptides. The phagocytic efficiency of CR3 depends on its activation via αvβ3 integrin and integrin-associated protein. Indeed, CR3-mediated phagocytosis of avirulent C. burnetii was abrogated in macrophages from integrin-associated protein−/− mice. In contrast, the internalization of virulent C. burnetii organisms involved the engagement of αvβ3 integrin but not that of CR3. The pretreatment of monocytes with virulent C. burnetii organisms prevented the CR3-mediated phagocytosis of zymosan particles and CR3 activation assessed by the expression of the 24 neo-epitope. We conclude that the virulence of C. burnetii is associated with the engagement of αvβ3 integrin and the impairment of CR3 activity, which probably results from uncoupling αvβ3 integrin from integrin-associated protein. This study describes a strategy not previously reported of phagocytosis modulation by intracellular pathogens.
Inhibition of Oligodendrocyte Apoptosis by Sublytic C5b-9 Is Associated with Enhanced Synthesis of Bcl-2 and Mediated by Inhibition of Caspase-3 Activation
Authors: Soane Lucian , Rus Horea , Niculescu Florin , Shin Moon L. 
Published: January 2023

Abstract
We have previously shown that generation of sublytic C5b-9, the membrane attack complex of complement, induces oligodendrocytes to enter cell cycle and reduces apoptotic cell death in vitro. In the present study, the cellular factors involved in apoptosis of oligodendrocyte progenitor cells and oligodendrocytes, and the inhibitory effect of C5b-9 on apoptotic process were investigated. Oligodendrocyte progenitor cells identified by mAb A2B5 that were isolated from neonatal rat brains were differentiated into oligodendrocytes in serum-free defined medium. The differentiation, which occurs simultaneously with apoptotic cell death, was associated with a rapid loss of bcl-2 mRNA and increased expression of caspase-3 mRNA. Activation of caspase-3 in differentiating cells was demonstrated by the generation of 17- and 12-kDa fragments of caspase-3 proenzyme and by cleavage of poly(ADP-ribose) polymerase, a specific caspase-3 substrate. Cell death associated with differentiation was inhibited by the caspase-3 inhibitor DEVD-CHO in a dose-dependent manner. Assembly of sublytic C5b-9 resulted in inhibition of caspase-3 activation. In addition, synthesis of BCL-2 protein in oligodendrocytes was significantly increased by C5b-9. The TNF-α-induced apoptosis of oligodendrocytes was also inhibited by C5b-9. These results indicate that up-regulation of BCL-2 protein and inhibition of caspase-3 activation are potential mechanisms by which C5b-9 increases survival of oligodendrocyte in vitro and possibly in vivo during inflammation and immune-mediated demyelination affecting the CNS.
Endogenous Monocyte Chemoattractant Protein-1 (MCP-1) Protects Mice in a Model of Acute Septic Peritonitis: Cross-Talk Between MCP-1 and Leukotriene B4
Authors: Matsukawa Akihiro , Hogaboam Cory M. , Lukacs Nickolas W. , Lincoln Pamela M. , Strieter Robert M. , Kunkel Steven L. 
Published: January 2023

AbstractWe investigated the involvement of monocyte chemoattractant protein (MCP)-1 in a murine model of septic peritonitis induced by cecal ligation and puncture (CLP). Initial studies demonstrated that CLP induced a dramatic increase in MCP-1 production in the peritoneum, followed by an increase in the recruitment of leukocytes. MCP-1 blockade with anti-MCP-1 antiserum significantly decreased the survival rate following CLP, which was accompanied by an enhanced recovery of viable bacteria from the peritoneum. This was likely due to the reduction in the recruitment and activation of both macrophages and neutrophils. To understand the mechanisms whereby MCP-1 may influence neutrophil infiltration, levels of chemokines known to attract neutrophils were monitored, which showed that peritoneal levels of macrophage-inflammatory protein (MIP)-2, KC, and MIP-1α were not altered with anti-MCP-1 Abs. However, anti-MCP-1 Abs reduced the peritoneal levels of leukotriene B4 (LTB4) by 59%. The i.p. injection of MCP-1 into normal mice resulted in elevated levels of LTB4 in the peritoneum. In vitro, MCP-1 stimulated the production of LTB4 from peritoneal macrophages, in a dose-dependent manner. A specific LTB4 receptor antagonist (CP-105,696) inhibited CLP-induced recruitment of both neutrophils and macrophages, which was accompanied by a reduced level of MCP-1 in the peritoneum. Finally, administration of CP-105,696 was extremely detrimental to the survival of mice following CLP. These experiments demonstrate that endogenous MCP-1 serves as an indirect mediator to attract neutrophils via the production of LTB4, and suggest the cross-talk can occur between MCP-1 and the lipid mediator LTB4 during septic peritonitis.
NH2- and COOH-Terminal Truncations of Murine Granulocyte Chemotactic Protein-2 Augment the In Vitro and In Vivo Neutrophil Chemotactic Potency
Authors: Wuyts Anja , D’Haese Anne , Cremers Valerie , Menten Patricia , Lenaerts Jean-Pierre , De Loof Arnold , Heremans Hubertine , Proost Paul , Van Damme Jo 
Published: January 2023

Abstract
Chemokines are important mediators of leukocyte migration during the inflammatory response. Post-translational modifications affect the biological potency of chemokines. In addition to previously identified NH2-terminally truncated forms, COOH-terminally truncated forms of the CXC chemokine murine granulocyte chemotactic protein-2 (GCP-2) were purified from conditioned medium of stimulated fibroblasts. The truncations generated 28 natural murine GCP-2 isoforms containing 69–92 residues, including most intermediate forms. Both NH2- and COOH-terminal truncations of GCP-2 resulted in enhanced chemotactic potency for human and murine neutrophils in vitro. The truncated isoform GCP-2(9–78) was 30-fold more potent than intact GCP-2(1–92)/LPS-induced CXC chemokine (LIX) at inducing an intracellular calcium increase in human neutrophils. After intradermal injection in mice, GCP-2(9–78) was also more effective than GCP-2(1–92)/LIX at inducing neutrophil infiltration. Similar to human IL-8 and GCP-2, murine GCP-2(9–78) and macrophage inflammatory protein-2 (MIP-2) induced calcium increases in both CXCR1 and CXCR2 transfectants. Murine GCP-2(9–78) could desensitize the calcium response induced by MIP-2 in human neutrophils and vice versa. Furthermore, MIP-2 and truncated GCP-2(9–78), but not intact GCP-2(1–92)/LIX, partially desensitized the calcium response to human IL-8 in human neutrophils. Taken together, these findings point to an important role of post-translationally modified GCP-2 to replace IL-8 in the mouse.
Transcriptional and Translational Regulation of Inflammatory Mediator Production by Endogenous TGF-β in Macrophages That Have Ingested Apoptotic Cells
Authors: McDonald Patrick P. , Fadok Valerie A. , Bratton Donna , Henson Peter M. 
Published: January 2023

Abstract
We recently reported that phagocytosis of apoptotic cells inhibits the release of inflammatory cytokines by human macrophages. In this paper we show that apoptotic cell uptake by mouse J774 macrophages also inhibits the synthesis and secretion of the chemokines, macrophage inflammatory protein-2 (Mip-2), KC, and Mip-1α (but not that of monocyte chemoattractant protein-1 (MCP-1)/JE), and increases TGF-β formation. Anti-TGF-β neutralizing Abs largely reversed the inhibitory effect of apoptotic cell uptake, and accordingly, exogenous TGF-β down-regulated the synthesis of the same mediators. Apoptotic cell ingestion or TGF-β also inhibited Mip-2 and Mip-1α gene expression in LPS-treated J774 cells, whereas TNF-α mRNA levels were unaffected. Importantly, TGF-β pretreatment of J774 cells did not significantly alter chemokine and TNF mRNA stability. Finally, we found that apoptotic cell uptake and TGF-β did not modulate NF-κB or AP-1 DNA binding in J774 cells. We conclude that the decreased production of chemokines and TNF resulting from apoptotic cell ingestion is largely mediated by a common event, i.e., feedback inhibition by endogenous TGF-β, but involves different mechanisms. Whereas TNF-α production appears to be translationally down-regulated, the suppression of most chemokines investigated appears to reflect transcriptional inhibition. In a broader context, the impairment of chemokine and TNF generation by apoptotic cell uptake might represent an important mechanism contributing to the resolution of inflammation. An additional consequence could be the selective recruitment of monocytes into inflammatory sites, as MCP-1/JE production by mouse macrophages was unaffected by apoptotic cell uptake, in contrast to other chemokines.
Urokinase Receptor (CD87) Aggregation Triggers Phosphoinositide Hydrolysis and Intracellular Calcium Mobilization in Mononuclear Phagocytes
Authors: Sitrin Robert G. , Pan Pauline M. , Harper Hollie A. , Blackwood R. Alexander , Todd Robert F. 
Published: January 2023

AbstractLeukocytes utilize urokinase receptors (uPAR; CD87) in adhesion, migration, and matrix proteolysis. uPAR aggregate at cell-substratum interfaces and at leading edges of migrating cells, so this study was undertaken to determine whether uPAR aggregation is capable of initiating activation signaling. Monocyte-like U937 cells were labeled with fluo-3-acetoxymethyl ester to quantitate intracellular Ca2+ concentrations ([Ca2+]i) by spectrofluorometry, and uPAR was aggregated by mAb cross-linking. uPAR aggregation induced highly reproducible increases in [Ca2+]i of 103.0 ± 10.9 nM (p &lt; 0.0001) and &gt;3-fold increases in cellular d-myoinositol 1,4,5-trisphosphate (Ins(1,4,5)P3) levels. Similar increases in [Ca2+]i were also elicited by uPAR aggregation in human monocytes, but cross-linking a control IgG2a had no effect on [Ca2+]i. Selectively cross-linking uPA-occupied uPAR with an anti-uPA mAb produced smaller increases in [Ca2+]i, but fully saturating uPAR with exogenous uPA enhanced the [Ca2+]i response to equal the effect of aggregating uPAR directly. Increased [Ca2+]i was inhibited by thapsigargin, herbimycin A, and U73122, but only partially reduced by low extracellular [Ca2+], indicating that uPAR aggregation increases [Ca2+]i by activating phospholipase C through a tyrosine kinase-dependent mechanism, generating Ins(1,4,5)P3 and releasing Ca2+ from Ins(1,4,5)P3-sensitive intracellular stores. Cross-linking the β2 integrin CR3 could not duplicate the effect of uPAR cross-linking, and uPAR-triggered Ca2+ mobilization was not blocked by anti-CR3 mAbs. These results indicate that uPAR aggregation initiates phosphoinositide hydrolysis by mechanisms that are not strictly dependent on associated uPA or CR3.
H-Ras Signals to Cytoskeletal Machinery in Induction of Integrin-Mediated Adhesion of T Cells
Authors: Tanaka Yoshiya , Minami Yasuhiro , Mine Shinichiro , Hirano Hideyasu , Hu Chang-Deng , Fujimoto Hiroko , Fujii Koichi , Saito Kazuyoshi , Tsukada Junichi , van Kooyk Yvette , Figdor Carl G. , Kataoka Tohru , Eto Sumiya 
Published: January 2023

AbstractThe adhesive function of integrins is regulated through cytoplasmic signaling. The present study was performed to investigate the relevance of cytoplasmic signaling and cytoskeletal assembly to integrin-mediated adhesion induced by chemokines. Adhesion of T cells induced by chemokines macrophage inflammatory protein (MIP)-1α and MIP-1β was inhibited by pertussis toxin, wortmannin, and cytochalasin B, suggesting that both G protein-sensitive phosphatidylinositol (PI) 3-kinase activation and cytoskeletal assemblies are involved. The chemokine-induced T cell adhesion could be mimicked by expression of small G proteins, fully activated H-RasV12, or H-RasV12Y40C mutant, which selectively binds to PI 3-kinase, in T cells, inducing activated form of LFA-1α and LFA-1-dependent adhesion to ICAM-1. H-Ras expression also induced F-actin polymerization which colocalized with profilin in T cells. Adult T cell leukemia (ATL) cells spontaneously adhered to ICAM-1, which depended on endogenous MIP-1α and MIP-1β through activation of G protein-sensitive PI 3-kinase. H-Ras signal pathway, leading to PI 3-kinase activation, also induced active configuration of LFA-1 and LFA-1-mediated adhesion of ATL cells, whereas expression of a dominant-negative H-Ras mutant failed to do. Profilin-dependent spontaneous polymerization of F-actin in ATL cells was reduced by PI 3-kinase inhibitors. In this paper we propose that H-Ras-mediated activation of PI 3-kinase can be involved in induction of LFA-1-dependent adhesion of T cells, which is relevant to chemokine-mediated signaling, and that profilin may form an important link between chemokine- and/or H-Ras-mediated signals and F-actin polymerization, which results in triggering of LFA-1 on T cells or leukemic T cells.
Chemokine and Chemokine Receptor Interactions Provide a Mechanism for Selective T Cell Recruitment to Specific Liver Compartments Within Hepatitis C-Infected Liver
Authors: Shields Philip. L. , Morland Clare M. , Salmon Michael , Qin Shixin , Hubscher Stefan G. , Adams David H. 
Published: January 2023

AbstractThe role played by chemokines in regulating the selective recruitment of lymphocytes to different tissue compartments in disease is poorly characterized. In hepatitis C infection, inflammation confined to portal areas is associated with a less aggressive course, whereas T cell infiltration of the liver parenchyma is associated with progressive liver injury and cirrhosis. We propose a mechanism to explain how lymphocytes are recruited to hepatic lobules during bursts of necroinflammatory activity in chronic hepatitis C infection. We report here that lymphocytes infiltrating hepatitis C-infected liver express high levels of the chemokine receptors CCR5 and CXCR3. However, whereas the CCR5 ligands macrophage inflammatory protein-1α and -1β were largely confined to vessels within portal tracts, the CXCR3 ligands IFN-inducible protein-10 and monokine-induced by IFN-γ were selectively up-regulated on sinusoidal endothelium. In vitro, human hepatic sinusoidal endothelial cells secreted IFN-inducible protein-10 and monokine-induced by IFN-γ in response to stimulation with IFN-γ in combination with either IL-1 or TNF-α. This suggests that intrahepatic Th1 cytokines drive the increased expression of IFN-inducible protein-10 and monokine-induced by IFN-γ and thereby promote the continuing recruitment of CXCR3-expressing T cells into the hepatic lobule in chronic hepatitis C infection.