bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protection from Collagen-Induced Arthritis in Granulocyte-Macrophage Colony-Stimulating Factor-Deficient Mice
Authors: Campbell Ian K. , Rich Melissa J. , Bischof Robert J. , Dunn Ashley R. , Grail Dianne , Hamilton John A. 
Published: December 2022

AbstractThe involvement of granulocyte-macrophage CSF (GM-CSF) in collagen-induced arthritis (CIA) was examined using GM-CSF-deficient mice. Although CIA is generally considered to be restricted to mice of the H-2q or H-2r haplotypes, we examined the role of GM-CSF in the CIA model using GM-CSF-deficient (−/−) and wild-type (+/+) mice on a C57BL/6 (H-2b) background. Mice were immunized by intradermal injection at the base of the tail with chick type II collagen followed by a repeat injection 21 days later. We found, based on both clinical and histologic assessments, that wild-type mice on this background developed severe CIA, while the GM-CSF-deficient mice had virtually no disease. Mice that were heterozygous for the GM-CSF gene (+/−) collectively displayed an intermediate response between those of the GM-CSF+/+ and GM-CSF−/− groups, suggesting a gene dosage effect. GM-CSF+/+ and GM-CSF+/− mice exhibited CIA responses ranging from mild (single digits) to severe swelling of all four paws, while in the few GM-CSF−/− mice that developed CIA the disease was confined to single digits. Despite the putative role of GM-CSF in dendritic cell development, GM-CSF-deficient mice exhibited both humoral and cellular (delayed-type hypersensitivity) responses to type II collagen; however, the cellular response was significantly reduced in the GM-CSF-deficient mice compared with the wild-type controls. These findings suggest that GM-CSF is required for CIA development in mice and support the idea that GM-CSF is a key cytokine in inflammatory joint disease.
A Complex Element Regulates IFN-γ-Stimulated Monocyte Chemoattractant Protein-1 Gene Transcription
Authors: Valente Anthony J. , Xie Jing-feng , Abramova Margaret A. , Wenzel Ulrich O. , Abboud Hanna E. , Graves Dana T. 
Published: December 2022

AbstractMonocyte chemoattractant protein-1 (MCP-1) is induced in chronic osseous inflammation, and is temporally and spatially correlated with monocyte recruitment. We investigated the mechanism of MCP-1 regulation in a human osteoblastic cell line in response to IFN-γ, a potent mediator of the immune inflammatory response. Nuclear run-on and stability studies demonstrated that IFN-γ stimulated MCP-1 transcription and did not enhance mRNA stabilization. Using MCP-1 promoter/reporter gene constructs, we determined that IFN-γ-enhanced MCP-1 transcription is regulated by a 29-bp element located at −227 relative to the ATG start codon. This element contains a 13-bp CT-rich sequence (GCTTCCCTTTCCT) adjacent to a IFN-γ activation site (GAS). Since deletion of the CT sequence enhanced both the magnitude and duration of IFN-γ-stimulated, GAS-mediated transcription, we have termed it the IFN response-inhibitory sequence (IRIS). The combined IRIS/GAS sequence is highly conserved in mouse, rat, and bovine MCP-1 genes. In gel-shift assays, nuclear extracts from IFN-γ-stimulated osteoblastic cells formed two specific inducible bands with labeled IRIS/GAS DNA. Both bands were supershifted by anti-STAT1 Abs, but not by Abs to STAT2, p48(ISGF-3γ), IFN-regulatory factor-1, or IFN-regulatory factor-2. Formation of one of the bands required the presence of the IRIS moiety. IRIS/GAS DNA also formed a number of specific complexes with constitutively expressed factors, none of which were affected by the above Abs. These studies establish a mechanism for IFN-γ-stimulated MCP-1 expression and identify a complex element that regulates MCP-1 gene transcription.
Evidence for IL-12-Activated Ca2+ and Tyrosine Signaling Pathways in Human Neutrophils
Authors: Collison Kate , Saleh Soad , Parhar Ranjit , Meyer Brian , Kwaasi Aaron , Al-Hussein Khalid , Al-Sedairy Sultan , Al-Mohanna Futwan 
Published: December 2022

AbstractThe cytokine IL-12 is proposed to play a bridging role between innate and adaptive immunity. Here we demonstrate that IL-12 binds specifically to human neutrophils. This binding leads to a transient increase in 1) intracellular free calcium due to its release from membrane-enclosed stores and its influx from extracellular medium, 2) actin polymerization, and 3) tyrosine phosphorylation. IL-12 treatment also leads to a concentration-dependent increase in reactive oxygen metabolite production. The effect of IL-12 is blocked by neutralizing Abs to IL-12. Inhibition of either calcium transient or tyrosine phosphorylation causes inhibition of reactive oxygen metabolite production. However, inhibition of actin polymerization enhances IL-12-induced oxidase activation. Our data suggest 1) a direct role for IL-12 in the activation of human neutrophils, and 2) a calcium-dependent signaling pathway for IL-12.
Immune Invasion of the Central Nervous System Parenchyma and Experimental Allergic Encephalomyelitis, But Not Leukocyte Extravasation from Blood, Are Prevented in Macrophage-Depleted Mice
Authors: Tran Elise H. , Hoekstra Karin , van Rooijen Nico , Dijkstra Christine D. , Owens Trevor 
Published: December 2022

AbstractOrgan-specific autoimmune diseases are characterized by infiltrates, including T lymphocytes and activated macrophages. Macrophages and secondarily activated tissue resident counterparts can both present Ag to and contribute to cytokine secretion by T lymphocytes. We have previously shown a crucial role of peripheral macrophages in experimental allergic encephalomyelitis (EAE), a Th1-mediated demyelinating disease that serves as a an animal model for multiple sclerosis (MS), by their depletion using mannosylated liposome-encapsulated dichloromethylene diphosphonate (Cl2MDP). Here we describe studies to investigate the mechanisms by which macrophages contribute to the lesion formation in EAE, by studying the effect of Cl2MDP-containing mannosylated liposomes (Cl2MDP-mnL) on adoptively transferred EAE in SJL/J mice. Adoptive transfer of EAE with myelin basic protein-reactive CD4+ T cells to SJL/J mice was abrogated by Cl2MDP-mnL treatment. CD4+ T cell and MHC II+ B220+ B cell extravasation from blood vessels and Th1 cytokine production were not inhibited. However, invasion of the central nervous system intraparenchymal tissues by lymphocytes, F4/80+, Mac-1+, and MOMA-1+ macrophages was almost completely blocked after treatment with Cl2MDP-mnL. Furthermore, in Cl2MDP-mnL-treated mice, the myelin sheaths appeared completely normal, whereas, in the control groups, marked demyelination occurred. Production of TNF-α and inducible nitric oxide synthase, both associated with macrophage/microglial activation, was inhibited. This intervention reveals a role for macrophages in regulating the invasion of autoreactive T cells and secondary glial recruitment that ordinarily lead to demyelinating pathology in EAE and multiple sclerosis.
Role of κII-A2 Light Chain CDR-3 Junctional Residues in Human Antibody Binding to theHaemophilus influenzaeType b Polysaccharide
Authors: Lucas Alexander H. , Moulton Karen D. , Reason Donald C. 
Published: December 2022

AbstractAbs using the κII-A2 V gene segment predominate the human Ab repertoire to the Haemophilus influenzae b (Hib) polysaccharide (PS). All A2 anti-Hib PS Abs sequenced to date possess a 10-amino acid L chain complementarity-determining region-3 (CDR-3) having an insertional arginine (Arg) at position 95a, the V-J junction. These findings suggest an essential requirement for this conserved Arg residue in determining Hib PS-binding affinity. We examined this requirement by performing chain recombination experiments in which a series of A2 L chains, differing at position 95a, were combined individually with an Fd region known to generate a Hib PS-combining site when paired with an A2-Arg(95a)-Jκ1 V region. Hib PS binding of the recombinant Fabs was evaluated quantitatively using a radioantigen-binding assay. Fabs having A2 L chains with either Arg or lysine in position 95a in combination with Jκ1 gave equivalent and strongest binding to Hib PS. Fabs having A2-Jκ1 L chains with either tyrosine, glycine, alanine, leucine, serine, or threonine in position 95a, or having an A2-Arg(95a)-Jκ3 L chain, gave intermediate binding. Fabs having A2-Jκ1 L chains with glutamate or aspartate at 95a or with no junctional residue showed little or no Hib PS binding. These results demonstrate the importance of L chain junctional residue, as well as Jκ usage and CDR-3 length, in determining Hib PS-binding affinity. Contrary to expectation, an Arg junctional residue is not essential for generating either high or intermediate affinity-binding sites.
Cutting Edge: A Novel Viral TNF Receptor Superfamily Member in Virulent Strains of Human Cytomegalovirus
Authors: Benedict Chris A. , Butrovich Kris D. , Lurain Nell S. , Corbeil Jacques , Rooney Isabelle , Schneider Pascal , Tschopp Jurg , Ware Carl F. 
Published: December 2022

Abstract
The UL144 open reading frame found in clinical isolates of human CMV (HCMV) encodes a structural homologue of the herpesvirus entry mediator, a member of the TNFR superfamily. UL144 is a type I transmembrane glycoprotein that is expressed early after infection of fibroblasts; however, it is retained intracellularly. A YXXZ motif in the highly conserved cytoplasmic tail contributes to UL144 subcellular distribution. The finding that no known ligand of the TNF family binds UL144 suggests that its mechanism of action is distinct from other known viral immune evasion genes. Specific Abs to UL144 can be detected in the serum of a subset of HCMV seropositive individuals infected with HIV. This work establishes a novel molecular link between the TNF superfamily and herpesvirus that may contribute to the ability of HCMV to escape immune clearance.
Direct Effects on Antigen-Presenting Cells and T Lymphocytes Explain the Adjuvanticity of a Nontoxic Cholera Toxin Mutant
Authors: Yamamoto Masafumi , Kiyono Hiroshi , Yamamoto Shingo , Batanero Eva , Kweon Mi-Na , Otake Shigeo , Azuma Miyuki , Takeda Yoshifumi , McGhee Jerry R. 
Published: December 2022

AbstractThe present study has elucidated two distinct mechanisms that may explain how a mutant of cholera toxin (mCT), E112K, retains adjuvant effects though it lacks ADP-ribosyltransferase activity and associated toxicity. In the first mechanism, we show that mCT E112K, like native cholera toxin (nCT), enhances B7-2 expression, but, to some extent, also enhances B7-1 on Peyer’s patch B cells and macrophages. Cocultivation of CD4+ T cells with E112K- or nCT-treated B cells and macrophages in the presence of anti-CD3 stimulation resulted in the induction of T cell-proliferative responses. Further, the responses were blocked by mAbs to B7-1 and/or B7-2; however, the effect of anti-B7-1 was minimal. In the second mechanism, addition of mCT E112K or nCT to anti-CD3 mAb-stimulated Peyer’s patch CD4+ T cells inhibited proliferative responses, while recombinant CT-B subunit (rCT-B) did not. Analysis of cytokine responses showed that both mCT E112K and nCT preferentially inhibited IFN-γ production. Interestingly, however, nCT, but not mCT E112K, induced apoptosis in CD4+ T cells activated via the TCR-CD3 complex. These results indicate that CT uses at least two pathways for inhibition of Th1 responses and that, while nCT induces cAMP accumulation that in turn leads to apoptosis in Th1-type cells, mCT E112K, which lacks ADP-ribosyltransferase activity, inhibits IFN-γ synthesis by a separate mechanism. Thus, mCT E112K, like nCT, induces adjuvant responses via up-regulation of mainly B7-2 on APCs and through preferential inhibition of Th1-type CD4+ T cell responses in the absence of ADP-ribosyltransferase activity.
CD47 Signals T Cell Death
Authors: Pettersen Rolf D. , Hestdal Kjetil , Olafsen Mette Kløvstad , Lie Sverre O. , Lindberg Frederik P. 
Published: December 2022

AbstractActivation-induced death of T cells regulates immune responses and is considered to involve apoptosis induced by ligation of Fas and TNF receptors. The role of other receptors in signaling T cell death is less clear. In this study we demonstrate that activation of specific epitopes on the Ig variable domain of CD47 rapidly induces apoptosis of T cells. A new mAb, Ad22, to this site induces apoptosis of Jurkat cells and CD3ε-stimulated PBMC, as determined by morphological changes, phosphatidylserine exposure on the cell surface, uptake of propidium iodide, and true counts by flow cytometry. In contrast, apoptosis was not observed following culture with anti-CD47 mAbs 2D3 or B6H12 directed to a distant or closely adjacent region, respectively. CD47-mediated cell death was independent of CD3, CD4, CD45, or p56lck involvement as demonstrated by studies with variant Jurkat cell lines deficient in these signaling pathways. However, coligation of CD3ε and CD47 enhanced phosphatidylserine externalization on Jurkat cells with functional CD3. Furthermore, normal T cells required preactivation to respond with CD47-induced apoptosis. CD47-mediated cell death appeared to proceed independent of Fas or TNF receptor signaling and did not involve characteristic DNA fragmentation or requirement for IL-1β-converting enzyme-like proteases or CPP32. Taken together, our data demonstrate that under appropriate conditions, CD47 activation results in very rapid T cell death, apparently mediated by a novel apoptotic pathway. Thus, CD47 may be critically involved in controlling the fate of activated T cells.
TCR-Mediated Involvement of CD4+ Transgenic T Cells in Spontaneous Inflammatory Bowel Disease in Lymphopenic Mice
Authors: Koh Woon-Puay , Chan Elsie , Scott Kate , McCaughan Geoffrey , France Malcolm , Fazekas de St. Groth Barbara 
Published: December 2022

AbstractSpontaneous colitis resembling ulcerative colitis developed in 3 of 10 independent TCR transgenic (Tg) mouse lines maintained under specific pathogen-free conditions. All three susceptible lines were CD4 lymphopenic, whereas resistant lines had normal numbers of CD4+ T cells. Thus, cytochrome c-specific 5C.C7 TCR Tg mice developed colitis only when crossed onto a SCID- or Rag-1-deficient background. A second line of lymphopenic cytochrome c-specific Tg mice bearing the AND TCR also developed colitis. In both cases, CD4+ T cells expressing the Tg-encoded TCR were preferentially activated in inflamed colons compared with lymph nodes or spleens. In contrast, Tg+CD4+ T cells remained quiescent in both inflamed and unaffected colons in another line of susceptible Tg mice carrying a TCR specific for myelin basic protein, suggesting a fortuitous cross-reactivity of the IEk-restricted cytochrome c-reactive AND and 5C.C7 TCRs with an Ag present in the gut. The percentage of CD4+ T cells expressing only endogenous TCR α-chains was increased consistently in inflamed colons in AND as well as 5C.C7 Rag-1−/− TCR Tg mice, suggesting that polyclonal CD4+ T cells were also involved in the pathogenesis of spontaneous colitis. Moreover, our data indicate that some α-chain rearrangement was still occurring in TCR Tg mice on a Rag-1−/− background, since activated CD4+ T cells expressing endogenously rearranged α-chains paired with the Tg-encoded β-chain were detected consistently in the colons of such mice.
Multiple NF-ATc Isoforms with Individual Transcriptional Properties Are Synthesized in T Lymphocytes
Authors: Chuvpilo Sergei , Avots Andris , Berberich-Siebelt Friederike , Glöckner Judith , Fischer Christian , Kerstan Andreas , Escher Cornelia , Inashkina Inna , Hlubek Falk , Jankevics Eriks , Brabletz Thomas , Serfling Edgar 
Published: December 2022

AbstractThe transcription factor NF-ATc that controls gene expression in T lymphocytes and embryonic cardiac cells is expressed in three prominent isoforms. This is due to alternative splice/polyadenylation events that lead to the predominant synthesis of two long isoforms in naive T cells and a shorter NF-ATc isoform in effector T cells. Whereas the previously described isoform NF-ATc/A contains a relatively short C terminus, the longer isoforms, B and C, span extra C-terminal peptides of 128 and 246 aa, respectively. We show here that in addition to the strong N-terminal trans-activation domain, TAD-A, which is common to all three NF-ATc isoforms, NF-ATc/C contains a second trans-activation domain, TAD-B, in its C-terminal peptide. Various stimuli of T cells that induce the activity of TAD-A also enhance the activity of TAD-B, but, unlike TAD-A, TAD-B remains unphosphorylated by protein from 12-O-tetradecanoyl 12-phorbol 13-acetate-stimulated T cells. The shorter C-terminal peptide of isoform NF-ATc/B exerts a suppressive transcriptional effect. These properties of NF-ATc/B and -C might be of importance for gene regulation in naive T lymphocytes in which NF-ATc/B and -C are predominantly synthesized.
Poxvirus-Encoded Serpins Do Not Prevent Cytolytic T Cell-Mediated Recovery from Primary Infections
Authors: Müllbacher Arno , Wallich Reinhard , Moyer Richard W. , Simon Markus M. 
Published: December 2022

AbstractPrevious observations that the highly conserved poxvirus-encoded serpins inhibit cytotoxic activities of alloreactive CTL via granule and/or Fas-mediated pathways was taken to indicate their involvement in immune evasion by poxviruses. We now show that interference with 51Cr release from target cells by ectromelia and cowpoxvirus is limited to alloreactive but not MHC-restricted CTL. The data are in support of the paramount importance of CTL and its effector molecule perforin in the recovery from primary ectromelia virus infection and question the role of serpins in the evasion of poxviruses from killing by CTL. Further analysis of poxvirus interference with target cell lysis by alloreactive CTL revealed that suppression primarily affects the Fas-mediated, and to a lesser extent, the granule exocytosis pathway. Serpin-2 is the main contributor to suppression for both killing pathways. In addition, inhibition of lysis was shown to be both target cell type- and MHC allotype-dependent. We hypothesize that differences in TCR affinities and/or state of activation between alloreactive and MHC-restricted CTL as well as the quality (origin) of target cells are responsible for the observed phenomenon.
Human Polymorphonuclear Leukocytes Produce IL-12, TNF-α, and the Chemokines Macrophage-Inflammatory Protein-1α and -1β in Response toToxoplasma gondiiAntigens
Authors: Bliss Susan K. , Marshall Anthony J. , Zhang Yin , Denkers Eric Y. 
Published: December 2022

AbstractThe induction of a type 1 inflammatory cytokine response is a key event in the initiation of immunity to Toxoplasma gondii. Because polymorphonuclear leukocytes rapidly respond to infection by exiting the peripheral blood and accumulating at a site of infection, we sought to determine whether these cells produce cytokines in response to T. gondii. When human peripheral blood neutrophils were stimulated with parasite Ag, they produced both IL-12 (p70) and TNF-α. Similarly, up-regulated expression of macrophage-inflammatory protein-1α (MIP-1α) and MIP-1β gene transcripts was induced. Kinetic analysis of IL-12 and TNF-α production revealed distinct patterns following stimulation by T. gondii or LPS. Exogenous TNF-α alone also provided a potent stimulus of MIP-1α and MIP-1β expression, and when neutralizing anti-TNF-α antiserum was included in cultures of parasite-stimulated cells, expression of these CC-family chemokines was partially blocked. These results establish that T. gondii possesses the ability of driving neutrophil proinflammatory cytokine production, and they suggest that parasite-induced MIP-1α and MIP-1β partly results from autocrine stimulation through TNF-α.
Purine Metabolites Suppress Proliferation of Human NK Cells Through a Lineage-Specific Purine Receptor
Authors: Miller Jeffrey S. , Cervenka Tereza , Lund Jeanne , Okazaki Ian J. , Moss Joel 
Published: December 2022

AbstractNK cell proliferation is suppressed in some patients with cancer by unknown mechanisms. Because purine metabolites released into the extracellular space during cell lysis may affect cell function, we hypothesized that these metabolites could serve as feedback regulators of NK cell proliferation. Sorted NK (CD56+/CD3−) cells were incubated with IL-2 (1000 U/ml) in a 4-day thymidine uptake assay with or without 10–10,000 μM of nucleotides. Adenine nucleotides inhibited NK cell proliferation, with ATP = ADP &gt; 5′-adenylylimidodiphosphate &gt; AMP = adenosine; ADP-ribose and nicotinamide adenine dinucleotide, but not nicotinamide or UTP, caused a dose-dependent suppression of thymidine uptake. A total of 100 μM ATP, a concentration that induced a maximal (80%) inhibition of thymidine uptake, did not inhibit cytotoxic activity against K562 targets. Because NK cells retained the ability to lyse K562 targets 4 days after exposure to 500 μM ATP or 1000 μM adenosine, inhibition of thymidine uptake was not due to cell death. Incubation of NK cells with dibutyryl cAMP and forskolin also suppressed thymidine uptake. Cholera toxin and pertussis toxin suppressed NK cell proliferation. Pertussis toxin did not block the adenine nucleotide effects. Further, ATP, but not adenosine or other nucleotides, markedly increased intracellular cAMP in a dose-dependent manner. The ATP-induced increase in cAMP was specific to cytolytic cells, because CD19+ B cells and CD4+ T cells did not increase their intracellular cAMP. These studies demonstrate that NK proliferation is regulated through purine receptors by adenine nucleotides, which may play a role in decreased NK cell activity. The response to adenine nucleotides is lineage-specific.
POMC Gene-Derived Peptides Activate Melanocortin Type 3 Receptor on Murine Macrophages, Suppress Cytokine Release, and Inhibit Neutrophil Migration in Acute Experimental Inflammation
Authors: Getting Stephen J. , Gibbs Linda , Clark Adrian J. L. , Flower Roderick J , Perretti Mauro 
Published: December 2022

AbstractTo investigate the relevance of adrenocorticotrophic hormone (ACTH) therapy in human gouty arthritis, we have tested the effect of several ACTH-related peptides in a murine model of experimental gout. Systemic treatment of mice with ACTH4–10 (MEHFRWG) (10–200 μg s.c.) inhibited neutrophil accumulation without altering peripheral blood cell counts or circulating corticosterone levels. A similar effect was seen with α- and β-melanocyte stimulating hormones (1–30 μg s.c.). In vivo release of the chemokine KC-(detected in the lavage fluids before maximal influx of neutrophils) was significantly reduced (−50 to −60%) by ACTH4–10. Macrophage activation in vitro, determined as phagocytosis and KC release, was inhibited by ACTH and ACTH4–10 with approximate IC50 values of 30 nM and 100 μM, respectively. The melanocortin receptor type 3/4 antagonist SHU9119 prevented the inhibitory actions of ACTH4–10 both in vitro and in vivo. However, melanocortin type 3, but not type 4, receptor mRNA was detected in mouse peritoneal macrophages by RT-PCR. Therefore, we propose that activation of this receptor type by ACTH4–10 and related amino acid sequences attenuates KC release (and possibly production of other cytokines) from macrophages with consequent inhibition of the host inflammatory response, thus providing a notional anti-inflammatory mechanism for ACTH that is unrelated to stimulation of glucocorticoid release.