bluuebunny/crossref_metadata_2025_split huggingface dataset:
IL-12 Promotes Drug-Induced Clearance ofMycobacterium aviumInfection in Mice
Authors: Doherty T. Mark , Sher Alan 
Published: January 2023

AbstractThe intracellular pathogen Mycobacterium avium is a major cause of opportunistic infection in AIDS patients and is difficult to manage using conventional chemotherapeutic approaches. In the current study, we describe a strategy for the treatment of M. avium in T cell-deficient hosts based on the simultaneous administration of antibiotics and the immunomodulatory cytokine IL-12. In contrast to SCID mice, which were partially resistant, animals lacking a functional IL-12 p40 gene were found to be highly susceptible to M. avium infection, suggesting that the cytokine can control bacterial growth even in immunodeficient mice. Indeed, rIL-12 that was injected into infected SCID mice in high doses caused small but significant reductions in splenic pathogen loads. Moreover, a lower dose of IL-12, when combined with the antimycobacterial drugs clarithromycin or rifabutin, induced a decrease in bacterial numbers that was significantly greater than that resulting from the administration of the cytokine or drug alone. A similar synergistic effect of IL-12 and antibiotics was seen when immunocompetent mice were treated with the same regimen. The activity of IL-12 in these experiments was shown to be dependent upon the induction of endogenous IFN-γ. Nevertheless, IFN-γ itself, even when given at a higher dose than IL-12, failed to significantly enhance antibiotic clearance of bacteria. Together these findings suggest that IL-12 may be a particularly potent adjunct for chemotherapy of M. avium infection in immunocompromised individuals and may result in more effective control of the pathogen without the need for increased drug dosage.
IL-5-Dependent Immunity to Microfilariae Is Independent of IL-4 in a Mouse Model of Onchocerciasis
Authors: Hogarth Philip J. , Taylor Mark J. , Bianco Albert E. 
Published: January 2023

AbstractTh2 lymphocyte responses under the control of IL-4 and IL-5 are frequently associated with protective responses to parasitic helminths. Studies on the role of these cytokines in acquired resistance to parasitic nematodes indicate that, in the case of gastrointestinal nematodes, immunity is mediated by IL-4, while immunity to tissue-dwelling nematodes is dependent on IL-5. Here we investigate the role of IL-5 and eosinophils in protective immunity to Onchocerca microfilariae in IL-4-deficient mice. In the absence of IL-4, and despite the up-regulation of Th1-type responses, immunity remains dependent on IL-5 and eosinophils. Protection was unaffected by the absence of Ab in B cell-deficient mice, confirming that IL-5 is not acting via either B cell differentiation, Ag presentation, or isotype switching mechanisms. These data demonstrate the dissociation of IL-4 and IL-5 in a functional model of protective immunity to a tissue dwelling nematode and cast doubt on the role of IL-4 in the generation of CD4+ T cell-mediated, IL-5-dependent immunity to Onchocerca microfilariae. Importantly, they also segregate T cell-mediated mechanisms of protective immunity from those characterized in ocular pathologic responses in onchocerciasis, which are dependent on IL-4.
T Cell- and NK Cell-Independent Inhibition of Hepatic Metastases by Systemic Administration of an IL-12-Expressing Recombinant Adenovirus
Authors: Siders William M. , Wright Paul W. , Hixon Julie A. , Alvord W. Gregory , Back Timothy C. , Wiltrout Robert H. , Fenton Robert G. 
Published: January 2023

AbstractIL-12 is a potent immunoregulatory cytokine that has been shown to mediate tumor regression in a variety of tumor models. We describe the construction of AdCMV-IL-12, a recombinant adenovirus that encodes both subunits of IL-12 under transcriptional control of the CMV promoter. This recombinant virus efficiently infects a wide variety of cell types leading to the production of high levels of biologically active IL-12. Because the liver is a primary site of infection after i.v.-administered adenovirus, we tested the therapeutic efficacy of this virus in a murine hepatic metastasis tumor model. Systemic administration of AdCMV-IL-12 dramatically inhibited the formation of 3-day Renca hepatic metastases (mean of 16 metastases per liver) compared with the control virus AdCMV-βgal (mean of 209) or vehicle alone (mean of 272). Histologic analysis indicated that metastatic growth inhibition was accompanied by a dramatic perivascular infiltrate consisting of T cells, macrophages, and neutrophils. Therapeutic efficacy was not diminished in animals depleted of CD4+ or CD8+ T cells, or in SCID mice, even after NK cell ablation. In the latter case, a hepatic perivascular infiltrate composed of macrophages and neutrophils was observed after AdCMV-IL-12-treatment, while numerous activated Kupffer cells were noted in the hepatic parenchyma. Analysis of therapy-induced changes in hepatic gene expression demonstrated increased levels of IP-10 and Mig RNAs, but no increase in iNOS, Fas, or FasL RNA levels was observed. Our data suggest a model of metastatic growth inhibition mediated by nonlymphocyte effector cells including macrophages and neutrophils and that may involve anti-angiogenic chemokines.
Reversible Expression of Tryptases and Chymases in the Jejunal Mast Cells of Mice Infected with Trichinella spiralis
Authors: Friend Daniel S. , Ghildyal Namit , Gurish Michael F. , Hunt John , Hu Xuzhen , Austen K. Frank , Stevens Richard L. 
Published: January 2023

Abstract
It is has been established that mouse mast cells (MCs) can reversibly alter their expression of serglycin proteoglycans and the homologous granule chymases that have been designated mouse MC protease (mMCP)-1, mMCP-2, and mMCP-5 in vivo. Nevertheless, it remained to be determined whether these immune cells could modify their expression of other chymases and the granule tryptases mMCP-6 and mMCP-7. As assessed immunohistochemically, we now show that MCs reversibly change their expression of the recently described chymase mMCP-9 and both tryptases as these cells traverse the jejunum during the amplification and regression stages of the reactive MC hyperplasia. In noninfected mice, most jejunal MCs reside in the submucosa and express mMCP-6 and mMCP-7, but not mMCP-9 or the chymase mMCP-2. During the inductive phase of the helminth-induced inflammation, when the jejunal MCs move from the submucosa to the tips of the villus, the MCs briefly express mMCP-9, cease expressing mMCP-6 and mMCP-7, and then express mMCP-2. During the recovery phase of the inflammation, jejunal MCs cease expressing mMCP-2 and then express varied combinations of mMCP-6, mMCP-7, and mMCP-9 as they move from the tips of the villus back toward the submucosa. In other model systems, mMCP-6 elicits neutrophil extravasation, and mMCP-7 regulates fibrin deposition and fibrinogen-mediated signaling events. Thus, the ability of a jejunal MC to reversibly alter its tryptase expression during an inflammatory event has important functional implications.
Sulfonylureas Inhibit Cytokine-Induced Eosinophil Survival and Activation
Authors: Bankers-Fulbright Jennifer L. , Kephart Gail M. , Loegering David A. , Bradford Annabel L. , Okada Shinji , Kita Hirohito , Gleich Gerald J. 
Published: January 2023

Abstract
Eosinophils play a key role in the pathogenesis of asthma and other allergic inflammatory diseases. We have previously shown that treatment of eosinophils with lidocaine preferentially inhibits IL-5-induced survival. This inhibition cannot be overcome by increasing concentrations of IL-5 and is not due to the blocking of Na+ channels by lidocaine. Here we report that one class of K+ channel blockers, the sulfonylureas, inhibits eosinophil survival in a manner similar to lidocaine. The sulfonylurea glyburide inhibits eosinophil survival even at high concentrations of IL-5. In contrast, increasing concentrations of IL-3 or granulocyte-macrophage CSF overcome glyburide inhibition. Glyburide also blocks cytokine-induced eosinophil superoxide production. Similar results were seen with the sulfonylureas tolbutamide and glipizide. Interestingly, the effects of glyburide are not antagonized by the ATP-sensitive K+ channel openers cromakalim, pinacidil, or diazoxide. Although Scatchard analysis of [3H]glyburide binding to eosinophil membranes indicated that the high affinity sulfonylurea receptor (SUR1) is not present on eosinophils, human eosinophils do express mRNA homologous to the sulfonylurea receptor family, in keeping with the presence of a sulfonylurea receptor. Finally, coculture of eosinophils with combinations of glyburide, lidocaine, and dexamethasone resulted in synergistic inhibition of cytokine-mediated eosinophil survival and superoxide production. These results have intriguing clinical implications for the treatment of eosinophil-associated diseases.
Prevention and Treatment of Experimental Autoimmune Encephalomyelitis by CNI-1493, a Macrophage-Deactivating Agent
Authors: Martiney James A. , Rajan Alice J. , Charles Peter C. , Cerami Anthony , Ulrich Peter C. , Macphail Stuart , Tracey Kevin J. , Brosnan Celia F. 
Published: January 2023

AbstractMultiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE), are characterized by episodic neurologic dysfunction, perivascular mononuclear cell inflammation occurring mainly in white matter, and demyelination. Strong circumstantial evidence supports the conclusion that macrophage activation and local production of proinflammatory cytokines are necessary for disease induction and lesion formation. We now report that CNI-1493, a small m.w. compound, which inhibits macrophage activation and subsequent proinflammatory cytokine production, suppresses EAE induced in the genetically susceptible SJL/J mouse. Treatment with 5 mg/kg/day completely suppressed mild disease (clinical index of 1.6 ± 0.5 in the untreated group as compared with 0.0 ± 0.0 for the treated group) and significantly reduced acute disease (clinical index of 4.3 ± 0.7 in the untreated group as compared with 0.5 ± 0.3 for the treated group). Suppression of clinical manifestations of the disease correlated with a significant decrease in histopathology and proinflammatory cytokine expression at the lesion site. Moreover, drug treatment during the chronic phase resulted in amelioration of clinical signs. The data presented here should prove useful in developing novel chemotherapeutic approaches for the treatment of MS.
Novel C5a Receptor Antagonists Regulate Neutrophil Functions In Vitro and In Vivo
Authors: Pellas Theodore C. , Boyar William , van Oostrum Jan , Wasvary James , Fryer Lynn R. , Pastor Gary , Sills Matthew , Braunwalder Albert , Yarwood Donna R. , Kramer Richard , Kimble Earl , Hadala Joseph , Haston William , Moreira-Ludewig Rocio , Uziel-Fusi Susan , Peters Paul , Bill Kurt , Wennogle Lawrence P. 
Published: January 2023

AbstractNovel recombinant human C5a receptor antagonists were discovered through modification of the C terminus of C5a. The C5a1–71T1M,C27S,Q71C monomer, (C5aRAM; CGS 27913), was a pure and potent functional antagonist. The importance of a C-terminal cysteine at position 71 to antagonist properties of C5aRAM was confirmed by studying C5a1–71 derivatives with replacements of Q71, C5a derivatives of various lengths (70–74) with C-terminal cysteines, and C5a derivatives of various lengths (71–74) with Q71C replacements. The majority of C5a1–71Q71 derivatives were agonists (C5a-like) in the human neutrophil C5a-induced intracellular calcium mobilization assay. The C5a1–71Q71C derivative was an antagonist. C5a derivatives of lengths 73 and 74 with C-terminal cysteines were agonists, while lengths 70 to 72 were antagonists. C5a derivatives of lengths 72, 73, and 74 with Q71C replacements were agonists, while, again, C5a1–71Q71C was an antagonist. C5aRAM and its adducts, including its dimer, C5aRAD (CGS 32359), were pure antagonists. Additionally, C5aRAM and C5aRAD inhibited binding of 125I-labeled recombinant human C5a to neutrophil membranes (Ki = 79 and 2 pM, respectively), C5a-stimulated neutrophil intracellular calcium mobilization (8 and 13 nM), CD11b integrin up-regulation (10 and 1 nM), superoxide generation (182 and 282 nM), lysozyme release (1 and 2 μM), and chemotaxis (11 and 7 μM). In vivo, intradermal injection of C5aRAM inhibited C5a-induced dermal edema in rabbits. Furthermore, a 5-mg/kg i.v. bolus of C5aRAD significantly inhibited C5a-induced neutropenia in micropigs when challenged with C5a 30 min after C5aRAD administration. C5aRAM and C5aRAD are novel, potent C5a receptor antagonists devoid of agonist or proinflammatory activity with demonstrated efficacy in vitro and in vivo.
Receptors for the Anaphylatoxin C5a (CD88) on Human Mesangial Cells
Authors: Wilmer W. A. , Kaumaya P. T. , Ember J. A. , Cosio F. G. 
Published: January 2023

AbstractIn these studies, we determined whether there are receptors for the anaphylatoxin C5a (C5aR, CD88) on human mesangial cells (HMC). To prepare Abs to C5aR, we first synthesized an immunogenic peptide spanning residues 8–32 of the molecule, and this peptide was used to immunize rabbits. Anti-C5aR antiserum, but not preimmune serum, stained fixed and unfixed HMC in culture. By Western blotting anti-C5aR, Abs identified a 49.6-kDa protein in HMC. By reverse-transcription PCR, a cDNA product of 558 bp was amplified corresponding to the expected size of C5aR cDNA. A cDNA of the same size was amplified simultaneously from human PBL. Restriction mapping of the products amplified from HMC and from PBL gave restriction fragments of the same size. Incubation of HMC with increasing doses of C5a caused a progressive increase in the levels of the transcription factors activator protein-1 (AP-1) and cAMP response element binding protein (CREB), but C5a had no effect on the level of nuclear factor-κB (NF-κB). The effects of C5a on AP-1 were concentration and time dependent and peaked after 60 min. In contrast, the C5a metabolite C5adesArg had no significant effect on AP-1 levels. Preincubation of HMC with rabbit anti-C5aR antiserum inhibited partially the effect of C5a on AP-1. However, anti-C5aR Abs alone had no appreciable effects on AP-1. C5a caused a significant up-regulation of mRNA for the early response genes c-jun and c-fos on HMC. These results provide evidence for the presence of C5aR in adult HMC in culture and indicate that, after binding to C5aR, the anaphylatoxin C5a causes significant up-regulation of certain transcription factors and early response genes.
Theiler’s Virus Infection of Genetically Susceptible Mice Induces Central Nervous System-Infiltrating CTLs with no Apparent Viral or Major Myelin Antigenic Specificity
Authors: Lin Xiaoqi , Pease Larry R. , Murray Paul D. , Rodriguez Moses 
Published: January 2023

AbstractIntracranial infection of susceptible mice with Theiler’s virus results in persistent infection and spinal cord demyelination similar to human multiple sclerosis. While central nervous system infiltrating lymphocytes (CNS-ILs) in these mice display no virus-specific CTL activity, the cells were found to be activated killers using a specificity-independent assay. We previously demonstrated that the depletion of T cells in persistently infected mice significantly decreases demyelinating disease. Consequently, we have investigated the killing pathways employed by CNS-ILs that are isolated from persistently infected animals, the relative contribution of CD4 and CD8 cells in the generation of these CTLs, and the reactivity of this cell population to two putative autoantigens in the CNS. In vitro or in vivo manipulation of T cell populations using Abs or genetic knockout strategies demonstrate that the cytotoxic activity is primarily mediated by CD8+ T cells, and that perforin is an important molecule in the effector pathway. Since effector functions in infected mice were not inhibited by the depletion of CD4 cells with mAb but was blocked genetically in CD4 knockout mice, CD4+ T cells appear to play a helper role in the generation of CD8+ CTLs. We found no evidence of autoimmune-mediated demyelination, as the CD8+ CTLs were not reactive to two major myelin autoantigens, myelin basic protein and proteolipid protein. Our finding that CNS-ILs that are isolated from mice susceptible to persistent virus infection are neither specific for virus or myelin autoantigens is consistent with the possibility that CD8+ CTLs mediate CNS damage as a result of nonspecific activation by virus.
Cutting Edge: Antigen-Dependent Regulation of Telomerase Activity in Murine T Cells
Authors: Hathcock Karen S. , Weng Nan-ping , Merica Rebecca , Jenkins Marc K. , Hodes Richard 
Published: January 2023

Abstract
Telomeres, structures on the ends of linear chromosomes, function to maintain chromosomal integrity. Telomere shortening occurs with cell division and provides a mechanism for limiting the replicative potential of normal human somatic cells. Telomerase, a ribonucleoprotein enzyme, synthesizes telomeric repeats on chromosomal termini, potentially extending the capacity for cell division. The present study demonstrates that resting T cells express little/no activity, and optimal Ag-specific induction of telomerase activity in vitro requires both TCR and CD28-B7 costimulatory signals. Regulation of telomerase in T cells during in vivo Ag-dependent activation was also assessed by adoptive transfer of TCR transgenic T cells and subsequent Ag challenge. Under these conditions, telomerase was induced in transgenic T cells coincident with a phase of extensive clonal expansion. These findings suggest that telomerase may represent an adoptive response that functions to preserve replicative potential in Ag-reactive lymphocytes.
Factors Involved in the Differentiation of TGF-β-Producing Cells from Naive CD4+ T Cells: IL-4 and IFN-γ Have Opposing Effects, While TGF-β Positively Regulates Its Own Production
Authors: Seder Robert A. , Marth Thomas , Sieve Myra C. , Strober Warren , Letterio John J. , Roberts Anita B. , Kelsall Brian 
Published: January 2023

AbstractTGF-β has been shown to play a central role in regulating inflammatory responses; thus, understanding the factors involved in the generation of TGF-β-producing cells could lead to interventions that are useful in effecting disease progression. In initial studies, the capacity of naive CD4+ T cells from TCR transgenic (Tg) mice to produce TGF-β following primary and secondary stimulation was assessed. TGF-β, IL-4, or IFN-γ production could not be detected from highly purified naive CD4+/lymphocyte endothelial cell adhesion molecule (LECAM)-1high cells following primary stimulation for 36 h with plate-bound anti-CD3, anti-CD28, and IL-2. This population was subsequently used to study the differentiation of TGF-β-producing CD4+ T cells. In further studies, naive CD4+/LECAM-1high cells from TCR transgenic mice of both the BALB/c and B10.A backgrounds were stimulated with T-depleted spleen cells (TDS) and specific peptide in the presence of various cytokines and/or cytokine antagonists for 5 days, restimulated, and TGF-β, IL-4, and IFN-γ production were measured. Priming conditions favoring high IL-4 production and/or low IFN-γ production greatly enhanced TGF-β production in secondary cultures. Furthermore, the presence of IL-10 in cultures was associated with an increase in TGF-β production following restimulation. The importance of IL-4 and IFN-γ in regulating TGF-β production was confirmed in studies showing that cells from IFN-γ−/− mice produced more TGF-β, while cells from IL-4−/− mice produced less TGF-β compared with wild-type controls. Finally, the addition of exogenous TGF-β to priming cultures significantly enhanced the production of TGF-β upon restimulation, demonstrating that TGF-β has a role in self-regulating its own production.
Macrophage-Derived Nitric Oxide Regulates T Cell Activation via Reversible Disruption of the Jak3/STAT5 Signaling Pathway
Authors: Bingisser Roland M. , Tilbrook Peta A. , Holt Patrick G. , Kees Ursula R. 
Published: January 2023

AbstractNitric oxide (NO) has been invoked as an important pathogenic factor in a wide range of immunologically mediated diseases. The present study demonstrates that macrophage-derived NO may conversely function to fine tune T cell-mediated inflammation via reversible dephosphorylation of intracellular signaling molecules, which are involved in the control of T cell proliferation. Thus, T cells activated in the presence of alveolar macrophages are unable to proliferate despite expression of IL-2R and secretion of IL-2. This process is reproduced by the NO generator S-nitroso-N-acetylpenicillamine and is inhibitable by the NO synthase inhibitor NG-methyl-l-arginine. Analysis of T cell lysates by immunoprecipitation with specific Abs and subsequent immunoblotting indicated marked reduction of tyrosine phosphorylation of Jak3 and STAT5 mediated by NO. Further studies indicated that NO-mediated T cell suppression was reversible by the guanylate cyclase inhibitors methylene blue and LY-83583 and was reproduced by a cell-permeable analogue of cyclic GMP, implicating guanylate cyclase activation as a key step in the inhibition of T cell activation by NO.
The Trophic Action of IL-7 on Pro-T Cells: Inhibition of Apoptosis of Pro-T1, -T2, and -T3 Cells Correlates with Bcl-2 and Bax Levels and Is Independent of Fas and p53 Pathways
Authors: Kim Kyungjae , Lee Chong-kil , Sayers Thomas J. , Muegge Kathrin , Durum Scott K. 
Published: January 2023

Abstract
Signals from the IL-7R are essential for normal thymocyte development. We isolated thymocytes from early developmental stages and observed that suspensions of pro-T1, -T2, and -T3 cells rapidly died in culture. Addition of IL-7 promoted their survival, but did not induce cell division. Pro-T4 cells did not undergo rapid cell death, and their survival was therefore independent of IL-7. Death in the absence of IL-7 showed the hallmarks of apoptosis, including DNA fragmentation and annexin V binding; however, caspase inhibitors blocked DNA fragmentation, but did not block cell death. The trophic effect of IL-7 was partially inhibited by blocking protein synthesis. The p53 pathway was not involved in this death pathway, since pro-T cells from p53−/− mice also underwent cell death in the absence of IL-7. The Fas/Fas ligand pathway was not involved in cell death, since Fas-deficient pro-T cells died normally in the absence of IL-7, anti-Fas Abs did not protect cells from death in the absence of IL-7, and Fas expression was undetectable on cells at these stages. The IL-7 trophic affect correlated with increased intracellular levels of Bcl-2 and decreased levels of Bax, whereas no Bcl-XL, Bcl-w, or Bad was detectable. Thus, maintaining a favorable Bcl-2/Bax ratio may account for the trophic action of IL-7.