bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sterically Stabilized Cationic Liposomes Improve the Uptake and Immunostimulatory Activity of CpG Oligonucleotides
Authors: Gursel Ihsan , Gursel Mayda , Ishii Ken J. , Klinman Dennis M. 
Published: April 2014

AbstractImmunostimulatory CpG oligonucleotides (ODN) show promise as immune adjuvants, anti-allergens, and immunoprotective agents. Increasing the bioavailability and duration of action of CpG ODN should improve their therapeutic utility. Encapsulating ODN in sterically stabilized cationic liposomes provides protection from serum nucleases while facilitating uptake by B cells, dendritic cells, and macrophages. In a pathogen challenge model, sterically stabilized cationic liposomes encapsulation doubled the duration of CpG ODN-induced immune protection. In an immunization model, coencapsulation of CpG ODN with protein Ag (OVA) magnified the resultant Ag-specific IFN-γ and IgG responses by 15- to 40-fold compared with Ag plus CpG ODN alone. These findings support the use of sterically stabilized cationic liposomes to significantly enhance the therapeutic efficacy of CpG ODN.
Cathelicidin Family of Antibacterial Peptides CAP18 and CAP11 Inhibit the Expression of TNF-α by Blocking the Binding of LPS to CD14+ Cells
Authors: Nagaoka Isao , Hirota Satoko , Niyonsaba François , Hirata Michimasa , Adachi Yoshiyuki , Tamura Hiroshi , Heumann Didier 
Published: April 2014

AbstractMammalian myeloid and epithelial cells express several kinds of antibacterial peptides (α-/β-defensins and cathelicidins) that contribute to the innate host defense by killing invading micro-organisms. In this study we evaluated the LPS-neutralizing activities of cathelicidin peptides human CAP18 (cationic antibacterial proteins of 18 kDa) and guinea pig CAP11 using the CD14+ murine macrophage cell line RAW264.7 and the murine endotoxin shock model. Flow cytometric analysis revealed that CAP18 and CAP11 inhibited the binding of FITC-conjugated LPS to RAW264.7 cells. Likewise, Northern and Western blot analyses indicated that CAP18 and CAP11 suppressed LPS-induced TNF-α mRNA and protein expression by RAW264.7 cells. Interestingly, CAP18 and CAP11 possessed LPS-binding activities, and they strongly suppressed the interaction of LPS with LPS binding protein that mediates the transport of LPS to CD14 to facilitate the activation of CD14+ cells by LPS. Moreover, when CAP18 and CAP11 were preincubated with RAW264.7 cells, they bound to the cell surface CD14 and inhibited the binding of FITC-LPS to the cells. Furthermore, in the murine endotoxin shock model, CAP18 or CAP11 administration inhibited the binding of LPS to CD14+ cells (peritoneal macrophages) and suppressed LPS-induced TNF-α expression by these cells. Together these observations indicate that cathelicidin peptides CAP18 and CAP11 probably exert protective actions against endotoxin shock by blocking the binding of LPS to CD14+ cells, thereby suppressing the production of cytokines by these cells via their potent binding activities for LPS and CD14.
Mycobacteria-Induced TNF-α and IL-10 Formation by Human Macrophages Is Differentially Regulated at the Level of Mitogen-Activated Protein Kinase Activity
Authors: Reiling Norbert , Blumenthal Antje , Flad Hans-Dieter , Ernst Martin , Ehlers Stefan 
Published: April 2014

AbstractThe clinical course of mycobacterial infections is linked to the capacity of pathogenic strains to modulate the initial antimycobacterial response of the macrophage. To elucidate some of the mechanisms involved, we studied early signal transduction events leading to cytokine formation by human monocyte-derived macrophages (MDM) in response to clinical isolates of Mycobacterium avium. TNF-α production induced by M. avium was inhibited by anti-CD14 mAbs, but not by Abs against the macrophage mannose receptor. Analysis of mitogen-activated protein (MAP) kinase activation (extracellular signal-regulated kinase 1/2, p38, and c-Jun NH2-terminal kinase) showed a rapid phosphorylation of all three subfamilies in response to M. avium, which was inhibited by anti-CD14 Abs. Using highly specific inhibitors of p38 (SB203580) and MAP kinase kinase-1 (PD98059), we found that activation of the extracellular signal-regulated kinase pathway, but not of p38, was essential for the M. avium-induced TNF-α formation. In contrast, IL-10 production was abrogated by the p38 inhibitor, but not by the MAP kinase kinase-1 inhibitor. In conclusion, M. avium-induced secretion of TNF-α and IL-10 by human macrophages is differentially regulated at the level of MAP kinase activity.
IL-12-Independent IFN-γ Production by T Cells in Experimental Chagas’ Disease Is Mediated by IL-18
Authors: Müller Uwe , Köhler Gabriele , Mossmann Horst , Schaub Günter A. , Alber Gottfried , Di Santo James P. , Brombacher Frank , Hölscher Christoph 
Published: April 2014

AbstractIL-12p35-deficient (IL-12p35−/−) mice were highly susceptible to Trypanosoma cruzi infection and succumbed during acute infection, demonstrating the crucial importance of endogenous IL-12 in resistance to experimental Chagas’ disease. Delayed immune responses were observed in mutant mice, although comparable IFN-γ and TNF-α blood levels as in wild-type mice were detected 2 wk postinfection. In vivo and in vitro analysis demonstrated that T cells, but not NK cells, were recruited to infected organs. Analysis of mice double deficient in the recombinase-activating gene 2 (RAG2) and IL-12p35, as well as studies involving T cell depletion, identified CD4+ T cells as the cellular source for IL-12-independent IFN-γ production. IL-18 was induced in IL-12p35−/− mice and was responsible for IFN-γ production, as demonstrated by in vivo IL-18 neutralization studies. In conclusion, evidence is presented for an IL-12-independent IFN-γ production in experimental Chagas’ disease that is T cell and IL-18 dependent.
N-Linked Glycosylations at Asn26 and Asn114 of Human MD-2 Are Required for Toll-Like Receptor 4-Mediated Activation of NF-κB by Lipopolysaccharide
Authors: Ohnishi Takahiro , Muroi Masashi , Tanamoto Ken-ichi 
Published: April 2014

Abstract
MD-2 is physically associated with Toll-like receptor 4 (TLR4) and is required for TLR4-mediated LPS signaling. Western blotting analysis revealed the presence of three forms of human (h)MD-2 with different electrophoretic mobilities. After N-glycosidase treatment of the cellular extract prepared from cells expressing hMD-2, only a single form with the fastest mobility was detected. Mutation of either one of two potential glycosylation sites (Asn26 and Asn114) of MD-2 resulted in the disappearance of the slowest mobility form, and only the fastest form was detected in hMD-2 carrying mutations at both Asn26 and Asn114. Although these mutants were expressed on the cell surface and maintained its ability to associate with human TLR4, these mutations or tunicamycin treatment substantially impaired the ability of MD-2 to complement TLR4-mediated activation of NF-κB by LPS. LPS binding to cells expressing CD14, TLR4, and MD-2 was unaffected by these mutations. These observations demonstrate that hMD-2 undergoes N-linked glycosylation at Asn26 and Asn114, and that these glycosylations are crucial for TLR4-mediated signal transduction of LPS.
Synergistic Induction of Apoptosis in Primary CD4+ T Cells by Macrophage-Tropic HIV-1 and TGF-β1
Authors: Wang Jinhai , Guan Ennan , Roderiquez Gregory , Norcross Michael A. 
Published: April 2014

AbstractDepletion of CD4+ T lymphocytes is a central immunological characteristic of HIV-1 infection. Although the mechanism of such CD4+ cell loss following macrophage-tropic (R5) HIV-1 infection remains unclear, interactions between viral and host cell factors are thought to play an important role in the pathogenesis of HIV-1 disease. Based on the observation that TGF-β1 enhanced expression of HIV chemokine coreceptors, the role of this host factor in virus effects was investigated using PBLs cultured in a nonmitogen-added system in the absence or presence of TGF-β1. Most CD4 cells in such cultures had the phenotype CD25−CD69−DR−Ki67− and were CD45RObrightCD45RAdim. Cultured cells had increased expression of CCR5 and CXCR4 and supported both HIV-1 entry and completion of viral reverse transcription. Virus production by cells cultured in the presence of IL-2 was inhibited by TGF-β1, and this inhibition was accompanied by a loss of T cells from the culture and an increase in CD4+ T cell apoptosis. Whereas R5X4 and X4 HIV-1 infection was sufficient to induce T cell apoptosis, R5 HIV-1 failed to induce apoptosis of PBLs in the absence of TGF-β1 despite the fact that R5 HIV-1 depletes CD4+ T cells in vivo. Increased apoptosis with HIV and TGF-β1 was associated with reduced levels of Bcl-2 and increased expression of apoptosis-inducing factor, caspase-3, and cleavage of BID, c-IAP-1, and X-linked inhibitor of apoptosis. These results show that TGF-β1 promotes depletion of CD4+ T cells after R5 HIV-1 infection by inducing apoptosis and suggest that TGF-β1 might contribute to the pathogenesis of HIV-1 infection in vivo.
Complementary Antitumor Immunity Induced by Plasmid DNA Encoding Secreted and Cytoplasmic Human ErbB-2
Authors: Piechocki Marie P. , Pilon Shari A. , Wei Wei-Zen 
Published: April 2014

AbstractA plasmid DNA was constructed to encode the N-terminal 505 aa of human ErbB-2 (E2, HER-2/neu) and designated as secreted ErbB-2 (secE2). Recombinant secE2 protein was detected in the transfected cells and was secreted as an 80-kDa glycoprotein. Vaccination of BALB/c mice with secE2 DNA induced both IgG1 and IgG2a ErbB-2-specific Abs and protected ∼90% of mice against mouse mammary tumor D2F2, which expressed human ErbB-2 (D2F2/E2). The efficacy of secE2 vaccine was comparable with that of wild-type ErbB-2 DNA, which encodes the entire 1258 aa of ErbB-2 protein, induced only IgG2a E2-specific Abs, and stimulated greater CTL activity. Immune lymphocytes were stimulated in vitro with irradiated 3T3 cells, which expressed ErbB-2, Kd, and B7.1. CTL activity was measured by the lysis of E2-positive target cells and by intracellular IFN-γ production. To enhance CTL activation, mice were immunized with a combination of secE2 and cytoplasmic E2 (cytE2); the latter encodes the 1258-aa ErbB-2 protein that was released into the cytoplasm upon synthesis. Significant increase in CTL activity was demonstrated after mice were immunized with the combined vaccines and all mice were protected from D2F2/E2 tumor growth. Therefore, secE2, which induced Th2 Ab and weak CTL, conferred similar protection as E2, which induced Th1 Ab and strong CTL. Combined vaccination with secE2 and cytE2 resulted in Th2 Ab, strong CTL, and the most effective protection against tumor growth. The strategy of coimmunization with DNA that direct Ags to different subcellular compartments may be adapted as appropriate to optimize immune outcome.
The Effect of an Anti-HLA-B27 Immune Response on CTL Recognition ofChlamydia
Authors: Popov Igor , Dela Cruz Charles S. , Barber Brian H. , Chiu Basil , Inman Robert D. 
Published: April 2014

AbstractThe interplay between triggering bacteria and HLA-B27 in the pathogenesis of the spondyloarthropathies remains one of the most active areas of investigation in the rheumatic diseases. This has proved difficult to study systematically in the clinical setting, and in this study we utilized a rat model to address the influence that B27-related immunity may have on the process of generating anti-Chlamydia immunity. When splenocytes from HLA-B27 DNA-immunized Lewis (LEW) animals received restimulation in vitro with Chlamydia-treated cells from B27-transgenic LEW rats, we observed that in addition to the expected CTL recognition of HLA-B27, there was also anti-Chlamydia CTL killing of Chlamydia-sensitized syngeneic fibroblast targets. This was not seen when responding cells in vitro were naive LEW splenocytes. To confirm the existence of CTLs recognizing both HLA-B27 and Chlamydia, LEW rats were immunized with B27-transgenic LEW cells, instead of the B27 DNA construct. Splenocytes from the immune rats were restimulated in vitro with Chlamydia-treated B27-transgenic LEW cells. In this instance, the CTLs retained the allele-specific recognition of HLA-B27, as well as recognition of Chlamydia-sensitized syngeneic fibroblasts. Thus, if there is prior expansion of an immune response against HLA-B27, then the resulting splenocytes demonstrate a reduced threshold for generating a primary anti-Chlamydia CTL response. These studies implicate a dynamic interrelationship between recognition of HLA-B27 and Chlamydia trachomatis. The results may have implications for deciphering the cellular basis of Chlamydia-induced reactive arthritis.
Borrelia burgdorferi-Induced Inflammation Facilitates Spirochete Adaptation and Variable Major Protein-Like Sequence Locus Recombination
Authors: Anguita Juan , Thomas Venetta , Samanta Swapna , Persinski Rafal , Hernanz Carmen , Barthold Stephen W. , Fikrig Erol 
Published: April 2014

AbstractSpirochete adaptation in vivo is associated with preferential Borrelia burgdorferi gene expression. In this paper, we show that the administration of B. burgdorferi-immune sera to IFN-γR-deficient mice that have been infected with B. burgdorferi N40 for 4 days causes spirochete clearance. In contrast, immune sera-mediated clearance of B. burgdorferi N40 is not apparent in immunocompetent mice, suggesting a role for IFN-γ-mediated responses in B. burgdorferi N40 host adaptation. B. burgdorferi-immune sera also induces clearance of B. burgdorferi N40 that have been passaged in vitro 75 times (B. burgdorferi N40-75), a derivative of B. burgdorferi N40 that does not rapidly adapt in vivo in immunocompetent mice. B. burgdorferi N40-75 produce lower levels of IFN-γ and IL-12 in mice than does B. burgdorferi N40, and the administration of these cytokines to B. burgdorferi N40-75-infected mice results in an increased spirochetal burden, further indicating that IFN-γ-mediated events promote B. burgdorferi survival. Differential immunoscreening and RT-PCR demonstrate that IFN-γ-mediated signals facilitate spirochete recombination at the variable major protein like sequence locus, a site for early antigenic variation in vivo, and that recombination rates by B. burgdorferi N40 are lower in IFN-γR-deficient mice than in control animals. These results suggest that the murine immune response can promote the in vivo adaptation of B. burgdorferi.
Sodium Stibogluconate Is a Potent Inhibitor of Protein Tyrosine Phosphatases and Augments Cytokine Responses in Hemopoietic Cell Lines
Authors: Pathak Manas K. , Yi Taolin 
Published: April 2014

AbstractUsing in vitro protein tyrosine phosphatase (PTPase) assays, we found that sodium stibogluconate, a drug used in treatment of leishmaniasis, is a potent inhibitor of PTPases Src homology PTPase1 (SHP-1), SHP-2, and PTP1B but not the dual-specificity phosphatase mitogen-activated protein kinase phosphatase 1. Sodium stibogluconate inhibited 99% of SHP-1 activity at 10 μg/ml, a therapeutic concentration of the drug for leishmaniasis. Similar degrees of inhibition of SHP-2 and PTP1B required 100 μg/ml sodium stibogluconate, demonstrating differential sensitivities of PTPases to the inhibitor. The drug appeared to target the SHP-1 domain because it showed similar in vitro inhibition of SHP-1 and a mutant protein containing the SHP-1 PTPase domain alone. Moreover, it forms a stable complex with the PTPase: in vitro inhibition of SHP-1 by the drug was not removed by a washing process effective in relieving the inhibition of SHP-1 by the reversible inhibitor suramin. The inhibition of cellular PTPases by the drug was suggested by its rapid induction of tyrosine phosphorylation of cellular proteins in Baf3 cells and its augmentation of IL-3-induced Janus family kinase 2/Stat5 tyrosine phosphorylation and proliferation of Baf3 cells. The augmentation of the opposite effects of GM-CSF and IFN-α on TF-1 cell growth by the drug indicated its broad activities in the signaling of various cytokines. These data represent the first evidence that sodium stibogluconate inhibits PTPases and augments cytokine responses. Our results provide novel insights into the pharmacological effects of the drug and suggest potential new therapeutic applications.
CTA1-DD-Immune Stimulating Complexes: a Novel, Rationally Designed Combined Mucosal Vaccine Adjuvant Effective with Nanogram Doses of Antigen
Authors: Mowat Allan M. I. , Donachie Anne M. , Jägewall Sara , Schön Karin , Löwenadler Björn , Dalsgaard Kristian , Kaastrup Peter , Lycke Nils 
Published: April 2014

AbstractMucosally active vaccine adjuvants that will prime a full range of local and systemic immune responses against defined antigenic epitopes are much needed. Cholera toxin and lipophilic immune stimulating complexes (ISCOMS) containing Quil A can both act as adjuvants for orally administered Ags, possibly by targeting different APCs. Recently, we have been successful in separating the adjuvant and toxic effects of cholera toxin by constructing a gene fusion protein, CTA1-DD, that combines the enzymatically active CTA1-subunit with a B cell-targeting moiety, D, derived from Staphylococcus aureus protein A. Here we have extended this work by combining CTA1-DD with ISCOMS, which normally target dendritic cells and/or macrophages. ISCOMS containing a fusion protein comprising the OVA323–339 peptide epitope linked to CTA1-DD were highly immunogenic when given in nanogram doses by the s.c., oral, or nasal routes, inducing a wide range of T cell-dependent immune responses. In contrast, ISCOMS containing the enzymatically inactive CTA1-R7K-DD mutant protein were much less effective, indicating that at least part of the activity of the combined vector requires the ADP-ribosylating property of CTA1. No toxicity was observed by any route. To our knowledge, this is the first report on the successful combination of two mechanistically different principles of adjuvant action. We conclude that rationally designed vectors consisting of CTA1-DD and ISCOMS may provide a novel strategy for the generation of potent and safe mucosal vaccines.
Urokinase Plasminogen Activator and Plasmin Efficiently Convert Hemofiltrate CC Chemokine 1 into Its Active [9–74] Processed Variant
Authors: Vakili Jalal , Ständker Ludger , Detheux Michel , Vassart Gilbert , Forssmann Wolf-Georg , Parmentier Marc 
Published: April 2014

Abstract
We have previously isolated from human hemofiltrate an N-terminally truncated form of the hemofiltrate CC chemokine 1 (HCC-1), and characterized HCC-1[9–74] as a strong agonist of CCR1, CCR5, and to a lower extent CCR3. In this study, we show that conditioned media from human tumor cell lines PC-3 and 143B contain proteolytic activities that convert HCC-1 into the [9–74] form. This activity was fully inhibited by inhibitors of urokinase-type plasminogen activator (uPA), including PA inhibitor-1, an anti-uPA mAb, and amiloride. Pure preparations of uPA processed HCC-1 with high efficiency, without further degrading HCC-1[9–74]. Plasmin could also generate HCC-1[9–74], but degraded the active product as well. The kinetics of HCC-1 cleavage by uPA and plasmin (Michaelis constant, Km, of 0.76 ± 0.4 μM for uPA, and 0.096 ± 0.05 μM for plasmin; catalytic rate constant, kcat: 3.36 ± 0.96 s−1 for uPA and 6 ± 3.6 s−1 for plasmin) are fully compatible with a role in vivo. The activation of an abundant inactive precursor into a broad-spectrum chemokine by uPA and plasmin directly links the production of uPA by numerous tumors and their ability to recruit mononuclear leukocytes, without the need for the transcriptional activation of chemokine genes.
Calcium-Independent Phospholipase A2 Is Required for Human Monocyte Chemotaxis to Monocyte Chemoattractant Protein 1
Authors: Carnevale Kevin A. , Cathcart Martha K. 
Published: April 2014

Abstract
Monocyte chemoattractant protein 1 (MCP-1) has an important influence on monocyte migration into sites of inflammation. Our understanding of the signal transduction pathways involved in the response of monocytes to MCP-1 is quite limited yet potentially significant for understanding and manipulating the inflammatory response. Prior studies have demonstrated a crucial regulatory role for cytosolic phospholipase A2 (cPLA2) in monocyte chemotaxis to MCP-1. In these studies we investigated the role for another PLA2, calcium-independent PLA2 (iPLA2) in comparison to cPLA2. Pharmacological inhibitors of PLA2 were found to substantially inhibit chemotaxis. Using antisense oligodeoxyribonucleotide treatment we found that iPLA2 expression is required for monocyte migration to MCP-1. Complete blocking of the chemotactic response was observed with inhibition of either iPLA2 or cPLA2 expression by their respective antisense oligodeoxyribonucleotide. In reconstitution experiments, lysophosphatidic acid completely restored MCP-1-stimulated migration in iPLA2-deficient monocytes, whereas lysophosphatidic acid was without effect in restoring migration in cPLA2-deficient monocytes. To the contrary, arachidonic acid fully restored migration of cPLA2-deficient monocytes while having no effect on the iPLA2-deficient monocytes. Additional studies revealed that neither enzyme appears to be upstream of the other indicating that iPLA2 and cPLA2 represent parallel regulatory pathways. These data demonstrate novel and distinct roles for these two phospholipases in this critical step in inflammation.
Trypanocidal Drug Benznidazole Impairs Lipopolysaccharide Induction of Macrophage Nitric Oxide Synthase Gene Transcription Through Inhibition of NF-κB Activation
Authors: Piaggio Eliane , Sancéau Josiane , Revelli Silvia , Bottasso Oscar , Wietzerbin Juana , Serra Esteban 
Published: April 2014

Abstract
In murine macrophages, inducible NO synthase II (NOSII) gene expression is promoted at a transcriptional level by LPS and/or IFN-γ with benznidazole (BZL), a trypanocidal drug, acting to down-regulate NOSII gene induction and hence inhibiting NO production. By performing transient transfection experiments, we now report that BZL also inhibited the expression of NOSII gene promoter or multimerized NF-κB binding site controlled reporter genes. By contrast, no effect was observed on the expression of a reporter gene under the control of the NOSII promoter-derived IFN regulatory factor element. EMSAs demonstrated that BZL inhibited the nuclear availability of NF-κB in stimulated macrophages. NF-κB is activated in macrophages by phosphorylation, ubiquitination, and subsequent proteolysis of IκB. Within this setting, Western blot was also performed to show that BZL blocked IκBα degradation. Collectively, these results demonstrate that BZL is able to specifically inhibit macrophage NF-κB activation after LPS plus IFN-γ stimulation.