bluuebunny/crossref_metadata_2025_split huggingface dataset:
Activation of the Mouse Ig Germline ε Promoter by IL-4 Is Dependent on AP-1 Transcription Factors
Authors: Shen Ching-Hung , Stavnezer Janet 
Published: April 2014

AbstractInduction of germline (GL) ε transcripts, an essential step preceding Ig isotype switching to IgE, requires activation of transcription factors by IL-4 and a B cell activator, e.g., CD40 ligand or LPS. We demonstrate that AP-1 (Fos and Jun), induced transiently by CD40 ligand or LPS, binds a DNA element in the mouse GL ε promoter. AP-1 synergizes with Stat6 to activate both the intact GL ε promoter and a minimal heterologous promoter driven by the AP-1 and Stat6 sites of the mouse GL ε promoter. By contrast, C/EBPβ, which trans-activates the human GL ε promoter, inhibits IL-4 induction of the mouse promoter, probably by attenuating the synergistic interaction between AP-1 and Stat6. Furthermore, AP-1 does not trans-activate the human GL ε promoter. Thus, induction of GL ε transcripts in mice and humans may be regulated differently. In addition, although mouse GL ε transcripts have a half-life of ∼100 min, the RNA level continues to increase for up to 24 h, and the promoter appears to be active for at least 2 days after B cell activation. Altogether, these data suggest that induction of AP-1 activity, although transient, is required for activation of the mouse GL ε promoter by IL-4-induced Stat6.
Isolation of the Melanoma-Associated Antigen p23 Using Antibody Phage Display
Authors: Li Jian , Pereira Sarita , Van Belle Patricia , Tsui Ping , Elder David , Speicher David , Deen Keith , Linnenbach Alban , Somasundaram Rajasekharan , Swoboda Rolf , Herlyn Dorothee 
Published: April 2014

Abstract
The general responsiveness of human melanoma to immunotherapy has been well established, but active immunotherapy of melanoma has been hampered by insufficient information on the immunogenicity of melanoma-associated Ags in patients. In this study, we isolated a recombinant phage-Fab clone (A10-5) from a phage-Fab library derived from the B cells of a melanoma patient in remission after immunotherapy. Purified A10-5 Fab bound at high levels to cultured melanoma cell lines and to tissue sections of metastatic and vertical growth phase primary melanoma, but not to radial growth phase primary melanoma, nevi, or normal skin. A10-5 Fab bound to both the surface and the cytoplasm of cultured melanoma cells, but only to the cytoplasm of cultured fibroblasts. Western blot analysis revealed A10-5 Fab reactivity with a 33- and a 23-kDa glycoprotein under nonreducing conditions, and with a 23-kDa protein only under reducing conditions. A cDNA with an open reading frame predicted to encode a 23-kDa protein was cloned by screening a melanoma cell cDNA library with A10-5 Fab. This protein (p23) is the human homologue of the murine tumor transplantation Ag P198 that interacts with the cytoplasmic domain of ErbB-3 expressed by melanoma cells. Thus, the Ab phage display method has identified a novel, stage-specific melanoma-associated Ag that may have therapeutic and diagnostic value.
A Totally Synthetic Polyoxime Malaria Vaccine Containing Plasmodium falciparum B Cell and Universal T Cell Epitopes Elicits Immune Responses in Volunteers of Diverse HLA Types
Authors: Nardin Elizabeth H. , Calvo-Calle J. Mauricio , Oliveira Giane A. , Nussenzweig Ruth S. , Schneider Martin , Tiercy Jean-Marie , Loutan Louis , Hochstrasser Denis , Rose Keith 
Published: April 2014

Abstract
This open-labeled phase I study provides the first demonstration of the immunogenicity of a precisely defined synthetic polyoxime malaria vaccine in volunteers of diverse HLA types. The polyoxime, designated (T1BT*)4-P3C, was constructed by chemoselective ligation, via oxime bonds, of a tetrabranched core with a peptide module containing B cell epitopes and a universal T cell epitope of the Plasmodium falciparum circumsporozoite protein. The triepitope polyoxime malaria vaccine was immunogenic in the absence of any exogenous adjuvant, using instead a core modified with the lipopeptide P3C as an endogenous adjuvant. This totally synthetic vaccine formulation can be characterized by mass spectroscopy, thus enabling the reproducible production of precisely defined vaccines for human use. The majority of the polyoxime-immunized volunteers (7/10) developed high levels of anti-repeat Abs that reacted with the native circumsporozoite on P. falciparum sporozoites. In addition, these seven volunteers all developed T cells specific for the universal epitope, termed T*, which was originally defined using CD4+ T cells from protected volunteers immunized with irradiated P. falciparum sporozoites. The excellent correlation of T*-specific cellular responses with high anti-repeat Ab titers suggests that the T* epitope functioned as a universal Th cell epitope, as predicted by previous peptide/HLA binding assays and by immunogenicity studies in mice of diverse H-2 haplotypes. The current phase I trial suggests that polyoximes may prove useful for the development of highly immunogenic, multicomponent synthetic vaccines for malaria, as well as for other pathogens.
Apoptosis Enhancement by the HIV-1 Nef Protein
Authors: Rasola Andrea , Gramaglia Daniela , Boccaccio Carla , Comoglio Paolo M. 
Published: April 2014

Abstract
The HIV-1 nef gene, essential for AIDS pathogenesis, encodes a 27-kDa protein (Nef) whose biochemical and biological functions are unclear. It has been suggested that Nef expression contributes to the T cell depletion observed during the disease by promoting their apoptosis. We report that in CD4+ human lymphoblastoid cell lines transfected with the nef cDNA obtained from three different HIV-1 strains, expression of the Nef protein enhances and accelerates the response to four unrelated apoptotic agents (staurosporine, anisomycin, camptothecin, and etoposide) but not to an anti-Fas agonist Ab. Nef reduces the expression of the anti-apoptotic proteins Bcl-2 and Bcl-XL and induces a striking enhancement of apoptotic hallmarks, including mitochondrial depolarization, exposure of phosphatidylserine on the cell surface, activation of caspase-3, and cleavage of the caspase target poly(ADP-ribose) polymerase. Interestingly, the peptide Z-Val-Ala-DL-Asp-fluoromethylketone (a broad-spectrum caspase inhibitor) reduces, but does not abolish, phosphatidylserine exposure, suggesting that Nef also activates a caspase-independent apoptotic pathway. Surprisingly, Nef expression increases DNA degradation but without causing oligonucleosomal fragmentation. An increased apoptotic response and down-modulation of Bcl-2/Bcl-XL following Nef expression are observed also in NIH-3T3 fibroblasts. These data show that Nef enhances programmed cell death in different cell types by affecting multiple critical components of the apoptotic machinery independently from the Fas pathway.
Cutting Edge: A NK Complex-Linked Locus Governs Acute Versus Latent Herpes Simplex Virus Infection of Neurons
Authors: Pereira Rosemarie A. , Scalzo Anthony , Simmons Anthony 
Published: April 2014

Abstract
Herpes simplex causes latent infections that periodically reactivate. Specific immunization attempts are failing to control herpes, prompting a fresh look at which host responses predominate. We report a NK complex-linked genetic locus, Rhs1, whose alleles influence the magnitude of experimental herpes simplex. Rhs1 provided rapid control of primary infection but caused a reciprocal increase in the number of latently infected neurons. Thus, in principle, establishment of latency is a consequence of efficient front line defense against herpesvirus infection. Based on conservation between human and mouse NK complexes, the data predict the presence of a human Rhs1 orthologue on chromosome 12p12–13.
Mycobacterium leprae-Specific, HLA Class II-Restricted Killing of Human Schwann Cells by CD4+ Th1 Cells: A Novel Immunopathogenic Mechanism of Nerve Damage in Leprosy
Authors: Spierings Eric , de Boer Tjitske , Wieles Brigitte , Adams Linda B. , Marani Enrico , Ottenhoff Tom H. M. 
Published: April 2014

AbstractPeripheral nerve damage is a major complication of reversal (or type-1) reactions in leprosy. The pathogenesis of nerve damage remains largely unresolved, but detailed in situ analyses suggest that type-1 T cells play an important role. Mycobacterium leprae is known to have a remarkable tropism for Schwann cells of the peripheral nerve. Reversal reactions in leprosy are often accompanied by severe and irreversible nerve destruction and are associated with increased cellular immune reactivity against M. leprae. Thus, a likely immunopathogenic mechanism of Schwann cell and nerve damage in leprosy is that infected Schwann cells process and present Ags of M. leprae to Ag-specific, inflammatory type-1 T cells and that these T cells subsequently damage and lyse infected Schwann cells. Thus far it has been difficult to study this directly because of the inability to grow large numbers of human Schwann cells. We now have established long-term human Schwann cell cultures from sural nerves and show that human Schwann cells express MHC class I and II, ICAM-1, and CD80 surface molecules involved in Ag presentation. Human Schwann cells process and present M. leprae, as well as recombinant proteins and peptides to MHC class II-restricted CD4+ T cells, and are efficiently killed by these activated T cells. These findings elucidate a novel mechanism that is likely involved in the immunopathogenesis of nerve damage in leprosy.
Murine IL-10 Gene Transfer Inhibits Established Collagen-Induced Arthritis and Reduces Adenovirus-Mediated Inflammatory Responses in Mouse Liver
Authors: Quattrocchi Emilia , Dallman Margaret J. , Dhillon Amar P. , Quaglia Alberto , Bagnato Gianfilippo , Feldmann Marc 
Published: April 2014

AbstractThe effects of homologous IL-10 administration during an established autoimmune disease are controversial, given its reported immunostimulatory and immunosuppressive properties. Studies of collagen-induced arthritis have shown efficacy with repeated administrations of IL-10; however, when the EBV IL-10 homologue was administered via adenovirus gene transfer technology the results were equivocal. Therefore, the present study was undertaken to elucidate the effects of prolonged homologous IL-10 administration via adenovirus-mediated gene delivery on the progression of established arthritis. Collagen type II (CII)-immunized mice received i.v. injections of 107 or 108 PFU of an E1-deleted adenoviral vector containing the murine IL-10 gene (AdIL-10), after arthritis onset. Mice were monitored for 3 wk for disease progression, and gene transduction was assessed by quantification of serum mIL-10. CII-specific cell-mediated and humoral immune responses were analyzed by lymph node cell proliferation, cytokine production, and anti-CII Ab responses. Furthermore, because adenoviral vectors have been reported to induce organ dysfunction due to cell-mediated immune responses to the viral Ags, we have also evaluated delayed-type hypersensitivity responses and reactive hepatitis to the systemically delivered adenovirus and whether the IL-10 produced could influence those responses. Sustained suppression of autoimmune arthritis and elevated serum levels of IL-10 were achieved in our study. AdIL-10 treatment reduced cell-mediated immune reactivity, but did not affect humoral responses. Furthermore, IL-10 was able to reduce, but not totally abrogate, adenovirus-induced hepatic inflammation. These findings provide further insights into the diverse interplay of immune processes involved in autoimmune inflammation and the mechanism of cytokine immunotherapy.
Differential Regulation of Th1 and Th2 Functions of NKT Cells by CD28 and CD40 Costimulatory Pathways
Authors: Hayakawa Yoshihiro , Takeda Kazuyoshi , Yagita Hideo , Van Kaer Luc , Saiki Ikuo , Okumura Ko 
Published: April 2014

AbstractVα14 NKT cells produce large amounts of IFN-γ and IL-4 upon recognition of their specific ligand α-galactosylceramide (α-GalCer) by their invariant TCR. We show here that NKT cells constitutively express CD28, and that blockade of CD28-CD80/CD86 interactions by anti-CD80 and anti-CD86 mAbs inhibits the α-GalCer-induced IFN-γ and IL-4 production by splenic Vα14 NKT cells. On the other, the blockade of CD40-CD154 interactions by anti-CD154 mAb inhibited α-GalCer-induced IFN-γ production, but not IL-4 production. Consistent with these findings, CD28-deficient mice showed impaired IFN-γ and IL-4 production in response to α-GalCer stimulation in vitro and in vivo, whereas production of IFN-γ but not IL-4 was impaired in CD40-deficient mice. Moreover, α-GalCer-induced Th1-type responses, represented by enhanced cytotoxic activity of splenic or hepatic mononuclear cells and antimetastatic effect, were impaired in both CD28-deficient mice and CD40-deficient mice. In contrast, α-GalCer-induced Th2-type responses, represented by serum IgE and IgG1 elevation, were impaired in the absence of the CD28 costimulatory pathway but not in the absence of the CD40 costimulatory pathway. These results indicate that CD28-CD80/CD86 and CD40-CD154 costimulatory pathways differentially contribute to the regulation of Th1 and Th2 functions of Vα14 NKT cells in vivo.
Characterization of Mouse Carboxypeptidase N Small Active Subunit Gene Structure
Authors: Matthews Kirstin W. , Wetsel Rick A. 
Published: April 2014

Abstract
Carboxypeptidase N (CPN) is a plasma zinc metalloprotease comprised of two small subunits that have enzymatic activity, and two large subunits, which protect the enzyme from degradation. CPN cleaves the carboxyl-terminal amino acids arginine and lysine from biologically active peptides such as complement anaphylatoxins, kinins, and fibrinopeptides. To delineate the murine CPN small subunit coding region, gene structure, and chromosome location, cDNA and genomic clones were isolated, characterized, and used in Northern and fluorescence in situ hybridization analyses. The results from this study demonstrate that the murine CPN small subunit gene is a single copy gene of ∼29 kb that is transcribed in the liver into a 1793-bp mRNA with an open reading frame of 1371 nucleotides encoding 457 aa. The gene contains nine exons ranging in size from 455 bp (exon 1) to 100 bp (exon 7), and eight introns ranging in size from 6.2 kb (intron 2) to 1.4 kb (intron 4). All intron/exon junctions follow the normal consensus rule. The mouse CPN small subunit gene localized to chromosomal band 19D2, which is syntenic to human chromosome 10q23–25. Primer extension experiments using mouse liver mRNA indicate one major transcriptional initiation site and three minor sites. Sequence analysis of the 5′-flanking region indicated a TATA-less promoter and numerous transcription factor binding sites, which may confer liver-specific expression of the CPN small subunit gene.
Combined Treatment of a Murine Breast Cancer Model with Type 5 Adenovirus Vectors Expressing Murine Angiostatin and IL-12: A Role for Combined Anti-Angiogenesis and Immunotherapy
Authors: Gyorffy Steve , Palmer Kay , Podor Thomas J. , Hitt Mary , Gauldie Jack 
Published: April 2014

Abstract
In this study, we used intratumor delivery of adenoviral vectors to induce a selective anti-tumor response by combining the potent angiogenesis inhibitor murine angiostatin (adenovirus (Ad)-angiostatin) with the powerful immune simulator and angiostatic cytokine murine IL-12 (Ad-IL-12). In a murine model of breast carcinoma, intratumor injection of Ad-angiostatin delayed mean tumor growth, as compared with control virus with an initial regression of tumor growth, in 65% of treated animals. However, all treated animals eventually succumbed to the tumors. Mice injected with Ad-IL-12 alone responded with an initial regression in 20% of treated animals, with only 13% developing a total regression. Coinjection of the vectors resulted in 96% of the treated animals developing an initial regression, with 54% undergoing a total regression of the tumor. These mice were resistant to tumor rechallenge and developed a strong CTL response. Frozen tumor sections were stained for microvessel density using an Ab against murine CD31, an endothelial cell marker. Automated image analysis revealed the mean microvessel density following the administration of Ad-angiostatin and Ad-IL-12 alone or in combination was significantly reduced compared with the control-treated tumor. In summary, we have shown that a short-term course of antiangiogenic therapy combined with immunotherapy can effectively shrink a solid tumor and vaccinate the animal against rechallenge. The rationale for this therapy is to limit the tumor size by attacking the vasculature with angiostatin, thereby allowing IL-12 to mount a T cell-specific response against the tumor Ag.
A Critical Role of Fc Receptor-Mediated Antibody-Dependent Phagocytosis in the Host Resistance to Blood-Stage Plasmodium berghei XAT Infection
Authors: Yoneto Toshihiko , Waki Seiji , Takai Toshihiro , Tagawa Yoh-ichi , Iwakura Yoichiro , Mizuguchi Junichiro , Nariuchi Hideo , Yoshimoto Takayuki 
Published: April 2014

Abstract
Plasmodium berghei XAT is an irradiation-induced attenuated variant derived from the lethal strain P. berghei NK65, and its blood-stage parasites are spontaneously cleared in immune competent mice. In the present study, we studied the mechanism of host resistance to blood-stage malaria infection using P. berghei XAT. Infection enhanced Ab-dependent phagocytosis of PRBC by splenic macrophages in wild-type C57BL/6 mice. In contrast, FcR γ-chain knockout (FcRγ−/−) mice, which lack the ability to mediate Ab-dependent phagocytosis and Ab-dependent cell-mediated cytotoxicity through FcγRI, FcγRII, and FcγRIII, could not induce Ab-dependent phagocytic activity. These FcRγ−/− mice showed increased susceptibility to the P. berghei XAT infection, with eventually fatal results, although they produced comparable amounts of IFN-γ by spleen cells and anti-XAT Abs in serum. In addition, passive transfer of anti-XAT IgG obtained from wild-type mice that had recovered from infection into FcRγ−/− mice could not suppress the increase in parasitemia, and almost all of these mice died after marked parasitemia. In contrast, passive transfer of anti-XAT IgG into control wild-type mice inhibited the increase in parasitemia. IFN-γ−/− mice, which were highly susceptible to the P. berghei XAT infection, failed to induce Ab-dependent phagocytic activity and also showed reduced production of serum anti-XAT IgG2a isotype compared with control wild-type mice. These results suggest that FcR-mediated Ab-dependent phagocytosis, which is located downstream of IFN-γ production, is important as an effector mechanism to eliminate PRBC in blood-stage P. berghei XAT infection.
Secretory IgA Specific for a Conserved Epitope on gp41 Envelope Glycoprotein Inhibits Epithelial Transcytosis of HIV-1
Authors: Alfsen Annette , Iniguez Pierre , Bouguyon Edwige , Bomsel Morgane 
Published: April 2014

Abstract
As one of the initial mucosal transmission pathways of HIV (HIV-1), epithelial cells translocate HIV-1 from apical to basolateral surface by nondegradative transcytosis. Transcytosis is initiated when HIV-1 envelope glycoproteins bind to the epithelial cell membrane. Here we show that the transmembrane gp41 subunit of the viral envelope binds to the epithelial glycosphingolipid galactosyl ceramide (Gal Cer), an alternative receptor for HIV-1, at a site involving the conserved ELDKWA epitope. Disrupting the raft organization of the Gal Cer-containing microdomains at the apical surface inhibited HIV-1 transcytosis. Immunological studies confirmed the critical role of the conserved ELDKWA hexapeptide in HIV-1 transcytosis. Mucosal IgA, but not IgG, from seropositive subjects targeted the conserved peptide, neutralized gp41 binding to Gal Cer, and blocked HIV-1 transcytosis. These results underscore the important role of secretory IgA in designing strategies for mucosal protection against HIV-1 infection.
A Potential Role for Annexin 1 as a Physiologic Mediator of Glucocorticoid-Induced L-Selectin Shedding from Myeloid Cells
Authors: Strausbaugh Holly J. , Rosen Steven D. 
Published: April 2014

AbstractGlucocorticoids can dampen inflammatory responses by inhibiting neutrophil recruitment to tissue sites. The detailed mechanism by which glucocorticoids exert this affect on neutrophils is unknown. L-selectin is a leukocyte cell surface receptor that is implicated in several steps of neutrophil recruitment. Recently, several studies have shown that systemic treatment of animals and humans with glucocorticoids induces decreased L-selectin expression on neutrophils, suggesting one mechanism by which inflammation may be negatively regulated. However, when neutrophils are treated in vitro with glucocorticoids, no effect on L-selectin expression is observed. Thus, the existence of an additional mediator is plausible. In this study, we investigate whether annexin 1 (ANX1), a recognized second messenger of glucocorticoids, could be such a mediator. We show that ANX1 induces a dose- and time-dependent decrease in L-selectin expression on both peripheral blood neutrophils and monocytes but has no effect on lymphocytes. The loss of L-selectin from neutrophils is due to shedding that is mediated by a cell surface metalloprotease (“sheddase”). Using cell shape and a β2 integrin activation epitope, we show that the ANX1-induced shedding of L-selectin appears to occur without overt cell activation. These data may provide the basis for further understanding of mechanisms involved in the down-regulation of inflammatory responses.
Phosphorylation of the Activation Loop of γ p21-Activated Kinase (γ-Pak) and Related Kinases (MSTs) in Normal and Stressed Neutrophils
Authors: Lian Jian P. , Toker Alex , Badwey John A. 
Published: April 2014

AbstractNeutrophils stimulated with a variety of chemoattractants exhibit a rapid activation of two p21-activated kinases (Paks) with molecular masses of ∼63 and 69 kDa (γ- and α-Pak). A number of in vitro studies suggest that modification of Thr402 in the activation loop (AL) of γ-Pak can play a critical role in the regulation of this kinase under certain circumstances. A phosphospecific Ab was generated to this region of Pak (pPak(AL)Ab). This Ab reacted with activated γ- and α-Pak from fMLP-stimulated neutrophils that contain the sequence KRXT(P)XXGTP in their ALs. The rapid but transient activation of Paks in normal stimulated neutrophils coincided with phosphorylation and dephosphorylation at the ALs of these enzymes. In contrast, stressed cells exhibited a prolonged phosphorylation at Thr402 in both intact γ-Pak and a proteolytic fragment of this kinase. The pPak(AL)Ab also reacted with the mammalian sterile twenty-like kinases (MSTs) (members of the Pak family) in osmotically stressed neutrophils and neutrophils treated with certain apoptotic agents (i.e., tumor promoters that inhibit type 1 and 2A protein phosphatases) but not in normal fMLP-stimulated cells. Thus, our results indicate that the AL of γ-Pak undergoes transient phosphorylation during normal neutrophil stimulation and chronic phosphorylation in stressed cells. In addition, we demonstrate that a number of MSTs are present in neutrophils and also undergo phosphorylation during stressful circumstances.