bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adenovirus-Transduced Dendritic Cells Injected into Skin or Lymph Node Prime Potent Simian Immunodeficiency Virus-Specific T Cell Immunity in Monkeys
Authors: Brown Kevin , Gao Wentao , Alber Sean , Trichel Anita , Murphey-Corb Michael , Watkins Simon C. , Gambotto Andrea , Barratt-Boyes Simon M. 
Published: April 2014

Abstract
Adenoviral vectors can be used to deliver complex Ag to dendritic cells (DC), and thus may be ideal for stimulating broad T cell responses to viral pathogens and tumors. To test this hypothesis in a relevant primate model, we used recombinant adenovirus serotype 5 vectors expressing SIV Gag Ag to transduce monocyte-derived DC from rhesus macaques, and then immunized donor animals either by intradermal or intranodal injections. T cell responses were evaluated by ELISPOT assay using previously frozen PBMC pulsed with pools of 15-mer peptides representing the Gag sequence. Immunization resulted in rapid and potent induction of T cell responses to multiple regions of Gag, with frequencies approaching 1 Gag-specific T cell per 500 uncultured PBMC. Surprisingly, intradermal and intranodal injections generated a similar intensity and breadth of response, indicating that administration of Ag-expressing DC by either route may be equally effective at inducing immune responses. Detailed analysis of two monkeys revealed CD8+ T cell responses to several peptide epitopes of Gag not previously described, at least two of which are restricted by MHC class I alleles not currently identified. Repeated vaccination did not induce T cell responses to the adenoviral vector and did not prevent Ag-expressing DC injected under the capsule of the lymph node from migrating to the paracortex and interposing between T cells. However, boost injections of adenovirus-transduced DC were generally limited in efficacy. These findings support the use of adenovirus-transduced DC in the therapy of HIV infection and cancer.
Tumor Vaccination after Allogeneic Bone Marrow Cell Reconstitution of the Nonmyeloablatively Conditioned Tumor-Bearing Murine Host
Authors: Zöller Margot 
Published: April 2014

Abstract
Allogeneic bone marrow cell reconstitution of the nonmyeloablatively conditioned host is supposed to provide an optimized platform for tumor vaccination. We recently showed that an allogeneic T cell-depleted graft was well accepted if the tumor-bearing host was NK depleted. Based on this finding, a vaccination protocol in tumor-bearing, nonmyeloablatively conditioned, allogeneically reconstituted mice was elaborated. Allogeneically reconstituted mice, bearing a renal cell carcinoma, received tumor-primed donor lymph node cells (LNC), which had or had not matured in the allogeneic host. Primed LNC were supported by tumor lysate-pulsed dendritic cells, which were donor or host derived. Optimal responses against the tumor were observed with host-tolerant, tumor-primed LNC in combination with host-derived dendritic cells. High frequencies of tumor-specific proliferating and CTLs were recorded; the survival time of tumor-bearing mice was significantly prolonged, and in &gt;50% of mice the tumor was completely rejected. Notably, severe graft-vs-host disease was observed in reconstituted mice that received tumor-primed LNC, which had not matured in the allogeneic host. However, graft-vs-host was not aggravated after vaccination with tumor-primed, host-tolerant LNC. Thus, the LNC were tolerant toward the host, but not toward the tumor. The finding convincingly demonstrates the feasibility and efficacy of tumor vaccination after allogeneic reconstitution of the nonmyeloablatively conditioned host.
Mutation of a Dibasic Amino Acid Motif Within the C Terminus of the P2X7 Nucleotide Receptor Results in Trafficking Defects and Impaired Function
Authors: Denlinger Loren C. , Sommer Julie A. , Parker Karen , Gudipaty Lalitha , Fisette Philip L. , Watters Jyoti W. , Proctor Richard A. , Dubyak George R. , Bertics Paul J. 
Published: April 2014

Abstract
Activation of the P2X7 receptor by extracellular nucleotides modulates multiple immune functions, including inflammatory mediator production, membrane fusion events, and apoptosis. Previous studies have revealed that the C terminus of this multimeric cation channel possesses a lipid-interaction motif that has been proposed to regulate receptor function. This domain is homologous to the LPS binding region of the LPS binding protein, and we demonstrated that two basic residues (Arg578, Lys579) within this motif are essential for LPS binding to P2X7 in vitro. Because P2X7 can influence LPS action, and because lipid interaction motifs modulate the trafficking of other ion channel-linked receptors, we hypothesized that this motif of P2X7 is critical for receptor function and trafficking. In these studies we mutated Arg578 and Lys579 of P2X7, and the expression profile, channel activity, and pore formation of the mutant were characterized in transfected human embryonic kidney 293 cells. In contrast with the wild-type receptor, the P2X7-R578E/K579E mutant fails to demonstrate surface immunoreactivity despite normal levels of total protein expression. This effect on the mutant receptor is unlikely to result from widespread defects in protein folding, because surface localization, determined using conformation-specific Abs, can be restored by growing the cells at 25°C, conditions that slow receptor recycling. Despite surface expression at reduced temperatures, at 25°C the P2X7-R578E/K579E mutant still exhibits greatly reduced sodium, potassium, and calcium channel activity when compared with the wild-type receptor, and cannot induce pore formation. These data suggest that the lipid interaction motif of the P2X7 C terminus controls receptor trafficking and modulates channel activity.
Cutting Edge: Cross-Presentation as a Mechanism for Efficient Recruitment of Tumor-Specific CTL to the Brain
Authors: Calzascia Thomas , Di Berardino-Besson Wilma , Wilmotte Rick , Masson Frédérick , Tribolet Nicolas de , Dietrich Pierre-Yves , Walker Paul R. 
Published: April 2014

Abstract
The number and localization of effector cells to the tumor site are crucial elements for immune rejection of solid tumors. However, for cerebral malignancies, antitumor responses need to be finely tuned to avoid neuropathologic consequences. In this study, we determine factors that regulate CTL localization and tumoricidal function after intracerebral implantation of tumors expressing model Ag. H-2bxd mice implanted with a CW3+ murine glioma lacking H-2Kd molecules necessary to present the CW3170–179 epitope demonstrate cross-priming of H-2Kd-restricted CTL, and moreover, Ag-dependent accumulation of functional H-2Kd/CW3170–179-specific CTL within the tumor bed. This implicates a role for cross-presentation not only in priming, but also in retention of fully differentiated CTL in the tumor stroma at the effector stage of the response. Modulating cross-presentation of Ag may be the key in regulating specific immune responses in the brain: either by augmenting protective responses or by down-modulating destructive autoimmune reactions.
Cutting Edge: Expansion of the KIR Locus by Unequal Crossing Over
Authors: Martin Maureen P. , Bashirova Arman , Traherne James , Trowsdale John , Carrington Mary 
Published: April 2014

Abstract
The killer Ig-like receptor (KIR) genes have high sequence similarity and are organized in a head-to-tail fashion. These properties may enhance misalignment of homologous chromosomes during synapsis preceding meiotic recombination, resulting in unequal crossing over. We have identified an extended KIR haplotype that contains a novel hybrid gene and two copies of each of two previously described KIR genes. A parsimonious mechanism for the derivation of this haplotype invokes unequal crossing over between two known ancestral KIR haplotypes. These data raise the possibility that unequal crossing over may be responsible in part for the expansion/contraction of KIR haplotypes as well as other homologous gene families that map in tandem.
Lymphoid Precursors in Intestinal Cryptopatches Express CCR6 and Undergo Dysregulated Development in the Absence of CCR6
Authors: Lügering Andreas , Kucharzik Torsten , Soler Dulce , Picarella Dominic , Hudson James T. , Williams Ifor R. 
Published: April 2014

AbstractSmall intestinal cryptopatches (CP) are the major anatomic site for extrathymic differentiation by precursors destined to become intestinal intraepithelial T lymphocytes (IEL). We found that mice deficient in CCR6 exhibited a 2.7-fold increase in the number of αβ TCR IEL, but little or no expansion of γδ TCR IEL. Among the αβ TCR IEL subsets, the CD4− CD8αα+ and CD4+ CD8αα+ subsets were preferentially expanded in CCR6 null mice. Because some CD8αα+ IEL can arise through extrathymic differentiation in CP, we investigated CCR6 expression by T lymphocyte precursors undergoing extrathymic differentiation in intestinal CP. In sections of CP, 50–60% of c-kit+ precursors were CCR6+. CD11c+ cells concentrated at the periphery of CP did not express CCR6. A subset of c-kit+, Lin− cells in lamina propria suspensions was CCR6+, but CCR6 was absent from c-kit+ precursors in bone marrow. CCR6 was absent from the vast majority of mature IEL. CCR6 is present on lymphocyte precursors in cryptopatches, expressed transiently during extrathymic IEL development, and is required for homeostatic regulation of intestinal IEL.
MHC Recognition by Hapten-Specific HLA-A2-Restricted CD8+ CTL
Authors: Gagnon Susan J. , Wang Zichun , Turner Richard , Damirjian Marale , Biddison William E. 
Published: April 2014

AbstractT cell recognition by peptide-specific αβ TCRs involves not only recognition of the peptide, but also recognition of multiple molecular features on the surface of the MHC molecule to which the peptide has been bound. We have previously shown that TCRs that are specific for five different peptides presented by HLA-A2 recognize similar molecular features on the surface of the α1 and α2 helices of the HLA-A2 molecule. We next asked whether these same molecular features of the HLA-A2 molecule would be recognized by hapten-specific HLA-A2-restricted TCRs, given that hapten-specific T cells frequently show reduced MHC dependence/restriction. The results show that a panel of CD8+ CTL that are specific for the hapten DNP bound to two different peptides presented by HLA-A2 do the following: 1) show stringent MHC restriction, and 2) are largely affected by the same mutations on the HLA-A2 molecule that affected recognition by peptide-specific CTL. A small subset of this panel of CD8+ CTL can recognize a mutant HLA-A2 molecule in the absence of hapten. These data suggest that TCR recognition of a divergent repertoire of ligands presented by HLA-A2 is largely dependent upon common structural elements in the central portion of the peptide-binding site.
In Vivo, Dendritic Cells Can Cross-Present Virus-Like Particles Using an Endosome-to-Cytosol Pathway
Authors: Morón Víctor Gabriel , Rueda Paloma , Sedlik Christine , Leclerc Claude 
Published: April 2014

AbstractRecombinant parvovirus-like particles (PPV-VLPs) are particulate exogenous Ags that induce strong CTL response in the absence of adjuvant. In the present report to decipher the mechanisms responsible for CTL activation by such exogenous Ag, we analyzed ex vivo and in vitro the mechanisms of capture and processing of PPV-VLPs by dendritic cells (DCs). In vivo, PPV-VLPs are very efficiently captured by CD8α− and CD8α+ DCs and then localize in late endosomes of DCs. Macropinocytosis and lipid rafts participate in PPV-VLPs capture. Processing of PPV-VLPs does not depend upon recycling of MHC class I molecules, but requires vacuolar acidification as well as proteasome activity, TAP translocation, and neosynthesis of MHC class I molecules. This study therefore shows that in vivo DCs can cross-present PPV-VLPs using an endosome-to-cytosol processing pathway.
Regulation of the Class II MHC Pathway in Primary Human Monocytes by Granulocyte-Macrophage Colony-Stimulating Factor
Authors: Hornell Tara M. C. , Beresford Guy W. , Bushey Alyssa , Boss Jeremy M. , Mellins Elizabeth D. 
Published: April 2014

AbstractGM-CSF stimulates the growth and differentiation of hematopoietic progenitors and also affects mature cell function. These effects have led to the use of GM-CSF as a vaccine adjuvant with promising results; however, the mechanisms underlying GM-CSF-mediated immune potentiation are incompletely understood. In this study, we investigated the hypothesis that the immune stimulatory role of GM-CSF is in part due to effects on class II MHC Ag presentation. We find that, in primary human monocytes treated for 24–48 h, GM-CSF increases surface class II MHC expression and decreases the relative level of the invariant chain-derived peptide, CLIP, bound to surface class II molecules. GM-CSF also increases expression of the costimulatory molecules CD86 and CD40, but not the differentiation marker CD1a or CD16. Furthermore, GM-CSF-treated monocytes are better stimulators in a mixed leukocyte reaction. Additional analyses of the class II pathway revealed that GM-CSF increases total protein and RNA levels of HLA-DR, DM, and DOα. Expression of class II transactivator (CIITA) types I and III, but not IV, transcripts increases in response to GM-CSF. Furthermore, GM-CSF increases the amount of CIITA associated with the DR promoter. Thus, our data argue that the proinflammatory role of GM-CSF is mediated in part through increased expression of key molecules involved in the class II MHC pathway via induction of CIITA.
TCRζ mRNA with an Alternatively Spliced 3′-Untranslated Region Detected in Systemic Lupus Erythematosus Patients Leads to the Down-Regulation of TCRζ and TCR/CD3 Complex
Authors: Tsuzaka Kensei , Fukuhara Izumi , Setoyama Yumiko , Yoshimoto Keiko , Suzuki Katsuya , Abe Tohru , Takeuchi Tsutomu 
Published: April 2014

AbstractThe reduction or absence of TCR ζ-chain (ζ) expression in systemic lupus erythematosus (SLE) patients is thought to be related to the pathogenesis of SLE. Recently, we reported the predominant expression of ζ mRNA containing an alternatively spliced 3′-untranslated region (3′UTR; ζmRNA/as-3′UTR) and a reduction in the expression of ζ mRNA containing the wild-type 3′UTR (ζmRNA/w-3′UTR) in T cells from SLE patients. Here we show that AS3′UTR mutants (MA5.8 cells deficient in ζ protein that have been transfected with ζmRNA/as-3′UTR) exhibit a reduction in the expression of TCR/CD3 complex and ζ protein on their cell surface as well as a reduction in the production of IL-2 after stimulation with anti-CD3 Ab compared with that in wild-type 3′UTR mutants (MA5.8 cells transfected with ζmRNA/w-3′UTR). Furthermore, the real-time PCR analyses demonstrated that the half-life of ζmRNA/as-3′UTR in AS3′UTR mutants (3 h) was much shorter than that of ζmRNA/w-3′UTR in wild-type 3′UTR mutants (15 h). Thus, the lower stability of ζmRNA/as-3′UTR, which is predominant in SLE T cells, may be responsible for the reduced expression of the TCR/CD3 complex, including ζ protein, in SLE T cells.
Membranous Cells in Nasal-Associated Lymphoid Tissue: A Portal of Entry for the Respiratory Mucosal Pathogen Group A Streptococcus
Authors: Park Hae-Sun , Francis Kevin P. , Yu Jun , Cleary P. Patrick 
Published: April 2014

Abstract
Human tonsils are suspected to be an antibiotic-impervious human reservoir for group A streptococcus. An intranasal infection model in mice and a bioluminescent-tagged strain were used to investigate this possibility. Viable streptococci were predominantly found both intra- and extracellularly in nasal-associated lymphoid tissue (NALT), a human tonsil homologue. Ulex europaeus-1, a membranous (M) cell-specific lectin, identified cells harboring streptococci at the epithelial surface of NALT and blocked bacterial colonization of this tissue. These results suggest that M cells in NALT transport this Gram-positive pathogen across the epithelial layers in a manner similar to those in Peyer’s patches, which permit enteric pathogens to invade deeper tissues from the gastrointestinal tract.
Anaphylatoxin C5a Induces Monocyte Recruitment and Differentiation into Dendritic Cells by TNF-α and Prostaglandin E2-Dependent Mechanisms
Authors: Soruri Afsaneh , Riggert Joachim , Schlott Thilo , Kiafard Ziba , Dettmer Claudia , Zwirner Jörg 
Published: April 2014

AbstractAlthough monocytes can be directed to develop into dendritic cells (DC) in vitro, the molecular mechanisms that induce their transformation in vivo are largely unknown. In the present study we employed an in vivo SCID mouse model to investigate the impact of two proinflammatory chemotaxins, the anaphylatoxin C5a and the chemokine macrophage inflammatory protein-1α (CCL3), on the differentiation of human monocytes and immature DC generated from monocytes in the presence of GM-CSF and IL-4. Both C5a and macrophage inflammatory protein-1α recruited human monocytes and immature DC into the peritoneal cavity of SCID mice, but only C5a induced their differentiation into phenotypically mature DC by 48 h after injection. Macrophages derived from monocytes by in vitro culture were resistant to C5a-mediated transformation in vivo. The effect of C5a was indirect, since C5a-stimulated TNF-α and PGE2 were found to be obligatory as well as sufficient to induce differentiation of monocytes. In contrast to monocytes, in vitro generated immature DC required TNF-α, but not PGE2, for their C5a-mediated maturation in vivo. C5a-transformed monocytes represented an inflammatory type of DC, as they constitutively secreted high amounts of TNF-α, but also retained the capacity to release the Th1 cytokine IL-12 p70 upon stimulation with CD40 ligand. In summary, we identified for the first time a cascade of inflammatory signals that can induce the transformation of monocytes into DC in vivo. This novel function emphasizes the important immunoregulatory role of C5a at the interface of innate and adaptive immunity.
Regulation of Eosinophilopoiesis in a Murine Model of Asthma
Authors: Hogan Mary Beth , Weissman David N. , Hubbs Ann F. , Gibson Laura F. , Piktel Debra , Landreth Kenneth S. 
Published: April 2014

AbstractEosinophilic inflammation plays a key role in tissue damage that characterizes asthma. Eosinophils are produced in bone marrow and recent observations in both mice and humans suggest that allergen exposure results in increased output of eosinophils from hemopoietic tissue in individuals with asthma. However, specific mechanisms that alter eosinophilopoiesis in this disease are poorly understood. The current study used a well-characterized murine animal model of asthma to evaluate alterations of eosinophil and eosinophil progenitor cells (CFU-eo) in mice during initial sensitization to allergen and to determine whether observed changes in either cell population were regulated by T lymphocytes. Following the first intranasal installation of OVA, we observed sequential temporal elevation of eosinophils in bone marrow, blood, and lung. In immunocompetent BALB/c mice, elevation of bone marrow eosinophils was accompanied by transient depletion of CFU-eo in that tissue. CFU-eo rebounded to elevated numbers before returning to normal baseline values following intranasal OVA exposure. In T cell-deficient BALB/c nude (BALB/cnu/nu) mice, CFU-eo were markedly elevated following allergen sensitization, in the absence of bone marrow or peripheral blood eosinophilia. These data suggest that eosinophilia of asthma results from alterations in two distinct hemopoietic regulatory mechanisms. Elevation of eosinophil progenitor cells in the bone marrow is T cell independent and likely results from altered bone marrow stromal cell function. Differentiation of eosinophil progenitor cells and phenotypic eosinophilia is T cell dependent and does not occur in athymic nude mice exposed to intranasal allergen.
Therapeutic Attenuation of Pulmonary Fibrosis Via Targeting of IL-4- and IL-13-Responsive Cells
Authors: Jakubzick Claudia , Choi Esther S. , Joshi Bharat H. , Keane Michael P. , Kunkel Steven L. , Puri Raj K. , Hogaboam Cory M. 
Published: April 2014

AbstractSevere forms of idiopathic interstitial pneumonia (IIP), such as usual interstitial pneumonia, can be impervious to modern steroid and immunosuppressive treatment regimens, thereby emphasizing the need for novel effective therapies. Consequently, research attention has been directed toward understanding the cytokine networks that may affect fibroblast activation and, hence, the progression of certain IIPs. This led us to investigate whether the specific targeting of resident lung cells responsive to IL-4 and IL-13 exerted a therapeutic effect in an experimental model of IIP, namely the bleomycin-induced model of pulmonary fibrosis. IL-4, IL-13, and their corresponding receptor subunits, IL-4Rα, IL-13Rα1, and IL-13Rα2, were maximally expressed at the mRNA and protein levels in whole lung samples on day 21 or 28 after an intratracheal bleomycin challenge. The intranasal administration of an IL-13 immunotoxin chimeric molecule (IL13-PE) from days 21–28, but not for 1-wk periods at earlier times, after bleomycin challenge had a significant therapeutic effect on histological and biochemical parameters of bleomycin-induced pulmonary fibrosis compared with the control group. The intranasal IL13-PE therapy significantly reduced the numbers of IL-4 and IL-13 receptor-positive mononuclear cells and macrophages and the levels of profibrotic cytokine and chemokine in the lungs of bleomycin-challenged mice on day 28. Thus, this study demonstrates that IL-4- and/or IL-13-binding cells are required for the maintenance of pulmonary fibrosis induced by bleomycin and highlights the importance of further investigation of antifibrotic therapeutics that target these cells during pulmonary fibrosis.
Activation of Cutaneous Protein Kinase Cα Induces Keratinocyte Apoptosis and Intraepidermal Inflammation by Independent Signaling Pathways
Authors: Cataisson Christophe , Joseloff Elizabeth , Murillas Rodolfo , Wang Alice , Atwell Coralyn , Torgerson Sara , Gerdes Michael , Subleski Jeffrey , Gao Ji-Liang , Murphy Philip M. , Wiltrout Robert H. , Vinson Charles , Yuspa Stuart H. 
Published: April 2014

Abstract
Skin keratinocytes are major mediators of host immune responses. The skin is also a target for immunologically based inflammation in many pathological states. Activation of protein kinase C (PKC) can induce cutaneous inflammation, but the precise role of each of six cutaneous PKC isoforms (α, δ, ε, η, ζ, μ) that regulate normal skin homeostasis or contribute to skin pathology has not been clarified. We generated transgenic mice that overexpress PKCα in the basal layer of the epidermis and the outer root sheath of hair follicles under the regulation of the bovine keratin 5 promoter. K5-PKCα transgenic mice exhibit severe intraepidermal neutrophilic inflammation and disruption of the epidermis and upper hair follicles when treated topically with 12-O-tetradecanoylphorbol-13-acetate (TPA). Both TPA and UVB cause apoptosis in transgenic skin, but only TPA evokes intraepidermal inflammation. TPA also induces apoptosis in cultured transgenic keratinocytes, and this is prevented by an AP-1 dominant-negative construct. However, inhibiting AP-1 in vivo does not abrogate intraepidermal inflammation. Transcripts for specific cytokines and chemokines are elevated in TPA-treated cultured transgenic keratinocytes, and conditioned culture medium from these cells promotes neutrophil migration in vitro. Chemokine expression and neutrophil migration are not diminished by inhibiting AP-1. Thus, PKCα activation induces keratinocyte apoptosis via an AP-1-dependent pathway and mediates chemokine induction and intraepidermal inflammation independently. This model system will be useful to define specific chemokines regulated by PKCα that promote intraepidermal neutrophilic inflammation, a condition that characterizes several human cutaneous diseases such as pustular psoriasis and acute generalized exanthematous pustulosis.