bluuebunny/crossref_metadata_2025_split huggingface dataset:
Definition of the Mamu A*01 Peptide Binding Specificity: Application to the Identification of Wild-Type and Optimized Ligands from Simian Immunodeficiency Virus Regulatory Proteins
Authors: Sidney John , Dzuris John L. , Newman Mark J. , Johnson R. Paul , Amitinder Kaur , Walker Christopher M. , Appella Ettore , Mothe Bianca , Watkins David I. , Sette Alessandro 
Published: April 2014

AbstractSingle amino acid substitution analogs of the known Mamu A*01 binding peptide gag 181-190 and libraries of naturally occurring sequences of viral or bacterial origin were used to rigorously define the peptide binding motif associated with Mamu A*01 molecules. The presence of S or T in position 2, P in position 3, and hydrophobic or aromatic residues at the C terminus is associated with optimal binding capacity. At each of these positions, additional residues are also tolerated but associated with significant decreases in binding capacity. The presence of at least two preferred and one tolerated residues at the three anchor positions is necessary for good Mamu A*01 binding; optimal ligand size is 8–9 residues. This detailed motif has been used to map potential epitopes from SIVmac239 regulatory proteins and to engineer peptides with increased binding capacity. A total of 13 wild type and 17 analog candidate epitopes were identified. Furthermore, our analysis reveals a significantly lower than expected frequency of epitopes in early regulatory proteins, suggesting a possible evolutionary- and/or immunoselection directed against variants of viral products that contain CTL epitopes.
A Single 3′α hs1,2 Enhancer in the Rabbit IgH Locus
Authors: Volgina Veronica V. , Kingzette Mae , Zhai Shi-Kang , Knight Katherine L. 
Published: April 2014

AbstractMultiple cis-acting elements including the intronic enhancer and the 3′α enhancer (3′αE) regulate expression of the Ig heavy chain genes during B cell development. A 3′αE is composed of DNase I-hypersensitive sites, hs1,2, hs3a,b, and hs4, found 3′ of the murine Cα gene as well as 3′ of both human Cα genes, Cα1 and Cα2. Rabbits have 13 Cα genes, and we tested whether a 3′αE is associated with each of these genes. To identify 3′αE regions we developed a rabbit hs1,2 probe and used this to search for enhancer homologues of human hs1,2 in a genomic fosmid library. We identified a single hs1,2 fragment 8-kb downstream of Cα13, the presumed 3′-most Cα gene. We also identified and partially sequenced a new Cα gene, Cα14, located 6 kb upstream of Cα13. Genomic Southern blot analysis confirmed that the rabbit genome contains only one hs1,2 enhancer region. We tested the enhancer activity of the hs1,2 with the SV40, VH, and Iα promoters using the luciferase reporter gene in transient transfection assays and found that it significantly enhanced the activity of SV40 and VH promoters and slightly enhanced an Iα promoter. We conclude that the rabbit has a single hs1,2 enhancer that resides at the 3′ end of the IgH gene cluster and may constitute one of the cis-elements regulating the expression of IgH genes.
Interplay of Cytokines and Adjuvants in the Regulation of Mucosal and Systemic HIV-Specific CTL
Authors: Belyakov Igor M. , Ahlers Jeffrey D. , Clements John D. , Strober Warren , Berzofsky Jay A. 
Published: April 2014

AbstractWe examined the interplay between cytokines and adjuvants to optimize the induction of CTL by a mucosal HIV peptide vaccine. We show synergy between IL-12 and GM-CSF when administered together with the HIV peptide PCLUS3–18IIIB and cholera toxin (CT) in the induction of CTL activity and protection against mucosal viral transmission. Further, we examine the efficacy of mutant Escherichia coli labile toxin, LT(R192G), as a less toxic adjuvant than CT. LT(R192G) was as effective as or more effective than CT at inducing a mucosal CTL response. Moreover, LT(R192G) was as effective without IL-12 as CT was when combined with IL-12, and the response elicited by LT(R192G) with the vaccine was not further enhanced by the addition of IL-12. GM-CSF synergized with LT(R192G) without exogenous IL-12. Therefore, LT(R192G) may induce a more favorable cytokine response by not inhibiting IL-12 production. In particular, less IL-4 is made after LT(R192G) than CT immunization, and the response is less susceptible to anti-IL-12 inhibition. Thus, the choice of mucosal adjuvant affects the cytokine environment, and the mucosal response and protection can be enhanced by manipulating the cytokine environment with synergistic cytokine combinations incorporated in the vaccine.
Depletion of a γδ T Cell Subset Can Increase Host Resistance to a Bacterial Infection
Authors: O’Brien Rebecca L. , Yin Xiang , Huber Sally A. , Ikuta Koichi , Born Willi K. 
Published: April 2014

Abstractγδ T lymphocytes have been shown to regulate immune responses in diverse experimental systems. Because distinct γδ T cell subsets, as defined by the usage of certain TCR V genes, preferentially respond in various diseases and disease models, we have hypothesized that the various γδ T cell subsets carry out different functions. To test this, we compared one particular γδ T cell subset, the Vγ1+ subset, which represents a major γδ T cell type in the lymphoid organs and blood of mice, to other subsets and to γδ T cells as a whole. Using Listeria monocytogenes infection as an infectious disease model, we found that bacterial containment improves in mice depleted of Vγ1+ γδ T cells, albeit mice lacking all γδ T cells are instead impaired in their ability to control Listeria expansion. Our findings indicate that Vγ1+ γδ T cells reduce the ability of the innate immune system to destroy Listeria, even though other γδ T cells as a whole promote clearance of this pathogen.
Intrapulmonary TNF Gene Therapy Reverses Sepsis-Induced Suppression of Lung Antibacterial Host Defense
Authors: Chen Gina H. , Reddy Raju C. , Newstead Michael W. , Tateda Kazuhiro , Kyasapura Bhavani L. , Standiford Theodore J. 
Published: April 2014

Abstract
Sepsis syndrome is frequently complicated by the development of nosocomial infections, particularly Gram-negative pneumonia. Although TNF-α (TNF) has been shown to mediate many of the pathophysiologic events in sepsis, this cytokine is a critical component of innate immune response within the lung. Therefore, we hypothesized that the transient transgenic expression of TNF within the lung during the postseptic period could augment host immunity against nosocomial pathogens. To test this, mice underwent 26-gauge cecal ligation and puncture (CLP) as a model of abdominal sepsis, followed 24 h later by intratracheal (i.t.) administration of Pseudomonas aeruginosa. In animals undergoing sham surgery followed by bacterial challenge, Pseudomonas were nearly completely cleared from the lungs by 24 h. In contrast, mice undergoing CLP were unable to clear P. aeruginosa and rapidly developed bacteremia. Alveolar macrophages (AM) recovered from mice 24 h after CLP produced significantly less TNF ex vivo, as compared with AM from sham animals. Furthermore, the adenoviral mediated transgenic expression of TNF within the lung increased survival in CLP animals challenged with Pseudomonas from 25% in animals receiving control vector to 91% in animals administered recombinant murine TNF adenoviral vector. Improved survival in recombinant murine TNF adenoviral vector-treated mice was associated with enhanced lung bacterial clearance and proinflammatory cytokine expression, as well as enhanced AM phagocytic activity and cytokine expression when cultured ex vivo. These observations suggest that intrapulmonary immunostimulation with TNF can reverse sepsis-induced impairment in antibacterial host defense.
μ-Opioid Induction of Monocyte Chemoattractant Protein-1, RANTES, and IFN-γ-Inducible Protein-10 Expression in Human Peripheral Blood Mononuclear Cells
Authors: Wetzel Michele A. , Steele Amber D. , Eisenstein Toby K. , Adler Martin W. , Henderson Earl E. , Rogers Thomas J. 
Published: April 2014

AbstractStrong evidence for the direct modulation of the immune system by opioids is well documented. μ-Opioids have been shown to alter the release of cytokines important for both host defense and the inflammatory response. Proinflammatory chemokines monocyte chemoattractant protein-1 (MCP-1), RANTES, and IFN-γ-inducible protein-10 (IP-10) play crucial roles in cell-mediated immune responses, proinflammatory reactions, and viral infections. In this report, we show that [d-Ala2,N-Me-Phe4,Gly-ol5]enkephalin (DAMGO), a μ-opioid-selective agonist, augments the expression in human PBMCs of MCP-1, RANTES, and IP-10 at both the mRNA and protein levels. Because of the proposed relationship between opioid abuse and HIV-1 infection, we also examined the impact of DAMGO on chemokine expression in HIV-infected cells. Our results show that DAMGO administration induces a significant increase in RANTES and IP-10 expression, while MCP-1 protein levels remain unaffected in PBMCs infected with the HIV-1 strain. In contrast, we show a dichotomous effect of DAMGO treatment on IP-10 protein levels expressed by T- and M-tropic HIV-infected PBMCs. The differential modulation of chemokine expression in T- and M-tropic HIV-1-infected PBMCs by opioids supports a detrimental role for opioids during HIV-1 infection. Modulation of chemokine expression may enhance trafficking of potential noninfected target cells to the site of active infection, thus directly contributing to HIV-1 replication and disease progression to AIDS.
Contribution of Cyclopentenone Prostaglandins to the Resolution of Inflammation Through the Potentiation of Apoptosis in Activated Macrophages
Authors: Hortelano Sonsoles , Castrillo Antonio , Alvarez Alberto M. , Boscá Lisardo 
Published: April 2014

Abstract
Activation of the macrophage cell line RAW 264.7 with LPS and IFN-γ induces apoptosis through the synthesis of high concentrations of NO due to the expression of NO synthase-2. In addition to NO, activated macrophages release other molecules involved in the inflammatory response, such as reactive oxygen intermediates and PGs. Treatment of macrophages with cyclopentenone PGs, which are synthesized late in the inflammatory onset, exerted a negative regulation on cell activation by impairing the expression of genes involved in host defense, among them NO synthase-2. However, despite the attenuation of NO synthesis, the percentage of apoptotic cells increased with respect to activated cells in the absence of cyclopentenone PGs. Analysis of the mechanisms by which these PGs enhanced apoptosis suggested a potentiation of superoxide anion synthesis that reacted with NO, leading to the formation of higher concentrations of peroxynitrite, a more reactive and proapoptotic molecule than the precursors. The effect of the cyclopentenone 15-deoxy-Δ12,14-PGJ2 on superoxide synthesis was dependent on p38 mitogen-activated protein kinase activity, but was independent of the interaction with peroxisomal proliferator-activated receptor γ. The potentiation of apoptosis induced by cyclopentenone PGs involved an increase in the release of cytochrome c from the mitochondria to the cytosol and in the nitration of this protein. These results suggest a role for cyclopentenone PGs in the resolution of inflammation by inducing apoptosis of activated cells.
An IFN-γ-Independent Proinflammatory Role of IL-18 in Murine Streptococcal Cell Wall Arthritis
Authors: Joosten Leo A. B. , van de Loo Fons A. J. , Lubberts Erik , Helsen Monique M. A. , Netea Mihai G. , van der Meer Jos W. M. , Dinarello Charles A. , van den Berg Wim B. 
Published: April 2014

AbstractIL-18 is a member of the IL-1 family of proteins that exerts proinflammatory effects. It was formally known as IFN-γ-inducing factor and is a pivotal cytokine for the development of Th1 responses. Apart from Th1 immune-stimulatory activity, IL-18 induces the production of proinflammatory cytokines such as TNF-α and IL-1 in vitro. The goal was to investigate the role of endogenous IL-18 in murine streptococcal cell wall (SCW)-induced arthritis. Furthermore, we investigated whether IL-18 neutralization had an impact on local TNF and IL-1 production. C57BL/6, BALB/c, and IFN-γ-deficient mice were injected with 2 mg of rabbit anti-murine IL-18 Abs shortly before induction of arthritis by intra-articular injection of 25 μg of SCW fragments into the right knee joint. Suppression of joint swelling was noted on days 1 and 2 of SCW arthritis after blockade of endogenous IL-18. Analysis of local cytokine concentrations showed that IL-18, TNF-α, and IL-1β levels were decreased. Severe inhibition of chondrocyte proteoglycan synthesis was seen in the vehicle-treated control animals, whereas a reversal of the inhibition of chondrocyte proteoglycan synthesis was found in the anti-IL-18-exposed animals. Blockade of endogenous IL-18 in IFN-γ-deficient mice showed results similar to those found in wild-type animals, identifying a role for IL-18 that is IFN-γ independent. The present study indicates that IL-18 is a proinflammatory cytokine during the onset of murine SCW arthritis, and this inflammatory role of IL-18 is IFN-γ independent.
CC Chemokine Receptor-2 Is Not Essential for the Development of Antigen-Induced Pulmonary Eosinophilia and Airway Hyperresponsiveness
Authors: MacLean James A. , De Sanctis George T. , Ackerman Kate G. , Drazen Jeffrey M. , Sauty Alain , DeHaan Elliot , Green Francis H. Y. , Charo Israel F. , Luster Andrew D. 
Published: April 2014

AbstractMonocyte chemoattractant proteins-1 and -5 have been implicated as important mediators of allergic pulmonary inflammation in murine models of asthma. The only identified receptor for these two chemokines to date is the CCR2. To study the role of CCR2 in a murine model of Ag-induced asthma, we compared the pathologic and physiological responses of CCR2−/− mice with those of wild-type (WT) littermates following immunization and challenge with OVA. OVA-immunized/OVA-challenged (OVA/OVA) WT and CCR2−/− mice developed significant increases in total cells recovered by bronchoalveolar lavage (BAL) compared with their respective OVA-immunized/PBS-challenged (OVA/PBS) control groups. There were no significant differences in BAL cell counts and differentials (i.e., macrophages, PMNs, lymphocytes, and eosinophils) between OVA/OVA WT and CCR2−/− mice. Serologic evaluation revealed no significant difference in total IgE and OVA-specific IgE between OVA/OVA WT mice and CCR2−/− mice. Lung mRNA expression and BAL cytokine protein levels of IL-4, IL-5, and IFN-γ were also similar in WT and CCR2−/− mice. Finally, OVA/OVA CCR2−/− mice developed increased airway hyper-responsiveness to a degree similar to that in WT mice. We conclude that following repeated airway challenges with Ag in sensitized mice, the development of Th2 responses (elevated IgE, pulmonary eosinophilia, and lung cytokine levels of IL-4 and IL5) and the development of airway hyper-responsiveness are not diminished by a deficiency in CCR2.
Cutaneous Inflammatory Disorder in Integrin αE (CD103)-Deficient Mice
Authors: Schön Michael P. , Schön Margarete , Warren Henry B. , Donohue John P. , Parker Christina M. 
Published: April 2014

AbstractThe integrin αEβ7 is thought to play an important role in the localization of mucosal, but not of cutaneous T lymphocytes. Thus, it was surprising that 89% of adult αE−/− mice on the 129/Sv × BALB/c background developed inflammatory skin lesions without an apparent infectious etiology. Skin inflammation correlated with αE deficiency in mice with a mixed 129/Sv × BALB/c background, but not in mice further backcrossed to BALB/c and housed in a second animal facility. These studies suggested that αE deficiency, in combination with other genetic and/or environmental factors, is involved in lesion development. The lesions were infiltrated by CD4+ T cells and neutrophils, and associated with increased expression of inflammatory cytokines. Furthermore, skin inflammation resulted from transfer of unfractionated αE−/− splenocytes into scid/scid mice, but not from transfer of wild-type splenocytes, suggesting that the lesions resulted from immune dysregulation. We also studied the role of αEβ7 in a murine model of hyperproliferative inflammatory skin disorders that is induced by transfer of minor histocompatibility-mismatched CD4+/CD45RBhigh T cells into scid/scid mice under specific environmental conditions. Under housing conditions that were permissive for lesion development, transfer of αE-deficient CD4+/CD45RBhigh T cells significantly exacerbated the cutaneous lesions as compared with lesions observed in mice reconstituted with wild-type donor cells. These experiments suggested that αE-expressing cells play an important role during the course of cutaneous inflammation. In addition, they suggest that αEβ7 deficiency, in combination with other genetic or environmental factors, is a risk factor for inflammatory skin disease.
CTLA-4 Gene Polymorphism at Position 49 in Exon 1 Reduces the Inhibitory Function of CTLA-4 and Contributes to the Pathogenesis of Graves’ Disease
Authors: Kouki Tsuyoshi , Sawai Yoshikuni , Gardine Cyprian A. , Fisfalen Maria-Elena , Alegre Maria-Luisa , DeGroot Leslie J. 
Published: April 2014

AbstractActivation of T cells requires at least two signals transduced by the Ag-specific TCR and a costimulatory ligand such as CD28. CTLA-4, expressed on activated T cells, binds to B7 present on APCs and functions as a negative regulator of T cell activation. Our laboratory previously reported the association of Graves’ disease (GD) with a specific CTLA-4 gene polymorphism. In theory, reduced expression or function of CTLA-4 might augment autoimmunity. In the present study, we categorized autoimmune thyroid disease patients and normal controls (NC) by genotyping a CTLA-4 exon 1 polymorphism and investigated the function of CTLA-4 in all subjects. PBMCs and DNA were prepared from GD (n = 45), Hashimoto’s thyroiditis (HT) (n = 18), and NC (n = 43). There were more GD patients with the G/G or A/G alleles (82.2% vs 65.1% in NC), and significantly fewer patients with the A/A allele (17.8% vs 34.9% in NC). In the presence of soluble blocking anti-human CTLA-4 mAb, T cell proliferation following incubation with allogeneic EBV-transformed B cells was augmented in a dose-dependent manner. Augmentation induced by CTLA-4 mAb was similar in GD and NC (GD, HT, NC = 156%, 164%, 175%, respectively). We related CTLA-4 polymorphism to mAb augmentation of T cell proliferation in each subgroup (GD, HT, NC). Although PBMC from individuals with the G/G alleles showed 132% augmentation, those with the A/A alleles showed 193% augmentation (p = 0.019). CTLA-4 polymorphism affects the inhibitory function of CTLA-4. The G allele is associated with reduced control of T cell proliferation and thus contributes to the pathogenesis of GD and presumably of other autoimmune diseases.
A Shift in the Phenotype of Melan-A-Specific CTL Identifies Melanoma Patients with an Active Tumor-Specific Immune Response
Authors: Dunbar P. Rod , Smith Caroline L. , Chao David , Salio Mariolina , Shepherd Dawn , Mirza Fareed , Lipp Martin , Lanzavecchia Antonio , Sallusto Federica , Evans Alun , Russell-Jones Robin , Harris Adrian L. , Cerundolo Vincenzo 
Published: April 2014

AbstractIn a significant proportion of melanoma patients, CTL specific for the melan-A26/7–35 epitope can be detected in peripheral blood using HLA-A2/peptide tetramers. However, the functional capacity of these CTL has been controversial, since although they prove to be effective killers after in vitro expansion, in some patients they have blunted activation responses ex vivo. We used phenotypic markers to characterize melan-A tetramer+ cells in both normal individuals and melanoma patients, and correlated these markers with ex vivo assays of CTL function. Melanoma patients with detectable melan-A tetramer+ cells in peripheral blood fell into two groups. Seven of thirteen patients had a CCR7+ CD45R0− CD45RA+ phenotype, the same as that found in some healthy controls, and this phenotype was associated with a lack of response to melan-A peptide ex vivo. In the remaining six patients, melan-A tetramer+ cells were shifted toward a CCR7− CD45R0+ CD45RA− phenotype, and responses to melan-A peptide could be readily demonstrated ex vivo. When lymph nodes infiltrated by melan-A-expressing melanoma cells were examined, a similar dichotomy emerged. These findings demonstrate that activation of melan-A-specific CTL occurs in only some patients with malignant melanoma, and that only patients with such active immune responses are capable of responding to Ag in ex vivo assays.
Identification of Distinct Surface-Expressed and Intracellular CXC-Chemokine Receptor 2 Glycoforms in Neutrophils:N-Glycosylation Is Essential for Maintenance of Receptor Surface Expression
Authors: Ludwig Andreas , Ehlert Jan E. , Flad Hans-Dieter , Brandt Ernst 
Published: April 2014

AbstractThe G protein-coupled CXC-chemokine receptor CXCR-2 mediates activation of neutrophil effector functions in response to multiple ligands, including IL-8 and neutrophil-activating peptide 2 (NAP-2). Although CXCR-2 has been successfully cloned and expressed in several cell lines, the molecular properties of the native neutrophil-expressed receptor have remained largely undefined. Here we report on the identification and characterization of distinct CXCR-2 glycoforms and their subcellular distribution in neutrophils. Immunoprecipitation and Western blot analyses of surface-expressed receptors covalently linked to IL-8 or NAP-2 as well as in their unloaded state revealed the occurrence of a single CXCR-2 variant with an apparent size of 56 kDa. According to deglycosylation experiments surface-expressed CXCR-2 carries two N-linked 9-kDa carbohydrate moieties that are both of complex structure. In addition, two other CXCR-2 variants of 38 and 40 kDa were found to occur exclusively intracellular and to carry N-glycosylations of high mannose or hybrid type. These receptors did not participate in ligand-induced receptor trafficking, while surface-expressed CXCR-2 was internalized and re-expressed following stimulation with NAP-2. By enzymatic removal of one 9-kDa carbohydrate moiety in surface-expressed CXCR-2 we can show that neither NAP-2-induced trafficking nor signaling of the receptor is dependent on its full glycosylation. Instead, glycosylation was found to protect CXCR-2 from proteolytic attack, as even partial deglycosylation is associated with serine protease-mediated disappearance of the receptor from the neutrophil surface. Thus, although not directly involved in signaling, glycosylation appears to be required to maintain neutrophil responsiveness to CXC-chemokines during inflammation.