HLA class I molecules consistently present internal influenza epitopes

Cytotoxic T lymphocytes (CTL) limit influenza virus replication and prevent morbidity and mortality upon recognition of HLA class I presented epitopes on the surface of virus infected cells, yet the number and origin of the viral epitopes that decorate the infected cell are unknown. To understand the presentation of influenza virus ligands by human MHC class I molecules, HLA-B*0702-presented viral peptides were directly identified following influenza infection. After transfection with soluble class I molecules, peptide ligands unique to infected cells were eluted from isolated MHC molecules and identified by comparative mass spectrometry (MS). Then CTL were gathered following infection with influenza and viral peptides were tested for immune recognition. We found that the class I molecule B*0702 presents 3-6 viral ligands following infection with different strains of influenza. Peptide ligands derived from the internal viral nucleoprotein (NP418-426 and NP 473-481) and from the internal viral polymerase subunit PB1 (PB1 329-337) were presented by B*0702 following infection with each of 3 different influenza strains; ligands NP418-426, NP 473-481, and PB1329-337 derived from internal viral proteins were consistently revealed by class I HLA. In contrast, ligands derived from hemagglutinin (HA) and matrix protein (M1) were presented intermittently on a strain-by-strain basis. When tested for immune recognition, HLA-B*0702 transgenic mice responded to NP418-426 and PB1 329-337 consistently and NP473-481 intermittently while ligands from HA and M1 were not recognized. These data demonstrate an emerging pattern whereby class I HLA reveal a handful of internal viral ligands and whereby CTL recognize consistently presented influenza ligands

HLA‐A23/HLA‐A24 serotypes and dementia interaction in the elderly: Association with increased soluble HLA class I molecules in plasma

MHC class I molecules regulate brain development and plasticity in mice and HLA class I molecules are associated with brain disorders in humans. We investigated the relationship between plasma-derived soluble human HLA class I molecules (sHLA class I), HLA class I serotypes and dementia. A cohort of HLA class I serotyped elderly subjects with no dementia/predementia (NpD, n = 28), or with dementia (D, n = 28) was studied. Multivariate analysis was used to examine the influence of dementia and HLA class I serotype on sHLA class I levels, and to compare sHLA class I within four groups according to the presence or absence of HLA-A23/A24 and dementia. HLA-A23/A24 and dementia, but not age, significantly influenced the level of sHLA class I. Importantly, the concurrent presence of HLA-A23/A24 and dementia was associated with higher levels of sHLA class I (p < 0.001). This study has shown that the simultaneous presence of HLA-A23/HLA-A24 and dementia is associated with high levels of serum sHLA class I molecules. Thus, sHLA class I could be considered a biomarker of neurodegeneration in certain HLA class I carriers.info:eu-repo/semantics/publishedVersio

Identification of Class I HLA T Cell Control Epitopes for West Nile Virus

The recent West Nile virus (WNV) outbreak in the United States underscores the importance of understanding human immune responses to this pathogen. Via the presentation of viral peptide ligands at the cell surface, class I HLA mediate the T cell recognition and killing of WNV infected cells. At this time, there are two key unknowns in regards to understanding protective T cell immunity: 1) the number of viral ligands presented by the HLA of infected cells, and 2) the distribution of T cell responses to these available HLA/viral complexes. Here, comparative mass spectroscopy was applied to determine the number of WNV peptides presented by the HLA-A*11:01 of infected cells after which T cell responses to these HLA/WNV complexes were assessed. Six viral peptides derived from capsid, NS3, NS4b, and NS5 were presented. When T cells from infected individuals were tested for reactivity to these six viral ligands, polyfunctional T cells were focused on the GTL9 WNV capsid peptide, ligands from NS3, NS4b, and NS5 were less immunogenic, and two ligands were largely inert, demonstrating that class I HLA reduce the WNV polyprotein to a handful of immune targets and that polyfunctional T cells recognize infections by zeroing in on particular HLA/WNV epitopes. Such dominant HLA/peptide epitopes are poised to drive the development of WNV vaccines that elicit protective T cells as well as providing key antigens for immunoassays that establish correlates of viral immunity. © 2013 Kaabinejadian et al

Valuing quality improvements in environmental goods: a case study for the Ticino river

Where prices are missing as an indicator of value, economic non-market valuation represents an important tool for efficient and transparent decision-making. Given that environmental goods and services are often priceless, environmental economists have a long history of applying valuation tools. Two prominent valuation approaches are the Contingent Valuation Method (CVM) and the Travel Cost Method (TCM). They have until recently been considered as competing valuation approaches. A main advantage of the CVM over the TCM is that it allows the net benefits of policies to be estimated without actually being implemented. However, this advantage comes at the cost of protest and strategic responses and other biases. On the other hand, the TCM has drawbacks in valuing environmental quality changes. Recent advances promise substantial improvements in the quality of economic analyses of environmental quality changes. One of them is the combination of revealed and stated preference data in order to estimate improvements in environmental quality. This thesis focuses on the estimation of benefits from environmental quality improvement, illustrated with a water low flow enhancement in the Ticino River. Low flows in rivers are a major negative externality of hydropower energy production, affecting, among others, recreational uses of rivers. A low flow alleviation could therefore result in substantial welfare increases. A Heckman sample selection model was used for model estimation in order to correct for sample selection bias. Quite significant annual increases in individual welfare resulted, confirming the importance of considering the recreational benefits in policy decisions. In fact, in taking decisions regarding a restoration of rivers for example through a low flow enhancement, it is important to take into account all the costs and benefits involved, both monetary and non-monetary. If, for example, benefits to recreational anglers, an important part of non-monetary benefits, were not included in a cost-benefit analysis, decision-making could seriously be biased to the detriment of the environment.Wenn Preise als Indikatoren für den Wert bestimmter Güter fehlen, spielen Nichtmarkt-Bewertungsmethoden eine wichtige Rolle zur effizienten und transparenten Entscheidungsfindung. Da Umweltgüter oft keine Preise haben, werden in der Umweltökonomie Nichtmarkt-Bewertungsmethoden schon lange angewandt. Die zwei bekanntesten Bewertungsmethoden sind die Contingent Valuation Methode (CVM) und die Reisekostenmethode (Travel Cost Method, TCM). Ein Hauptvorteil der CVM gegenüber der TCM besteht darin, dass der Nutzen einer Massnahme geschätzt werden kann, ohne dass diese tatsächlich implementiert wird. Dieser Vorteil hat jedoch seinen Preis: die Methode ist anfällig auf Protest- und strategische Antworten, die die Resultate verzerren können. Auf der anderen Seite ist es schwierig mit der TCM den Nutzen von Qualitätsänderungen zu bewerten. Bis anhin haben diese Ansätze als gegensätzlich (competing) gegolten. Neuerdings werden die beiden Ansätze miteinander kombiniert. Damit sollen die Schwächen der einzelnen Methoden minimiert und die Stärken hervorgehoben und genutzt werden. Die Kombination ist besonders vielversprechend für die Analyse von Umweltverbesserungen. In dieser Dissertation wird die Anwendung einer möglichen Kombination offenbarter und bekundeter Präferenzen für die Monetarisierung des Nutzens einer Restwassermengenerhöhung im Fluss Ticino illustriert. Geringe Restwassermengen in Flüssen ist eine der wichtigsten negativen Externalitäten der Wasserkraft. Neben ökologischen und ästhetischen Schäden führen geringe Restwassermengen in den Flüssen zu Nutzeneinbussen bei Freizeitfischern und anderen Freizeitnutzern. Eine Erhöhung der Restwassermengen würde deshalb zu einer Wohlfahrtserhöhung führen. Für die Schätzung der Nachfrage wurde ein Heckman sample selection model angewandt, um die Verzerrung zu korrigieren, die dadurch entsteht, dass nur positive Werte der abhängigen Variablen „Ausflüge“ beobachtet werden können. Die Resultate zeigen, dass eine Restwassermengenerhöhung zu einer substantiellen jährlichen individuellen Wohlfahrtserhöhung führen würde. Damit wird die Wichtigkeit des Freizeitnutzens, den die Tessiner Flüsse stiften, offensichtlich. Die Entscheidung bezüglich einer Restwassermengenerhöhung bedarf deshalb der Berücksichtigung aller monetären und nicht-monetären Kosten und Nutzen

T-Cell Tolerance for Variability in an HLA Class I-Presented Influenza A Virus Epitope▿

To escape immune recognition, viruses acquire amino acid substitutions in class I human leukocyte antigen (HLA)-presented cytotoxic T-lymphocyte (CTL) epitopes. Such viral escape mutations may (i) prevent peptide processing, (ii) diminish class I HLA binding, or (iii) alter T-cell recognition. Because residues 418 to 426 of the hypervariable influenza A virus nucleoprotein (NP418-426) epitope are consistently bound by class I HLA and presented to CTL, we assessed the impact that intraepitope sequence variability has upon T-cell recognition. CTL elicited by intranasal influenza virus infection were tested for their cross-recognition of 20 natural NP418-426 epitope variants. Six of the variant epitopes, of both H1N1 and H3N2 origin, were cross-recognized by CTL while the remaining NP418-426 epitope variants escaped targeting. A pattern emerged whereby variability at position 5 (P5) within the epitope reduced T-cell recognition, changes at P4 or P6 enabled CTL escape, and a mutation at P8 enhanced T-cell recognition. These data demonstrate that substitutions at P4 and/or P6 facilitate influenza virus escape from T-cell recognition and provide a model for the number, nature, and location of viral mutations that influence T-cell cross-recognition

Direct quantitative measurement of the kinetics of HLA-specific antibody interactions with isolated HLA proteins

HLA specific antibodies vary in their pathogenicity and this is likely to be the net effect of constant chain usage, quantity, specificity, and affinity. Here we have measured the affinity of human monoclonal antibodies for a range of HLA proteins. Purified antibodies and ligands allowed dynamic interactions to be measured directly by surface plasmon resonance. Physiochemical differences between pairs of ligands were quantified using electrostatic mismatch and hydrophobic mismatch scores. All antibodies were characterized by fast on-rates and slow off rates but with a wide range of association rates (kon, 3.63-24.25 × 10(5) per mol per second) and dissociation rates (koff, 0.99-10.93 × 10(-3) per second). Dissociation constants (KD) ranged from 5.9 × 10(-10) M to 3.0 × 10(-8) M. SN320G6 has approximately a twenty-fold greater affinity for HLA A2 compared with SN607D8, but has a similar affinity for HLA-A2 and B57. In contrast, SN607D8 has greater than a twofold greater affinity for HLA-A2 compared with A68. Similarly, WK1D12 has about a threefold greater affinity for HLA-B27 compared with B7. The higher affinity interactions correlate with the specificity of stimulating antigen. This is the first study to directly measure the binding kinetics and affinity constants for human alloantibodies against HLA

Identification and Mapping of Keratinocyte Muscarinic Acetylcholine Receptor Subtypes in Human Epidermis11Presented at the 17th International Congress of Biochemistry and Molecular Biology in conjunction with the Annual Meeting of the American Society for Biochemistry and Molecular Biology, San Francisco, California, August 25 1997, and at the Third Tricontinental Meeting of the Society for Investigative Dermatology, the European Society for Dermatological Research and the Japanese Society for Investigative Dermatology, Cologne, Germany, May 9 1998, and published in the form of an abstract in the Faseb Journal 11:A1057 1997 and Journal of Investigative Dermatology 110:579 1998, respectively.

Acetylcholine mediates cell-to-cell communications in the skin. Human epidermal keratinocytes respond to acetylcholine via two classes of cell-surface receptors, the nicotinic and the muscarinic cholinergic receptors. High affinity muscarinic acetylcholine receptors (mAChR) have been found on keratinocyte cell surfaces at high density. These receptors mediate effects of muscarinic drugs on keratinocyte viability, proliferation, adhesion, lateral migration, and differentiation. In this study, we investigated the molecular structure of keratinocyte mAChR and their location in human epidermis. Polymerase chain reaction amplification of cDNA sequences uniquely present within the third cytoplasmic loop of each subtype demonstrated the expression of the m1, m3, m4, and m5 mAChR subtypes. To visualize these mAChR, we raised rabbit anti-sera to synthetic peptide analogs of the carboxyl terminal regions of each subtype. The antibodies selectively bound to keratinocyte mAChR subtypes in immunoblotting membranes and epidermis, both of which could be abolished by preincubating the anti-serum with the peptide used for immunization. The immunofluorescent staining patterns produced by each antibody in the epidermis suggested that the profile of keratinocyte mAChR changes during epidermal turnover. The semiquantitative analysis of fluorescence revealed that basal cells predominantly expressed m3, prickle cells had equally high levels of m4 and m5, and granular cells mostly possessed m1. Thus, the results of this study demonstrate for the first time the presence of m1, m3, m4, and m5 mAChR in epidermal keratinocytes. Because keratinocytes express a unique combination of mAChR subtypes at each stage of their development in the epidermis, each receptor may regulate a specific cell function. Hence, a single cytotransmitter, acetylcholine, and muscarinic drugs may exert different biologic effects on keratinocytes at different stages of their maturation