1,720,970 research outputs found
Tissue-resident and memory properties of human T-cell and NK-cell subsets
No full textEfficient immune responses to invading pathogens are the result of the complex but coordinated synergy between a variety of cell types from both the innate and adaptive arms of the immune system. While adaptive and innate immune responses are highly complementary, some cells types within these two systems perform similar functions, underscoring the need for redundancy and increased flexibility. In this review, we will discuss the striking shared features of immunological memory and tissue residency recently discovered between T cells, a component of the adaptive immune system, and natural killer (NK) cells, members generally assigned to the innate compartment. Specifically, we will focus on the T-cell and NK-cell diversity at the single cell level, on the discrete function of specific subsets, and on their anatomical location. Finally, we will discuss the implication of such diversity in the generation of long-term memory. This article is protected by copyright
Natural Cytotoxicity Receptors: Broader Expression Patterns and Functions in Innate and Adaptive Immune Cells
Full text linkNatural cytotoxicity receptors (NCRs) have been classically defined as activating receptors delivering potent signals to Natural Killer (NK) cells in order to lyze harmful cells and to produce inflammatory cytokines. Indeed, the elicitation of NK cell effector functions after engagement of NCRs with their ligands on tumor or virus infected cells without the need for prior antigen recognition is one of the main mechanisms that allow a rapid clearance of target cells.The three known NCRs, NKp46, NKp44, and NKp30, comprise a family of germline encoded Ig-like trans-membrane (TM) receptors. Until recently, NCRs were thought to be NK cell specific surface molecules, thus making it possible to easily distinguish NK cells from phenotypically similar cell types. Moreover, it has also been found that the surface expression of NKp46 is conserved on NK cells across mammalian species. This discovery allowed for the use of NKp46 as a reliable marker to identify NK cells in different animal models, a comparison that was not possible before due to the lack of a common and comprehensive receptor repertoire between different species. However, several studies over the recent few years indicated that NCR expression is not exclusively confined to NK cells, but is also present on populations of T as well as of NK-like lymphocytes. These insights raised the hypothesis that the induced expression of NCRs on certain T cell subsets is governed by defined mechanisms involving the engagement of the T cell receptor (TCR) and the action of pro-inflammatory cytokines. In turn, the acquisition of NCRs by T cell subsets is also associated with a functional independence of these Ig-like TM receptors from TCR signaling. Here, we review these novel findings with respect to NCR-mediated functions of NK cells and we also discuss the functional consequences of NCR expression on non-NK cells, with a particular focus on the T cell compartment
Dopamine inhibits the effector functions of activated NK cells via the upregulation of the D5 receptor
No full textSeveral lines of evidence indicate that dopamine (DA) plays a key role in the cross-talk between the nervous and immune systems. In this study, we disclose a novel immune-regulatory role for DA: inhibition of effector functions of activated NK lymphocytes via the selective upregulation of the D5 dopaminergic receptor in response to prolonged cell stimulation with rIL-2. Indeed, engagement of this D1-like inhibitory receptor following binding with DA suppresses NK cell proliferation and synthesis of IFN-γ. The inhibition of IFN-γ production occurs through blocking the repressor activity of the p50/c-REL dimer of the NF-κB complex. Indeed, the stimulation of the D5 receptor on rIL-2-activated NK cells inhibits the binding of p50 to the microRNA 29a promoter, thus inducing a de novo synthesis of this miRNA. In turn, the increased levels of microRNA 29a were inversely correlated with the ability of NK cells to produce IFN-γ. Taken together, our findings demonstrated that DA switches off activated NK cells, thus representing a checkpoint exerted by the nervous system to control the reactivity of these innate immune effectors in response to activation stimuli and to avoid the establishment of chronic and pathologic inflammatory processes
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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