1,720,995 research outputs found
Interferon-g promotes exaggerated cytokine production in keratinocytes cultured from patients with atopic dermatitis
No full textRecent studies suggest that skin keratinocytes from patients with atopic dermatitis (AD) and nonatopic subjects differ in their intrinsic ability to respond to proinflammatory stimuli. In this study keratinocyte cultures established from the normal-looking skin of six adult patients with AD and six healthy, nonatopic control subjects were compared in their response to interferon (IFN)-γ, a potent proinflammatory lymphokine whose expression is increased in chronic AID lesions. Basal expression of IFN-γ receptor as well as IFN-γ-induced membrane expression of HLA-DR and intercellular adhesion molecule (ICAM)-1 were evaluated by flow cytometry. Keratinocyte release of IL-1α, IL-1 receptor antagonist (IL-1ra), granulocyte-macrophage colony stimulating factor (GM-CSF), and tumor necrosis factor (TNF)-α were measured by ELISA on culture supernatants after treatment with IFN-γ or medium alone. Expression of membrane IFN-γ receptor was similar in keratinocytes cultured from nonatopic subjects and subjects with AD. IFN-γ (10 to 500 U/ml) induced comparable levels of membrane HLA-DR and ICAM-1 in both groups of keratinocytes. In contrast, spontaneous release of IL-1α, IL-1ra, GM-CSF, and TNF-α was increased in the supernatants of unstimulated keratinocytes from patients with An compared with keratinocytes from control subjects, with IL-1ra and GM-CSF reaching statistically significant difference. Moreover, IFN-γ-induced release of all the cytokines tested was much higher for keratinocytes from patients with AD, but the IL-1ra/IL-1α ratio for the two groups of keratinocytes was not substantially different, either basally or after IFN-γ stimulation. The results indicate that keratinocytes from patients with AD are hyperresponsive to IFN-γ in terms of cytokine release
Human dendritic cells are superior to B cells at presenting a major histocompatibility complex class II-restricted heterologous antigen expressed on recombinant Streptococcus gordonii
No full textBacteria are being actively investigated as vaccine carriers for inducing or boosting protective immune responses. In this study, human monocyte-derived dendritic cells (DCs) and normal B cells were compared for their capacity to present the C fragment of tetanus toxin (TTFC), expressed on the surface of recombinant Streptococcus gordonii, to specific CD4(+) T lymphocytes. DCs were more efficient than B cells at presenting soluble TTFC and remarkably more capable of presenting bacterium-associated TTFC both in terms of the amount of antigen required to obtain a given T-cell response and on a per-cell basis. This difference was associated with a much lower capacity of B cells to endocytose soluble TTFC and phagocytose recombinant S. gordonii. In addition, S. gordonii induced the phenotypic maturation of DCs but not of B cells. The results thus indicate that DCs but not B cells play a crucial role in the amplification of class II-restricted immune responses induced by immunization with recombinant gram-positive bacteria
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
Adenosine triphosphate (ATP) induces a distorted maturation of dendritic cells and inhibits their capacity to initiate TH1 responses.
No full textDendritic cells (DCs) express functional purinergic receptors, but the effects of purine nucleotides on DCs functions have been only marginally investigated. Here we report the ability of ATP to affect the maturation and antigen presenting function of monocyte-derived DCs in vitro. Chronic stimulation of DCs with low, non cytotoxic ATP doses, but not with UTP, increased membrane expression of CD54, CD80, CD86 and CD83 as well as their capacity of inducing T lymphocyte proliferation in the primary mixed leukocyte reaction assay. Moreover, ATP enhanced LPS- or sCD40L-induced DC membrane maturation. On the other hand, ATP markedly and dose-dependently inhibited the production of TNF-alpha, IL-6 and IL-12 by LPS-stimulated DCs. In contrast, IL-10 production was only slightly affected. These effects did not require ATP metabolism as they were shared by the poorly hydrolyzable ATP analog ATP-gamma-S and were not prevented by specific inhibitors of the adenosine receptors. In addition, ATP activity was not blocked by treating DCs with indomethacin, suggesting that it was not mediated by prostaglandins. More interesting, T cell lines generated from allogeneic naive CD45RA+ T cells with DCs matured in the presence of ATP, produced lower amounts of IFN-gamma and higher levels of IL-4, IL-5 and IL-10. Addition of IL-12 and/or anti-IL-10 mAb restored IFN-gamma production, and reduced IL-4, IL-5 and IL-10 release. The results indicate that chronic stimulation with ATP, although induces phenotypic maturation, can potently inhibit the ability of maturing DCs to initiate Th1 responses
Extracellular ATP induces a distorted maturation of dendritic cells and inhibits their capacity to initiate T-helper 1 responses.
No full textVariations 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
L'allergene maggiore di Parietaria judaica Parj 1.0101 contiene una regione capace di legare LPS e con attività immunomodulatoria
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