Search results for "HLA"
showing 10 items of 664 documents
Partial tyrosinase-specific self tolerance by HLA-A*0201-restricted cytotoxic T lymphocytes in mice and man
2003
The human tyrosinase (hTyr) (369-377) cytotoxic T lymphocyte (CTL) epitope is presented by malignant melanoma and various nontransformed cells in association with human leukocyte antigen (HLA)-A*0201 (A2.1) and used for vaccination-based immunotherapy of melanoma patients. Its mouse homologue, mTyr (369-377), is naturally processed and bound by A2.1 with equivalent efficacy and thus enabled us to explore the effect of self tolerance on Tyr-specific T cells in different lines of A2.1 transgenic (Tg) mice and man. We found that self Tyr-reactive CTL in Tg mice and, importantly, in man were affected by partial tolerance resulting in only residual T lymphocytes of higher avidity for self Tyr al…
Analysis of TCR Vbeta repertoire and cytokine gene expression in patients with idiopathic dilated cardiomyopathy
2001
Although the etiopathogenesis of idiopathic dilated cardiomyopathy (IDC) is still unclear, it is widely accepted that a complex interplay between viral infections and immune mechanisms is the basis of disease genesis. Previously, we showed that heart-infiltrating T cells of patients suffering from acute, fulminant Coxsackie virus B3+-IDC shared a preferential usage of three variable gene segments of the T cell receptor beta chain-(TCR-Vbeta) encoding families Vbeta3, 7 and 13.1. This indicated the possible presence of a superantigen-driven immune response. Here, we further investigated the IDC immunological scenario by analysing different phenotypes of heart-infiltrating cells: TCR repertoi…
Markers of Inflammation and Infection Influence the Outcome of Patients With Baseline Asymptomatic Carotid Lesions
2005
Background and Purpose— It is still in debate whether the evaluation of markers of infection and inflammation may be of importance for cerebrovascular and cardiovascular prevention, and we aimed to investigate this field in a prospective 5-year clinical follow-up study in patients with early stages of atherosclerosis. Methods— We studied 668 subjects divided in 3 groups according to the results of carotid ultrasound examination: (1) normal subjects, if intima-media thickness (IMT) was <0.9 mm; (2) with IMT, if IMT was between 0.9 and 1.5 mm; and (3) with asymptomatic carotid plaque, if IMT was >1.5 mm. Traditional cardiovascular risk factors were investigated, and laboratory analysis…
Impact of infectious burden on progression of carotid atherosclerosis.
2002
Background and Purpose— Recent findings suggest a causative role of infections in the pathogenesis of atherosclerosis. The extent of atherosclerosis and the prognosis of patients with atherosclerosis seem to be increased by the number of infections to which an individual has been exposed. In a prospective study, we evaluated the effect of 8 pathogens and the aggregate pathogen burden on the progression of carotid atherosclerosis. Methods— In 504 patients (74.9% men; age, 62.9±10 years), we measured intima-media thickness and prevalence of carotid artery stenosis. Follow-up measurements after a mean of 2.5 years were available in 427 patients (85%). Blood samples were taken, and IgG or IgA …
Melanoma-Reactive Class I-Restricted Cytotoxic T Cell Clones Are Stimulated by Dendritic Cells Loaded with Synthetic Peptides, but Fail to Respond to…
2003
Abstract Immunization with heat shock proteins (hsp) isolated from cancer cells has been shown to induce a protective antitumor response. The mechanism of hsp-dependent cellular immunity has been attributed to a variety of immunological activities mediated by hsp. Hsp have been shown to bind antigenic peptides, trim the bound peptides by intrinsic enzymatic activity, improve endocytosis of the chaperoned peptides by APCs, and enhance the ability of APCs to stimulate peptide-specific T cells. We have investigated the potential capacity of hsp70 and gp96 to function as a mediator for Ag-specific CTL stimulation in an in vitro model for human melanoma. Repetitive stimulation of PBLs by autolog…
Infecciones por clamidias
2007
Las clamidias son un grupo peculiar de bacterias, cuyo ciclo vital transcurre en parte en el interior de las células. Tienen la propiedad de adherirse a determinados epitelios, en los que pueden acabar produciendo infecciones. Existen tres especies patógenas para el hombre: Chlamydia trachomatis, que produce infecciones fundamentalmente en los epitelios genital y urinario, y C. psittaci y C. pneumoniae, que producen fundamentalmente infecciones respiratorias. A las dos últimas se les clasifica en la actualidad en un género diferente, el de las Chlamydophilas.
Consecutive binding of chlorophylls a and b during the assembly in vitro of light-harvesting chlorophyll-a/b protein (LHCIIb).
2006
The apoprotein of the major light-harvesting chlorophyll a/b complex (LHCIIb) is post-translationally imported into the chloroplast, where membrane insertion, protein folding, and pigment binding take place. The sequence and molecular mechanism of the latter steps is largely unknown. The complex spontaneously self-organises in vitro to form structurally authentic LHCIIb upon reconstituting the unfolded recombinant protein with the pigments chlorophyll a, b, and carotenoids in detergent micelles. Former measurements of LHCIIb assembly had revealed two apparent kinetic phases, a faster one (tau1) in the range of 10 s to 1 min, and a slower one (tau2) in the range of several min. To unravel th…
Chlamydomonas reinhardtii in the landscape of pigments.
2004
▪ Abstract This review focuses on the biosynthesis of pigments in the unicellular alga Chlamydomonas reinhardtii and their physiological and regulatory functions in the context of information gathered from studies of other photosynthetic organisms. C. reinhardtii is serving as an important model organism for studies of photosynthesis and the pigments associated with the photosynthetic apparatus. Despite extensive information pertaining to the biosynthetic pathways critical for making chlorophylls and carotenoids, we are just beginning to understand the control of these pathways, the coordination between pigment and apoprotein synthesis, and the interactions between the activities of these…
Endogenous fluctuations of DNA topology in the chloroplast of Chlamydomonas reinhardtii.
1998
DNA supercoiling in the chloroplast of the unicellular green alga Chlamydomonas reinhardtii was found to change with a diurnal rhythm in cells growing in alternating 12-h dark-12-h light periods. Highest and lowest DNA superhelicities occurred at the beginning and towards the end of the 12-h light periods, respectively. The fluctuations in DNA supercoiling occurred concurrently and in the same direction in two separate parts of the chloroplast genome, one containing the genes psaB, rbcL, and atpA and the other containing the atpB gene. Fluctuations were not confined to transcribed DNA regions, indicating simultaneous changes in DNA conformation all over the chloroplast genome. Because the d…
The redox state regulates RNA degradation in the chloroplast of Chlamydomonas reinhardtii.
1999
Abstract A Chlamydomonas reinhardtii chloroplast transformant, designated MU7, carrying a chimeric (rbcL promoter: β-glucuronidase [GUS]:psaB 3′ end) gene whose transcripts have been found previously to be unstable in light (half-life of 20 min in light as opposed to a half-life of 5 h in the dark), was used to study the role of electron transport and of the redox state in the degradation of chloroplast transcripts in the light. Blocking photosynthetic electron transport with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) prevented the light-dependent breakdown of the pool of GUS transcripts in MU7 cells. Diamide, an oxidizing agent, caused a measurable delay in the degradation of GUS trans…