Search results for "Histocompatibility"
showing 10 items of 473 documents
Reduced CD4 and CD8 expression in human thymuses treated with soluble CD4.
1991
Recent data suggest that accessory molecules like CD4 and CD8 act as co-receptors in intrathymic T-cell development. Soluble CD4 (sCD4) molecules offer a novel experimental approach to investigate the relevance of CD4 interaction with its putative intrathymic receptor for T-cell maturation. We attempted to inhibit binding of surface CD4 on thymocytes to its intrathymic receptor competitively by introduction of human sCD4 into human thymus tissue cultures. Our results demonstrate that sCD4, while not affecting peripheral T-cell responses as shown in control experiments, significantly affects intrathymic development of T lymphocytes. Immature CD4CD8 double positive (DP) thymocytes responded w…
Importance of the inducible costimulator molecule for the induction of allergic immune responses and its decreased expression on T helper cells after…
2004
The inducible costimulator (ICOS), a newly identified member of the CD28 receptor family that is induced after T-cell activation, and its ligand (ICOSL), being expressed on activated monocytes and dendritic cells play a key role in T-cell-mediated immune responses. As ICOS costimulation also seems to regulate T helper 2 effector cells, the aim of this study was to analyse the function of this molecule in allergic immune responses and their specific therapy, mainly venom immunotherapy (VIT). CD4+ T cells from grass pollen-, or bee or wasp venom-allergic donors were stimulated in the presence of autologous mature dendritic cells, which were pulsed with different allergen doses. In this system…
Association between HFE mutations and acute myocardial infarction: a study in patients from Northern and Southern Italy.
2003
There is interest in the role of iron in age-related diseases such as atherosclerosis. Tissue iron deposition could be harmful, because Fe(2+) can react with H(2)O(2) to form OH(-) radicals and Fe(2+) can react with O(2) to form reactive oxygen species. Free radicals react with cell membranes and cell organelles and could lead to the development of atherosclerosis by initiating lipid peroxidation. Hereditary hemochromatosis provides an opportunity for studying the effects of iron on cardiovascular disease. Some studies have shown that individuals who carried HFE mutations may be at greater risk of developing coronary heart disease than those without the mutations. In contrast, a large numbe…
A TNF-α Promoter Polymorphism Is Associated with Juvenile Onset Psoriasis and Psoriatic Arthritis
1997
Tumor necrosis factor-α is considered to be one of the important mediators in the pathogenesis of psoriasis. A strong association of juvenile onset psoriasis with the major histocompatibility complex encoded HLA-Cw6 antigen has been reported but it is unclear whether Cw6 itself or a closely linked gene is involved in the pathogenesis. This study has focused on the association of promoter polymorphisms of the major histocompatibility complex encoded tumor necrosis factor-α gene with psoriasis and psoriatic arthritis. Tumor necrosis factor-α promoter polymorphisms were sought by sequence-specific oligonucleotide hybridization and by direct sequencing in Caucasian patients with juvenile onset …
Pathogenesis of autoimmune diseases associated with 8.1 ancestral haplotype: effect of multiple gene interactions.
2003
Genetic studies have shown that individuals with certain HLA alleles have a higher risk of specific autoimmune disease than those without these alleles. Particularly, the association in all Caucasian populations of an impressive number of autoimmune diseases with genes from the HLA-B8,DR3 haplotype that is part of the ancestral haplotype (AH) 8.1 HLA-A1, Cw7, B8, TNFAB*a2b3, TNFN*S, C2*C, Bf*s, C4A*Q0, C4B*1, DRB1*0301, DRB3*0101, DQA1*0501, DQB1*0201 has been reported by different research groups. This haplotype, the more common one in northern Europe, is also associated in healthy subjects with a number of immune system dysfunctions. It has been proposed that a small number of genes withi…
Characterization of the overlap syndrome of primary biliary cirrhosis (PBC) and autoimmune hepatitis: Evidence for it being a hepatitic form of PBC i…
1999
Some patients with autoimmune liver disease present with a clinical and/or histological picture showing characteristic findings of both autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC). Various names, mostly overlap syndrome, have been used to describe these cases, which have thus far not been more closely characterized. The aim of this study was the comparison of 20 patients with overlapping features to representative patients considered suffering from typical AIH or typical PBC (20 patients in each group). We found these patients to indeed show a very mixed picture of both conditions biochemically, serologically, and histologically. However, closer analysis suggested that al…
Detection of antigen-specific T-cells with MHC/peptide-tetramer-complexes
2002
Abstract Tetramer analysis is a novel technique in immunological research that has dramatically changed our knowledge of the immune response to viral and bacterial pathogens, to tumors and in autoimmune disease. Through the formation of major histocompatibility complex (MHC)/peptide-tetrameric complexes it can provide accurate counts of antigen-specific T-cells and it allows their phenotypical and functional analysis. We review the strengths of this method and use the analysis of peripheral blood lymphocytes (PBL) from a patient with melanoma as a paradigm for the detection of tetramer-binding T-cells. The implementation of tetramer-guided analysis in immunomonitoring allows the ex vivo tes…
Genetics and novel aspects of therapies in systemic lupus erythematosus.
2015
Autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis, autoimmune hepatitis and inflammatory bowel disease, have complex pathogeneses and the factors which cause these disorders are not well understood. But all have in common that they arise from a dysfunction of the immune system, interpreting self components as foreign antigens. Systemic lupus erythematosus (SLE) is one of these complex inflammatory disorders that mainly affects women and can lead to inflammation and severe damage of virtually any tissue and organ. Recently, the application of advanced techniques of genome-wide scanning revealed more genetic information about SLE than previously possible. These case-contro…
Experimental confirmation of the 'protein traffic hypothesis' by routine diagnostic tests
2010
The 'protein traffic hypothesis' suggests that the inflammation associated with autoimmune disease, trauma and disturbances of blood circulation is the result of misguided protein trafficking. The hypothesis divides the antigen spectrum into an intracellular component and an extracellular component. While the intracellular component is recognised by MHC class-I molecules and is presented to CD8 T-lymphocytes, the extracellular component is recognised by MHC class-II molecules and is presented to CD4 T-lymphocytes. To test this hypothesis, CD4 and CD8 T-cell counts of 271 HIV-negative patients of the University Hospital, Mainz, Germany were examined retrospectively. The results corroborate t…
An inherited deficiency of the third component of complement, C3, in guinea pigs
1986
Hereditary deficiency of the third component of complement, C3, is found very seldom in the human. C3 deficiency is associated with severe bacterial infections revealing the central role of C3 in complement activation via the classical or alternative pathway. We describe a new hereditary C3 deficiency in strain 2 guinea pigs. Serum from these animals had a markedly reduced lytic activity in a standard assay for complement-dependent, antibody-mediated cytotoxicity. In functional assays of individual components, the hemolytic activity of the components C4, C2, C5 and of factors B, D and H was in the normal range. The functional C3 titer, and similarly C3 antigenic activity in the serum of the…