Search results for "HLA-B8 Antigen"
showing 10 items of 21 documents
Biological Basis of the HLA-B8,DR3-Associated Progression of Acquired Immune Deficiency Syndrome
1998
The factors influencing the evolution of human immunodeficiency virus (HIV) infection are not fully known, but the host genotype undoubtedly plays a role in determining the outcome of the disease by affecting the immune response to HIV. The role of the host human leukocyte antigen (HLA) genotype in the regulation of susceptibility to HIV infection and expression has been studied extensively in different major risk groups. Certain HLA alleles and haplotypes, being associated with aberrant immune responses independently from HIV infection, have been reported to facilitate the rapid progression of disorders related to HIV infection. Particularly, the association of rapid acquired immunodeficie…
T-cell activation in HLA-B8,DR3-positive individuals early antigen expression defect in vitro
1995
The HLA-B8, DR3 haplotype is overrepresented in several autoimmune diseases, implying that genes predisposing to these disorders are linked to this haplotype. In the patients affected by these diseases, as well as in healthy HLA-B8, DR3 individuals, various dysfunctions reflecting an impairment of T-cell activation have been found. To better characterize T-cell impairment of HLA-B8, DR3-positive healthy individuals, we analyzed the surface expression of early (CD69) and late (CD71) activation phenotypes. MNC cultures were stimulated with PHA and used for T-cell phenotyping by flow cytometry analysis. The results showed that the percentage of CD69+ T cells was significantly decreased in MNC …
Pathogenesis of autoimmune diseases associated with 8.1 ancestral haplotype: a genetically determined defect of C4 influences immunological parameter…
2003
Abstract Subjects with certain HLA alleles have a higher risk of specific autoimmune diseases than those without these alleles. The 8.1 ancestral haplotype (AH) is a common Caucasoid haplotype carried by most people who type for HLA-B8,DR3. It is unique in its association with a wide range of immunopathological diseases. To gain insight into the identification of the mechanism(s) of disease susceptibility of 8.1 AH carriers, we have investigated the prevalence of circulating immune complexes and non-organ-specific autoantibodies in healthy carriers of the haplotype. The results show that carriers of 8.1 AH display both a significant increased prevalence of immune complexes and higher titers…
Genetic control of immune response in carriers of the 8.1 ancestral haplotype: correlation with levels of IgG subclasses: its relevance in the pathog…
2007
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) seems to be associated with susceptibility to autoimmune diseases. Different mechanisms are probably involved in increasing autoimmunity, such as unbalanced cytokine production and the lack of C4A protein. So AH 8.1 modifies immune response in many ways. In this study we demonstrate that IgG2 serum levels were significantly lower in 8.1 AH carriers than in 8.1 AH non-carriers. On the contrary, as regards IgG1, IgG3, IgG4 serum levels, no significant differences were observed between the two groups. In AH 8.1 carriers low IgG2 levels might take to slower cl…
Genetic control of immune response in carriers of ancestral haplotype 8.1: the study of chemotaxis.
2007
In all caucasian populations the association of an impressive number of autoimmune diseases with genes from the HLA-B8, DR3 hap- lotype 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, which is more common in northern Europe, is also associated with a number of immune system dysfunctions in healthy subjects. Analyzing the data according to gender, some dysfunc- tions are observed in women but not in men, in agreement with the role of X-linked genes and/or estrogens in the development and progression of autoimmune diseases.…
Natural killer and lymphokine-activated killer activity in HLA-B8,DR3-positive subjects.
1993
Abstract The haplotype HLA-B8,DR3 is over-represented in several autoimmune diseases, implying that genes predisposing people to these disorders are linked to this haplotype. In these diseases, various dysfunctions reflecting an impairment of the immune system have been found. Several reports indicate also that in HLA-B8,DR3-positive healthy subjects similar disorders may be demonstrated. In the present work, we have evaluated NK and LAK activity in these subjects. The study has been performed on monocyte-depleted peripheral blood MNCs by using the K-562 cell line as a target for NK activity and the HL-60 cell line for as a target LAK activity. LAK cells were obtained by incubating MNCs for…
Markers of T Lymphocyte Activation in HLA-B8, DR3 Positive Individuals
1990
Many autoimmune diseases are associated in Caucasians with HLA-B8 and/or HLA-DR3 antigens. There is evidence that bearers of these antigens may display significant changes in immune parameters when compared to individuals not having these antigens. Recently, increased numbers of blood activated T lymphocytes have been reported in the majority of these diseases. The increase in activated blood T lymphocytes is paradoxically characterized by an in vitro impairment of T cell activation. Particularly, an inadequate production of interleukins has been observed. We have studied blood levels of activated T cells in HLA-typed, healthy subjects. The results show that the percentage of activated T ce…
HLA-B8,DR3 haplotype affects lymphocyte blood levels
1997
The number of lymphocytes in the blood is constant, pointing to an effective control of circulating lymphocyte values. The mechanisms of this regulation are uncertain, although it is likely that the number of blood lymphocytes is conditioned by hormones, homing factors and cytokines whose production is at least partly restrained by genetic factors. Particularly genetic factors linked to major histocompatibility complex (MHC) appear to be involved. In human beings a decreased number of blood lymphocytes has been described in healthy subjects carrying the Human Leucocyte Antigens (HLA) haplotype HLA-B8,DR3. In the present study, to inquire into the mechanisms of this lymphocyte decreased numb…
HLA-B8,DR3 phenotype and lymphocyte responses to phytohaemagglutinin.
1990
Several reports have shown that HLA-B8,DR3 positive subjects may display some changes in immune parameters when compared with HLA-B8,DR3 negative ones and are prone to develop several immunological diseases. In the present study we have analysed the proliferative response to phytohaemagglutin (PHA) in HLA-typed healthy subjects. A twin method was also employed to assess the role of genetic and environmental factors in the regulation of the response to the mitogen. It was not possible to demonstrate any difference in proliferative response to optimal doses of PHA between groups of subjects carrying or not carrying the HLA-B8,DR3 phenotype. When suboptimal responses were studied, however, the…
A genetically determined high setting of TNF-alpha influences immunologic parameters of HLA-B8,DR3 positive subjects: implications for autoimmunity.
2001
The 8.1 ancestral haplotype (AH) is a common Caucasoid haplotype carried by most people who type for HLA-B8,DR3. It seems unique in its association with a wide range of immunopathologic diseases. Healthy subjects bearing this haplotype demonstrate several alterations of immune response. This article will focus on the identification of the mechanism(s) of disease susceptibility of 8.1 AH. In 13 carriers of 8.1 AH, and 43 negative patients, enzyme immune assays serum levels of tumor necrosis factor (TNF)-alpha, soluble endothelial leukocyte adhesion molecule-1 (sELAM-1), cortisol, and interleukin(IL)-10 were determined. In addition, quantification of cytokine produced in vitro after mitogen s…