Search results for "HLA-B"

HLA-A, -B and -DRB1 allele frequencies in Cyrenaica population (Libya) and genetic relationships with other populations.

2011

Abstract The frequencies of HLA-A, HLA-B and HLA-DRB1 alleles in 118 unrelated Libyans from Benghazi (Cyrenaica) were analysed using high resolution typing and compared with other populations. Their relatedness has been tested by correspondence analyses and principal component analysis. The most frequent HLA-A alleles were A ∗ 02:01:01:01 (15.7%), A ∗ 01:01:01:01 (11.4%) and A ∗ 03:01:01:01 (9.3%). For the HLA-B locus, the commonest allele was HLA-B ∗ 50:01:01 (14.4%) followed by B ∗ 51:01:01 (9.8%) and B ∗ 08:01:01 (6.4%). For the HLA-DRB1 locus, the commonest was HLA-DRB1 ∗ 07:01:01:01 (16.9%) followed by DRB1 ∗ 03:01:01:01 (13.6%) and DRB1 ∗ 13:02:01 (9.3%). The most frequent two-locus h…

RAPID AND EFFICIENT ANTIGEN PROCESSING AND PRESENTATION OF A PROTECTIVE AND IMMUNODOMINANT HLA-B*27-RESTRICTED HEPATITIS C VIRUS-SPECIFIC CD8+T CELL …

2012

HLA-B*27 exerts protective effects in hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infections. While the immunological and virological features of HLA-B*27-mediated protection are not fully understood, there is growing evidence that the presentation of specific immunodominant HLA-B*27-restricted CD8+ T-cell epitopes contributes to this phenomenon in both infections. Indeed, protection can be linked to single immunodominant CD8+ T-cell epitopes and functional constraints on escape mutations within these epitopes. To better define the immunological mechanisms underlying HLA-B*27-mediated protection in HCV infection, we analyzed the functional avidity, functional profile, ant…

Antigens of the major histocompatibility complex in patients with chronic discoid lupus erythematosus.

1990

summary The frequencies of the major histocompatability complex class I, class II and class III antigens were determined in 130 patients (88 women and 42 men) with chronic discoid lupus erythematosus, and compared with those of 764 healthy controls. A significant increase in HLA-B7 (38.0% in the patients vs. 25·8% in the control group), HLA-B8 (29·5% vs. 17·4%), HLA-Cw7 (58·9% vs. 26·1%), HLA-DR2 (46·9% vs. 29·7%), HLA-DR3 (32·0% vs. 19·4%), HLA-DQwi (76·6% vs. 60·5%), and a decrease in HLA-A2 (41·9% vs. 55·7%) was found. The calculated relative risk values for the respective antigens markedly increased when two or more antigens were present in one patient, with a maximum relative risk valu…

Molecular evidence of HLA-B27 in a historical case of ankylosing spondylitis

2005

Role of HLA-B α-3 domain amino acid position 194 in HIV disease progression

2013

HLA class I molecules play a role in the regulation of innate immune response. Therefore, the interaction of HLA class I molecules with different activating and inhibitory receptors leads to balancing the immune response. Among the different family of receptors, NK receptors KIR3DL1/S1 and LIR1, play a major role. Aim of this study was to evaluate the role of amino acid polymorphic positions of HLA class I molecules interacting with NK receptors in HIV progression. In order to minimize the influence of viral variability, a cohort of children with a nosocomial monophyletic HIV-1 infection from the Benghazi Children Hospital has been evaluated. To assess the role of single amino acid position…

Features of TAP-independent MHC class I ligands revealed by quantitative mass spectrometry.

2008

TAP is responsible for transferring cytosolic peptides into the ER, where they can be loaded onto MHC molecules. Deletion of TAP results in a drastic reduction of MHC class I surface expression and alters the presented peptide pattern. This key molecule in antigen processing is tackled by several viruses and lost in some tumors, rendering the altered cells less vulnerable to T cell-based immune surveillance. Using the TAP-deficient cell line LCL721.174 and its TAP-expressing progenitor cell line LCL721.45, we identified and quantified more than 160 HLA ligands, 50 of which were presented TAP-independently. Peptides which were predominantly presented on the TAP-deficient LCL721.174 cell line…

Tumor associated antigens in human renal cell carcinoma: MHC restricted recognition by cytotoxic T lymphocytes.

1996

Based on previous studies in human melanoma leading to the molecular cloning of genes encoding peptide antigens recognized by MHC-restricted cytotoxic T lymphocytes (CTL) we extended our efforts to renal cancer systems established in tissue culture. In two patients we obtained stable CD8+ CTL clones with high cytolytic activity for the corresponding autologous tumor cell line in vitro. Neither autologous EBV-transformed B lymphocytes or PHA-activated PBL nor natural killer targets K562 were lysed by these CTL clones. MZ1257-RCC CTL5-30 lysed autologous tumor cells as well as normal kidney cell cultures in an HLA-A2 restricted fashion. Further specificity analysis showed cross reactivity wit…

A tyrosinase nonapeptide presented by HLA-B44 is recognized on a human melanoma by autologous cytolytic T lymphocytes

1996

The human tyrosinase gene has been reported previously to code for two distinct antigens recognized on HLA-A2 melanoma cells by autologous cytolytic T lymphocytes (CTL). By stimulating lymphocytes of melanoma patient MZ2 with a subclone of the tumor cell line of this patient, we obtained a CTL clone that lysed this subclone but did not lyse other subcloncs of the Same melanoma cell line. The sensitive melanoma subclone was found to express a much higher level of tyrosinase than the others, suggesting that the antigen recognized bv the CTL might be encoded by tyrosinase. Transfection of a tyrosinase cDNA demonstrated that the CTL clone indeed recognized a tyrosinase product presented by HLA-…

RUNX3 and T-Bet in Immunopathogenesis of Ankylosing Spondylitis—Novel Targets for Therapy?

2019

Susceptibility to ankylosing spondylitis (AS) is polygenic with more than 100 genes identified to date. These include HLA-B27 and the aminopeptidases (ERAP1, ERAP2, and LNPEPS), which are involved in antigen processing and presentation to T-cells, and several genes (IL23R, IL6R, STAT3, JAK2, IL1R1/2, IL12B, and IL7R) involved in IL23 driven pathways of inflammation. AS is also strongly associated with polymorphisms in two transcription factors, RUNX3 and T-bet (encoded by TBX21), which are important in T-cell development and function. The influence of these genes on the pathogenesis of AS and their potential for identifying drug targets is discussed here.

THU0406 ULTRASONOGRAPHIC INVOLVEMENT OF THE ANTERIOR CHEST WALL IN SPONDYLOARTHRITIS, A FIVE YEARS FOLLOW UP STUDY

2019

Background Spondyloarthrits is characterized by inflammatory back pain. Anterior chest wall pain is common and a previous study reported a prevalence a 37% of ultrasonographic lesions of this anatomical region [1]. Objectives The objective of this study is to evaluate, in patient with Spondyloarthritis, the prevalence of ACW ultrasonographic lesions after a follow up of 5 years and to identify factors associated with the development of new lesions. Methods This a monocentric and prospective study including patients with Spondyloarthritis meeting the ASAS 2009 criteria. Patients were followed during five years. ultrasound B mode and power Doppler examination of the two sternoclavicular joint…