Hepatocellular carcinoma risk variant modulates lncRNA HLA-DQB1-AS1 expression via a long-range enhancer-promoter interaction.

Substantial evidence highlighted the critical role of long non-coding RNAs (lncRNA) in driving hepatocarcinogenesis. We hypothesized that functional variants in genome-wide association studies (GWASs) associated loci might alter the expression levels of lncRNAs and contribute to the development of hepatocellular carcinoma (HCC). Here, we prioritized potentially cis-expression quantitative trait loci-based single nucleotide polymorphism (SNP)-lncRNA association together with the physical interaction by the analyses from Hi-C data in GWAS loci of chronic hepatitis B and HCC. Subsequently, by leveraging two-stage case-control study (1738 hepatitis B [HBV]) related HCC cases and 1988 HBV persistent carriers) and biological assays, we identified that rs2647046 was significantly associated with HCC risk (odds ratio = 1.26, 95% CI = 1.11 to 1.43, P = 4.14 × 10-4). Luciferase reporter assays and electrophoretic mobility shift assays showed that rs2647046 A allele significantly increased transcriptional activity via influencing transcript factor binding affinity. Allele-specific chromosome conformation capture assays revealed that enhancer with rs2647046 interacted with the HLA-DQB1-AS1 promoter to allele-specifically influence its expression by CTCF-mediated long-range loop. Cell proliferation assays indicated that HLA-DQB1-AS1 is a potential oncogene in HCC. Our study showed HLA-DQB1-AS1 regulated by a causal SNP in a long-range interaction manner conferred the susceptibility to HCC, suggesting an important mechanism of modulating lncRNA expression for risk-associated SNPs in the etiology of HCC.

HLAs associated with perampanel-induced psychiatric adverse effects in a Korean population.

Perampanel (PER) is a new-generation antiepileptic drug that has an occasional but significant shortcoming, psychiatric adverse effects (PAEs). Recently, antiepileptic drug-related adverse reactions, such as skin rash and even PAEs, have been discovered to be correlated with certain human leukocyte antigen (HLA) types. Thus, we aimed to analyze specific HLA alleles as risk factors for PER-PAEs. We prospectively enrolled 17 patients with epilepsy who were prescribed PER between May 2016 and Jul 2018 at Seoul National University Hospital and developed PAEs while taking PER. Their HLA types were analyzed compared to those of 19 patients in the PAE-tolerant group and the general Korean population. In silico docking was performed with two different computational programs, AutoDock Vina and SwissDock, to theoretically evaluate the binding affinity of PER in the grooves of the specific HLA alleles. The HLA-DQB1*06:01, DRB1*08:03, and B*54:01 alleles were significantly associated with the patients who developed PER-PAEs compared with the general Korean population (odds ratio [OR] 3.94, p = 0.008, OR 9.24, p = 0.037, and OR 3.25, p = 0.041, respectively). As a haplotype, the combination of the three alleles was significantly more frequent in the PER-PAE group than in both the PER-tolerant group and the general Korean population. DQB1*06:01 and B*54:01 also demonstrated higher docking scores with PER than other alleles. This is the first study to analyze the association of PER-PAEs with specific HLA genotypes. Our results suggest that an HLA-associated genetic predisposition and a possible immunological mechanism are involved in the occurrence of PER-PAEs.

Combined 5-hydroxymethylcytosine content of human leucocyte antigen-B and human leucocyte antigen-DQB1 as novel biomarker for anti-tuberculosis drug-induced liver injury.

This study investigated the diagnostic value of 5-methylcytosine (5-mC) and 5-hydroxymethylcytosine (5-hmC) contents of human leucocyte antigen (HLA)-B and HLA-DQB1 in anti-tuberculosis drug-induced liver injury (ADLI). In total, 110 ADLI patients and 120 patients without ADLI controls were enrolled. Enzyme-linked immunosorbent assay (ELISA) was used to detect the 5-mC and 5-hmC content in DNA from peripheral blood leucocytes. The univariate analysis showed that smoking, drinking, and 5-mC and 5-hmC content of HLA-B and HLA-DQB1 were significantly associated with ADLI. After adjusting for drinking and smoking, we found that 5-mC content of HLA-B and HLA-DQB1 were associated with ADLI (odds ratio [OR] = 0.251 and 0.347, respectively) and 5-hmC contents of HLA-B and HLA-DQB1 were also associated with ADLI (OR = 1.848 and 4.705, respectively). Receiver operating characteristic (ROC) analysis indicated that the 5-hmC contents of both HLA-B and HLA-DQB1 were more clinically significant than the 5-mC contents were. The combined 5-hmC level of HLA-B and HLA-DQB1 was the best diagnostic biomarker for ADLI, with the highest areas under the curve (AUC) for 0.953, sensitivity for 0.900 and specificity for 0.875. Therefore, combined 5-hmC levels of HLA-B and HLA-DQB1 could be significant evidence for diagnosis of ADLI.

Allele-specific expression changes dynamically during T cell activation in HLA and other autoimmune loci.

Genetic studies have revealed that autoimmune susceptibility variants are over-represented in memory CD4+ T cell regulatory elements1-3. Understanding how genetic variation affects gene expression in different T cell physiological states is essential for deciphering genetic mechanisms of autoimmunity4,5. Here, we characterized the dynamics of genetic regulatory effects at eight time points during memory CD4+ T cell activation with high-depth RNA-seq in healthy individuals. We discovered widespread, dynamic allele-specific expression across the genome, where the balance of alleles changes over time. These genes were enriched fourfold within autoimmune loci. We found pervasive dynamic regulatory effects within six HLA genes. HLA-DQB1 alleles had one of three distinct transcriptional regulatory programs. Using CRISPR-Cas9 genomic editing we demonstrated that a promoter variant is causal for T cell-specific control of HLA-DQB1 expression. Our study shows that genetic variation in cis-regulatory elements affects gene expression in a manner dependent on lymphocyte activation status, contributing to the interindividual complexity of immune responses.

Mother-child histocompatibility and risk of rheumatoid arthritis and systemic lupus erythematosus among mothers.

The study objective was to test the hypothesis that having histocompatible children increases the risk of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), possibly by contributing to the persistence of fetal cells acquired during pregnancy. We conducted a case control study using data from the UC San Francisco Mother Child Immunogenetic Study and studies at the Inova Translational Medicine Institute. We imputed human leukocyte antigen (HLA) alleles and minor histocompatibility antigens (mHags). We created a variable of exposure to histocompatible children. We estimated an average sequence similarity matching (SSM) score for each mother based on discordant mother-child alleles as a measure of histocompatibility. We used logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals. A total of 138 RA, 117 SLE, and 913 control mothers were analyzed. Increased risk of RA was associated with having any child compatible at HLA-B (OR 1.9; 1.2-3.1), DPB1 (OR 1.8; 1.2-2.6) or DQB1 (OR 1.8; 1.2-2.7). Compatibility at mHag ZAPHIR was associated with reduced risk of SLE among mothers carrying the HLA-restriction allele B*07:02 (n = 262; OR 0.4; 0.2-0.8). Our findings support the hypothesis that mother-child histocompatibility is associated with risk of RA and SLE.

Tristetraprolin/ZFP36 Regulates the Turnover of Autoimmune-Associated HLA-DQ mRNAs.

HLA class II genes encode highly polymorphic heterodimeric proteins functioning to present antigens to T cells and stimulate a specific immune response. Many HLA genes are strongly associated with autoimmune diseases as they stimulate self-antigen specific CD4+ T cells driving pathogenic responses against host tissues or organs. High expression of HLA class II risk genes is associated with autoimmune diseases, influencing the strength of the CD4+ T-mediated autoimmune response. The expression of HLA class II genes is regulated at both transcriptional and post-transcriptional levels. Protein components of the RNP complex binding the 3'UTR and affecting mRNA processing have previously been identified. Following on from this, the regulation of HLA-DQ2.5 risk genes, the main susceptibility genetic factor for celiac disease (CD), was investigated. The DQ2.5 molecule, encoded by HLA-DQA1*05 and HLA-DQB1*02 alleles, presents the antigenic gluten peptides to CD4+ T lymphocytes, activating the autoimmune response. The zinc-finger protein Tristetraprolin (TTP) or ZFP36 was identified to be a component of the RNP complex and has been described as a factor modulating mRNA stability. The 3'UTR of CD-associated HLA-DQA1*05 and HLA-DQB1*02 mRNAs do not contain canonical TTP binding consensus sequences, therefore an in silico approach focusing on mRNA secondary structure accessibility and stability was undertaken. Key structural differences specific to the CD-associated mRNAs were uncovered, allowing them to strongly interact with TTP through their 3'UTR, conferring a rapid turnover, in contrast to lower affinity binding to HLA non-CD associated mRNA.

HLA class II-Restricted CD8+ T cells in HIV-1 Virus Controllers.

A paradigm shifting study demonstrated that induction of MHC class E and II-restricted CD8+ T cells was associated with the clearance of SIV infection in rhesus macaques. Another recent study highlighted the presence of HIV-1-specific class II-restricted CD8+ T cells in HIV-1 patients who naturally control infection (virus controllers; VCs). However, questions regarding class II-restricted CD8+ T cells ontogeny, distribution across different HIV-1 disease states and their role in viral control remain unclear. In this study, we investigated the distribution and anti-viral properties of HLA-DRB1*0701 and DQB1*0501 class II-restricted CD8+ T cells in different HIV-1 patient cohorts; and whether class II-restricted CD8+ T cells represent a unique T cell subset. We show that memory class II-restricted CD8+ T cell responses were more often detectable in VCs than in chronically infected patients, but not in healthy seronegative donors. We also demonstrate that VC CD8+ T cells inhibit virus replication in both a class I- and class II-dependent manner, and that in two VC patients the class II-restricted CD8+ T cells with an anti-viral gene signature expressed both CD4+ and CD8+ T cell lineage-specific genes. These data demonstrated that anti-viral memory class II-restricted CD8+ T cells with hybrid CD4+ and CD8+ features are present during natural HIV-1 infection.

Solid-State NMR Investigations of the MHC II Transmembrane Domains: Topological Equilibria and Lipid Interactions.

The major histocompatibility complex class II (MHC II) membrane proteins are key players in the adaptive immune response. An aberrant function of these molecules is associated with a large number of autoimmune diseases such as diabetes type I and chronic inflammatory diseases. The MHC class II is assembled from DQ alpha 1 and DQ beta 1 which come together as a heterodimer through GXXXG-mediated protein-protein interactions and a highly specific protein-sphingomyelin-C18 interaction motif located on DQA1. This association can have important consequences in regulating the function of these membrane proteins. Here, we investigated the structure and topology of the DQA1 and DQB1 transmembrane helical domains by CD-, oriented 2H and 15N solid-state NMR spectroscopies. The spectra at peptide-to-lipid ratios of 0.5 to 2 mol% are indicative of a topological equilibrium involving a helix crossing the membrane with a tilt angle of about 20° and another transmembrane topology with around 30° tilt. The latter is probably representing a dimer. Furthermore, at the lowest peptide-to-lipid ratio, a third polypeptide population becomes obvious. Interestingly, the DQB1 and to a lesser extent the DQA1 transmembrane helical domains exhibit a strong fatty acyl chain disordering effect on the inner segments of the 2H-labelled palmitoyl chain of POPC bilayers. This phosphatidylcholine disordering requires the presence of sphingomyelin-C18 suggesting that the ensemble of transmembrane polypeptide and sphingolipid exerts positive curvature strain.

Association of HLA-DQB1*03:01 and DRB1*11:01 with spontaneous clearance of hepatitis C virus in Chinese Li ethnicity, an ethnic group genetically distinct from Chinese Han ethnicity and infected with unique HCV subtype.

Specific human leukocyte antigen (HLA) class I and class II alleles have been associated with spontaneous clearance or persistent infection of hepatitis C virus (HCV), which seemed to be restricted by the host's ethnicity and viral genotype. Recently we reported a high prevalence and spontaneous clearance rate of HCV in a cohort of Chinese Li ethnicity who were infected with new variants of HCV genotype 6. In this study, we found that the distribution of HLA class I and class II alleles in HCV infected individuals of Chinese Li ethnicity (n = 143) was distinct from that of Chinese Han ethnicity which was reported in our previous study. HLA-DRB1*11:01 and DQB1*03:01 were more prevalent in Chinese Li subjects who cleared HCV spontaneously than those who were chronically infected (P = .036 and P = .024, respectively), which were consistent with our previous report regarding the Chinese Han population. Multivariate logistic regression analysis showed that DQB1*03:01 (odds ratio = 3.899, P = .017), but not DRB1*11:01, associated with HCV spontaneous clearance, independent of age, sex, and IFNL3 genotype. Because DQB1*03:01 and DRB1*11:01 were tightly linked because of linkage disequilibrium, our results clearly supported the associations of these two alleles with HCV spontaneous clearance in Chinese Li as well as Han ethnicity.

Association of HLA class II alleles/haplotypes and amino acid variations in the peptide binding pockets with rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is an autoimmune, inflammatory disease, caused by environmental and genetic factors. AIM: To elucidate the association of human leukocyte antigen (HLA)-DRB1*/DQB1* alleles/haplotypes and the variations of polymorphic amino acid changes in peptide binding pockets in RA patients from south India. METHODS: HLA typing was performed in 176 RA patients and 176 healthy controls by polymerase chain reaction-sequence-specific primers method. RESULTS: Strong susceptible association for alleles such as DRB1*04:01(odds ratio [OR] = 3.66), 04:06 (OR = 3.81), 03:01 (OR = 2.93), 06:01 (OR = 2.53) and protective association for alleles such as DRB1*13:01 (OR = 0.17), 14:01 (OR = 0.15), 05:02 (OR = 0.17), and 05:03 (OR = 0.338) were observed in RA patients. The 2-locus haplotypes such as 04-02:01 (OR = 3.844), 04-06:01 (OR = 6.57), 07-03:01 (OR = 6.16), 07-06:01 (OR = 3.42), 12-06:01 (OR = 5.24), 15-03:01 (OR = 4.69) with susceptible and DRB1*14-DQB1*05:03 (OR = 0.078) with protective associations were observed in RA patients. The acid-base analysis revealed that the basic group BB allele was positively associated (OR = 2.372) and the acidic group AA allele was negatively associated (OR = 0.086). The analysis on shared epitopes has revealed that the combination QKRAA+, (Q)RRAA+ or (Q)RRAA- was positively associated with RA (OR = 2.78). The amino acid variation at HLA-DQß molecule revealed susceptible associations for residues E86 and L87 (P1); E74 (P3); A13 , Y26 , I/S28 , T28 , I71 and E74 (P4); L9 , T30 , D37 and D57 (P9), whereas, the amino acids A86 and T87 (P1); S74 (P3); G13/26 , A71 and S74 (P4); H30 and T37 , S57 (P9), showed protective associations. CONCLUSIONS: Alleles DRB1*04:06 and*04:01 showed strong susceptible and DRB1*13:01 and *14:01 showed protective associations in RA patients. The amino acid variations in DQß molecules revealed significant molecular markers for susceptibility to and protection from RA in south India.

A Joint Modeling Approach for Childhood Meat, Fish and Egg Consumption and the Risk of Advanced Islet Autoimmunity.

Several dietary factors have been suspected to play a role in the development of advanced islet autoimmunity (IA) and/or type 1 diabetes (T1D), but the evidence is fragmentary. A prospective population-based cohort of 6081 Finnish newborn infants with HLA-DQB1-conferred susceptibility to T1D was followed up to 15 years of age. Diabetes-associated autoantibodies and diet were assessed at 3- to 12-month intervals. We aimed to study the association between consumption of selected foods and the development of advanced IA longitudinally with Cox regression models (CRM), basic joint models (JM) and joint latent class mixed models (JLCMM). The associations of these foods to T1D risk were also studied to investigate consistency between alternative endpoints. The JM showed a marginal association between meat consumption and advanced IA: the hazard ratio adjusted for selected confounding factors was 1.06 (95% CI: 1.00, 1.12). The JLCMM identified two classes in the consumption trajectories of fish and a marginal protective association for high consumers compared to low consumers: the adjusted hazard ratio was 0.68 (0.44, 1.05). Similar findings were obtained for T1D risk with adjusted hazard ratios of 1.13 (1.02, 1.24) for meat and 0.45 (0.23, 0.86) for fish consumption. Estimates from the CRMs were closer to unity and CIs were narrower compared to the JMs. Findings indicate that intake of meat might be directly and fish inversely associated with the development of advanced IA and T1D, and that disease hazards in longitudinal nutritional epidemiology are more appropriately modeled by joint models than with naive approaches.

Determination of HLA-A, -B, -C, -DRB1 and -DQB1 allele and haplotype frequencies in heart failure patients.

AIMS: Cell therapy can be used to repair functionally impaired organs and tissues in humans. Although autologous cells have an immunological advantage, it is difficult to obtain high cell numbers for therapy. Well-characterized banks of cells with human leukocyte antigens (HLA) that are representative of a given population are thus needed. The present study investigates the HLA allele and haplotype frequencies in a cohort of heart failure (HF) patients. METHODS AND RESULTS: We carried out the HLA typing and the allele and haplotype frequency analysis in 247 ambulatory HF patients. We determined HLA class I (A, B, and C) and class II (DRB1 and DQB1) using next-generation sequencing technology. The allele frequencies were obtained using Python for Population Genomics (PyPop) software, and HLA haplotypes were estimated using HaploStats. A total of 30 HLA-A, 56 HLA-B, 23 HLA-C, 36 HLA-DRB1, and 15 HLA-DQB1 distinct alleles were identified within the studied cohort. The genotype frequencies of all five HLA loci were in Hardy-Weinberg equilibrium. We detected differences in HLA allele frequencies among patients when the etiological cause of HF was considered. There were a total of 494 five-loci haplotypes, five of which were present six or more times. Moreover, the most common estimated HLA haplotype was HLA-A*01:01, HLA-B*08:01, HLA-C*07:01, HLA-DRB1*03:01, and HLA-DQB1*02:01 (6.07% haplotype frequency per patient). Remarkably, the 11 most frequent haplotypes would cover 31.17% of the patients of the cohort in need of allogeneic cell therapy. CONCLUSIONS: Our findings could be useful for improving allogeneic cell administration outcomes without concomitant immunosuppression.

Early-onset autoimmune vitiligo associated with an enhancer variant haplotype that upregulates class II HLA expression.

Vitiligo is an autoimmune disease in which melanocyte destruction causes skin depigmentation, with 49 loci known from previous GWAS. Aiming to define vitiligo subtypes, we discovered that age-of-onset is bimodal; one-third of cases have early onset (mean 10.3 years) and two-thirds later onset (mean 34.0 years). In the early-onset subgroup we found novel association with MHC class II region indel rs145954018, and independent association with the principal MHC class II locus from previous GWAS, represented by rs9271597; greatest association was with rs145954018del-rs9271597A haplotype (P = 2.40 × 10-86, OR = 8.10). Both rs145954018 and rs9271597 are located within lymphoid-specific enhancers, and the rs145954018del-rs9271597A haplotype is specifically associated with increased expression of HLA-DQB1 mRNA and HLA-DQ protein by monocytes and dendritic cells. Thus, for vitiligo, MHC regulatory variation confers extreme risk, more important than HLA coding variation. MHC regulatory variation may represent a significant component of genetic risk for other autoimmune diseases.

The roles of HLA-DQB1 gene polymorphisms in hepatitis B virus infection.

BACKGROUND: Infection with the hepatitis B virus (HBV) is an independent risk factor for liver cirrhosis and hepatocellular carcinoma, polymorphisms in HLA-DQB1 play an important role in HBV infections. METHODS: This study examined the relationships between HLA-DQB1 alleles and HBV infection susceptibility among 256 HBV carriers and 433 healthy controls. Venous blood samples were subjected to DQB1 high-resolution typing and testing for interferon-gamma, interleukin-4 (IL-4), interleukin-10, and DQB1 mRNA expression. A meta-analysis was also performed using relevant case-control studies that evaluated the associations of HLA-DQB1 alleles with HBV infection and clearance. RESULTS: We found that HLA-DQB1*06:03 protected against HBV infection. Levels of IFN-γ and IL-4 were significantly elevated in HBV cases with HLA-DQB1*06:05 (vs. HLA-DQB1*05:03), and the HBV group had higher DQB1 mRNA expression than the healthy control group with HLA-DQB1*05:03 and HLA-DQB1*06:02. The meta-analysis revealed that HLA-DQB1*04:01, HLA-DQB1*05:02, HLA-DQB1*05:03, and HLA-DQB1*06:01 were risk factors for HBV infection susceptibility, while HLA-DQB1*05:01, HLA-DQB1*06:03, and HLA-DQB1*06:04 protected against HBV infection. Spontaneous HBV clearance was associated withHLA-DQB1*06:04, while chronic HBV infection was associated with HLA-DQB1*02:01 and HLA-DQB1*05:02. CONCLUSION: DBQ1 typing can be used to identify patients who have elevated risks of HBV infection (i.e., patients with HLA-DQB1*04:01, HLA-DQB1*05:02, HLA-DQB1*05:03, and HLA-DQB1*06:01) or elevated risks of chronic HBV infection (i.e., patients with HLA-DQB1*02:01 and HLA-DQB1*05:02).

Heightened expression of HLA-DQB1 and HLA-DQB2 in pre-implantation biopsies predicts poor late kidney graft function.

BACKGROUND: Accurate pre-transplant prediction of late graft function remains an unmet need in kidney transplantation. The aim of this study was to evaluate HLA genes expression levels in pre-implantation biopsies (PIB) of deceased donor kidneys as markers for long-term graft outcome. METHODS: HLA genes expression analysis was initially performed using microarray data of 53 PIB, previously generated by our laboratory. The validation analysis was performed by real-time PCR in 116 PIB from an independent cohort. RESULTS: The microarray data showed association between high expression levels of HLA class II genes, especially HLA-DQB1 and -DQB2, in kidneys from young (18 to 49-year-old) donors and poor (eGFR < 45 mL/min/1.73 m2) 1- and 5-year graft function. A subsequent study in an independent cohort, in which only HLA-DQB2 expression was evaluated, validated the association between increased HLA-DQB2 expression in PIB of kidneys from young donors and poor 1-year graft function: expression levels ≥0.0025 relative units conferred an odds ratio of 22.5, with positive and negative predictive values of 71.4% and 90.0%, respectively. CONCLUSION: Heightened expression of HLA-DQB1 and -DQB2 in PIB are promising tools for pre-transplant risk assessment of poor late graft function in transplants with kidneys from 18 to 49-year-old donors.

The association of HLA-DQB1*0602 but not HLA-DRB1*15 with obstructive sleep apnea.

PURPOSE: Obstructive sleep apnea (OSA) is a sleep breathing disorder with unclear multifactorial pathogenesis. This study aimed to investigate the association between OSA and two human leukocyte antigens (HLA) alleles; DQB1*0602 and DRB1*15. METHODS: Forty patients with OSA and 40 control subjects were enrolled in the study. OSA diagnosis was made utilizing the Apnea-Hypopnea Index (AHI)≥5 in overnight polysomnography (PSG). AHI was also used to determine OSA severity. Controls were randomly selected from healthy volunteers who had a low risk for OSA, utilizing the Berlin Questionnaire. Polymerase chain reaction (PCR) using Sequence Specific Primers (PCR-SSPs) was used to determine the association between HLA (HLA-DQB1*0602 and HLA-DRB1*15) and OSA, then statistical analyses of the results were performed. RESULTS: HLA-DQB1*0602 allele was found in 85% of all OSA patients and 50% of controls (P< 0.001). In patients with severe OSA, HLA-DQB1*0602 was present in the 92.9% compared with 66.7% in non-severe OSA (P=0.05). HLA-DRB1*15 allele was found in 15% of OSA patients and 20% of controls, with no difference between the two groups (P=0.556). No statistical difference was found in HLA-DRB1*15 between severe and non-severe OSA (P=0.499). After adjusting for gender, HLA-DQB1*0602 allele was associated with increased odds of OSA (OR = 6.17, 95% CI 1.87-20.3, p = 0.003), but HLA-DRB1*15 allele was not associated with OSA (OR 0.45, 95% CI 0.12-1.73, p = 0.242). CONCLUSIONS: The presence of HLA-DQB1*0602 allele, but not HLA-DRB1*15 allele, was significantly associated with OSA.

The HLA DRB1*03:01 allele is associated with NMO regardless of the NMO-IgG status in Brazilian patients from Rio de Janeiro.

The aim of this study was to analyze the HLA class II alleles in neuromyelitis optica (NMO) and MS patients from Rio de Janeiro to clarify whether the pattern of genetic predisposition in NMO is different from the one seen in MS or whether it is possible to determine specific alleles of susceptibility or resistance. The DR3 haplotype was over represented in NMO while the DR15 was over represented in MS. The HLA-DRB1*03:01 allele was associated with NMO regardless the NMO-IgG status but did not influence the long term disability. The comparison of the allele and haplotype frequencies significantly discriminated patients with NMO vs. MS.

Influences of HLA DRB1, DQA1 and DQB1 on T-cell recognition of epitopes and of larger regions of the botulinum neurotoxin molecule.

Previously, we have examined the proliferative responses of T-cells from 25 patients and 8 controls to 32 light chain (L1-L32) and 60 heavy chain peptides (N1-N29, C1-C31) representing the entire clostridium botulinum neurotoxin type A (BoNT/A)[OM1-OM3]. In the current work, these T-cell responses were analyzed in the context of the patients HLA-DRB1, DQA1 and DQB1 variation. There were strong associations between the DQA1*01:02 and its derived haplotypes and cumulative T-cell proliferative responses. With or without HLA based differentiation the responses showed marked correlation. Inter-epitope correlation of responses demonstrably associated with particular regions (peptides N1-N29) peaking in the region covered by of N18-29. A second region of higher correlation was observed close to the carboxyl terminal of the heavy chain. Region N15 to N29 was found to have a significantly lower Stimulation Indices when DRB1*01:01-DQA1*01:01-DQB1*05:01 was present. This pattern was also evident in the HLA analysis where DQA1*01:02 associations were collectively most significant in the N1-N13 & C16-C31 region. Responses in these regions correlated well with one another. HLA-specific correlation analysis revealed that DQA1*01:01 bearing haplotype had the strongest inter-epitope correlations despite having a generally negative association with simulation indices. Structural and immunogenic implications of these findings are discussed.

HLA-DQ ß1 alleles associated with Epstein-Barr virus (EBV) infectivity and EBV gp42 binding to cells.

Epstein-Barr virus (EBV) infects B cells and ~95% of adults are infected. EBV glycoprotein gp42 is essential for entry of virus into B cells. EBV gp42 binds to the ß1 chain of HLA-DQ, -DR, and -DP on B cells, and uses these molecules for infection. To investigate if certain HLA-DQ alleles are associated with EBV seronegativity, we recruited ~3,300 healthy adult blood donors, identified 106 EBV-seronegative individuals, and randomly selected a control group of EBV-seropositive donors from the donor pool. A larger than expected proportion of EBV-seronegative subjects were HLA-DQ ß1 *04/*05 and *06/*06, and to a lesser extent, *02/*03, compared with the control group, while a larger than expected portion of EBV-seropositive persons were HLA-DQ ß1 *02/*02. We examined the ability of EBV gp42 to bind to different HLA-DQ molecules using human and mouse cells stably expressing these alleles. EBV gp42 bound less effectively to cells expressing HLA-DQ ß1 *04/*05, *06/*06, or *03/*03 than to cells expressing HLA-DQ ß1 *02/*02. These data are consistent with our observations of increased EBV seronegativity with DQ ß1 *04/*05 or *06/*06 alleles. These findings emphasize the importance of a single genetic locus (HLA-DQ ß1) to influence infectivity with EBV.