The HLA-B/-C haplotype block contains major determinants for host control of HIV.
ABSTRACT: A genome-wide association study of people with incident human immunodeficiency virus (HIV) infection selected from nine different cohorts identified allelic polymorphisms, which associated with either viral set point (HCP5 and 5' HLA-C) or with HIV disease progression (RNF39 and ZNRD1). To determine the influence of these polymorphisms on host control of HIV, we carried out a population-based association study. The analysis revealed complete linkage disequilibrium between HCP5 and HLA-B*5701/HLA-Cw*06, a modest effect of 5' HLA-C on viral set point in the absence of HLA-B*5701, and no influence of the RNF39 /ZNRD1 extended haplotype on HIV disease progression. No correlation was found between the infection status and any of these genetic variants (P>0.1, Fisher's exact test). These findings suggest a pattern of strong linkage disequilibrium consistent with an HLA-B/-C haplotype block, making identification of a causal variant difficult, and underscore the importance of validating polymorphisms in putative determinants for host control by association analysis of independent populations.
Project description:A recent genome-wide association study (GWAS) suggested that polymorphisms in or around the genes HCP5, HLA-C and ZNRD1 confer restriction against HIV-1 viral replication or disease progression. Here, we also find that these alleles are associated with different aspects of HIV disease, albeit mainly in European Americans. Additionally, we offer that because the GWAS cohort was a subset of HIV-positive individuals, selected based in part on having a low viral load, the observed associations for viral load are magnified compared with those we detect in a large well-characterized prospective natural history cohort of HIV-1-infected persons. We also find that because of linkage disequilibrium (LD) patterns, the dominant viral load- and disease-influencing associations for the ZNRD1 or HLA-C and HCP5 alleles are apparent mainly when these alleles are present in HLA-A10- or HLA-B*57-containing haplotypes, respectively. ZNRD1 alleles lacking HLA-A10 did not confer disease protection whereas ZNRD1-A10 haplotypes did. When examined in isolation, the HCP5-G allele associates with a slow disease course and lower viral loads. However, in multivariate models, after partitioning out the protective effects of B*57, the HCP5-G allele associates with disease-acceleration and enhanced viral replication; these associations for HCP5-G are otherwise obscured because of the very strong LD between this allele and a subset of protective B*57 alleles. Furthermore, HCP5 and HLA-C alleles stratify B*57-containing genotypes into those that associate with either striking disease retardation or progressive disease, providing one explanation for the long-standing conundrum of why some HLA-B*57-carrying individuals are long-term non-progressors, whereas others exhibit progressive disease. Collectively, these data generally underscore the strong dependence of genotype-phenotype relationships upon cohort design, phenotype selection, LD patterns and populations studied. They specifically demonstrate that the influence of ZNRD1 alleles on disease progression rates are attributable to HLA-A10, help clarify the relationship between the HCP5, HLA-C and HLA-B*57 alleles, and reaffirm a critical role of HLA-B*57 alleles in HIV disease. Furthermore, as the protective B*57-containing genotypes convey striking salutary effects independent of their strong impact on viral control, it is conceivable that T cell-based therapeutic vaccine strategies aimed at reducing viral loads may be inadequate for limiting AIDS progression, raising the potential need for complementary strategies that target viral load-independent determinants of pathogenesis.
Project description:A single-nucleotide polymorphism (rs2395029) in the HCP5 gene associated with HLA-B*5701 is correlated with lower HIV-1 viral set point. The two allelic forms of coding region were ectopically expressed in TZM-bl cells for an effect on HIV-1 replication. No significant HIV-1 restriction was observed in the cells with infectivity assays throughout HIV-1 life cycle, suggesting that the association of HCP5 variant with viral control is likely due to HLA-B*5701-related effect or other functional variants in the haplotype or both.
Project description:OBJECTIVE:In a recent genome-wide association study of HIV-1-infected individuals in the Euro-CHAVI cohort, viral load set-point was strongly associated with genotypes defined by two single nucleotide polymorphisms (SNPs) (rs9264942 and rs2395029) within the human major histocompatibility complex (MHC) region on chromosome 6. We attempted to confirm this finding in African-Americans and to address whether these SNPs are in linkage disequilibrium with human leukocyte antigen (HLA) class I alleles that mediate innate and adaptive immunity. DESIGN:Our analyses relied on 121 African-American adolescents with chronic HIV-1 infection and quarterly immunological and virological outcome measures in the absence of therapy. METHODS:PCR-based techniques were used to genotype two SNPs along with HLA class I alleles. Their associations with HIV-1 viral load set-point and longitudinal CD4+ and CD8+CD38+ T cell counts were tested in univariate and multivariable models. RESULTS:The CC genotype at rs9264942 was associated with reduced viral load, but not with immunological outcomes or category of disease control. Consistent associations of favorable virologic outcomes were observed with B*57 (mostly B*5703) but not with rs2395029G allele at the HCP5 locus, which is in absolute linkage disequilibrium with B*5701 (in individuals of European descent), and not B*5703. CONCLUSION:Although rs9264942 and B*57 (but not rs2395029G) are clearly associated with control of viral load set-point among African-Americans, fine-mapping of MHC SNPs in populations of African and European descent should help reveal the causative variants and the underlying functional mechanisms.
Project description:ZNRD1 was identified as a host protein required for the completion of the human immunodeficiency virus (HIV) lifecycle in a genome-wide screen using small interfering RNA gene silencing. Subsequently, a genome-wide association study (GWAS) of host determinants for HIV-1 disease identified an association of single nucleotide polymorphisms (SNPs) in the ZNRD1 region with CD4(+) T-cell depletion.We investigated the effects of SNPs in the ZNRD1 region on human immunodeficiency virus type 1 (HIV-1) infection and progression to clinical outcomes in 5 US-based HIV-1 longitudinal cohorts consisting of men who have sex with men, males with hemophilia, and injection drug users (IDUs) (n = 1865). SNP function was evaluated by electrophoretic mobility shift assay and promoter luciferase assay.A haplotype in the ZNRD1 gene showed significant association with a 35% decreased risk of HIV-1 acquisition (OR = 0.65, 95% CI, .47-.89), independent of HLA-C rs9264942, in European Americans. The SNP rs3132130 tagging this haplotype, located in the ZNRD1 5' upstream region, caused a loss of nuclear factor binding and decrease in ZNRD1 promoter activity. ZNRD1 variants also affected HIV-1 disease progression in European- and African-American cohorts.This study provides novel evidence that ZNRD1 polymorphism may confer host resistance to HIV-1 acquisition.
Project description:Patients demonstrate notable variations in disease progression following human immunodeficiency virus (HIV) infection. We aimed to identify ZNRD1 and RNF39 genetic variants linked to AIDS progression. We conducted a genetic association study in HIV-1-infected Han Chinese patients residing in Taiwan. The clinical characteristics of 143 HIV-1-infected patients were measured, and patients were split into 2 groups: AIDS progression and AIDS non-progression. Genotyping of ZNRD1 and RNF39 was performed in all participants. We found that patients in the AIDS progression group had higher HIV-1 viral loads and lower CD4 cell counts than did patients in the AIDS non-progression group. The frequency of the AA genotype of ZNRD1 (rs16896970) was lower in the AIDS progression group than in the AIDS non-progression group. Patients with AA genotypes had lower levels of HIV-1 viral loads and higher levels of CD4 cell counts than did patients with AG+GG genotypes. AIDS progression in patients with the AA group is significantly different from that in patients with the AG and GG groups by using Kaplan-Meier survival analysis. The hazard ratio for progression was lower in the AA group than in the AG and GG groups. We identified a SNP that contributes to AIDS progression in HIV-1-infected patients in this population. This SNP had a significant protective influence on AIDS progression, and polymorphisms of the ZNRD1 gene may play a role in the pathogenesis of HIV-1 infection.
Project description:DNA variants in the tumor necrosis factor-? (TNF) and linked lymphotoxin-? genes, and specific alleles of the highly polymorphic human leukocyte antigen B (HLA-B) gene have been implicated in a plethora of immune and infectious diseases. However, the tight linkage disequilibrium characterizing the central region of the human major histocompatibility complex (MHC) containing these gene loci has made difficult the unequivocal interpretation of genetic association data. To alleviate these difficulties and facilitate the design of more focused follow-up studies, we investigated the structure and distribution of HLA-B-specific MHC haplotypes reconstructed in a European population from unphased genotypes at a set of 25 single nucleotide polymorphism sites spanning a 66-kilobase long region across TNF. Consistent with the published data, we found limited genetic diversity across the so-called TNF block, with the emergence of seven common MHC haplotypes, termed TNF block super-haplotypes. We also found that the ancestral haplotype 8.1 shares a TNF block haplotype with HLA-B*4402. HLA-B*5701, a known protective allele in HIV-1 pathogenesis, occurred in a unique TNF block haplotype.
Project description:Disease relapse occurs in unrelated cord blood transplantation (CBT) even when the alleles of human leukocyte antigen (HLA) are fully matched between donor and recipient. This is similar to that observed in other types of hematopoietic stem cell transplantation. Fourteen single nucleotide polymorphisms (SNPs) within the HLA region have been reported previously by Petersdorf et al. and Piras et al. as transplantation determinants in unrelated hematopoietic cell transplantation. In this study, the genomic sequences within 500 base pairs upstream and downstream of the fourteen transplantation-related SNPs from 53 patients and their HLA-matched unrelated donors were analyzed for determining whether or not genetic variants, conferred by either recipient or donor SNP genotype or by recipient-donor SNP mismatching, were associated with the risk of relapse. Seven SNPs were associated with the risk of relapse in unrelated CBT. These included the donor genotype with the SNPs of rs2523675 and rs2518028 at the telomeric end of HCP5 gene, rs2071479 in the intron of the HLA-DOB gene, and rs2523958 in the MICD gene; and the recipient genotype with SNPs of rs9276982 in the HLA-DOA gene, and rs435766 and rs380924 in the MICD gene. As measured by pair-wise linkage disequilibrium (LD) with D' as the parameter for normalized standard measurement of LD which compares the observed and expected frequencies of one haplotype comprised by alleles at different loci, rs2523675 had high LD with rs4713466 (D' = 0.86) and rs2523676 (D' = 0.91) in the HCP5 gene. The rs2518028 had no LD with all other SNPs except rs2523675 (D' = 0.76). This study provides the basis for developing a method or algorithm for selecting better unrelated CBT candidate donors.
Project description:Association of two HLA class I variants with HIV-1 pretreatment viremia, CD4+ T cell count at the care-entry and CD4+ T cell nadir.414 HIV-positive Caucasians (30% women) aged 19-73 years were genotyped for HLA-C -35 (rs9264942) and HLA-B*5701 variants. HIV-1 viral load, as well as CD4+ T cell count at care-entry and nadir, were compared across alleles, genotypes and haplotypes.HLA-C -35 C/C genotype was found in 17.6% patients, C/T genotype in 48.1%, and T/T genotype in 34.3% patients. HLA-B*5701 variant was present in 5.8% of studied population. HIV plasma viremia in the group with C allele was significantly lower (p=0.0002) compared to T/T group [mean:4.66 log (SD:1.03) vs. 5.07 (SD:0.85) log HIV-RNA copies/ml, respectively], while CD4+ T cell count at baseline was notably higher among C allele carriers compared to T/T homozygotes [median: 318 (IQR:127-537) cells/μl vs. median: 203 (IQR:55-410) cells/μl, respectively] (p=0.0007). Moreover, CD4+ T cell nadir among patients with C allele [median: 205 (IQR:83.5-390) cells/μl] was significantly higher compared to T/T group [median: 133 (IQR:46-328) cells/μl] (p=0.006). Among cases with HLA-B*5701 allele, significantly lower pretreatment viremia and higher baseline CD4+ T cell count were found (mean: 4.08 [SD: 1.2] vs. mean: 4.84 [SD:0.97] log HIV-RNA copies/ml, p=0.003 and 431 vs. 270 cells/μl, p=0.04, respectively) compared to HLA-B*5701 negative individuals. The lowest viremia (mean: 3.85 log [SD:1.3]) HIV-RNA copies/ml and the highest baseline and nadir CD4+ T cell [median: 476 (IQR:304-682) vs. median: 361 (IQR: 205-574) cells/μl, respectively) were found in individuals with HLA-B*5701(+)/HLA-C -35 C/C haplotype.HLA-C -35 C and HLA-B*5701 allele exert a favorable effect on the immunological (higher baseline and nadir CD4+ T cell count) and virologic (lower pretreatment HIV viral load) variables. This protective effect is additive for the compound HLA-B*5701(+)/HLA-C -35 C/C haplotype.
Project description:CONTEXT:The genetic background of young-onset Graves disease (GD) remains largely unknown. An intronic variant in human leukocyte antigen (HLA) complex P5 (HCP5) has previously been associated with GD susceptibility and age of onset in a cohort of Polish patients. OBJECTIVE:We aimed to investigate the association of the HCP5 variant rs3094228 with GD susceptibility and age of onset in a UK cohort and conduct a meta-analysis of UK and Polish data. DESIGN AND PARTICIPANTS:rs3094228 was genotyped in 469 UK patients with GD using Taqman chemistry. Genotype frequencies were compared with genotypic data available from the Wellcome Trust case-control consortium using logistic regression analysis. To determine whether rs3094228 is independently associated with age of GD onset, the HLA DRB1*0301 tagging variant, rs535777, was also genotyped. RESULTS:The C allele of rs3094228 was overrepresented in the UK GD cohort compared with controls (P?allele=5.08?×?10-9, odds ratio 1.76; [95% confidence interval, 1.46-2.13]). This association was more marked in young-onset GD (<30 years) (P?allele=1.70?×?10-10 vs P?allele=0.0008). The meta-analysis of UK and Polish data supported the association of the C allele with GD susceptibility (P?allele=1.79?×?10-5) and age of onset (P?allele=5.63?×?10-8). Haplotype analysis demonstrated that rs3094228 is associated with age of GD onset (P?=?2.39?×?10-6) independent of linkage disequilibrium with HLA DRB1*0301. CONCLUSION:The rs3094228 HCP5 polymorphism is independently associated with GD susceptibility and age of onset in a UK GD cohort. Our findings indicate a potential role of long noncoding ribonucleic acids, including HCP5, in GD pathogenesis, particularly in the younger population.
Project description:A large body of functional and epidemiological evidence have previously illustrated the impact of specific MHC class I subtypes on clinical outcome during HIV-1 infection, and these observations have recently been re-iterated in genome wide association studies (GWAS). Yet because of the complexities surrounding GWAS-based approaches and the lack of knowledge relating to the identity of rarer single nucleotide polymorphism (SNP) variants, it has proved difficult to discover independent causal variants associated with favourable immune control. This is especially true of the candidate variants within the HLA region where many of the recently proposed disease influencing SNPs appear to reflect linkage with 'protective' MHC class I alleles. Yet causal MHC-linked SNPs may exist but remain overlooked owing to the complexities associated with their identification. Here we focus on the ancestral TNF? promoter -237A variant (rs361525), shown historically to be in complete linkage disequilibrium with the 'protective' HLA-B*5701 allele. Many of the ancestral SNPs within the extended TNF? promoter have been associated with both autoimmune conditions and disease outcomes, however, the direct role of these variants on TNF? expression remains controversial. Yet, because of the important role played by TNF? in HIV-1 infection, and given the proximity of the -237 SNP to the core promoter, its location within a putative repressor region previously characterized in mice, and its disruption of a methylation-susceptible CpG dinucleotide motif, we chose to carefully evaluate its impact on TNF? production. Using a variety of approaches we now demonstrate that carriage of the A SNP is associated with lower TNF? production, via a mechanism not readily explained by promoter methylation nor the binding of transcription factors or repressors. We propose that the -237A variant could represent a minor causal SNP that additionally contributes to the HLA-B*5701-mediated 'protective' effect during HIV-1 infection.