HLA-DPA1 Alleles Research Articles

Characterisation of two new HLA-DPA1 alleles: HLA-DPA1*02:139 and -DPA1*02:140N.

HLA-DPA1*02:139 and -DPA1*02:140N, two novel HLA-DPA1 alleles detected by next-generation sequencing.

Report from the extended HLA-DPA1 ~ promoter ~ HLA-DPB1 haplotype of the 18th international HLA and immunogenetics workshop.

The primary goal of the HLA-DPA1 ~ promoter ~ HLA-DPB1 haplotype component of the 18th IHIWS was to characterise the extended haplotypes within the HLA-DP region and survey the extent of genetic diversity in this region across human populations. In this report, we analysed single-nucleotide polymorphisms (SNPs) in 255 subjects from 6 different cohorts. The results from the HLA-DP haplotype component have validated findings from the initial pilot study. SNPs in this region were inherited in strong linkage, particularly HLA-DPA1, SNP-linked promoter haplotypes and motifs in exon 2 of HLA-DPB1. We reported 17 SNP-linked haplotypes in the promoter region. Together with HLA-DPA1 and HLA-DPB1 alleles, they formed 74 distinct extended HLA-DP haplotypes in 438 sequences. We also observed the presence of region-specific alleles and promoter haplotypes. Our approach involved phasing extended SNPs including promoter SNPs, HLA-DPA1 and HLA-DPB1 alleles, in a 22 kb region, GRCh38/hg38 (chr6:33,064,111-33,086,679), followed by clustering of these SNPs as one extended haplotype. This hierarchical clustering revealed four major clades, suggesting that haplotypes within each clade may have diverged from a common ancestral haplotype and undergone similar evolutionary processes. The correlation between HLA-DPA1 and the promoter region raises questions about the role of HLA-DPA1 antigen in the heterodimer. This finding requires validation on a larger sample size specifically designed for anthropological analysis. Nevertheless, the results from this study highlight the clinical potential of selecting better-matched donors for patients awaiting haematopoietic stem cell transplants from genetically overlapping groups that share common ancestral haplotypes.

Discovery of three novel HLA-DPA1 alleles, HLA-DPA1*01:147N, 01:03:47, and 02:106 using next-generation sequencing.

Characterization of three novel HLA-DPA1 alleles bearing null, synonymous, and non-synonymous mutations.

Four new HLA-DPA1 intronic variants detected by next-generation sequencing.

Four novel HLA-DPA1 alleles, -DPA1*01:03:01:59, -DPA1*01:03:01:60, -DPA1*02:01:01:30, and -DPA1*02:01:01:31, characterized in Spanish individuals.

Human leucocyte antigens profiling in Malay female patients with systemic lupus erythematosus: are we the same or different?

ObjectiveSLE is a heterogeneous autoimmune disease, in terms of clinical presentation, incidence and severity across diverse ethnic populations. We investigated the human leucocyte antigens (HLA) profile (ie, HLA-A, HLA-B and...

Association of HLA-DPA1, HLA-DPB1, and HLA-DQB1 Alleles With the Long-Term and Booster Immune Responses of Young Adults Vaccinated Against the Hepatitis B Virus as Neonates.

The neonatal hepatitis B vaccination (HBVac) was implemented 35 years ago in Taiwan, but many vaccinees exhibit inadequate long-term vaccine-induced seroprotective hepatitis B surface antibody (anti-HBs) levels. We investigated the association of the human leukocyte antigen (HLA) alleles (DPA1, DPB1, DQA1, and DQB1) with the long-term immunological response to the neonatal HBVac and adolescent booster HBVac in a Taiwanese cohort. We divided 281 Han students (median age 22, age range 17–29 years) into the following groups: (1) Group A (n = 61): anti-HBs titer ≥ 10 mIU/mL at the beginning of the study; (2) Group B (n = 75): anti-HBs level > 1000 mIU/mL after the first booster; (3) Group C (n = 37): anti-HBs level < 10 mIU/mL after the first booster; and (4) Group D (n = 5): anti-HBs level < 10 mIU/mL after three boosters. DQA1, DQB1, DPA1, and DPB1 typing of the participants was performed using sequence-specific oligonucleotides. Associations of HLA alleles and haplotypes with effects on neonatal HBVac and booster HBVac were examined through logistic regression analysis and Fisher’s exact test. A false discovery rate-based measure of significance, the q-value, was used for multiple comparisons, and an association was considered significant if the corresponding q-value was < 0.1. DPA1 alleles were associated with the long-term immunological response to the neonatal HBVac. The estimated odds ratio (OR) of the lack of HBV protective immunity when carrying an additional DPA1*01 and DPA1*02 was 0.36 [95% confidence interval (CI) = 0.17–0.76, p = 0.0076] and 2.39 (95% CI = 1.17–4.87, p = 0.016), respectively. DPB1 and DQB1 alleles were associated with a response to the adolescent booster vaccination. The estimated ORs of being nonresponsive to the first booster when carrying an additional DPB1*05 and DQB1*02 were 2.11 (95% CI = 1.13–3.93, p = 0.019) and 3.73 (95% CI = 1.43–9.71, p = 0.0070), respectively. All DPB1*03 carriers responded to the first booster (p of Fisher’s exact test = 0.0045). In our study, we discovered that HLA-DPA1 was primarily associated with the long-term response of primary infantile HBVac, and HLA-DPB1 and HLA-DQB1 exhibited associations with the HBV booster vaccination.

Relationship between HLA-DPA1 mRNA expression and susceptibility to hepatitis B.

Chronic hepatitis B virus (HBV) infection is influenced by both viral and host factors. In genome-wide association studies, the human leucocyte antigen HLA-DPA1 and related polymorphism rs3077 were found to be associated with susceptibility to and spontaneous clearance of HBV infection. Here, we evaluated the association between HLA-DPA1 mRNA expression and the risk of HBV infection. HLA-DPA1 and rs3077 polymorphisms were investigated in 169 patients with chronic HBV and 217 healthy controls (HCs) from Sichuan Han blood donors using sequence-based typing and meta-analysis for HLA-DPA1 alleles. HLA-DPA1 mRNA levels were measured by real-time polymerase chain reaction. The results showed that HLA-DPA1 and rs3077 were associated with HBV infection in the Sichuan population. Rs3077T and DPA1*01:03 played protective roles in HBV infection, and rs3077C and DPA1*02:02 increased susceptibility to HBV infection. We found that the HLA-DPA1 mRNA expression was decreased in the CHB group; in particular, the 3077CT, 3077TT, DPA1*01:03 and DPA1*02:01 alleles showed a significant decrease. Our results demonstrated, for the first time, that expression of HLA-DPA1 alleles and rs3077 affected the risk of HBV infection. Genotypes with lower HLA-DPA1 expression had a greater susceptibility to HBV infection. Thus, further independent studies are needed to strengthen the associations of these polymorphisms with susceptibility to and clearance of HBV infection in Chinese populations.

First report on HLA-DPA1 gene allelic distribution in the general Lebanese population

AimsHLA-DPA1 is an important marker in bone marrow and organ transplantation and a highly emerging screening parameter in histocompatibility laboratories. Being highly polymorphic, it has another significant value in detecting population origins and migrations. This is the first study to assess DPA1 allele frequencies in an Arab population. MethodsThe HLA DPA1 alleles were identified using the One-Lambda assays on a Luminex reverse SSO DNA typing system. Our study included 101 individuals coming from different Lebanese geographical areas representing the different communities and religious sects of the country. ResultsWe compared the results of this study to 16 different populations and found very interesting similarities and differences between Lebanese people and individuals of European ancestry. ConclusionThis study is the first to describe the different allelic frequencies of HLA-DPA1 in the Lebanese population and will serve as a template that can be later used for disease association studies both at the level of the country and internationally.

Effect of HLA-DPA1 alleles on chronic hepatitis B prognosis and treatment response.

OBJECTIVE:Chronic hepatitis B (CHB) is a major health problem. The outcome of hepatitis B virus (HBV) infection is associated with variations in HLA-DPA1 alleles. The aim of this study was to investigate possible associations of HLA-DPA1 alleles with treatment response and with hepatitis B virus e antigen (HBeAg) seroconversion.METHODS:Eight different HLA-DPA1 alleles from 246 CHB patients were genotyped by polymerase chain reaction with sequence-specific primers at high resolution to investigate the association of HLA-DPA1 alleles with treatment response, development of cirrhosis, HBeAg seroconversion, and disease reoccurrence upon HBeAg loss.RESULTS:There was no significant association between HLA-DPA1 alleles and treatment response, development of cirrhosis, or HBeAg seroconversion. However, HLA-DPA1*04:01 allele was significantly more frequently found in patients who redeveloped disease upon HBeAg seroconversion (100% vs 36.8%: p=0.037; Fisher’s exact test).CONCLUSION:HLA-DPA1*04:01 allele may be a risk factor for reoccurrence of CHB after HBeAg seroconversion.

Association of HLA-DPA1 and -DPB1 polymorphisms with Posner-Schlossman syndrome among southern Chinese Han population

To assess the association of HLA-DPA1 and -DPB1 polymorphisms with Posner-Schlossman syndrome (PSS) in southern Chinese Han population. A total of 100 randomly selected PSS patients of southern Chinese Han origin were served as the experimental group, while 128 unrelated healthy blood donors of the same origin were served as the control group. All samples were subjected to sequencing-based typing (SBT) for exon 2 of HLA-DPA1 and -DPB1 loci in both directions. HLA genotype was assigned using an Assign 3.5 HLA SBT software. The allele frequencies and haplotype frequencies of HLA-DPA1 and -DPB1 of the two groups were compared. x² test, P value and odds ratio (OR) value were calculated. Six HLA-DPA1 alleles in the experimental group and 4 HLA-DPA1 alleles in the healthy control group were identified. The allelic frequency for HLA-DPA1*02:01 in the experimental group was significantly lower than the control group (4.50% vs. 12.109%; x²=8.124, P=0.004). Sixteen HLA-DPB1 alleles were identified in both the experimental and control groups. The allelic frequencies for HLA-DPB1*14:01 and - DPB1*17:01 in the experimental group were significantly lower than those of the control group ( DPB1*14:01: 1.00% vs. 4.688%, x²=5.130, P=0.024; DPB1*17:01: 0% vs. 2.344%, x²=3.897, P=0.048). The DPA1-DPB1 haplotypes for the experimental and control groups were 23 and 25, respectively. The haplotype frequencies for both DPA1*02:01- DPB1*14:01 and DPA1*02:01- DPB1*17:01 were significantly lower than those of the control group. DPA1*02:01- DPB1*14:01 and DPA1*02:01- DPB1*17:01 haplotypes may provide considerable protection effect against PSS in the southern Chinese Han population.

Development of a high-throughput sequence-based typing assay for human leukocyte antigen loci

To develop a reliable assay for simultaneous sequence-based typing (SBT) of HLA-DPA1 and HLA-DPB1, and to apply it for the study of allelic polymorphisms in southern Chinese Han population. Based on full-length HLA-DPA1 and HLA-DPB1 allelic sequences, locus-specific PCR primers were designed and applied to amplify the target sequence encompassing the entire exon 2 of HLA-DPA1 and HLA-DPB1. PCR products were purified with magnetic beads, and run through an ABI 3730 DNA sequencer. Genotypes were assigned with an Assign 3.5 SBT software. The target sequences of HLA-DPA1 and HLA-DPB1 were both amplified with the PCR procedure. Little background and noise was observed in the derived sequences. Among 176 non-related healthy individuals, 4 HLA-DPA1 alleles with the frequencies of DPA1*02:02 (0.589) > DPA1*01:03 (0.284) > DPA1*02:01 (0.096) > DPA1*04:01 (0.031) were identified. In addition, 14 HLA-DPB1 alleles, including 4 common alleles (with a frequency of more than 5%, namely DPB1*05:01, DPB1*02:01, DPB1*04:01 and DPB1*02:02), 7 alleles with a frequency ranging from 1%-5% and 3 alleles with a frequency of less than 1% were identified. The results of HLA-DPB1 genotyping were all in accordance with the typing results derived from an Atria AlleleSEQR HLA-DPB1 kit. A reliable technique has been established for simultaneous genotyping of HLA-DPA1 and HLA-DPB1, which may have a broad application in population and disease association studies.

Non-invasive screening of HLA-DPA1 and HLA-DPB1 alleles for persistent hepatitis B virus infection: Susceptibility for vertical transmission and toward a personalized approach for vaccination and treatment

BackgroundPolymorphisms in the major histocompatibility complex (MHC) and non-MHC genes were recently reported to be associated with persistent hepatitis B virus (HBV) infection and host response to hepatitis B vaccine in Asian populations. We aimed to confirm the associations in Chinese population and develop a non-invasive screening method for the risk loci. MethodsWe genotyped 2 risk alleles on the MHC loci, HLA-DPA1 (rs3077) and HLA-DPB1 (rs9277535), and 1 risk allele near a non-MHC gene, FOXP1 (rs6789153) using high-resolution melting curve analysis. With minimal processing steps and time, salivary DNA was extracted with a modified protocol of a blood kit. We compared the genotyping fidelity between peripheral blood DNA and salivary DNA. ResultsBoth rs3077 and rs9277535, but not rs6789153, are significantly associated with CHB in Chinese population (p-value<0.001). High genotype concordance between different sources of genomic DNA was obtained. ConclusionsGenotyping salivary DNA using our modified methods provides a non-invasive fast screening for host susceptibility loci. The transmission mechanism of hepatitis B can now be modified by adding genetic susceptibility to the traditional vertical transmission model of hepatitis B.

Analysis of the HLA-DPA1 and HLA-DPB1 polymorphism of Zhejiang Han population by PCR-sequence based typing

To investigate the polymorphisms of HLA-DPA1 and HLA-DPB1 loci of Han population in Zhejiang province of China. The alleles of HLA-DPA1 and HLA-DPB1 loci in 100 unrelated healthy individuals were analyzed using polymerase chain reaction-sequence based typing. Eight HLA-DPA1 alleles and 19 HLA-DPB1 alleles were found in the population. The HLA-DPA1 alleles with higher frequencies were DPA1*020202 (47.0%), DPA1*010301 (38.5%) and DPA1*020101(10.5%). The HLA-DPB1 alleles with higher frequencies were DPB1*0501, DPB1*020102 and DPB1*040101. The frequencies were 39.5%, 13.5% and 13.0%, respectively. A total of 44 estimated DPA1-DPB1 haplotypes were detected. The HLA-DPA1*020202-DPB1*0501(29.5%) was the most frequent haplotype. The polymorphism data of the HLA-DPA1 and -DPB1 were obtained in Han population in Zhejiang province of China. There was linkage disequilibrium between the two loci.

03/02017 Recycle of wet desulfurization (H 2S) liquid on fuel gas : Zhou, J.-H. et al. Hebei Jianzhu Keji Xueyuan Xuebao, Ziran Kexueban, 2002, 19, (2), 11–14. (In Chinese)

We determined the base sequences of the HLA-DPA1 gene from four B-lymphoblastoid cell lines (CB6B, LKT3, AMAI, and T7526) that showed distinct electrophoretic patterns of single-stranded polymerase chain reaction products of the HLA-DPA1 gene. The novel HLA-DPA1 alleles of CB6B, LKT3, AMAI, and T7526 were designated DPA1∗02021, DPA1∗02022, DPA1∗0301, and DPA1∗0401, respectively. Although there was only one base substitution between DPA1∗02021 and DPA1∗02022, the single-strand conformation polymorphism of these two alleles was clearly demonstrated by electrophoresis in a nondenaturing polyacrylamide gel containing 10% glycerol. In addition, we genotyped for the HLA-DPA1 gene of healthy unrelated Oriental individuals—i.e., 227 Japanese, 88 Papua New Guineans, and 41 Buyi-Chinese—to demonstrate the ethnic distribution of the HLA-DPA1 alleles.

Potential binding modes of beryllium with the class II major histocompatibility complex HLA-DP: a combined theoretical and structural database study

In an effort to understand the molecular basis of chronic beryllium disease (CBD), a study of the chemical relationship between beryllium, antigen, and the major histocompatibility complex II, HLA-DP, was undertaken. A homology model of the HLA-DP protein was developed. An analysis of the sequences of HLA-DPB1 and HLA-DPA1 alleles most common among CBD patients revealed several carboxylate rich regions in the peptide-binding cleft. These regions contain many hard Lewis base sites that may provide bonding opportunities for beryllium, a hard Lewis acid. Quantum chemistry calculations and structural database results support the presence of beryllium clusters, bridged by carboxylate, hydroxo, and/or oxo ligands, in the HLA-DP binding cleft. These results strongly suggest that beryllium clusters are an integral part of the antigen, and may even act solely as antigen. This work provides an initial model for thinking about beryllium interactions with proteins relevant to CBD and other metal-induced diseases.

Short-form HLA-DP typing with 48 primer mixes using the polymerase chain reaction and sequence-specific primers.

We have developed a short-form SSP-based HLA-DP typing system for routine use adapted from a comprehensive HLA-DP typing method described by Gilchrist et at. (1998). Our short-form system detects 93 alleles, including the 18 most common HLA-DPB1 alleles and eight HLA-DPA1 alleles. The primer mixes described were tested using the PCR-SSP Manager (Bunce et al., 1998) database to confirm the specificity of selected primers, and to detect potentially ambiguous amplifications. This short-form HLA-DP typing system was validated using 50 fully typed samples obtained through the UCLA International DNA Exchange. All samples gave 100% concordance with the consensus type. Our laboratory routinely uses a PCR-SSP based system of 48 primer mixes for HLA-DRB and HLA-DQB typing. The advantage of the short-form HLA-DP typing system described here is that the additional 48 HLA-DP primer mixes required can be included on the second half of a 96-well format tray. This method now enables a full HLA class II typing at the level of allele group resolution in 2 1/2 h.

Flow Cytometry-Based Minisequencing: A New Platform for High-Throughput Single-Nucleotide Polymorphism Scoring

Single-nucleotide polymorphisms (SNPs) are the most abundant type of human genetic variation. These variable sites are present at high density in the genome, making them powerful tools for mapping and diagnosing disease-related alleles. We have developed a sensitive and rapid flow cytometry-based assay for the multiplexed analysis of SNPs based on polymerase-mediated primer extension, or minisequencing, using microspheres as solid supports. The new method involves subnanomolar concentrations of sample in small volumes (∼10 μl) which can be analyzed at rates of one sample per minute or faster, without a wash step. Further, genomic analysis using multiplexing microsphere arrays (GAMMArrays), enables the simultaneous analysis of dozens, and potentially hundreds of SNPs per sample. We have tested the new method by genotyping the Glu69 variant from the HLA DPB1 locus, a SNP associated with chronic beryllium disease, as well as HLA DPA1 alleles using the multiplexed method. The results demonstrate the sensitivity and accuracy of flow cytometry-based minisequencing, a powerful new tool for genome- and global-scale SNP analysis.

Matching for HLA DPA1 and DPB1 alleles in unrelated bone marrow transplantation

The impact of donor-recipient DPA1 and DPB1 matching was examined in 122 unrelated bone marrow transplant pairs. All pairs were serologically matched at the time of transplantation for HLA class I and II and a majority also DRB1 allele matched. Retrospective A, B, C, DRB1, DQA1, DQB1 in addition to DPA1 and DPB1 allele matching was performed by molecular techniques. The percentage of pairs that were allele matched was as follows; HLA-A = 91% ( n = 80), HLA-B = 94% ( n = 80), HLA-C = 78% ( n = 80), HLA-DRB1 = 96% ( n = 122), HLA-DQA1 = 99% ( n = 80), HLA-DQB1 = 92% ( n = 122). 92 recipient/donor pairs with informative clinical data were available for analysis. DPA1 identity (no incompatibility in either direction) was observed in 57% and DPA1 compatibility in 76% of pairs with no apparent beneficial effect of matching on patient survival or Graft Versus Host Disease (GVHD). DPB1 identity was observed in 11% and compatibility in 27% of pairs. A significant improvement in patient survival was observed in DPB1 matched compared to one DPB1 mismatch ( p < 0.01) and combined one and two DPB1 mismatched transplants ( p = 0.03). This beneficial effect remained when allele mismatches at HLA-A, B, C, DRB1, DQA1, DQB1 were excluded ( p = 0.05, p = 0.03, respectively). There was a significant association of increased frequency of severe GVHD (grades III–IV) compared to mild GVHD (grades I–II) with DPB1 mismatched transplants compared to DPB1 matched transplants ( p = 0.04). In DPB1 mismatched transplants an association between patient survival and matching for individual DPB1 polymorphic regions was not observed; however in the HLA-A, B, DRB1, DQA1, DQB1 allele matched transplants a non significant increase in the frequency of Grade IV GVHD was observed in recipients who were negative compared to those who were positive for DPB1 alleles coding for glutamic acid at position 69.

Comprehensive HLA‐DP typing using polymerase chain reaction with sequence‐specific primers and 95 sequence‐specific primer mixes

HLA-DP is the third of the class II molecules. Its role is antigen presentation, and it has been suggested to play a part in the susceptibility to certain diseases such as berylliosis, sarcoidosis and juvenile chronic arthritis. The standard typing method is SSO typing, although other methods have been used. Probably the best is sequence-based typing, but this is time-consuming and requires expensive equipment. We describe a method for comprehensive HLA-DPB1 and HLA-DPA1 typing using sequence-specific primers. This method has the advantages that it is rapid - typing a single DNA sample takes under 3 hours - and does not require any special equipment or reagents. The method has been shown to be highly accurate by typing 60 cell line DNA samples in which there was 100% agreement between the types obtained and the published information. Similarly typing of 20 DNA samples previously typed by sequence-based typing gave 100% concordance. We used the method to type DNA samples from 102 UK Caucasoid kidney donors. The allele frequencies agree with previously published data. Linkage disequilibria between HLA-DPB1, HLA-DPA1 and the other class II antigens have been investigated. Strong linkage disequilibria exist between certain HLA-DPB1 and HLA-DPA1 alleles. This is unsurprising in view of their proximity on the chromosome. More unexpectedly, the data also suggest that genes further away along the chromosome are in linkage disequilibrium with HLA-DP, forming extended haplotypes.

HLA-DPA1 typing by PCR amplification with sequence-specific primers (PCR-SSP) and distribution of DPA1 alleles in Caucasian, African and Oriental populations.

In the present study PCR primers were designed for detecting all known DPA1 variability, i.e., the presently recognized six DPA1 alleles 0103 to 0401, and also for separation of the four DPA1*02 alleles, by PCR amplification with sequence-specific primers (PCR-SSP). For each sample seven different PCR reactions were performed which allowed the identification of all DPA1 alleles and the resolution of all DPA1 genotypes. Forty-eight cell lines and 100 donor spleen cells were investigated by the DPA1 PCR-SSP technique. In the forty-eight known workshop cell-lines no false positive or false negative results were obtained. The 100 donor spleen cells were only typed by the PCR-SSP technique and in their DNAs only one or two DPA1 alleles were found. Twenty cell lines and twenty donor spleen cells were typed on two separate occasions and interpreted blindly. The reproducibility between the repeated typings was 100%. The length of the specific products ranged from 103 to 258 base pairs and the amplification patterns obtained were easy to interpret. In conclusion, DPA1 typing by the PCR-SSP method is an accurate typing technique with high sensitivity, specificity and reproducibility. Analysis of the distribution of DPA1 alleles was performed in 100 Caucasian samples, 100 African samples and 80 Oriental samples, including separation of the four of HLA-DPA1 alleles. Each ethnic group appeared to have one (Caucasians), or two (Africans and Orientals), frequent DPA1 allele(s) and a high frequency of DPA1 homozygotes, suggesting that, like for the DPB1 locus, balancing selection does not appear to be affecting the evolution of the DPA1 locus.