Genome-Wide Association Study Identifies IFIH1 and HLA-DQB1*05:02 Loci Associated With Anti-NMDAR Encephalitis.

BACKGROUND AND OBJECTIVES: Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is a rare autoimmune neurologic disorder, the genetic etiology of which remains poorly understood. Our study aims to investigate the genetic basis of this disease in the Chinese Han population. METHODS: We performed a genome-wide association study and fine-mapping study within the major histocompatibility complex (MHC) region of 413 Chinese patients with anti-NMDAR encephalitis recruited from 6 large tertiary hospitals and 7,127 healthy controls. RESULTS: Our genome-wide association analysis identified a strong association at the IFIH1 locus on chromosome 2q24.2 (rs3747517, p = 1.06 × 10-8, OR = 1.55, 95% CI, 1.34-1.80), outside of the human leukocyte antigen (HLA) region. Furthermore, through a fine-mapping study of the MHC region, we discovered associations for 3 specific HLA class I and II alleles. Notably, HLA-DQB1*05:02 (p = 1.43 × 10-12; OR, 2.10; 95% CI 1.70-2.59) demonstrates the strongest association among classical HLA alleles, closely followed by HLA-A*11:01 (p = 4.36 × 10-7; OR, 1.52; 95% CI 1.29-1.79) and HLA-A*02:07 (p = 1.28 × 10-8; OR, 1.87; 95% CI 1.50-2.31). In addition, we uncovered 2 main HLA amino acid variation associated with anti-NMDAR encephalitis including HLA-DQß1-126H (p = 1.43 × 10-12; OR, 2.10; 95% CI 1.70-2.59), exhibiting a predisposing effect, and HLA-B-97R (p = 3.40 × 10-8; OR, 0.63; 95% CI 0.53-0.74), conferring a protective effect. Computational docking analysis suggested a close relationship between the NR1 subunit of NMDAR and DQB1*05:02. DISCUSSION: Our findings indicate that genetic variation in IFIH1, involved in the type I interferon signaling pathway and innate immunity, along with variations in the HLA class I and class II genes, has substantial implications for the susceptibility to anti-NMDAR encephalitis in the Chinese Han population.

The novel HLA-A*36:14 allele characterised by two different sequencing-based typing techniques.

The novel allele HLA-A*36:14 differs from HLA-A*36:01:01:01 by one non-synonymous nucleotide substitution in exon 4.

The novel HLA-A*30:01:23 allele characterised by two different sequencing-based typing techniques.

The novel allele HLA-A*30:01:23 differs from HLA-A*30:01:01:01 by one synonymous nucleotide substitution in exon 2.

Two novel HLA class I alleles: HLA-A*02:1148 and HLA-B*44:386.

Identification of the novel HLA-A*02:1148 and HLA-B*44:386 alleles by next-generation sequencing.

[Pharmacogenetic testing for prevention of severe cutaneous adverse drug reactions].

Pharmacogenetic testing benefits patients by predicting drug efficacy and risk of adverse drug reactions (ADRs). Pharmacogenetic biomarkers useful in clinical practice include drug-metabolizing enzyme and drug transporter genes and human leukocyte antigen (HLA) genes. HLA genes, which are important molecules involved in human immunity, have long been analyzed for associations with ADRs, such as skin rash, drug-induced liver injury, and agranulocytosis. HLA is composed of many genes, each of which has dozens of different types (alleles), and many HLA alleles associated with ADRs have been reported. The odds ratios in the association of HLA alleles range from approximately 5 to several thousand, indicating a very large impact on the risk of ADRs. Thus, HLA genetic testing prior to initiation of drug therapy is expected to make a significant contribution to avoiding ADRs, but to demonstrate the clinical utility, it is necessary to prospectively show the effects of medical interventions based on the test results. We conducted the GENCAT study, a prospective, multicenter, single-arm clinical trial to investigate the impact of a therapeutic intervention based on the HLA-A*31:01 test on the incidence of carbamazepine-induced skin rash. HLA-A*31:01-positive patients were treated with an alternative drug such as valproic acid, and the study showed an approximately 60% reduction in the incidence of carbamazepine-induced skin rash. It is expected that the genetic test, which has demonstrated clinical utility, will lead to the establishment of safer and more appropriate stratified medicine by reflecting the information in clinical practice guidelines.

Discovery of the novel HLA-A*01:01:01:112 allele in a Greek volunteer bone marrow donor.

HLA-A*01:01:01:112 differs from the HLA-A*01:01:01:01 allele by one nucleotide substitution in the 5'UTR.

Strong humoral response after Covid-19 vaccination correlates with the common HLA allele A*03:01 and protection from breakthrough infection.

Few data exist on the role of genetic factors involving the HLA system on response to Covid-19 vaccines. Moving from suggestions of a previous study investigating the association of some HLA alleles with humoral response to BNT162b2, we here compared the HLA allele frequencies among weak (n = 111) and strong (n = 123) responders, defined as those healthcare workers with the lowest and the highest anti-Spike antibody levels after vaccination. Individuals with clinical history of Covid-19 or positive anti-nucleocapside antibodies were excluded. We found the common HLA-A*03:01 allele as an independent predictor of strong humoral response (OR = 12.46, 95% CI: 4.41-35.21, p < 0.0001), together with younger age of vaccines (p = 0.004). Correlation between antibody levels and protection from breakthrough infection has been observed, with a 2-year cumulative incidence of 42% and 63% among strong and weak responders, respectively (p = 0.03). Due to the high frequency of HLA-A*03:01 and the need for seasonal vaccinations against SARS-CoV-2 mutants, our findings provide useful information about the inter-individual differences observed in humoral response after Covid-19 vaccine and might support further studies on the next seasonal vaccines.

Identification of the novel HLA-A*02:01:01:251 allele in a candidate bone marrow donor by next-generation sequencing.

A single nucleotide mismatch within intron 1 differentiates HLA-A*02:01:01:251 from the HLA-A*02:01:01:01 allele.

HLA Gene Polymorphisms in Romanian Patients with Chronic Lymphocytic Leukemia.

Materials and Methods: This study included 66 patients with CLL, diagnosed between 2020 and 2022, and 100 healthy controls. HLA class I and class II genes (HLA-A/B/C, HLA-DQA1/DQB1/DPA1/DPB1, and HLA-DRB1/3/4/5) were investigated using next-generation sequencing technology. Results: Several HLA alleles were strongly associated with CLL. The most important finding was that HLA-DRB1∗04:02:01 (p=0.001, OR = 1.05) and HLA-DRB3∗02:01:01 (p=0.009, OR = 1.03) have a predisposing role in CLL development. Moreover, we identified that HLA-A∗24:02:01 0.01 (p=0.01, OR = 0.38), HLA-DQA1∗05:05:01 (p=0.01, OR = 0.56), HLA-DQB1∗03:02:01 (p=0.03, OR = 0.40), and HLA-DRB4∗01:03:01 (p=0.03, OR = 0.54 alleles have protective roles. Correlations between HLA expression and gender showed that women had a higher expression of protective HLA alleles when compared to men. Conclusions: Our data are the first to indicate that in Romanian patients with CLL, the HLA-A∗24:02:01 and HLA-DQA1∗05:05:01 alleles have a protective role against CLL development, whereas HLA-DRB1∗04:02:01 and HLA-DRB3∗02:01:01alleles are positively associated with CLL.

Development and characterization of a cell donor registry for virus-specific T cell manufacture in a blood bank.

Adoptive cell therapy using virus-specific T cells (VST) is a strategy for treating common opportunistic viral infections after transplantation, particularly when these infections do not resolve through antiviral drug therapy. The availability of third-party healthy donors allows for the immediate use of cells for allogeneic therapy in cases where patients lack an appropriate donor. Here, we present the creation of a cell donor registry of human leukocyte antigen (HLA)-typed blood donors, REDOCEL, a strategic initiative to ensure the availability of compatible cells for donation when needed. Currently, the registry consists of 597 healthy donors with a median age of 29 years, 54% of whom are women. The most represented blood groups were A positive and O positive, with 36.52% and 34.51%, respectively. Also, donors were screened for cytomegalovirus (CMV) and Epstein-Barr virus (EBV). Almost 65% of donors were CMV-seropositive, while less than 5% were EBV-seronegative. Of the CMV-seropositive donors, 98% were also EBV-seropositive. High-resolution HLA-A, -B, -C, -DRB1 and -DQB1 allele and haplotype frequencies were determined in the registry. Prevalent HLA alleles and haplotypes were well represented to ensure donor-recipient HLA-matching, including alleles reported to present viral immunodominant epitopes. Since the functional establishment of REDOCEL, in May 2019, 87 effective donations have been collected, and the effective availability of donors with the first call has been greater than 75%. Thus, almost 89% of patients receiving an effective donation had available at least 5/10 HLA-matched cell donors (HLA-A, -B, -C, -DRB1, and -DQB1). To summarize, based on our experience, a cell donor registry from previously HLA-typed blood donors is a useful tool for facilitating access to VST therapy.

Immunogenetic Background of Chronic Lymphoproliferative Disorders in Romanian Patients-Case Control Study.

BACKGROUND AND OBJECTIVES: The implications of the genetic component in the initiation and development of chronic lymphoproliferative disorders have been the subject of intense research efforts. Some of the most important genes involved in the occurrence and evolution of these pathologies are the HLA genes. The aim of this study is to analyze, for the first time, possible associations between chronic lymphoproliferative diseases and certain HLA alleles in the Romanian population. MATERIALS AND METHODS: This study included 38 patients with chronic lymphoproliferative disorders, diagnosed between 2021 and 2022 at Fundeni Clinical Institute, Bucharest, Romania, and 50 healthy controls. HLA class I and class II genes (HLA-A/B/C, HLA-DQB1/DPB1/DRB1) were investigated by doing high resolution genotyping using sequence specific primers (SSP). RESULTS: Several HLA alleles were strongly associated with chronic lymphoproliferative disorders. The most important finding was that the HLA-C*02:02 (p = 0.002, OR = 1.101), and HLA-C*12:02 (p = 0.002, OR = 1.101) have a predisposing role in the development of chronic lymphoproliferative disorders. Moreover, we identified that HLA-A*11:01 (p = 0.01, OR = 0.16), HLA-B*35:02 (p = 0.037, OR = 0.94), HLA-B*81:01 (p = 0.037, OR = 0.94), HLA-C*07:02 (p = 0.036, OR = 0.34), HLA-DRB1*11:01 (p = 0.021, OR = 0.19), and HLA-DRB1*13:02 (p = 0.037, OR = 0.94), alleles have protective roles. CONCLUSIONS: Our study indicates that HLA-C*02:02 and HLA-C*12:02 are positively associated with chronic lymphoproliferative disorders for our Romanian patients while HLA-DRB1*11:01, HLA-DRB1*13:02, and HLA-B*35:02 alleles have a protective role against these diseases.

Afamitresgene autoleucel for advanced synovial sarcoma and myxoid round cell liposarcoma (SPEARHEAD-1): an international, open-label, phase 2 trial.

BACKGROUND: Afamitresgene autoleucel (afami-cel) showed acceptable safety and promising efficacy in a phase 1 trial (NCT03132922). The aim of this study was to further evaluate the efficacy of afami-cel for the treatment of patients with HLA-A*02 and MAGE-A4-expressing advanced synovial sarcoma or myxoid round cell liposarcoma. METHODS: SPEARHEAD-1 was an open-label, non-randomised, phase 2 trial done across 23 sites in Canada, the USA, and Europe. The trial included three cohorts, of which the main investigational cohort (cohort 1) is reported here. Cohort 1 included patients with HLA-A*02, aged 16-75 years, with metastatic or unresectable synovial sarcoma or myxoid round cell liposarcoma (confirmed by cytogenetics) expressing MAGE-A4, and who had received at least one previous line of anthracycline-containing or ifosfamide-containing chemotherapy. Patients received a single intravenous dose of afami-cel (transduced dose range 1·0 × 109-10·0 × 109 T cells) after lymphodepletion. The primary endpoint was overall response rate in cohort 1, assessed by a masked independent review committee using Response Evaluation Criteria in Solid Tumours (version 1.1) in the modified intention-to-treat population (all patients who received afami-cel). Adverse events, including those of special interest (cytokine release syndrome, prolonged cytopenia, and neurotoxicity), were monitored and are reported for the modified intention-to-treat population. This trial is registered at ClinicalTrials.gov, NCT04044768; recruitment is closed and follow-up is ongoing for cohorts 1 and 2, and recruitment is open for cohort 3. FINDINGS: Between Dec 17, 2019, and July 27, 2021, 52 patients with cytogenetically confirmed synovial sarcoma (n=44) and myxoid round cell liposarcoma (n=8) were enrolled and received afami-cel in cohort 1. Patients were heavily pre-treated (median three [IQR two to four] previous lines of systemic therapy). Median follow-up time was 32·6 months (IQR 29·4-36·1). Overall response rate was 37% (19 of 52; 95% CI 24-51) overall, 39% (17 of 44; 24-55) for patients with synovial sarcoma, and 25% (two of eight; 3-65) for patients with myxoid round cell liposarcoma. Cytokine release syndrome occurred in 37 (71%) of 52 of patients (one grade 3 event). Cytopenias were the most common grade 3 or worse adverse events (lymphopenia in 50 [96%], neutropenia 44 [85%], leukopenia 42 [81%] of 52 patients). No treatment-related deaths occurred. INTERPRETATION: Afami-cel treatment resulted in durable responses in heavily pre-treated patients with HLA-A*02 and MAGE-A4-expressing synovial sarcoma. This study shows that T-cell receptor therapy can be used to effectively target solid tumours and provides rationale to expand this approach to other solid malignancies. FUNDING: Adaptimmune.

Platelet transfusions in haploidentical haematopoietic stem cell allograft candidates: Protecting HLA-A and HLA-B antigens through eplet analysis.

In patients awaiting an allogeneic haematopoietic stem cell transplantation, platelet transfusion is a risk factor for anti-HLA class I immunization because the resulting donor-specific antibodies complicate the allograft process. The objective of the present study was to determine the feasibility of a novel eplet-based strategy for identifying HLA class I mismatches between potential donors and the recipient when pre-allograft platelet transfusions were required. We included 114 recipient/haploidentical relative pairs. For each pair, we entered HLA-class I typing data into the HLA Eplet Mismatch calculator, defined the list of mismatched eplets (for the recipient versus donor direction) and thus identified the shared HLAs to be avoided. Using this list of HLAs, we defined the theoretical availability of platelet components (PCs) by calculating the virtual panel-reactive antibody (vPRA). We also determined the number of PCs actually available in France by querying the regional transfusion centre's database. The mean ± standard deviation number of highly/moderately exposed eplets to be avoided in platelet transfusions was 5.8 ± 3.3, which led to the prohibition of 38.5 ± 2 HLAs-A and -B. Taking into account the mismatched antigens and the eplet load, the mean ± standard deviation theoretical availability of PCs (according to the vPRA) was respectively 34.49% ± 1.95% for HLA-A and 80% ± 2.3% for HLA-B. A vPRA value below 94.9% for highly or moderately exposed eplets would predict that 10 PCs were actually available nationally. Although epitope protection of HLA molecules is feasible, it significantly restricts the choice of PCs.

Tumor beta2-microglobulin and HLA-A expression is increased by immunotherapy and can predict response to CIT in association with other biomarkers.

Background: Downregulation of MHC class I expression and/or defects in the antigen presentation pathways are commonly reported in human cancers. Numerous studies previously have explored extensively the molecular mechanisms that underlie HLA-class I and Beta2-Microglobulin (B2M) downregulation. However, the techniques presently available to detect expression of MHC class I proteins lack the robustness, specificity and sensitivity needed for systematic integration and analysis in clinical trials. Furthermore, the dynamics of HLA-class I and B2M expression have not been comprehensively studied as a potential biomarker for immunotherapy. Methods: Using novel, validated, immunohistochemistry (IHC)-based methods for quantifying B2M and HLA-A in tumor samples from diverse cancer types, we have determined loss of B2M and HLA-A proteins in 336 archived, primary specimens and 329 biopsies from metastatic patients collected during Roche-sponsored Phase 1 clinical trials investigating novel immunotherapy candidates as monotherapy or in combination with CPI. Results: Up to 56% of cases with B2M or HLA-A loss were noted in the investigated tumor types. The frequency of loss was dependent on indication and stage of disease and revealed heterogeneous expression patterns across patients. B2M and HLA-A loss was increased in metastatic lesions compared to primary tumors, indicating selection of MHC class I low clones in metastatic and refractory tumor cells. High on-treatment B2M expression correlated with successful clinical outcome (RECIST), while high baseline B2M did not. A treatment-induced increase of B2M expression was noted in most of the patients with low B2M levels at baseline. The triple biomarker combination of B2M, CD8 and PDL1 strongly improved response prediction to cancer immunotherapy. Conclusion: Our results indicate that B2M and HLA-A loss occurs frequently in tumors and is reversed in most instances following immunotherapy which supports the conclusion that MHC class I loss is not the dominant resistance mechanism to CPI treatment. This investigation reveals a highly dynamic expression of HLA-A and B2M in tumors affected by indication, metastatic status, immunophenotype and immunotherapy treatment. Baseline expression levels of B2M on tumors may be of utility as a constituent of a biomarker panel used for selecting patients for immunotherapy clinical trials.

Selective pressure mediated by influenza virus M158-66 epitope-specific CD8+T cells promotes accumulation of extra-epitopic amino acid substitutions associated with viral resistance to these T cells.

Influenza viruses are notorious for their capacity to evade host immunity. Not only can they evade recognition by virus-neutralizing antibodies, there is also evidence that they accumulate mutations in epitopes recognized by virus-specific CD8+T cells. In addition, we have shown previously that human influenza A viruses were less well recognized than avian influenza viruses by CD8+T cells directed to the highly conserved, HLA-A*02:01 restricted M158-66 epitope located in the Matrix 1 (M1) protein. Amino acid differences at residues outside the epitope were responsible for the differential recognition, and it was hypothesized that this reflected immune adaptation of human influenza viruses to selective pressure exerted by M158-66-specific CD8+T cells in the human population. In the present study, we tested this hypothesis and investigated if selective pressure exerted by M158-66 epitope-specific CD8+T cells could drive mutations at the extra-epitopic residues in vitro. To this end, isogenic influenza A viruses with the M1 gene of a human or an avian influenza virus were serially passaged in human lung epithelial A549 cells that transgenically express the HLA-A*02:01 molecule or not, in the presence or absence of M158-66 epitope-specific CD8+T cells. Especially in the virus with the M1 gene of an avian influenza virus, variants emerged with mutations at the extra-epitopic residues associated with reduced recognition by M158-66-specific T cells as detected by Next Generation Sequencing. Although the emergence of these variants was observed in the absence of selective pressure exerted by M158-66 epitope-specific CD8+T cells, their proportion was much larger in the presence of this selective pressure.

[Establishment and validation of prediction models for human leukocyte antigen haplotypes and human leukocyte antigen genotypes].

Objective: To establish prediction models for human leukocyte antigen (HLA) haplotypes and HLA genotypes, and verify the prediction accuracy. Methods: The prediction models were established based on the characteristic of HLA haplotype inheritance and linkage disequilibrium (LD), as well as the invention patents and software copyrights obtained. The models include algorithm and reference databases such as HLA A-C-B-DRB1-DQB1 high-resolution haplotypes database, B-C and DRB1-DQB1 LD database, G group alleles table, and NMDP Code alleles table. The prediction algorithm involves data processing, comparison with reference data, filtering results, probability calculation and ranking, confidence degree estimation, and output of prediction results. The accuracy of the predictions was verified by comparing them with the correct results, and the relationship between prediction accuracy and the probability distribution and confidence degree of the predicted results was analyzed. Results: The HLA haplotypes and genotypes prediction models were established. The prediction algorithm included the prediction of A-C-B-DRB1-DQB1 haplotypes according to HLA-A, B, DRB1, C, DQB1 genotypes, the prediction of C and DQB1 high-resolution results according to A, B and DRB1 high-resolution results, and the prediction of A, B, DRB1, C and DQB1 high resolution results according to the A, B and DRB1 intermediate or low resolution results. Validation results of "Predicting A-C-B-DRB1-DQB1 haplotypes basing on HLA-A, B, DRB1, C, DQB1 genotypes" model: for 787 data, the accuracy was 94.0% (740/787) with 740 correct predictions, 34 incorrect predictions, and 13 instances with no predicted results. For 847 data, the accuracy was 100% (847/847). The 2 411 and 2 594 haplotype combinations predicted from 787 and 847 data were grouped according to confidence degree, the accuracy was 100% (48/48, 114/114) for a confidence degree of 1, 96.2% (303/315) and 97.8% (409/418) for a confidence degree of 2 respectively. Validation results of "Predicting A, B, DRB1 and C, DQB1 high-resolution genotypes basing on HLA-A, B, DRB1 high, intermediate, or low resolution genotypes" model: when predicting C and DQB1 high resolution genotypes basing on A, B, and DRB1 high resolution genotypes, 89.3% (1 459/1 634) of the predictions were correct. The accuracy for the top 2 predicted probability (GPP) ranking was 79.2% (1 156/1 459), and for the top 10, it was 95.0% (1 386/1 459). Furthermore, when GPP≥90% and GPP 50%-90%, the prediction accuracy was 81.3% (209/257) and 72.8% (447/614) respectively. The accuracy of predicting C and DQB1 high resolution genotypes basing on the results of A, B, and DRB1 high resolution genotypes from the China Marrow Donor Program was 87.0% (20/23). The accuracy of predicting A, B, DRB1, C, and DQB1 high resolution genotypes basing on the results of A, B, and DRB1 intermediate or low-resolution genotypes was 70.0% (7/10) and 52.5% (21/40) respectively. When predicting whether the patient is likely to have a HLA 10/10 matched donor, the accuracy of the top 2 GPP combinations with a proportion of ≥50% was 85.7% (6/7). Conclusions: When using A, B, DRB1, C, DQB1 genotypes to predict A-C-B-DRB1-DQB1 haplotype combinations, the results with a confidence degree of 1 and 2 are reliable. When predicting C and DQB1 genotypes according to A, B and DRB1 genotypes, the top 10 results ranked by GPP are reliable, and the top 2 results with GPP≥50% are more reliable.

[Analysis of transfusion effect of different platelet matching schemes in patients with platelet transfusion refractoriness].

Objective: To analyze the transfusion effect of different platelet matching schemes in patients with platelet transfusion refractoriness (PTR). Methods: A total of 94 patients with PTR received by Taiyuan Blood Center from January to December 2021 were retrospectively analyzed, including 26 males and 68 females, aged 53(34,66) years. Platelet antibody screening was performed by enzyme-linked immunosorbent assay (ELISA). For patients with positive human leukocyte antigen (HLA) class Ⅰ antibodies, Luminex platform liquid chip assay was used to identify the specificity of antibodies, and platelets with missing allelic expression antigen corresponding to their specific antibodies were found in the platelet donor gene database established in our laboratory. For patients with negative class HLA-Ⅰ antibody screening, medium and high-resolution HLA-A and B alleles were genotyped by polymerase chain reaction restriction sequence specific oligonucleotide (PCR-SSO), and the compatible platelets were searched from the platelet donor gene database by HLA cross-reactive group genotype matching scheme or directly selected by serological cross-matching. The PCI compliance rate and total transfusion effective rate of different mismatch site groups and different matching scheme groups were statistically analyzed. Results: Platelet antibody was detected in 39 of 94 PTR patients with a positive rate of 41.5%, and all of them were HLA-Ⅰ antibodies, and 1 case was accompanied by human platelet antigen (HPA) antibody. A total of 134 times of compatible platelets were supplied to 39 patients with HLA-Ⅰ antibody positive by using antibody avoidance matching method. And the total effective rate of transfusion was 97.8% (131/134); The PCI compliance rates of HLA-A antigen mismatch, HLA-B antigen mismatch and HLA-A and B antigen mismatch groups were 81.6% (31/38), 86.5% (32/37) and 78.6% (22/28), respectively. The total effective rate of transfusion was 97.4% (37/38), 94.6% (35/37) and 100% (28/28), respectively, with no statistical significance (all P>0.05). A total of 118 times of compatible platelets were provided by HLA antigen cross-reaction group genotype matching and serological cross-matching, 90 transfusion effects were collected during follow-up, and the total effective rate was 76.7% (69/90). Conclusion: The combination of different platelet matching schemes can improve the PCI compliance rate and the total effective rate of transfusion in PTR patients.

[Pathogenetic analysis of transfusion-related acute lung injury caused by human leukocytes antigen antibody against human leukocyte antigen].

From September 2019 to October 2020, pathogenetic analysis of three patients clinically diagnosed as transfusion-related acute lung injury (TRALI) caused by human leukocyte antibodies was conducted by Guangzhou Blood Centre, including 2 males and 1 female, aged 56, 50 and 20 years old, respectively. Solid phase agglutination, anti-human globulin test and flow cytometry method were used to detect the presence of antibodies against patients. Sequencing-based human leukocyte antigen (HLA-SBT) typing technique was used to detect the human leukocyte antigen (HLA) genotypes of patients. Lifecodes single antigen class Ⅰ/Ⅱ kit (LSA-Ⅰ/Ⅱ) were used to detect the specificity of HLA-class Ⅰ and class Ⅱ antibodies in donor blood by Luminex 200 liquid suspension chip system. The HLA specific antibodies and corresponding epitopes in donors were also analyzed. The results showed that　HLA class Ⅰ or class Ⅱ specific antibodies against TRALI patients were detected in the blood donors. The plasma of donor 3 received by patient 1 contained antibodies against the patient's HLA-DRB1*09∶01 antigen, and the epitopes mediating the antibody reaction of the donor and recipient were 70R, 31I, 70QA. There were antibodies against the HLA-A*11∶02, HLA-A*11∶01, DRB1*12∶02, and DRB1*09∶01 antigens of patient 2 in the plasma of donor 4, and the associated antigenic epitopes were 151AHA, 57V, and 16Y. Antibodies against the HLA-DRB1*14∶04, DRB1*11∶01, and DPB1*05∶01 antigens of patient 3 were present in the plasma of donor 6 and donor 7, and the associated epitopes were 96HK, 140TV, 13SE, and 111K.　Three cases of TRALI were confirmed to be caused by HLA antibodies through laboratory analysis, and human leukocyte antibody detection should be paid attention in clinically suspected cases of TRALI, and targeted diagnosis and treatment should be given.

Identification of the HLA-A*11:463 allele in a Chinese patient and his father.

HLA-A*11:463 has one nucleotide change from HLA-A*11:01:01:01 at nucleotide 508 changing Lysine (146) to Glutamine.

Molecular mechanism of specific HLA-A mRNA recognition by the RNA-binding-protein hMEX3B to promote tumor immune escape.

Immunotherapy, including immune checkpoint inhibitors and adoptive cell transfer, has obtained great progress, but their efficiencies vary among patients due to the genetic and epigenetic differences. Human MEX3B (hMEX3B) protein is an RNA-binding protein that contains two KH domains at the N-terminus and a RING domain at its C-terminus, which has the activity of E3 ubiquitin ligase and is essential for RNA degradation. Current evidence suggests that hMEX3B is involved in many important biological processes, including tumor immune evasion and HLA-A regulation, but the sequence of substrate RNA recognized by hMEX3B and the functional molecular mechanisms are unclear. Here, we first screened the optimized hMEX3B binding sequence on the HLA-A mRNA and reported that the two tandem KH domains can bind with their substrate one hundred times more than the individual KH domains. We systematically investigated the binding characteristics between the two KH domains and their RNA substrates by nuclear magnetic resonance (NMR). Based on this information and the small-angle X-ray scattering (SAXS) data, we used molecular dynamics simulations to obtain structural models of KH domains in complex with their corresponding RNAs. By analyzing the models, we noticed that on the KH domains' variable loops, there were two pairs of threonines and arginines that can disrupt the recognition of the RNA completely, and this influence had also been verified both in vitro and in vivo. Finally, we presented a functional model of the hMEX3B protein, which indicated that hMEX3B regulated the degradation of its substrate mRNAs in many biological processes. Taken together, our research illustrated how the hMEX3B protein played a key role in translation inhibition during the immune response to tumor cells and provided an idea and a lead for the study of the molecular mechanism and function of other MEX3 family proteins.