Human Leukocyte Antigen Research Articles

B-052 Celiac Disease Risk Assessment of HLA-DQ Typing in IgA Deficient Patients

Abstract Background Celiac disease (CeD) is a chronic autoimmune disorder triggered by the ingestion of gluten in persons with the genetic risk factors human leukocyte antigens (HLA)-DQ2 and DQ8. Diagnostic evaluation of patients with suspected CeD often includes serology tests for tissue transglutaminase (tTG) antibodies. While the presence of HLA-DQ2 or DQ8 is required for the initiation and development of CeD, the genetic risk associated with the various alleles is not equivalent. Previous studies in patients with normal total IgA demonstrated the risk gradients of various HLA-DQ2 and DQ8 heterodimers in CeD. However, the impact of both gene variants in IgA deficient patients has not been investigated. In this study, HLA-DQ2 and HLA-DQ8 as risk factors for tTG-IgG positivity in IgA deficient patients were evaluated. Methods Retrospective data was collected from a cohort of individuals (n=3,515) with IgA concentrations below the age-dependent reference interval with suspicion for CeD who were tested for HLA-DQ genotyping and tTG-IgG (reference interval < 6 U/mL) at Mayo Clinic Laboratories. Total IgA was measured using quantitative nephelometry (Siemens BN™ II System); HLA typing was performed using the reverse SSO DNA typing assay (LABType SSO kits). tTG-IgG was determined by enzyme-linked immunosorbent assay (QUANTA Lite R h-tTG, Werfen Diagnostics) on the Dynex Agility System. The prevalence and frequency distribution of HLA-DQ2 and DQ8 haplotypes were determined and the odds ratio (OR) was calculated to evaluate the risk gradient for tTG-IgG positivity based on different HLA-DQ variants. Results Among IgA deficient patients, 58% (n=2,041) expressed HLA-DQ2 or DQ8 haplotypes. Relative to patients without permissive alleles, patients homozygous for HLA-DQ2.5 exhibited a significantly increased risk for tTG-IgG positivity (OR = 10.98, 95% CI: 6.56-18.18, p < 0.001) while those homozygous for HLA-DQ2.2 and DQ8 did not (DQ2.2/DQ2.2_OR = 0.72, 95% CI: 0.04-3.44, p = 0.75; DQ8/DQ8_OR = 0.96, 95% CI: 0.05-4.64, p = 0.97). Patients heterozygous for HLA-DQ2.5 (DQ2.5/x) displayed a lower odds ratio relative to homozygous patients (OR = 3.31, 95% CI: 2.29-4.82, p < 0.001); however, the risk for tTG-IgG positivity increased in the presence of HLA-DQ2.2 (DQ2.5/DQ2.2_OR = 7.59, 95% CI: 4.48-12.65, p < 0.001) or HLA-DQ8 (DQ2.5/DQ8_OR = 6.26, 95% CI: 3.55-10.73, p < 0.001) alleles. Conversely, in the absence of HLA-DQ2.5, HLA-DQ2.2 heterozygotes (DQ2.2/x_OR = 2.80, 95% CI: 1.77-4.39, p < 0.001) and HLA-DQ8 heterozygotes (DQ8/x_OR = 0.99, 95% CI: 0.52-1.77, p = 0.99) displayed lower correlations with tTG-IgG positivity, suggesting a potential risk elevation for tTG-IgG positivity is associated with the combination of DQ2.5 and DQ2.2 or DQ8. Conclusions Our study indicates the risk gradient of HLA-DQ genes in IgA deficient patients. Overall, compared to patients without HLA-DQ2 or DQ8 haplotypes, the homozygous HLA-DQ2.5 genotype had the highest correlation with tTG-IgG positivity, followed by HLA-DQ2.5/DQ2.2 and HLA-DQ2.5/DQ8 heterodimers. The results suggest that HLA-DQ2.2 or HLA-DQ8 alone does not confer risk, but when in the presence of HLA-DQ2.5 these alleles may increase the risk for tTG-IgG positivity. Results from this study shed light on the risk of CeD in patients with IgA deficiency.

HLA-B27 Frequency and its Association with Ankylosing Spondylitis in Indian Population: A Multi-City Analysis from a Single-Center Study

The human leukocyte antigen HLA-B*27 is a Class 1 antigen of the major histocompatibility complex (MHC) with B locus and has been established in association with pathogenesis of Ankylosing Spondylitis (AS) since 1973. AS is a multifactorial disease which occurs due to interaction between genes, environment, mechanical stress, microbiota and infection. The ankylosing spondylitis is characterized by inflammation of spine, backpain, stiffness of lower back and hips, extrarticular organs such as eyes, and cardiovascular system. In severe cases this may cause the fusion of vertebrae. The current study highlights the mechanism involved in the pathogenesis of AS with a focus to investigate the frequency of HLA B*27 in suspected cases of AS. The patients were recruited from rheumatology clinics of India from age group of 13-69 years. Patients with suspected cases of AS who met the clinical criteria for AS were tested for HLA-B*27. One thousands and four patients were tested for HLA B*27 using RTPCR method. Out of 1004 subjects, 124 (12.35%) were positive for HLA-B*27. Among these, Male/Female ratio was 2.7. Majority of subjects were from North India. The current study highlights the HLA B27 positivity in association with pathogenesis of AS and indicates that HLA B27 serves as a rapid prognostic and diagnostic genetic marker for detection of AS.

No association between migraine and HLA alleles in a cohort of 13,210 individuals with migraine from the Danish Blood Donor Study.

To determine the association between human leukocyte antigen (HLA) alleles and migraine, migraine subtypes, and sex-specific factors. It has long been hypothesized that inflammation contributes to migraine pathophysiology. This study examined the association between migraine and alleles in the HLA system, a key player in immune response and genetic diversity. We performed a case-control study and included 13,210 individuals with migraine and 86,738 controls. All participants were part of the Danish Blood Donor Study Genomic Cohort. Participants were genotyped and 111 HLA alleles on 15 HLA genes were imputed. We examined the association between HLA alleles and migraine subtypes, considering sex-specific differences. We found no association between HLA alleles and migraine, neither overall, nor in the sex-specific analysis. In the migraine subtype analysis, three HLA alleles were associated with migraine without aura; however, these associations could not be replicated in an independent Icelandic cohort (2191 individuals with migraine without aura and 278,858 controls). Furthermore, we found no association between HLA alleles and migraine with aura or chronic migraine. We found no evidence of an association between the HLA system and migraine, suggesting that genetic factors related to the HLA system do not play a significant role in migraine susceptibility.

HLA Genetic Variants in COVID-19 Susceptibility: Assessing Diversity in Indian and Global Populations

Background: The rapid spread of the SARS-CoV-2 virus has had a global impact on various ethnic groups. In order to assess the genetic predisposition of the Indian population towards COVID-19, a comparative analysis was conducted using the Human Leukocyte Antigen (HLA) to investigate the frequencies of polymorphisms directly or potentially associated with COVID-19 susceptibility, severity, immune response, and fatal outcomes in comparison to other major populations. Objectives: The objective of this study is to evaluate the genetic predisposition of the Indian population to COVID-19 by analyzing the frequencies and associations of Human Leukocyte Antigen (HLA) polymorphisms. In addition, by delineating the role of specific HLA variants in the Indian context, the study seeks to enhance our understanding of genetic factors influencing COVID-19 impact and contribute to personalized approaches for disease management and prevention across diverse ethnic groups. Methods: We collected allelic information for DRB1 gene from 653 populations globally, as documented in The Allele Frequency Net Database (AFND). Data on COVID-19 susceptibility, severity, mortality, and protective factors were obtained from a previous global study. This study aimed to compare the specific frequencies of HLA-DRB1* in different ethnic groups, including other Indian populations with COVID-19-associated alleles and protective factors. Results: HLA-DRB1*01 was identified as a significant determinant of COVID-19 susceptibility among patients in 28 states of Mexico, whereas DRB1*08 in Saudi Arabian populations, DRB1*09:01 in Japanese populations, and DRB1*15:01 in Italian populations also showed this association. Likewise, DRB1*04 in the Iranian population played a role in disease severity, and DRB1*08 in the Italian population was associated with mortality in COVID-19 patients. In addition, alleles DRB1*01:01 and DRB1*04:01 were found to exhibit a protective role in Northeast England, whereas DRB1*04 demonstrated protective effects in Saudi Arabian populations. Conclusion: The involvement of HLA in COVID-19 requires further investigation, and epidemiological studies should focus on HLA profiles as determinants of the host immune system. Prolonged homozygosity in particular genomic regions could potentially increase susceptibility to COVID-19 infection. Therefore, prudent management strategies are recommended for this pandemic in isolated communities in India and worldwide.

Immunocytochemistry assessment of vocal fold regeneration after cell-based implant in rabbits.

Cell-based outer vocal fold replacement (COVR) offers a potential treatment for severe vocal fold scarring or cancer reconstruction. Previous work in rabbits using human adipose-derived stem cells (ASC) in fibrin suggested that a hybrid structure emerged within 2 months, containing both implanted and host cells. This project uses immunocytochemistry to better define the phenotypic fate of implanted cells and features of the extracellular environment. Immunocytochemistry was performed on sections collected from rabbits 2 months after COVR implantation or scar surgery. Cellular targets included human leukocyte antigen (HLA), CD31, and smooth muscle actin (SMA). HLA was present in all implanted sections and was used to identify human cells. In adjacent sections, HLA-positive cells were identified expressing CD31. SMA was not identified in the same cells as HLA. These markers were also present in injured vocal folds not receiving COVR. SMA protein content did not differ according to treatment. Implanted human ASC persist in rabbit vocal folds. Some appear to express CD31, an endothelial marker. Smooth muscle actin, a marker of myofibroblast phenotype, was present in all sections regardless of treatment, and was not identified in hASC. Host cells also infiltrate the structure, producing a hybrid host-graft vocal fold.

Perioperative chemoimmunotherapy induces strong immune responses and long-term survival in patients with HLA class I-deficient non-small cell lung cancer

BackgroundLoss of human leukocyte antigen (HLA) class I expression and loss of heterozygosity (LOH) are common events implicated in the primary resistance of non-small cell lung cancer (NSCLC) to immunotherapy....

Human Leukocyte Antigen (HLA)-Incompatible Kidney Transplantation Shows Similar Outcomes Compared with HLA-Compatible Kidney Transplantation after Early Rejection

Human Leukocyte Antigen (HLA)-Incompatible Kidney Transplantation Shows Similar Outcomes Compared with HLA-Compatible Kidney Transplantation after Early Rejection

CAR-T cells based on a TCR mimic nanobody targeting HPV16 E6 exhibit antitumor activity against cervical cancer

The E6 and E7 oncoproteins of human papillomavirus (HPV) are considered promising targets for HPV-related cancers. In this study, we evaluated novel T cell receptor mimic (TCRm) nanobodies targeting E629-38 peptide complexed with human leukocyte antigen (HLA)-A*02:01 in the chimeric antigen receptor (CAR) format. We isolated two dromedary camel nanobodies, F5 and G9, through phage display screening. F5 bound more efficiently to the complex expressed on cells, including peptide pulsed T2, overexpressed 293E6, and cervical cancer lines CaSki and SS4050, compared to G9. CAR-T cells based on the F5 nanobody specifically killed target cells, including 293E6, CaSki, and SS4050 in vitro, through activation of NFAT and NF-κB signaling. Importantly, F5 CAR-T cells inhibited the growth of CaSki and SS4050 tumor xenografts in mice. These findings demonstrate that HPV-16+ cervical cancer can be targeted by F5 nanobody-based CAR-T cells, offering a valuable alternative strategy for treating HPV-16+ malignancies.

Targeting HLA-E-overexpressing cancers with a NKG2A/C switch receptor

Human leukocyte antigen (HLA)-E is overexpressed by a large proportion of solid tumors, including malignant glioblastoma, and acts as a major checkpoint for NKG2A+ CD8+ Tcells and natural killer (NK) cells in the tumor microenvironment and circulation. This axis operates alongside PD-L1 to inhibit effector responses by T and NK cells. We engineered a chimeric A/C switch receptor, combining the high HLA-E binding affinity of the NKG2A receptor ectodomain with the activating signaling of the NKG2C receptor endodomain. The cytotoxic function of A/C switch-transduced NK and Tcells was evaluated against tumor cells with varying levels of HLA-E expression. Invivo efficacy was assessed using a xenograft model of glioblastoma. A/C switch-transduced NK and Tcells exhibited superior and specific cytotoxicity against tumor cells with medium to high HLA-E expression. A/C switch-expressing human Tcells demonstrated enhanced anti-tumor function in a glioblastoma xenograft model. The activity of the modified Tcells was governed by an equilibrium between A/C switch levels and HLA-E expression, creating a therapeutic window to minimize on-target, off-tumor toxicities. Normal cells remained insensitive to A/C switch Tcells, even after interferon (IFN)-γ pretreatment to induce HLA-E expression. The A/C switch receptor effectively targets tumor cells expressing high levels of HLA-E, either alone or in combination with other engineered specificities, to overcome the suppressive NKG2A/HLA-E checkpoint. This approach offers a promising therapeutic strategy with a favorable safety profile for targeting HLA-E-overexpressing tumors. This work was funded by The Research Council of Norway, the Norwegian Cancer Society, and the National Cancer Institute.

Dendritic cells pulsed with multifunctional Wilms’ tumor 1 (WT1) peptides combined with multiagent chemotherapy modulate the tumor microenvironment and enable conversion surgery in pancreatic cancer

BackgroundWe aimed to develop a chemoimmunotherapy regimen consisting of a novel Wilms’ tumor 1 (WT1) peptide-pulsed dendritic cell (WT1-DC) vaccine and multiagent chemotherapy and to investigate the safety, clinical outcomes,...

Intratumoral STING agonist reverses immune evasion in PD-(L)1-refractory Merkel cell carcinoma: mechanistic insights from detailed biomarker analyses

BackgroundAntibodies blocking programmed death (PD)-1 or its ligand (PD-L1) have revolutionized cancer care, but many patients do not experience durable benefits. Novel treatments to stimulate antitumor immunity are needed in...

Analysis of ANO6, HAPLN1, and EDIL3 Polymorphisms in Patients with Ankylosing Spondylitis in a Chinese Han Population: A Case-Control Study.

Background: Earlier research has demonstrated a genetic basis for the susceptibility to ankylosing spondylitis (AS) and the severity of AS. By employing a genome-wide association study, recent work has established a correlation between the susceptibility to AS and the ANO6, HAPLN, and EDIL3 genes in a Western study population-though alternative studies have not corroborated these findings. This study aims to examine the effects of ANO6, HAPLN1, and EDIL3 polymorphisms on the susceptibility and severity of AS among the predominantly Chinese Han population. Methods: The study involved the collection of blood samples from 497 patients with AS and 498 nonrelated healthy individuals. All participants in the study were human leukocyte antigen (HLA) HLA-B27 positive and of Han Chinese descent. Illness severity was the criteria used for classifying patients with AS. Thirteen tagSNPs in ANO6, HAPLN1, and EDIL3 were chosen and then subjected to genetic typing. Analysis was conducted on the occurrence rates of various genotypes and alleles between the control group and patients with varying AS severity. Results: Following Bonferroni correction, it was found that the rs4768085 and rs17095830 single nucleotide polymorphism (SNPs) in ANO6 were related to the susceptibility to AS. Further, the rs6869296 SNP in HAPLN1 and the rs2301071 SNP between EDIL3 and HAPLN1 were also related to AS susceptibility. Regarding AS severity, the rs4768085, rs2897868, rs7965430, and rs11182965 SNPs in ANO6 were found to be associated. Conclusions: Among the Han population in China, the ANO6 and HAPLN1 genes are related to the susceptibility to AS; the ANO6 gene is also associated with the severity of AS.

Structural Identification of Immunodominant Human Leukocyte Antigen (HLA) Epitopes Targeted by HLA-Specific Antibodies in Kidney Allograft Recipients

Structural Identification of Immunodominant Human Leukocyte Antigen (HLA) Epitopes Targeted by HLA-Specific Antibodies in Kidney Allograft Recipients

HERV-Derived Syncytin-1 and Syncytin-2 as Sources of Linear and Discontinuous Epitopes in Antiphospholipid Syndrome: A Pivotal Computational Study.

To date, no studies have investigated the potential reactivation of human endogenous retroviruses (HERVs) in the pathogenesis of antiphospholipid syndrome (APS). HERV-derived syncytin-1 and syncytin-2 are localized in the plasma membrane of cells and physiologically expressed during pregnancy. The current study aimed to determine whether the epitopes of syncytins can trigger an immune response leading to APS in genetically predisposed individuals. The TepiTool, ABCpred, and DiscoTope servers were utilized to predict T-cell and B-cell epitopes by inputting the FASTA sequences and 3D structures of syncytin-1, syncytin-2, and β2-glycoprotein I (β2GPI), which served as a reference antigen for APS. T-cell epitopes were selected based on their binding to a panel of human leukocyte antigen (HLA) class II alleles associated with APS according to the literature. Epitope predictions for the different proteins were statistically compared using GraphPad Prism. For syncytin-1, we identified a total of 721 T-cell epitopes, 51 linear B-cell epitopes, and up to 40 conformational epitopes. For syncytin-2, we predicted 705 T-cell epitopes and 28 linear B-cell epitopes, but a lower number of conformational epitopes, which also exhibited lower B-cell receptor (BCR)-binding scores. The predicted T-cell and B-cell conformational epitopes of both syncytin-1 and syncytin-2 demonstrated significantly higher binding affinity to selected HLA alleles and BCR compared with β2GPI. Furthermore, syncytin-1 exhibited significantly higher immunogenicity than syncytin-2. Both syncytin-1 and syncytin-2 are computationally endowed with potential epitopes that may activate either T cells or B cells in individuals genetically predisposed to APS. While these findings may illuminate the possible role of HERVs in the development of APS, they warrant validation in further laboratory studies.

Comparison of Extended-Release and Immediate-Release Tacrolimus for Preventing De Novo Human Leukocyte Antigen (HLA) Sensitisation in Patients with Failed Allografts

Comparison of Extended-Release and Immediate-Release Tacrolimus for Preventing De Novo Human Leukocyte Antigen (HLA) Sensitisation in Patients with Failed Allografts

Derivation of Human Leukocyte Antigen Molecular Mismatch Risk Thresholds in a Diverse Cohort of Kidney Transplant Recipients

Derivation of Human Leukocyte Antigen Molecular Mismatch Risk Thresholds in a Diverse Cohort of Kidney Transplant Recipients

P1.06B.13 Blood-Based Loss of Heterozygosity in Human Leukocyte Antigen Class I Alleles Reveals Resistance to Immunotherapy in Non-Small Cell Lung Cancer

P1.06B.13 Blood-Based Loss of Heterozygosity in Human Leukocyte Antigen Class I Alleles Reveals Resistance to Immunotherapy in Non-Small Cell Lung Cancer

The clinical value of serum long non-coding RNA human leukocyte antigen complex group 11/microRNA-532-3p in the diagnosis and prognosis of patients with acute myocardial infarction undergoing percutaneous coronary intervention

BackgroundAcute myocardial infarction (AMI) is a cardiovascular disease with the highest morbidity and mortality rate in the world. Several studies have suggested that abnormal regulation of non-coding RNAs (ncRNAs) may play a vital role in the occurrence and progress of AMI.ObjectiveThe purpose of this study was to investigate the clinical values of human leukocyte antigen complex group 11 (HCG11) or miR-532-3p in the diagnosis and prognosis of patients with AMI after percutaneous coronary intervention (PCI).MethodsThe clinical data of 100 AMI patients who underwent PCI were analyzed retrospectively. According to whether major adverse cardiovascular events (MACE) occurred after PCI, they were divided into MACE group (n = 38) and non-MACE group (n = 62). Basic clinical data and serum HCG11 and miR-532-3p levels were analyzed. Multivariate Cox regression analysis was performed to evaluate the risk factors for MACE, and the receiver operator characteristic (ROC) curve was constructed to assess the clinical predictive value of HCG11 and miR-532-3p for MACE.ResultsCompared with the control group, the serum HCG11 level and miR-532-3p in AMI patients were significantly increased or decreased, and the serum levels of HCG11 and miR-532-3p in the MACE group were significantly increased and decreased, compared with those in non-MACE group. Multivariate Cox regression showed that HCG11 and miR-532-3p were risk factors for MACE occurrence. ROC curve investigated that HCG11 combined with miR-532-3p has accurate predictive value for MACE.ConclusionThis study showed that serum HCG11 and miR-532-3p have certain predictive value for MACE after PCI in patients with AMI.

Single-cell transcriptome atlas revealed bronchoalveolar immune features related to disease severity in pediatric Mycoplasma pneumoniae pneumonia.

The mechanisms underlying protective immunity in mild Mycoplasma pneumoniae pneumonia (MPP) and the pathogenesis of severe MPP, characterized by dysregulated immune responses, remain unclear. Here, we performed single-cell RNA sequencing (scRNA-seq) to profile bronchoalveolar lavage fluid (BALF) samples from 13 healthy donors and 24 hospitalized pediatric patients with MPP, covering both mild and severe cases. Severe MPP patients exhibited high levels of exhausted T cells and M1-like macrophages, with the exhaustion of T cells attributed to persistent type I interferon signaling and inadequate assistance from CD4+ T cells. Significant cell-cell interactions between exhausted T cells and programmed death-ligand 1+ (PD-L1+) macrophages were detected in severe patients, potentially mediated through inhibitor molecules (e.g., PD1) and their receptors (e.g., PD-L1), as well as human leukocyte antigen class I molecules and their receptors (e.g., KLRC1/D2), resulting in the dysfunction of anti-MP immune responses. Mild MPP patients were featured by an increased abundance of neutrophils, coupled with enhanced activation, contributing to protective immunity. Together, our study provides a detailed characterization of the BALF immune landscape in MPP patients, revealing distinct immune characteristics between mild and severe cases, which offers a valuable resource for understanding MPP immunopathogenesis and formulating effective therapeutic strategies.

581P Toxic autophagic vacuolar myopathies and the role of human leukocyte antigen class I molecules and membrane attack complex in its pathogenesis

581P Toxic autophagic vacuolar myopathies and the role of human leukocyte antigen class I molecules and membrane attack complex in its pathogenesis