Unique motif shared by HLA-B*59:01 and HLA-B*55:02 is associated with methazolamide-induced Stevens-Johnson syndrome and toxic epidermal necrolysis in Han Chinese

BACKGROUND

Methazolamide (MTZ) has been occasionally linked to the lethal Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), which are associated with HLA-B*59:01. However, some MTZ-induced SJS/TEN (MTZ-SJS/TEN) cases are negative for HLA-B*59:01, implying that other genetic factors besides HLA-B*59:01 are contributing to MTZ-SJS/TEN.

OBJECTIVES

To comprehensively identify HLA and non-HLA genetic susceptibility to MTZ-SJS/TEN in Han Chinese.

METHODS

Eighteen patients with MTZ-SJS/TEN, 806 subjects of the population control and 74 MTZ-tolerant individuals were enrolled in this study. Both exome-wide and HLA-based association studies were conducted. Molecular docking analysis was employed to simulate the interactions between MTZ and risk HLA proteins.

RESULTS

We found a strong signal in the major histocompatibility complex region on chromosome 6 with 22 SNPs reaching exome-wide significance. Compared with MTZ-tolerant controls, a significant association of HLA-B*59:01 with MTZ-SJS/TEN was validated (odds ratio [OR] = 146.00, 95% confidence interval [CI]: 16.12-1321.98; P = 6.19 × 10^-10 ). Moreover, 66.7% of MTZ-SJS/TEN patients negative for HLA-B*59:01 were carriers of HLA-B*55:02, while 2.7% of the tolerant individuals were observed with HLA-B*55:02 (OR = 71.00, 95% CI: 7.84-643.10; P = 1.43 × 10^-4 ). Within HLA-B protein, the E45-L116 motif could completely explain the association of HLA-B*59:01 and HLA-B*55:02 with MTZ-SJS/TEN (OR = 119.33, 95% CI: 29.19-1227.96; P = 4.36 × 10^-13 ). Molecular docking analysis indicated that MTZ binds more stably to the pocket of HLA-B*59:01 and HLA-B*55:02 than to that of non-risk alleles of HLA-B*40:01 and HLA-C*01:02.

CONCLUSIONS

This study confirmed the association of HLA-B*59:01 with MTZ-SJS/TEN and identified HLA-B*55:02 as a novel risk allele in Han Chinese with the largest sample size to date. Notably, the rs41562914(A)-rs12697944(A) haplotype, encoding E45-L116, is capable of serving as a powerful genetic predictor for MTZ-SJS/TEN with a sensitivity of 89% and specificity of 96%.

HLA alleles measured from COVID-19 patient transcriptomes reveal associations with disease prognosis in a New York cohort

BACKGROUND

The Human Leukocyte Antigen (HLA) gene locus plays a fundamental role in human immunity, and it is established that certain HLA alleles are disease determinants. Previously, we have identified prevalent HLA class I and class II alleles, including DPA1*02:02, in two small patient cohorts at the COVID-19 pandemic onset.

METHODS

We have since analyzed a larger public patient cohort data (n = 126 patients) with controls, associated demographic and clinical data. By combining the predictive power of multiple in silico HLA predictors, we report on HLA-I and HLA-II alleles, along with their associated risk significance.

RESULTS

We observe HLA-II DPA1*02:02 at a higher frequency in the COVID-19 positive cohort (29%) when compared to the COVID-negative control group (Fisher's exact test [FET] p = 0.0174). Having this allele, however, does not appear to put this cohort's patients at an increased risk of hospitalization. Inspection of COVID-19 disease severity outcomes, including admission to intensive care, reveal nominally significant risk associations with A*11:01 (FET p = 0.0078) and C*04:01 (FET p = 0.0087). The association with severe disease outcome is especially evident for patients with C*04:01, where disease prognosis measured by mechanical ventilation-free days was statistically significant after multiple hypothesis correction (Bonferroni p = 0.0323). While prevalence of some of these alleles falls below statistical significance after Bonferroni correction, COVID-19 patients with HLA-I C*04:01 tend to fare worse overall. This HLA allele may hold potential clinical value.

Extracellular crosslinking mass spectrometry reveals HLA class I - HLA class II interactions on the cell surface

Human Leukocyte Antigen (HLA) complexes are critical cell-surface protein assemblies that facilitate T-cell surveillance of almost all cell types in the body. While T-cell receptor binding to HLA class I and class II complexes is well-described with detailed structural information, the nature of cis HLA interactions within the plasma membrane of the surveyed cells remains to be better characterized, as protein-protein interactions in the membrane environment are technically challenging to profile. Here we performed extracellular chemical crosslinking on intact antigen presenting cells to specifically elucidate protein-protein interactions present in the external plasma membrane. We found that the crosslink dataset was dominated by inter- and intra-protein crosslinks involving HLA molecules, which enabled not only the construction of an HLA-centric plasma membrane protein interaction map, but also revealed multiple modes of HLA class I - HLA class II interactions with further structural modeling based on crosslinker distance restraints. Collectively, our data demonstrate that HLA molecules colocalize and can be densely packed on the plasma membrane.

Understanding the genetic contribution of the human leukocyte antigen system to common major psychiatric disorders in a world pandemic context

The human leukocyte antigen (HLA) is a complex genetic system that encodes proteins which predominantly regulate immune/inflammatory processes. It can be involved in a variety of immuno-inflammatory disorders ranging from infections to autoimmunity and cancers. The HLA system is also suggested to be involved in neurodevelopment and neuroplasticity, especially through microglia regulation and synaptic pruning. Consequently, this highly polymorphic gene region has recently emerged as a major player in the etiology of several major psychiatric disorders, such as schizophrenia, autism spectrum disorder and bipolar disorder and with less evidence for major depressive disorders and attention deficit hyperactivity disorder. We thus review here the role of HLA genes in particular subgroups of psychiatric disorders and foresee their potential implication in future research. In particular, given the prominent role that the HLA system plays in the regulation of viral infection, this review is particularly timely in the context of the Covid-19 pandemic.

COVID-19 coronavirus vaccine T cell epitope prediction analysis based on distributions of HLA class I loci (HLA-A, -B, -C) across global populations

T cell immunity, such as CD4 and/or CD8 T cell responses, plays a vital role in controlling the virus infection and pathological damage. Several studies have reported SARS-CoV-2 proteins could serve as ideal vaccine candidates against SARS-CoV-2 infection by activating the T cell responses. In the current study, based on the SARS-CoV-2 sequence and distribution of host human leukocyte antigen (HLA), we predicted the possible epitopes for the vaccine against SARS-CoV-2 infections. Firstly, the current study retrieved the SARS-CoV-2 S and N protein sequences from the NCBI Database. Then, using the Immune Epitope Database Analysis Resource, we predicted the CTL epitopes of the SARS-CoV-2 S and N proteins according to worldwide frequency distributions of HLA-A, -B, and -C alleles (>1%). Our results predicted 90 and 106 epitopes of N and S proteins, respectively. Epitope cluster analysis showed 16 and 34 respective clusters of SARS-CoV-2 N and S proteins, which covered 95.91% and 96.14% of the global population, respectively. After epitope conservancy analysis, 8 N protein epitopes and 6 S protein epitopes showed conservancy within two SARS-CoV-2 types. Of these 14 epitopes, 13 could cover SARS coronavirus and Bat SARS-like coronavirus. The remaining epitope (KWPWYIWLGF_1211-1220) could cover MERS coronavirus. Finally, the 14-epitope combination could vaccinate 89.60% of all individuals worldwide. Our results propose single or combined CTL epitopes predicted in the current study as candidates for vaccines to effectively control SARS-CoV-2 infection and development.

Role of Human Leukocyte Antigens at the Feto-Maternal Interface in Normal and Pathological Pregnancy: An Update

The successful maternal tolerance of the semi-allogeneic fetus provides an apparent immunologic paradox. Indeed, deep invasion of placental trophoblast cells into maternal uterine tissue and the following growth of the fetus have to be tolerated by a pregnant woman’s immune system. Among the various possible protective mechanisms that may be involved in human pregnancy, the expression of a non-classical pattern of human leukocyte antigen (HLA) class I molecules and the complete lack of expression of HLA class II molecules in placental tissues seem to be the most relevant mechanisms of fetal escape from maternal immune recognition. The importance of HLA molecules in fetal toleration by the maternal immune system is highlighted by pregnancy complications occurring in cases of abnormal HLA molecule expression at the maternal–fetal interface. In this review, we summarize evidences about the role of placental HLA molecules in normal and pathological pregnancies.

HLA predictions from the bronchoalveolar lavage fluid samples of five patients at the early stage of the wuhan seafood market COVID-19 outbreak

We are in the midst of a global viral pandemic, one with no cure and a high mortality rate. The Human Leukocyte Antigen (HLA) gene complex plays a critical role in host immunity. We predicted HLA class I and II alleles from the transcriptome sequencing data prepared from the bronchoalveolar lavage fluid samples of five patients at the early stage of the COVID-19 outbreak. We identified the HLA-I allele A*24:02 in four out of five patients, which is higher than the expected frequency (17.2%) in the South Han Chinese population. The difference is statistically significant with a p-value less than 10-4. Our analysis results may help provide future insights on disease susceptibility.

High-resolution characterization of allelic and haplotypic HLA frequency distribution in a Spanish population using high-throughput next-generation sequencing

Next-generation sequencing (NGS) at the HLA-A, -B, -C, -DPA1, -DPB1, -DQA1, -DQB1, -DRB1 and -DRB3/4/5 loci was performed on 282 healthy unrelated individuals from different major regions of Spain. High-resolution HLA genotypes defined by full sequencing of class I loci and extended coverage of class II loci were obtained to determine allele frequencies and also to estimate extended haplotype frequencies. HLA alleles were typed at the highest resolution level (4-field level, 4FL); with exception of a minor deviation in HLA-DPA1, no statistically significant deviations from expected Hardy Weinberg Equilibrium (HWE) proportions were observed for all other HLA loci. This study provides new 4FL-allele and -haplotype frequencies estimated for the first time in the Spanish population. Furthermore, our results describe extended haplotypes (including the less frequently typed HLA-DPA1 and HLA-DQA1 loci) and show distinctive haplotype associations found at 4FL-allele definition in this Spanish population study. The distinctive allelic and haplotypic diversity found at the 4FL reveals the high level of heterozygosity and specific haplotypic associations displayed that were not apparent at 2-field level (2FL). Overall, these results may contribute as a useful reference source for future population studies, for HLA-disease association studies as a healthy control group dataset and for improving donor recruitment strategies of bone marrow registries. HLA genotyping data of this Spanish population cohort was also included in the 17th International Histocompatibility and Immunogenetics Workshop (IHIW) as part of the study of HLA diversity in unrelated worldwide populations using NGS.

Human Leukocyte Antigen similarity decreases partners' and strangers' body odor attractiveness for women not using hormonal contraception

The Human Leukocyte Antigen (HLA) is a gene complex that encodes important elements of the human immune system. HLA profile is communicated via olfaction and interindividual diversity is assumed to be advantageous for mate choice. Additionally, HLA diversity appears to enhance satisfaction and sexual attraction in existing romantic partnerships. However, whether this effect is transmitted via body odors and whether it results in an attraction towards HLA-dissimilar individuals and/or an avoidance of HLA-similar ones remains unclear. In the present study, we genotyped couples and asked each participant to rate a body odor sample from their partner and from three strangers of the opposite sex who expressed a similar or dissimilar HLA-B and HLA-C genotype. We found no statistically significant preference for HLA similarity or dissimilarity in men. Among women, the observed effects differed depending on hormonal contraception status. Like men, women on hormonal contraception did not exhibit significant HLA-related preferences. However, for women not using hormonal contraceptives, odors from HLA-B and HLA-C similar donors were significantly less attractive than those from HLA-dissimilar donors, regardless of whether the samples were from a partner or a stranger. Our findings support the hypothesis that HLA similarity is perceived via body odors and that such similarity affects human attraction. This mechanism may serve an evolutionarily adaptive function in preventing prospective offspring from having decreased immunocompetence, or decreasing the chance of kin mating.

Unrelated hematopoietic stem cell registry and the role of the Hematopoietic Stem Cell Bank

Background

The hematopoietic stem cell bank has been actively recruiting registrants since 1994. This study systematically reviews its operations and outcomes over the last 20 years.

Methods

Retrospective data on a total of 47,711 registrants were reviewed. Relevant data were processed using PASW Statistics for Windows, version 18.0.

Results

As of 2013, the Korean Network for Organ Sharing database contained 265,307 registrants. Of these, 49,037 (18%) registrants committed to hematopoietic cell donation from 1994 to 2013. Fifty-seven percent of the registrants were men, and 43% were women. The reasons for opting out of the registry included refusal to donate (70%), family refusal (28%), and others (2%). The donation willingness of registrants was significantly higher than those who refused to receive a mail to confirm their continued enrollment (χ²=6.103, P=0.013). The bank successfully coordinated a total of 512 donors among newly matched donors from 1995 to 2013, of which the bone marrow and peripheral blood stem cell accounted for 40.8% and 59.2% of the total donations, respectively.

Conclusion

Our recruitment activities focus on promoting voluntary registration and the importance of updating personal contact information. We expect that these data may be useful for diverse studies and demonstrate the positive impacts on the donation program.

Reduced Human Leukocyte Antigen (HLA) Protection in Gulf War Illness (GWI)

Background

Gulf War Illness (GWI) is a disease of unknown etiology with symptoms suggesting the involvement of an immune process. Here we tested the hypothesis that Human Leukocyte Antigen (HLA) composition might differ between veterans with and without GWI.

Methods

We identified 144 unique alleles of Class I and II HLA genes in 82 veterans (66 with and 16 without GWI). We tested the hypothesis that a subset of HLA alleles may classify veterans in their respective group using a stepwise linear discriminant analysis. In addition, each participant rated symptom severity in 6 domains according to established GWI criteria, and an overall symptom severity was calculated.

Findings

We found 6 Class II alleles that classified participants 84.1% correctly (13/16 control and 56/66 GWI). The number of copies of the 6 alleles was significantly higher in the control group, suggesting a protective role. This was supported by a significant negative dependence of overall symptom severity on the number of allele copies, such that symptom severity was lower in participants with larger numbers of allele copies.

Interpretation

These results indicate a reduced HLA protection (i.e. genetic susceptibility) in veterans with GWI.

Funding

University of Minnesota and U.S. Department of Veterans Affairs.

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Differences in Human Leukocyte Antigen distinguished veterans with Gulf War Illness (GWI) from healthy Gulf War era veterans.

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Veterans with GWI show genetic susceptibility which is associated with increased severity of hallmark symptoms of GWI.

A large number of Gulf War veterans suffer from diffuse and debilitating symptoms that resemble altered immune functioning. This study evaluated whether the Human Leukocyte Antigen (HLA) gene, which is central to immune functioning, differs between veterans with GWI and unaffected Gulf War veterans. The findings highlight robust differences in HLA composition between the two groups and suggest that veterans with GWI are characterized by genetic susceptibility that confers risk for typical GWI symptoms. These findings provide compelling genetic evidence of immune dysfunction in GWI.

Etiopathogenesis and neurobiology of narcolepsy: a review

Narcolepsy is a chronic lifelong sleep disorder and it often leaves a debilitating effect on the quality of life of the sufferer. This disorder is characterized by a tetrad of excessive daytime sleepiness, cataplexy (brief loss of muscle tone following strong emotion), hypnogogic hallucinations and sleep paralysis. There are two distinct subgroups of Narcolepsy: Narcolepsy with cataplexy and Narcolepsy without cataplexy. For over 100 years, clinicians have recognised narcolepsy, but only in the last few decades have scientists been able to shed light on the true cause and pathogenesis of narcolepsy. Recent studies have shown that a loss of the hypothalamic neuropeptide Hypocretin/Orexincauses Narcolepsy with cataplexy and that an autoimmune mechanism may be responsible for this loss. Our understanding of the neurophysiologic aspect of narcolepsy has also significantly improved. The basic neural mechanisms behind sleepiness and cataplexy, the two defining symptoms of narcolepsy have started to become clearer. In this review, we have provided a detailed account of the key aspects of etiopathogenesis and neurobiology of narcolepsy, along with a critical appraisal of the more recent and interesting causal associations.We have also looked at the contributions of neuroimaging to the etiopathogenesis of Narcolepsy.