Systematic identification of minor histocompatibility antigens predicts outcomes of allogeneic hematopoietic cell transplantation.

T cell alloreactivity against minor histocompatibility antigens (mHAgs)-polymorphic peptides resulting from donor-recipient (D-R) disparity at sites of genetic polymorphisms-is at the core of the therapeutic effect of allogeneic hematopoietic cell transplantation (allo-HCT). Despite the crucial role of mHAgs in graft-versus-leukemia (GvL) and graft-versus-host disease (GvHD) reactions, it remains challenging to consistently link patient-specific mHAg repertoires to clinical outcomes. Here we devise an analytic framework to systematically identify mHAgs, including their detection on HLA class I ligandomes and functional verification of their immunogenicity. The method relies on the integration of polymorphism detection by whole-exome sequencing of germline DNA from D-R pairs with organ-specific transcriptional- and proteome-level expression. Application of this pipeline to 220 HLA-matched allo-HCT D-R pairs demonstrated that total and organ-specific mHAg load could independently predict the occurrence of acute GvHD and chronic pulmonary GvHD, respectively, and defined promising GvL targets, confirmed in a validation cohort of 58 D-R pairs, for the prevention or treatment of post-transplant disease recurrence.

Detection and annotation of transposable element insertions and deletions on the human genome using nanopore sequencing.

Repetitive sequences represent about 45% of the human genome. Some are transposable elements (TEs) with the ability to change their position in the genome, creating genetic variability both as insertions or deletions, with potential pathogenic consequences. We used long-read nanopore sequencing to identify TE variants in the genomes of 24 patients with antithrombin deficiency. We identified 7 344 TE insertions and 3 056 TE deletions, 2 926 were not previously described in publicly available databases. The insertions affected 3 955 genes, with 6 insertions located in exons, 3 929 in introns, and 147 in promoters. Potential functional impact was evaluated with gene annotation and enrichment analysis, which suggested a strong relationship with neuron-related functions and autism. We conclude that this study encourages the generation of a complete map of TEs in the human genome, which will be useful for identifying new TEs involved in genetic disorders.

Integrated Immunopeptidomic and Proteomic Analysis of COVID-19 lung biopsies.

Introduction: Severe respiratory illness is the most prominent manifestation of patients infected with SARS-CoV-2, and yet the molecular mechanisms underlying severe lung disease in COVID-19 affected patients still require elucidation. Human leukocyte antigen class I (HLA-I) expression is crucial for antigen presentation and the host's response to SARS-CoV-2. Methods: To gain insights into the immune response and molecular pathways involved in severe lung disease, we performed immunopeptidomic and proteomic analyses of lung tissues recovered at four COVID-19 autopsy and six non-COVID-19 transplants. Results: We found signals of tissue injury and regeneration in lung fibroblast and alveolar type I/II cells, resulting in the production of highly immunogenic self-antigens within the lungs of COVID-19 patients. We also identified immune activation of the M2c macrophage as the primary source of HLA-I presentation and immunogenicity in this context. Additionally, we identified 28 lung signatures that can serve as early plasma markers for predicting infection and severe COVID-19 disease. These protein signatures were predominantly expressed in macrophages and epithelial cells and were associated with complement and coagulation cascades. Discussion: Our findings emphasize the significant role of macrophage-mediated immunity in the development of severe lung disease in COVID-19 patients.

Older Adults' Use of and Interest in Technology and Applications for Health Management: A Survey Study.

Background: Older adults face challenges with managing their medications, obtaining health education, and accessing health services. Mobile health (mHealth), defined as any medical or public health practice facilitated through mobile devices, could help to overcome these difficulties. Objectives: To determine what technologies and apps are in current use by older adults, to explore the types of technologies and apps that may be of interest to people in this age group, to explore concerns about technologies, and to examine any age-related differences. Methods: Adults 60 years of age or older were invited to complete a 35-item electronic survey, in either French or English, which was distributed through social media and by email from organizations working with older adults. The survey was conducted in mid-2020. Results: A total of 266 respondents completed some or all of the survey. Most participants had a mobile phone (229/243, 94.2%), and approximately one-third (78/222, 35.1%) had used a health-related app in the previous 12 months; this level of usage was consistent across age groups. Most respondents were interested in using an app to improve their health (171/225, 76.0%), with variation by age: highest among those 60-64 years of age (82/95, 86.3%), lower among those 80 years or older (40/52, 76.9%), and lowest among those 65-69 years of age (6/14, 42.9%). Most older adults were interested in using an app to ask questions of pharmacists (161/219, 73.5%) and to review their medications (154/218, 70.6%). Participants' mHealth concerns focused on costs, disclosure of personal information, effectiveness, usability, and endorsement by health care providers. The study limitations included challenges related to electronic recruitment and survey distribution, as well as a high representation of participants with postsecondary education. Conclusions: These findings suggest that a substantial proportion of older adults are already using and are interested in using mHealth for health information, to ask questions, and/or to review their medications with a health care team member.

Contexte: Les personnes âgées sont confrontées à des difficultés pour gérer leurs médicaments, s'informer sur la santé et accéder aux services de santé. Les applications de « santé mobile ¼, définies comme toute pratique médicale ou de santé publique facilitée par des appareils mobiles, pourraient aider à surmonter ces difficultés. Objectifs: Déterminer quelles technologies et applications sont actuellement utilisées par les aînés; examiner celles qui pourraient être intéressantes dans cette tranche d'âge; étudier les préoccupations concernant les technologies et examiner les différences liées à l'âge. Méthodes: Des adultes d'au moins 60 ans ont été invités à répondre à un sondage électronique comprenant 35 questions en français ou en anglais. Ce sondage, mené à la mi-2020, a été diffusé par des organismes travaillant avec des aînés via les médias sociaux et par courriel. Résultats: Au total, 266 participants y ont répondu en partie ou en totalité. La plupart des répondants avaient un téléphone portable (229/243, 94,2 %) et environ un tiers (78/222, 35,1 %) avaient utilisé une application liée à la santé au cours des 12 derniers mois; ce taux d'utilisation était constant tous groupes d'âge confondus. La plupart des répondants souhaitaient utiliser une application pour améliorer leur santé (171/225, 76,0 %), avec des variations du taux d'utilisation selon l'âge : le plus élevé chez les 60 à 64 ans (82/95, 86,3 %), un peu moins chez les 80 ans ou plus (40/52, 76,9 %), et le plus bas chez les 65 à 69 ans (6/14, 42,9 %). La plupart des personnes âgées souhaitent utiliser une application pour poser des questions aux pharmaciens (161/219, 73,5 %) et pour s'informer sur leurs médicaments (154/218, 70,6 %). Les préoccupations des participants en matière de « santé mobile ¼ portaient sur les coûts, la divulgation d'informations personnelles, l'efficacité, la convivialité et l'approbation par les prestataires de soins de santé. On notera, parmi les limites de l'étude, les défis liés au recrutement électronique et à la distribution électronique des sondages, ainsi qu'une forte représentation de participants ayant fait des études postsecondaires. Conclusions: Ces résultats portent à croire qu'une proportion importante d'adultes âgés utilisent déjà la technologie de « santé mobile ¼ et souhaitent l'utiliser pour obtenir des informations sur la santé, poser des questions et/ou s'informer sur leurs médicaments auprès d'un membre de l'équipe de soins de santé.

Density functional theory investigation of mechanisms of degradation reactions of sulfonated PEEK membranes with OH radicals in fuel cells: addition-elimination reactions and acid catalyzed water elimination.

Sulfonated polyether (ether) ketone or sulfonated PEEK (sPEEK) membranes are one possible candidate for proton-transfer membranes in hydrogen fuel cells. Reaction with hydroxy radicals is expected to be a significant source of degradation of these membranes during fuel cell operation. In this work, the reactivity of the sPEEK polymer molecule with OH radicals is studied by M062X hybrid density functional calculations of the energetics of several reaction paths in a water environment as modeled by polarized continuum model calculations. Reactants, products, encounter minima and transition states are optimized for a reaction pathway in which OH addition is followed by acid-catalyzed water elimination which cationizes the polymer, degradation is expected to follow this reaction as the unstable cation then undergoes bond-breaking or other reactions. Two pathways for this acid-catalyzed cationization, one in which a water molecule plays the role of an additional co-catalyst, are reported. Further calculations explore reaction pathways in which addition of OH to the polymer is followed by bond breaking reactions which would break the polymer chain or the bond between the polymer and sulfonyl groups. Examination of the free energy barriers to all these reactions, relative to reactants, suggests that these direct bond-breaking reactions may compete somewhat with acid-catalyzed water elimination following OH addition. Supplementary Information: The online version contains supplementary material available at 10.1007/s00214-023-02981-2.

Impact of allele-specific anti-human leukocyte antigen class I antibodies on organ allocation.

Technological advances in the field of histocompatibility have allowed us to define anti-human leukocyte antigen (HLA) antibody specificity at the allelic level. However, how allele-specific antibodies affect organ allocation is poorly studied. We examined allelic specificities of class I HLA antibodies in 6726 consecutive serum samples from 2953 transplant candidates and evaluated their impact on the corresponding crossmatch and organ allocation. Out of 17 class I HLA antigens represented by >1 allele in the LABScreen single antigen bead assay, 12 had potential allele-specific reactivity. Taking advantage of our unbiased cohort of deceased donor-candidate testing (123,135 complement-dependent cytotoxicity crossmatches between 2014 and 2017), we estimated that the presence of allele-specific antibody detected using a single antigen bead assay (median fluorescence intensity, >3000) against only the rare allele was a poor predictor of a positive complement-dependent cytotoxicity crossmatch, with a positive predictive value of 0% to 7%, compared with 52.5% in allele-concordant class I HLA antibodies against A or B locus antigens. Further, we confirmed allele-specific reactivity using flow crossmatch in 3 scenarios: A11:01/A11:02, A68:01/A68:02, and B44:02/B44:03. Our results suggest that allele-specific antibodies may unnecessarily exclude transplant candidates (up to 10%) from organ offers by overcalling unacceptable antigens; incorporation of selective reactivity pattern in allocation may promote precision matching and more equitable allocation.

Density functional theory investigation of mechanisms of degradation reactions of sulfonated PEEK membranes with OH radicals in fuel cells: Addition-elimination reactions and acid catalyzed water elimination.

Sulfonated polyether (ether) ketone, or sulfonated PEEK (sPEEK) membranes are one possible candidate for proton-transfer membranes in hydrogen fuel cells. Reaction with hydroxy radicals is expected to be a significant source of degradation of these membranes during fuel cell operation. In this work, the reactivity of the sPEEK polymer molecule with OH radicals is studied by M062X hybrid density functional calculations of the energetics of several reaction paths in a water environment as modeled by polarized continuum model (PCM) calculations. Reactants, products, encounter minima and transition states are optimized for a reaction pathway in which OH addition is followed by acid-catalyzed water elimination which cationizes the polymer, degradation is expected to follow this reaction as the unstable cation then undergoes bond-breaking or other reactions. Two pathways for this acid-catalyzed cationization, one in which a water molecule plays the role of an additional co-catalyst, are reported. Further calculations explore reaction pathways in which addition of OH to the polymer is followed by bond breaking reactions which would break the polymer chain or the bond between the polymer and sulfonyl groups. Examination of the free energy barriers to all these reactions, relative to reactants, suggest that these direct bond-breaking reactions may compete somewhat with acid-catalyzed water elimination following OH addition.

Evaluation and clinical impact of a pharmacist-led, interdisciplinary service focusing on education, monitoring and toxicity management of immune checkpoint inhibitors.

INTRODUCTION: Immune-related adverse events are complications of immune checkpoint inhibitors which require robust patient education and proactive follow-up to ensure timely identification and management. Oncology pharmacist practice models with other anticancer modalities have been well documented, but there is limited evidence assessing the spectrum of pharmacist interventions in patients receiving immune checkpoint inhibitor(s) and the impact of these interventions on patient outcomes. METHODS: Patients initiated on immune checkpoint inhibitor(s) from 1 January 2016 to 31 August 2019 were included for data collection and analysis. Part 1 featured an intensive pharmacist follow-up cohort (study cohort) and summarized pharmacist interventions. Part 2 compared patient outcomes between the study cohort and a standard of care cohort (control cohort) from a different oncology centre. Patient outcomes included emergency department visits not resulting in admission, hospitalizations due to immune-related adverse event(s), immune checkpoint inhibitor cycles received, treatment discontinuation due to immune-related adverse event(s), completion of finite programmed death-1/death-1 ligand treatment course and completion of ipilimumab. Clinical outcomes were compared using a retrospective, matched cohort design based on age, cancer diagnosis and immune checkpoint inhibitor(s). RESULTS: A total of 143 patients were included in Part 1 encompassing 1664 pharmacist recommendations across 11 categories. The matched cohort yielded 92 matches (n = 184) with a higher odds of immune checkpoint inhibitor discontinuation due to immune-related adverse event(s) in the control cohort (odds ratio (OR) (95% confidence interval (CI)) = 5.5 (1.2-24.8); p = 0.022). CONCLUSION: Intensive immune-related adverse event education, proactive follow-up and immune-related adverse event management by pharmacists result in clinically meaningful interventions which correlate to improved patient outcomes, namely lower odds of treatment discontinuation due to immune-related adverse event(s).

Reversal of viral and epigenetic HLA class I repression in Merkel cell carcinoma.

Cancers avoid immune surveillance through an array of mechanisms, including perturbation of HLA class I antigen presentation. Merkel cell carcinoma (MCC) is an aggressive, HLA-I-low, neuroendocrine carcinoma of the skin often caused by the Merkel cell polyomavirus (MCPyV). Through the characterization of 11 newly generated MCC patient-derived cell lines, we identified transcriptional suppression of several class I antigen presentation genes. To systematically identify regulators of HLA-I loss in MCC, we performed parallel, genome-scale, gain- and loss-of-function screens in a patient-derived MCPyV-positive cell line and identified MYCL and the non-canonical Polycomb repressive complex 1.1 (PRC1.1) as HLA-I repressors. We observed physical interaction of MYCL with the MCPyV small T viral antigen, supporting a mechanism of virally mediated HLA-I suppression. We further identify the PRC1.1 component USP7 as a pharmacologic target to restore HLA-I expression in MCC.

Ectopic extramammary Paget disease in thoracic location.

Extramammary Paget disease (EMPD) is a rare skin cancer that affects areas with a high concentration of apocrine glands including genital, axillary, and anal skin. When it affects other locations it is called ectopic extramammary Paget disease (E-EMPD) and is uncommon. To date, there are only 45 case reports to the best of our knowledge. The clinical manifestation is typically a soft, red or bright pink patch or plaque with scattered white islands of hyperkeratosis and erosion. Diagnostic confirmation requires conventional histology with immunohistochemistry. The importance of immunohistochemical staining for the diagnosis of primary neoplasia, without underlying malignancy, is highlighted. We report the first Latin American confirmed case, to our knowledge, of primary E-EMPD in a 55-year-old man with a 1-year history of asymptomatic thoracic plaque.

Mechanism of EBV inducing anti-tumour immunity and its therapeutic use.

Tumour-associated antigens (TAAs) comprise a large set of non-mutated cellular antigens recognized by T cells in human and murine cancers. Their potential as targets for immunotherapy has been explored for more than two decades1, yet the origins of TAA-specific T cells remain unclear. While tumour cells may be an important source of TAAs for T cell priming2, several recent studies suggest that infection with some viruses, including Epstein-Barr virus and influenza virus can elicit T cell responses against abnormally expressed cellular antigens that function as TAAs3,4. However, the cellular and molecular basis of such responses remains undefined. Here we show that expression of the Epstein-Barr virus signalling protein LMP1 in B cells provokes T cell responses to multiple TAAs. LMP1 signalling leads to overexpression of many cellular antigens previously shown to be TAAs, their presentation on major histocompatibility complex classes I (MHC-I) and II (MHC-II) (mainly through the endogenous pathway) and the upregulation of costimulatory ligands CD70 and OX40L, thereby inducing potent cytotoxic CD4+ and CD8+ T cell responses. These findings delineate a mechanism of infection-induced anti-tumour immunity. Furthermore, by ectopically expressing LMP1 in tumour B cells from patients with cancer and thereby enabling them to prime T cells, we develop a general approach for rapid production of autologous cytotoxic CD4+ T cells against a wide range of endogenous tumour antigens, such as TAAs and neoantigens, for treating B cell malignancies. This work stresses the need to revisit classical concepts concerning viral and tumour immunity, which will be critical to fully understand the impact of common infections on human health and to improve the rational design of immune approaches to treatment of cancers.

A large peptidome dataset improves HLA class I epitope prediction across most of the human population.

Prediction of HLA epitopes is important for the development of cancer immunotherapies and vaccines. However, current prediction algorithms have limited predictive power, in part because they were not trained on high-quality epitope datasets covering a broad range of HLA alleles. To enable prediction of endogenous HLA class I-associated peptides across a large fraction of the human population, we used mass spectrometry to profile >185,000 peptides eluted from 95 HLA-A, -B, -C and -G mono-allelic cell lines. We identified canonical peptide motifs per HLA allele, unique and shared binding submotifs across alleles and distinct motifs associated with different peptide lengths. By integrating these data with transcript abundance and peptide processing, we developed HLAthena, providing allele-and-length-specific and pan-allele-pan-length prediction models for endogenous peptide presentation. These models predicted endogenous HLA class I-associated ligands with 1.5-fold improvement in positive predictive value compared with existing tools and correctly identified >75% of HLA-bound peptides that were observed experimentally in 11 patient-derived tumor cell lines.

Immunity to X-linked inhibitor of apoptosis protein (XIAP) in malignant melanoma and check-point blockade.

Expression of inhibitors of apoptosis protein (IAP) family members is associated with poor prognosis in cancer patients. Immunity to ML-IAP (livin) and survivin has been well studied in patients with a variety of tumors. XIAP, the most potent inhibitor of apoptosis, is widely expressed in melanoma. To better define its potential role as an immunogenic target, cellular and humoral responses to XIAP were investigated in patients with advanced melanoma. An overlapping peptide library covering the full length of the XIAP protein was used to screen T cell responses of peripheral blood mononuclear cells (PBMC) from stage-IV melanoma patients treated with or without anti-CTLA4 (ipilimumab). The screen identified an array of peptides that predominantly induced CD4+ T cell responses. XIAP epitope-specific CD4+ T cells revealed proliferative responses to melanoma cells that express XIAP. Humoral responses to XIAP were also explored. Cellular and humoral responses to XIAP were associated with beneficial clinical outcomes after ipilimumab-based treatment, supporting XIAP as a potential therapeutic target.

Recurrent genetic HLA loss in AML relapsed after matched unrelated allogeneic hematopoietic cell transplantation.

Immune evasion is a hallmark of cancer and a central mechanism underlying acquired resistance to immune therapy. In allogeneic hematopoietic cell transplantation (alloHCT), late relapses can arise after prolonged alloreactive T-cell control, but the molecular mechanisms of immune escape remain unclear. To identify mechanisms of immune evasion, we performed a genetic analysis of serial samples from 25 patients with myeloid malignancies who relapsed ≥1 year after alloHCT. Using targeted sequencing and microarray analysis to determine HLA allele-specific copy number, we identified copy-neutral loss of heterozygosity events and focal deletions spanning class 1 HLA genes in 2 of 12 recipients of matched unrelated-donor HCT and in 1 of 4 recipients of mismatched unrelated-donor HCT. Relapsed clones, although highly related to their antecedent pretransplantation malignancies, frequently acquired additional mutations in transcription factors and mitogenic signaling genes. Previously, the study of relapse after haploidentical HCT established the paradigm of immune evasion via loss of mismatched HLA. Here, in the context of matched unrelated-donor HCT, HLA loss provides genetic evidence that allogeneic immune recognition may be mediated by minor histocompatibility antigens and suggests opportunities for novel immunologic approaches for relapse prevention.

Effects of Age Discrimination on Self-perceptions of Aging and Cancer Risk Behaviors.

BACKGROUND AND OBJECTIVES: Almost one-third of older adults report experiencing age discrimination. We hypothesized sequential links between older adults' everyday experiences of age discrimination and future health behaviors related to cancer risk through self-perceptions of aging (SPA). RESEARCH DESIGN AND METHODS: Participants were community-dwelling respondents (age: 51-96 years) from the 2008, 2012, and 2014 waves of the Health and Retirement Study (N = 4,467). Generalized path models estimated the immediate and enduring effects of age discrimination in 2008 on proximal SPA in 2012 and distal health behaviors in 2014. RESULTS: Age discrimination was associated with lower positive SPA and higher negative SPA in 2012. The effect of age discrimination on physical activity, smoking, and drinking in 2014 was mediated by positive and negative SPA in 2012. Through subsequent SPA, those who experienced age discrimination in 2008 were less likely to engage in regular moderate physical activity, more likely to smoke, and less likely to drink more than 3 times per week in 2014. Analysis of change in positive and negative SPA showed the effect of age discrimination on physical activity to be mediated by change in positive, but not negative, SPA. DISCUSSION AND IMPLICATIONS: The enduring effects of age discrimination were found through a reduction in positive SPA. Elevating positive SPA could be as important as reducing negative SPA for future health behaviors related to cancer risk.

Neoantigen vaccine generates intratumoral T cell responses in phase Ib glioblastoma trial.

Neoantigens, which are derived from tumour-specific protein-coding mutations, are exempt from central tolerance, can generate robust immune responses1,2 and can function as bona fide antigens that facilitate tumour rejection3. Here we demonstrate that a strategy that uses multi-epitope, personalized neoantigen vaccination, which has previously been tested in patients with high-risk melanoma4-6, is feasible for tumours such as glioblastoma, which typically have a relatively low mutation load1,7 and an immunologically 'cold' tumour microenvironment8. We used personalized neoantigen-targeting vaccines to immunize patients newly diagnosed with glioblastoma following surgical resection and conventional radiotherapy in a phase I/Ib study. Patients who did not receive dexamethasone-a highly potent corticosteroid that is frequently prescribed to treat cerebral oedema in patients with glioblastoma-generated circulating polyfunctional neoantigen-specific CD4+ and CD8+ T cell responses that were enriched in a memory phenotype and showed an increase in the number of tumour-infiltrating T cells. Using single-cell T cell receptor analysis, we provide evidence that neoantigen-specific T cells from the peripheral blood can migrate into an intracranial glioblastoma tumour. Neoantigen-targeting vaccines thus have the potential to favourably alter the immune milieu of glioblastoma.