Nanoarchitected metal/ceramic interpenetrating phase composites

Architected metals and ceramics with nanoscale cellular designs, e.g., nanolattices, are currently subject of extensive investigation. By harnessing extreme material size effects, nanolattices demonstrated classically inaccessible properties at low density, with exceptional potential for superior lightweight materials. This study expands the concept of nanoarchitecture to dense metal/ceramic composites, presenting co-continuous architectures of three-dimensional printed pyrolytic carbon shell reinforcements and electrodeposited nickel matrices. We demonstrate ductile compressive deformability with elongated ultrahigh strength plateaus, resulting in an extremely high combination of compressive strength and strain energy absorption. Simultaneously, property-to-weight ratios outperform those of lightweight nanolattices. Superior to cellular nanoarchitectures, interpenetrating nanocomposites may combine multiple size-dependent characteristics, whether mechanical or functional, which are radically antagonistic in existing materials. This provides a pathway toward previously unobtainable multifunctionality, extending far beyond lightweight structure applications.

Abstract 3168: Immunopeptidome-defined acute myeloid leukemia progenitor cell-associated antigens are targeted in vivo by AML patients’ T cells

Despite recent advances and the approval of novel molecular therapies in acute myeloid leukemia (AML), the disease is still characterized by high relapse rates and poor overall survival due to the persistence of therapy-resistant residual leukemic progenitor cells (LPCs). T cell-based immunotherapy has been suggested as a novel therapeutic option to eliminate minimal residual disease and achieve long-lasting remissions. One main prerequisite for immunotherapy development is the selection of immunogenic targets that show natural, high-frequent, and tumor-exclusive presentation on the cell surface of malignant cells. In a previous study we characterized the antigenic landscape of AML by mass spectrometry to identify AML-specific T cell epitopes (Berlin et al. Leukemia 2015). Here, we aimed to analyze the immunopeptidome of primary AML progenitor cells (n = 10, purity >80% CD34+CD38-) to identify LPC-associated antigens that enable the specific targeting of AML LPCs. Additionally, we analyzed an extended set of AML patient samples (n = 47) to screen for naturally presented neoepitopes and to identify broadly applicable AML-associated target antigens that are presented on both AML blasts and LPCs.

We identified more than 16,000 HLA class I- and 17,000 HLA class II-presented peptides on LPCs and 72,000 HLA class I and 61,000 HLA class II peptides in the total AML cohort. Comparative profiling of LPCs, AML blasts, and a benign tissue database (n = 332) revealed HLA class I- and HLA class II-presented LPC-exclusive as well as frequently presented AML-associated antigens on both AML blasts and LPCs. Besides these tumor-exclusive self-peptides, we detected naturally presented neoepitopes derived from two frequent mutations (NPM1 and IDH2) in this low-mutational burden malignancy.

For immunogenicity analyses we selected 16 HLA class I- and 15 HLA class II-restricted peptides comprising unmutated as well as mutation-derived antigens. In vitro priming experiments showed the induction of peptide-specific, multi-functional, and cytotoxic CD8+ effector cells in samples of healthy volunteers and AML patients.

We were able to detect strong preexisting memory T cell responses targeting LPC-associated antigens in AML patients with detection frequencies of up to 20%. Retrospective analyses revealed that patients with preexisting peptide-specific T cell responses showed improved overall survival compared to patients without any memory responses against our targets.

Taken together, we identified novel, naturally presented, LPC-exclusive, and AML-associated self-antigens and neoepitopes presented on both AML blasts and LPCs. We could demonstrate the immunogenicity of 14/16 (88%) HLA class I and 13/15 (87%) HLA class II antigens highlighting their potential as promising targets for T cell-based immunotherapy approaches to eliminate minimal residual disease in AML patients.

Citation Format: Annika Nelde, Heiko Schuster, Tatjana Bilich, Jens Bauer, Malte Roerden, Sarah Schroeder, Jonas S. Heitmann, Elke Rücker-Braun, Hans-Georg Rammensee, Helmut R. Salih, Juliane S. Walz. Immunopeptidome-defined acute myeloid leukemia progenitor cell-associated antigens are targeted in vivo by AML patients’ T cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3168.

Abstract 3555: Immunopeptidomics-guided tumor antigen warehouse design for peptide-based immunotherapy in head and neck squamous cell carcinomas

Head and neck squamous cell carcinomas (HNSCC) are the sixth most common malignancies worldwide. 45% of patients are diagnosed at a late tumor stage associated with poor survival. For metastatic, unresectable or recurrent (m/uR) HNSCC, immune checkpoint inhibition (ICI) was recently approved as a novel therapeutic option showing significant survival benefits compared to standard chemotherapy-based treatment. However, response to ICI is still limited to a small number of patients calling for further improvement of T cell-based immunotherapies. Peptide-based approaches, which rely on the specific immune recognition of tumor-associated human leukocyte antigen (HLA) presented peptides, represent promising and low side effect treatment options. Peptide vaccination has been shown to enhance and induce long-term anti-tumoral immune responses and even clinical responses in HNSCC patients. However, current vaccines are either monovalent, based on patient-individual tumor-specific mutations or restricted to a single HLA allotype and therefore neither widely applicable nor suitable for reliable studies and large-scale production. In this study, using mass spectrometry (MS) -based immunopeptidome analysis of a large cohort of HNSCC patient (n = 30) tumor and adjacent benign samples, we established a tumor-associated off-the-shelf peptide warehouse for broadly applicable personalized therapies. The malignant dataset, comprising 91651 HLA ligands, was compared to adjacent benign and various benign tissues (www.hla-ligand-atlas.org) to identify tumor-exclusive antigens. Further antigen selection was based on allotype-specific high frequent presentation. In total, 23 frequently presented and tumor-exclusive HNSCC-associated peptides were selected for six of the most common HLA class I allotypes (A*01, A*02, A*24, B*15, B*35, B*40) covering >75% of the world population, as well as five HLA class II presented peptides binding various different HLA class II allotypes. Immunogenicity was validated by IFN-γ ELISPOT screening for spontaneous preexisting T cell responses targeting the respective peptides as well as by in vitro priming experiments of naïve T cells in HNSCC patients and healthy volunteers. Furthermore, immunopeptidome analyses identified these antigens in patient plasma samples providing first evidence for “liquid biopsy” immunopeptidome analysis without the need of primary tumor tissue. A phase I study evaluating safety, immunogenicity as well as first efficacy of this warehouse-based vaccine in combination with ICI in HNSCC patients is currently being set up, with personalized peptide selection based on individual HLA-allotype and MS analysis of patient tumor/plasma sample. In conclusion, we here designed a peptide warehouse that enables a polyvalent and widely applicable but still personalized peptide vaccination in HNSCC patients.

Citation Format: Sarah Schroeder, Thorben Gross, Annika Nelde, Marcel Wacker, Jens Bauer, Jonas Rieth, Marissa Dubbelaar, Lena Muehlenbruch, Yacine Maringer, Paul-Stefan Mauz, Martin Sailer, Julia Philipp, Sven Becker, Thomas Breuer, Helmut R. Salih, Hans-Georg Rammensee, Hubert Löwenheim, Juliane S. Walz. Immunopeptidomics-guided tumor antigen warehouse design for peptide-based immunotherapy in head and neck squamous cell carcinomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3555.

Abstract 1375: The intra-tumoral spatial heterogeneity of T-cell antigens in glioblastoma: An integrated multi-omics approach

Glioblastoma is the most common primary malignant neoplasm of the central nervous system in adults. Current treatment options comprise maximal surgical resection followed by radiation and/or chemotherapy with temozolomide. However, these procedures are unable to eliminate all tumor cells, which in turn lead to disease recurrence accounting for the poor prognosis. Glioblastoma is a highly infiltrative tumor in which recurrence originates from the unresectable peritumoral infiltration zone. Thus, novel treatment options specifically targeting the tumor cells in the infiltration zone are needed to prevent relapse and enable long-lasting remission. In this work, we performed multi-omics spatial analysis of the necrotic center (NEC), the gadolinium contrast-enhanced region (T1), and the infiltration zone (INF) to assess immunological relevant aspects of tumor heterogeneity. By integrating mass spectrometry-based immunopeptidome analysis with next generation sequencing methods (whole exome and RNA sequencing, DNA methylation), we aimed to identify the intra-tumoral regional heterogeneity of T cell antigens with a special focus on the peritumoral infiltration zone. For multi-omics analysis, HLA peptides and genetic material from 15 glioblastoma patients were extracted and analyzed from the three zones NEC, T1, INF and for four patients additionally from adjacent benign (BEN) brain tissue. A total of 24,699 unique HLA class I and 17,394 HLA class II peptides were identified. Comparative profiling of peptides from our study and a benign tissue database (in-house (n=429) combined with HLA ligand atlas (https://hla-ligand-atlas.org)) revealed that 6% (970/15,579), 5% (829/16,442) and 5% (725/13,891) of HLA class I peptides were exclusively presented in the INF, T1 and NEC zone, respectively. 6% (394/7,150), 7% (589/8,736) and 13% (1,725/12,908) of HLA class II peptides showed exclusive representation in the INF, T1 and NEC zone, respectively. Importantly, due to the spatial analysis of the immunopeptidome, we revealed 970 HLA class I and 394 HLA class II peptides exclusively presented in the INF zone. Interestingly, one INF-associated HLA class I peptide, which showed frequent presentation in 36% of glioblastoma immunopeptidomes, is derived from the brain and acute leukemia cytoplasmic protein (BAALC), a highly expressed cell cycle inducer (via MEK kinase-1) in several cancers, including glioblastoma. Integrated RNA/DNA sequencing enabled a greater understanding of spatial tumor antigen presentation and lead to the identification of INF-specific neoepitopes derived from tumor-specific mutations. In summary, we identified the intra-tumoral regional heterogeneity of tumor antigens, which could be used in the future for specific immunotherapy approaches targeting the infiltration zone of glioblastoma.

Citation Format: Marcel Wacker, Gioele Medici, Marissa Dubbelaar, Jens Bauer, Annika Nelde, Luca Regli, Michael Weller, Helmut R. Salih, Hans-Georg Rammensee, Marian C. Neidert, Juliane S. Walz. The intra-tumoral spatial heterogeneity of T-cell antigens in glioblastoma: An integrated multi-omics approach [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1375.

Abstract 2008: The oncogenic fusion protein DNAJB1-PRKACA can be actively targeted by peptide-based immunotherapy in fibrolamellar hepatocellular carcinoma

Fibrolamellar hepatocellular carcinoma (FL-HCC) is a rare tumor disease, which affects children and adolescents without history of primary liver disease. Beside surgical resection established treatment options are lacking for FL-HCC. Recently, the DNAJB1-PRKACA fusion transcript was identified as the oncogenic driver of tumor pathogenesis in 100% of FL-HCC patients. Here, we investigated the role of the DNAJB1-PRKACA fusion protein as a source for immunogenic neoepitopes and showed first immunotherapeutic application of these antigens in a FL-HCC patient.HLA class I- and class II-presented neoantigens derived from the DNAJB1-PRKACA fusion protein were predicted in silico using NetMHCpan 4.1 and SYFPEITHI 1.0, or NetMHCIIpan 4.0, respectively. With this workflow nine binding cores of nine amino acid length for a total of 1290 different HLA class II alleles, as well as 13 HLA class I ligands for the 20 most frequent HLA class I allotypes (European population, iedb.org) were identified. Cellular processing and HLA presentation of DNAJB1-PRKACA-derived peptides was proven by liquid chromatography-coupled tandem mass spectrometry (LC-MS/MS) of DNAJB1-PRKACA-transduced HCC cell lines. Immunogenicity of DNAJB1-PRKACA-derived peptides was assessed for the HLA class II peptide (PII-1) and the HLA-A*24 peptide (PA*24) by in vitro priming experiments which showed an induction of multifunctional peptide-specific CD4+ and CD8+ T cells, respectively, with expression of CD107a, IFNγ, and TNF upon peptide-pulsing. Furthermore, PA*24-specific T cells showed antigen-specific lysis of autologous peptide-loaded target cells and single-cell next-generation sequencing (10x Genomics) of PA*24-specific CD8+ T cells further enabled the identification of DNAJB1-PRKACA-reactive T cell receptors. Based on these preclinical data we applied a peptide vaccine, consisting of three HLA class I ligands (PA*02, PB*44, and PC*05) and PII-1 spanning the DNAJB1-PRKACA fusion region, to a 15-year old patient with histologically confirmed FL-HCC, who experienced multiple tumor relapses after early liver transplant due to unresectable FL-HCC not responsive to chemotherapy. After two vaccinations in vivo induction of multifunctional CD4+ T cells targeting PII-1 and PB*44 was observed by IFNγ ELISPOT. Single-cell RNA sequencing of vaccine-induced CD4+ T cells revealed distinct gene expression clusters of T cell activation and high TCR clonality. DNAJB1-PRKACA-specific T cells persisted in peripheral blood and were accompanied by relapse free survival of the patient until now, more than one year post vaccination. These findings identified the DNAJB1-PRKACA fusion transcript as novel prime source for broadly applicable neoepitopes and corresponding TCRs and provide first evidence for their application in cancer immunotherapy of FL-HCC.

Citation Format: Jens Bauer, Natalie Köhler, Yacine Maringer, Philip Bucher, Tatjana Bilich, Melissa Zwick, Severin Dicks, Annika Nelde, Marissa Dubbelaar, Jonas Scheid, Marcel Wacker, Jonas J. Heitmann, Sarah Schroeder, Jonas Rieth, Monika Denk, Marion Richter, Reinhild Klein, Irina Bonzheim, Julia Luibrand, Ursula Holzer, Martin Ebinger, Ines B. Brecht, Michael Bitzer, Melanie Boerries, Helmut R. Salih, Hans-Georg Rammensee, Stephan Hailfinger, Juliane S. Walz. The oncogenic fusion protein DNAJB1-PRKACA can be actively targeted by peptide-based immunotherapy in fibrolamellar hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2008.

Upstream open reading frames regulate translation of cancer-associated transcripts and encode HLA-presented immunogenic tumor antigens

BACKGROUND

Upstream open reading frames (uORFs) represent translational control elements within eukaryotic transcript leader sequences. Recent data showed that uORFs can encode for biologically active proteins and human leukocyte antigen (HLA)-presented peptides in malignant and benign cells suggesting their potential role in cancer cell development and survival. However, the role of uORFs in translational regulation of cancer-associated transcripts as well as in cancer immune surveillance is still incompletely understood.

METHODS

We examined the translational regulatory effect of 29 uORFs in 13 cancer-associated genes by dual-luciferase assays. Cellular expression and localization of uORF-encoded peptides (uPeptides) were investigated by immunoblotting and immunofluorescence-based microscopy. Furthermore, we utilized mass spectrometry-based immunopeptidome analyses in an extensive dataset of primary malignant and benign tissue samples for the identification of naturally presented uORF-derived HLA-presented peptides screening for more than 2000 uORFs.

RESULTS

We provide experimental evidence for similarly effective translational regulation of cancer-associated transcripts through uORFs initiated by either canonical AUG codons or by alternative translation initiation sites (aTISs). We further demonstrate frequent cellular expression and reveal occasional specific cellular localization of uORF-derived peptides, suggesting uPeptide-specific biological implications. Immunopeptidome analyses delineated a set of 125 naturally presented uORF-derived HLA-presented peptides. Comparative immunopeptidome profiling of malignant and benign tissue-derived immunopeptidomes identified several tumor-associated uORF-derived HLA ligands capable to induce multifunctional T cell responses.

CONCLUSION

Our data provide direct evidence for the frequent expression of uPeptides in benign and malignant human tissues, suggesting a potentially widespread function of uPeptides in cancer biology. These findings may inspire novel approaches in direct molecular as well as immunotherapeutic targeting of cancer-associated uORFs and uPeptides.

[Integrated care concepts and multidisciplinary process chains in a radiological context]

Modern patient-centered and cost-efficient care concepts in hospitals require the mapping of multidisciplinary process chains into clinical pathways. Clinical decision support systems and operations research methods use algorithms to classify patients into homogeneous groups and to model a complete clinical pathway for scheduling individual procedures. An improvement of the economic situation of the care facility can be achieved through improved resource utilization, reduced patient waiting times and a shortening of the length of stay. The interdisciplinary use of centrally stored interoperable information and comprehensive care management via information technology (IT) services lay the foundation for the dissolution of traditional IT system architectures in medicine and the development of flexibly integrable modern system platforms. New IT approaches such as the semantically standardized definition of procedures and resource properties, the use of clinical decision support systems and the use of service-oriented system architectures form the basis for the deep integration of radiology services into comprehensive interdisciplinary care concepts.

Keratinocyte differentiation antigen-specific T cells in immune checkpoint inhibitor-treated NSCLC patients are associated with improved survival

Immune checkpoint inhibitors (ICIs) have improved the survival of patients with non-small cell lung cancer (NSCLC) by reinvigorating tumor-specific T cell responses. However, the specificity of such T cells and the human leukocyte antigen (HLA)-associated epitopes recognized, remain elusive. In this study, we identified NSCLC T cell epitopes of recently described NSCLC-associated antigens, termed keratinocyte differentiation antigens. Epitopes of these antigens were presented by HLA-A 03:01 and HLA-C 04:01 and were associated with responses to ICI therapy. Patients with CD8⁺ T cell responses to these epitopes had improved overall and progression-free survival. T cells specific for such epitopes could eliminate HLA class I-matched NSCLC cells ex vivo and were enriched in patient lung tumors. The identification of novel lung cancer HLA-associated epitopes that correlate with improved ICI-dependent treatment outcomes suggests that keratinocyte-specific proteins are important tumor-associated antigens in NSCLC. These findings improve our understanding of the mechanisms of ICI therapy and may help support the development of vaccination strategies to improve ICI-based treatment of these tumors.

Immunopeptidomics-Guided Warehouse Design for Peptide-Based Immunotherapy in Chronic Lymphocytic Leukemia

Antigen-specific immunotherapies, in particular peptide vaccines, depend on the recognition of naturally presented antigens derived from mutated and unmutated gene products on human leukocyte antigens, and represent a promising low-side-effect concept for cancer treatment. So far, the broad application of peptide vaccines in cancer patients is hampered by challenges of time- and cost-intensive personalized vaccine design, and the lack of neoepitopes from tumor-specific mutations, especially in low-mutational burden malignancies. In this study, we developed an immunopeptidome-guided workflow for the design of tumor-associated off-the-shelf peptide warehouses for broadly applicable personalized therapeutics. Comparative mass spectrometry-based immunopeptidome analyses of primary chronic lymphocytic leukemia (CLL) samples, as representative example of low-mutational burden tumor entities, and a dataset of benign tissue samples enabled the identification of high-frequent non-mutated CLL-associated antigens. These antigens were further shown to be recognized by pre-existing and de novo induced T cells in CLL patients and healthy volunteers, and were evaluated as pre-manufactured warehouse for the construction of personalized multi-peptide vaccines in a first clinical trial for CLL (NCT04688385). This workflow for the design of peptide warehouses is easily transferable to other tumor entities and can provide the foundation for the development of broad personalized T cell-based immunotherapy approaches.

Preexisting and Post-COVID-19 Immune Responses to SARS-CoV-2 in Patients with Cancer

Patients with cancer, in particular patients with hematologic malignancies, are at increased risk for critical illness upon COVID-19. We here assessed antibody as well as CD4⁺ and CD8⁺ T-cell responses in unexposed and SARS-CoV-2-infected patients with cancer to characterize SARS-CoV-2 immunity and to identify immunologic parameters contributing to COVID-19 outcome. Unexposed patients with hematologic malignancies presented with reduced prevalence of preexisting SARS-CoV-2 cross-reactive CD4⁺ T-cell responses and signs of T-cell exhaustion compared with patients with solid tumors and healthy volunteers. Whereas SARS-CoV-2 antibody responses did not differ between patients with COVID-19 and cancer and healthy volunteers, intensity, expandability, and diversity of SARS-CoV-2 T-cell responses were profoundly reduced in patients with cancer, and the latter associated with a severe course of COVID-19. This identifies impaired SARS-CoV-2 T-cell immunity as a potential determinant for dismal outcome of COVID-19 in patients with cancer. SIGNIFICANCE: This first comprehensive analysis of SARS-CoV-2 immune responses in patients with cancer reports on the potential implications of impaired SARS-CoV-2 T-cell responses for understanding pathophysiology and predicting severity of COVID-19, which in turn might allow for the development of therapeutic measures and vaccines for this vulnerable patient population.See related commentary by Salomé and Horowitz, p. 1877.This article is highlighted in the In This Issue feature, p. 1861.

T cell and antibody kinetics delineate SARS-CoV-2 peptides mediating long-term immune responses in COVID-19 convalescent individuals

Long-term immunological memory to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is crucial for the development of population-level immunity, which is the aim of vaccination approaches. Reports on rapidly decreasing antibody titers have led to questions regarding the efficacy of humoral immunity alone. The relevance of T cell memory after coronavirus disease 2019 (COVID-19) remains unclear. Here, we investigated SARS-CoV-2 antibody and T cell responses in matched samples of COVID-19 convalescent individuals up to 6 months after infection. Longitudinal analysis revealed decreasing and stable spike- and nucleocapsid-specific antibody responses, respectively. In contrast, functional T cell responses remained robust, and even increased, in both frequency and intensity. Single peptide mapping of T cell diversity over time identified open reading frame-independent, dominant T cell epitopes mediating long-term SARS-CoV-2 T cell responses. Identification of these epitopes may be fundamental for COVID-19 vaccine design.

Tensegrity Metamaterials: Toward Failure-Resistant Engineering Systems through Delocalized Deformation

Failure of materials and structures is inherently linked to localized mechanisms, from shear banding in metals, to crack propagation in ceramics and collapse of space-trusses after buckling of individual struts. In lightweight structures, localized deformation causes catastrophic failure, limiting their application to small strain regimes. To ensure robustness under real-world nonlinear loading scenarios, overdesigned linear-elastic constructions are adopted. Here, the concept of delocalized deformation as a pathway to failure-resistant structures and materials is introduced. Space-tileable tensegrity metamaterials achieving delocalized deformation via the discontinuity of their compression members are presented. Unprecedented failure resistance is shown, with up to 25-fold enhancement in deformability and orders of magnitude increased energy absorption capability without failure over same-strength state-of-the-art lattice architectures. This study provides important groundwork for design of superior engineering systems, from reusable impact protection systems to adaptive load-bearing structures.

Effect of vitamin D deficiency on depressive symptoms in child and adolescent psychiatric patients: results of a randomized controlled trial

PURPOSE

While observational studies revealed inverse associations between serum vitamin D levels [25(OH)D] and depression, randomized controlled trials (RCT) in children and adolescents are lacking. This RCT examined the effect of an untreated vitamin D deficiency compared to an immediate vitamin D3 supplementation on depression scores in children and adolescents during standard day and in-patient psychiatric treatment.

METHODS

Patients with vitamin D deficiency [25(OH)D ≤ 30 nmol/l] and at least mild depression [Beck Depression Inventory II (BDI-II) > 13] (n = 113) were 1:1 randomized into verum (VG; 2640 IU vitamin D3/d) or placebo group (PG) in a double-blind manner. During the intervention period of 28 days, both groups additionally received treatment as usual. BDI-II scores were assessed as primary outcome, DISYPS-II (Diagnostic System for Mental Disorders in Childhood and Adolescence, Self- and Parent Rating) and serum total 25(OH)D were secondary outcomes.

RESULTS

At admission, 49.3% of the screened patients (n = 280) had vitamin D deficiency. Although the intervention led to a higher increase of 25(OH)D levels in the VG than in the PG (treatment difference: + 14 ng/ml; 95% CI 4.86-23.77; p = 0.003), the change in BDI-II scores did not differ (+ 1.3; 95% CI - 2.22 to 4.81; p = 0.466). In contrast, DISYPS parental ratings revealed pronounced improvements of depressive symptoms in the VG (- 0.68; 95% CI - 1.23 to - 0.13; p = 0.016).

CONCLUSION

Whereas this study failed to show a vitamin D supplementation effect on self-rated depression in adolescent in- or daycare patients, parents reported less depressive symptoms in VG at the end of our study. Future trials should consider clinician-rated depressive symptoms as primary outcome.

TRIAL REGISTRATION

"German Clinical Trials Register" ( https://www.drks.de ), registration number: DRKS00009758.

Technical note: Validation of an in-house bovine serum enzyme immunoassay for progesterone measurement

Measuring circulating progesterone (P4) of dairy cows is a key component of many research studies dealing with basic and applied reproduction physiology. The gold standard in dairy cows for the measurement of P4 in serum is radioimmunoassay (RIA), but it generates radioactive waste and requires licensed facilities. The purpose of this study was to develop and validate an in-house competitive enzyme immunoassay (EIA) to measure the P4 concentration in serum of dairy cattle. The secondary objective was to validate a commercial EIA. In the present study, a competitive EIA was developed using commercially available antibodies and conjugates. Ninety-six well microtiter plates were coated with the secondary antibody and incubated overnight. Following a washing step, the wells were blocked using the primary antibody. Serum samples were prepared by first extracting P4 using petroleum ether, then diluted in working conjugate solution. Samples were pipetted into the coated and blocked plates, then the matching HRP conjugate label (P4-3-HRP, East Coast Bio, North Berwick, ME) was added. The plates were incubated for 2 h, then washed. The substrate solution was added, and the plate was incubated up to 1 h at room temperature in the dark until a blue color had developed. A stop solution was added, and the optical density measured on a microplate reader was set at 450 nm. The binding proportion was calculated by a visible spectrum absorbance reader, and the amount of P4 was calculated using a log-logit regression line. The commercial EIA was executed as suggested by the manufacturer. The validation of the in-house EIA was done by calculating the inter- and intraassay coefficients of variation (CV) and evaluating the parallelism of diluted samples. The results from the in-house and commercial EIA were also compared with the ones from the RIA graphically (scatterplots and Bland-Altman plots) and statistically, using the Spearman correlation coefficient (r) and the Cohen's kappa statistics using a threshold of 1.0 ng/mL (κ). For the in-house EIA, the intraassay CV were all <10%, but the interassay for samples with small and large P4 concentration had CV of 12.5 and 11.0%, respectively. The correlations between the results from the EIA and the RIA were strong (in-house: r = 0.90; commercial: r = 0.83). At small concentrations (<1.0 ng/mL), however, the correlation with the gold standard was weak (in-house: r = 0.27; commercial: r = 0.14). This was likely due to the lack of accuracy at small concentrations, also shown by the absence of parallelism in samples ≤0.4 ng/mL. In conclusion, results from both the in-house and commercial EIA strongly correlated with the gold standard, but less so at smaller concentrations. The in-house EIA offers good accuracy to measure P4 in samples with a concentration >0.4 ng/mL, and a perfect agreement with RIA using a threshold of 1.0 ng/mL.

SARS-CoV-2-derived peptides define heterologous and COVID-19-induced T cell recognition

T cell immunity is central for the control of viral infections. To characterize T cell immunity, but also for the development of vaccines, identification of exact viral T cell epitopes is fundamental. Here we identify and characterize multiple dominant and subdominant SARS-CoV-2 HLA class I and HLA-DR peptides as potential T cell epitopes in COVID-19 convalescent and unexposed individuals. SARS-CoV-2-specific peptides enabled detection of post-infectious T cell immunity, even in seronegative convalescent individuals. Cross-reactive SARS-CoV-2 peptides revealed pre-existing T cell responses in 81% of unexposed individuals and validated similarity with common cold coronaviruses, providing a functional basis for heterologous immunity in SARS-CoV-2 infection. Diversity of SARS-CoV-2 T cell responses was associated with mild symptoms of COVID-19, providing evidence that immunity requires recognition of multiple epitopes. Together, the proposed SARS-CoV-2 T cell epitopes enable identification of heterologous and post-infectious T cell immunity and facilitate development of diagnostic, preventive and therapeutic measures for COVID-19.

[Consent management and workflows for cross-sectoral patient records and teleconsultations]

Cross-enterprise electronic patient records are a key element in the design of interoperable medical care networks and process chains. However, the different requirements concerning type, performance and quality assurance of available communication services within the different healthcare sectors still require that the hospitals participate in various secure communication networks which have to be bridged for cross-sectoral communication. Cross-institutional pathways for telemedicine, however, can be mapped both within and across sectoral boundaries via automated process chains using the IHE (Integrating the Healthcare Enterprise) defined integration profile CrossEnterprise Document Sharing (XDS) and associated integration profiles. The provision of medical documents in a cross-institutional patient record outside of defined medical pathways requires differentiated authorization management. In this respect, consent documents according to the IHE APPC (Advanced Patient Privacy Consents) profile enable the documentation of the patient's consent, including information about planned authorized people, document types, period and type of document access allowed. Providing access control to medical documentation by the patients themselves is an essential part of the required focusing of medical services on patients. New interoperability standards optimized for use on mobile devices, such as FHIR (Fast Healthcare Interoperability Resources), will enable simplified delivery of patient-centered health records and other medical services on mobile platforms in the future.