Targeting allogeneic HLA-DP: diversity, specificity and magnitude of T-cell responses

Following HLA-DP-mismatched alloSCT and DLI, donor T cells show allogeneic (allo) HLA-DP-specific reactivity, resulting in a graft-versus-leukemia (GvL) effect with or without coinciding graft-versus-host disease (GvHD). The contribution of alloHLA-DP-specific T cells to the occurrence of GvL and GvHD may depend on several factors including the expression of HLA-DP on hematopoietic and non-hematopoietic patient cells and the magnitude of the allo-HLA-DP-specific immune responses. The magnitude of the allo-HLA-DP-specific immune responses provoked by HLA-DP-mismatched antigen-presenting cells (APC) is influenced by the immunogenicity of the mismatched target HLA-DP allele(s) and the specificity and diversity of allo-HLA-DP-specific T-cell repertoires. In this thesis, we investigated in vitro the composition of allo-HLA-DP-specific T-cell repertoires and the magnitude and diversity of allo-HLA-DP-specific immune responses provoked under different stimulatory conditions. LUMC / Geneeskund

Intelligent pattern recognition of a SLM machine process and sensor data

Selective Laser Melting is an additive manufacturing process, in which the research has been increasing over the past few years to meet customer-specific requirements. Therefore, new manufacturing parameters have been monitored raising the number of sensors in the machines. Consequently, it leads to a bigger amount of data and difficulties to perform manual data analysis. In order to improve the analysis, this paper illustrates a possibility of pattern recognition using a different historical process and sensors data from a SLM machine. The results are evaluated using an intelligent tool for algorithms configuration and data analysis developed at Fraunhofer IPK

Adaptives Entwicklungstool zur intelligenten Konfigurierung von Condition-Monitoring-Algorithmen

Die Verfügbarkeit von Produktionsmaschinen und Anlagen hängt überwiegend vom Zustand ihrer verschleißanfälligen mechanischen Komponenten ab. Ein Maschinenausfall wird in der Regel durch Verschleiß dieser Komponenten verursacht. Das Condition Monitoring von verschleißkritischen Komponenten führt zur Vermeidung ungeplanter Maschinenausfälle und zur Erhöhung der Verfügbarkeit von Produktionsmaschinen und Anlagen. Hierbei ist die Entwicklung geeigneter, zuverlässiger und robuster Auswertealgorithmen ein elementares Kernstück einer Condition-Monitoring-Lösung. Das übergeordnete Ziel der vorliegenden Dissertationsarbeit ist es, durch die Entwicklung einer innovativen Vorgehensweise zur Konfigurierung von Algorithmen für die Datenanalyse, den Entwicklungsaufwand zukünftiger Algorithmen für verschiedene Zustandsüberwachungsanwendungen zu reduzieren. Hierzu wurde ein Tool zur Evaluierung dieser Vorgehensweise entwickelt und anhand verschiedener Use Cases unter realitätsnahen Betriebsbedingungen evaluiert. Das entwickelte Tool dient als Werkzeug zur Realisierung diverser Auswertealgorithmen für unterschiedliche Condition-Monitoring-Anwendungen

Targeting allogeneic HLA-DP: diversity, specificity and magnitude of T-cell responses

Following HLA-DP-mismatched alloSCT and DLI, donor T cells show allogeneic (allo) HLA-DP-specific reactivity, resulting in a graft-versus-leukemia (GvL) effect with or without coinciding graft-versus-host disease (GvHD). The contribution of alloHLA-DP-specific T cells to the occurrence of GvL and GvHD may depend on several factors including the expression of HLA-DP on hematopoietic and non-hematopoietic patient cells and the magnitude of the allo-HLA-DP-specific immune responses. The magnitude of the allo-HLA-DP-specific immune responses provoked by HLA-DP-mismatched antigen-presenting cells (APC) is influenced by the immunogenicity of the mismatched target HLA-DP allele(s) and the specificity and diversity of allo-HLA-DP-specific T-cell repertoires. In this thesis, we investigated in vitro the composition of allo-HLA-DP-specific T-cell repertoires and the magnitude and diversity of allo-HLA-DP-specific immune responses provoked under different stimulatory conditions. </p

Targeting allogeneic HLA-DP: diversity, specificity and magnitude of T-cell responses

Following HLA-DP-mismatched alloSCT and DLI, donor T cells show allogeneic (allo) HLA-DP-specific reactivity, resulting in a graft-versus-leukemia (GvL) effect with or without coinciding graft-versus-host disease (GvHD). The contribution of alloHLA-DP-specific T cells to the occurrence of GvL and GvHD may depend on several factors including the expression of HLA-DP on hematopoietic and non-hematopoietic patient cells and the magnitude of the allo-HLA-DP-specific immune responses. The magnitude of the allo-HLA-DP-specific immune responses provoked by HLA-DP-mismatched antigen-presenting cells (APC) is influenced by the immunogenicity of the mismatched target HLA-DP allele(s) and the specificity and diversity of allo-HLA-DP-specific T-cell repertoires. In this thesis, we investigated in vitro the composition of allo-HLA-DP-specific T-cell repertoires and the magnitude and diversity of allo-HLA-DP-specific immune responses provoked under different stimulatory conditions. </p

Reliability updating of existing quay walls based on the effects of past performance: Introduction of a novel mathematical application in the probabilistic assessment and evaluation of quay walls

In practice, many structures among which quay walls are designed according the Dutch national guidelines (CUR). Dutch national practical guidelines (NPR), with guidelines for renovation, is still in development for the building industry. These guidelines follow the Dutch Norms (NEN) and Annexes. The guidelines propose procedures in which newly-built or existing quay walls are designed. This study investigates the effects of past performance on the semi-probabilistic level I method for the purpose of design and evaluation of quay walls. This research is performed with a case study considering a CUR class III quay wall from. The objective of this research is gathering insight into the different aspects of past performance, among which degradation and information about survived years, on the reliability level and corresponding influence factors. Firstly, prior analyses including deterministic validation are performed. The output resulting from characteristic values of the cross-section is validated by means of Blum and analyses with the subgrade reaction method. The computed deterministic output appears to be in accordance with the results from the reference study. Afterwards, prior probabilistic analyses were performed in which the reliability, weight factors and corresponding partial safety factors are reconsidered. Failure mechanism ’yielding of front wall’ is a frequent phenomenon and is assessed in this research. Level II FORM is used for the calculation and level III Importance sampling for the validation. The cross-section is adjusted according the reference case and the results are reasonably in compliance with the results found by GeoDelft for CUR class III. The computed 50 year reliability index β = 4.53 and corresponds well to the target reliability level of βt = 4.5. Additionally, the situation in which random input variables are correlated and model uncertainty is included, is considered as well. These correlations and model uncertainty are determined based on previous researches among which. The cohesion of clay, internal friction angles, wall friction angles and water levels are correlated. The model uncertainty factor is lognormally distributed and applies as multiplication factor on the maximum bending moment. Explicitly, the latter results in a significant influence on the limit state. Effects given the reference period are considered as well. Large numbers of the dominant load variable q are simulated. The (extreme value) distribution converges to a Gumbel distribution with σ = 0.61. The stochastic distribution of the dominant load is transformed from and to different reference periods: 1, 5, 10, 25, 50 and 100 years. Eventually, for posterior analyses the 50 year reference case is translated to an annual situation in which the annual reliability index and sensitivity factors are derived. Including model uncertainty and cross correlated random variables, one finds a reliability index β = 2.33 as assumption for the posterior analyses. The Equivalent Planes method (EPM) has already been applied in the field of flood defences for reliability updating. This method formulates an failure plane equivalent to two or more combined limit states. In this research, the method has been applied in the temporal context. This means that the Equivalent Planes method is considered in the derivation of the reliability given effect(s) of past performance. The annual reliability index and sensitivity factors are used in this reliability updating method. The autocorrelation represents the correlation of the concerned variable in time. Time-dependent variables including uniform load and water levels assume an auto-correlation of 0, other parameters initially assume an auto-correlation equal to 1. The annual reliability index and sensitivity values are iteratively applied in this method for combining limit states. The equivalent failure plane Z uses a simplified expression in the standard normal space. Eventually a time-dependent reliability curve, as presented by the green line in figure 1, is found. Without model uncertainty, the blue curve is obtained. A higher initial annual reliability index results in a relatively smaller increase of the conditional reliability index. Hence, the effect of past performance decreases when a higher start value of the reliability index is used. Due to the reduced cross-correlation between the water levels on both sides, the time-dependent reliability significantly increases. At last, the time-related effects of quay walls are considered. These effects include: • The irreducible time-dependent uncertainty related to the model uncertainty factor. Randomness or natural variation is included in the model uncertainty factor. This is performed by considering situations with a reduced autocorrelation ρ(Zi, Zj) (0.25, 0.50 and 0.75). The reducible time-dependent uncertainty of load variables including q, wa and wp. Knowledge uncertainties (epistemic uncertainties) are reducible in time, meaning autocorrelation approaching 1. The autocorrelations of the considered variables distributions are derived by using transformed random distributions. • Degradation by corrosion of the stiffest elements in the steel front wall. Corrosion is studied by considering the effects of a log normally distributed wall thickness loss according to corrosion curve 3. This corrosion rate affects the primary element characteristics of the equivalent combined wall. The correlation between the water levels on the active and passive is reconsidered and changed from 0.75 to 0.25. As follows, the below figures show the annual development of the annual reliability as a function of time t. Notice that the annual reliability index increases as the extent to which the uncertainty is epistemic increases. Further, the reliability converges less rapid to larger value(s) in case of auto-correlation approaching 0. In this research, corrosion is considered as an epistemic uncertainty. Two modelling approaches have been considered: an engineering approach, a second order approach. The engineering approach solely considers a reducing section modulus W, whereas the second order approach is additionally including the second moment of inertia I. Corrosion curve 3 results in both approaches to a flattening of the conditional reliability index as time progresses. In addition, the speed in which the influence of time-independent epistemic uncertainties decreases, is less in case of corrosion. Hence, the involvement of stochastic degradation negatively affects the extent to which the uncertainties are reducible. The updated reliability index is also calculated per reference period. This is performed with probabilistic calculation rules. The corresponding sensitivity values, given survival of previous years (see figure(s) 5), can be used in the semi-probabilistic level I method for derivation of the updated partial safety factors. These factors can be applied in the derivation of the design values per random variable considering a service life time t. Hence, the reliability of a quay wall and the transformed sensitivity coefficients can be updated with the Equivalent Planes method. Incorporation of degradation and other time-related effects is seemingly possible. However, further research with finite element modelling is recommended for verification purposes.Civil Engineering | Structural Engineering | Hydraulic Structure

Priming of Allo-HLA-DP-Specific Reactivity from the Naive T Cell Compartment Is Not Exclusively Mediated by Professional Antigen-Presenting Cells

Allogeneic (allo) stem cell transplantation is applied to patients suffering from hematologic malignancies to replace the diseased hematopoietic system with cells derived from a donor stem cell graft. The majority of 10/10matched unrelated donors are HLA-DP-mismatched, and this may result in varying degrees of the graft-versusleukemia (GVL) effect with or without the occurrence of graft-versus-host disease (GVHD). Allo-HLA-reactive T cells are commonly present in the donor T cell repertoire, and thus a very profound alloreactive immune response can be provoked in the HLA-DP-mismatched setting. The magnitude and the diversity of the allo-HLA-DP-specific immune response likely dictates the balance between the occurrence of GVL and/or GVHD after transplantation. To understand the nature of the allo-HLA-DP-specific immune response provoked under different stimulatory conditions, immune responses were induced from both the naive and memory T cell compartments using either HLA-DP-mismatched professional antigen-presenting cells (APCs) (monocyte-derived dendritic cells [allo-DCs]) or HLA-DP-mismatched nonprofessional APCs (skin-derived fibroblasts [allo-fibroblasts]) as stimulator cells. In this study, we observed that allo-HLA-DP-reactive T cells could be provoked from both the naive and memory compartments by both types of APCs. However, the magnitude of the allo-HLA-DP-specific immune response was greater when stimulation was performed with allo-DCs. Moreover, we found that the frequency of allo-HLA-DPreactive T cells was greater in the naive T cell compartment compared with the memory T cell compartment, but we observed a comparable lineage specificity of these allo-HLA-DP-specific reactivities. Overall, the data from this study illustrate that the presence of professional APCs of recipient origin will mostly dictate the magnitude of the allo-HLA-DP-specific immune response derived from both the naive and memory T cell compartments, but does not exclusively mediate the induction of these immune responses. (C) 2020 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.Immunobiology of allogeneic stem cell transplantation and immunotherapy of hematological disease

Long-term in vitro persistence of magnetic properties after magnetic bead-based cell separation of T cells

Magnetic-activated cell sorting (MACS) using magnetic nanoparticles coated with specific antibodies is commonly used in immunology research. For in vitro isolation purposes, it is important to know to what extent the magnetic properties remain present in the isolated cell populations and whether it has consequences for sequential isolations. We hypothesized that only upon cell division, cells will lose their magnetic properties via dilution of the particles in/on their daughter cells. We analysed residual magnetic properties of cells that divided vs cells that did not divide after magnetic bead-based cell separation. As a model, we isolated T cells using beads targeting the non-modulating surface molecule CD45RO. Cells were labelled with the cell division tracking dye PKH and cultured under different conditions to induce variable degrees of cell division. We demonstrate that T cells that underwent no, or only minimal, cell divisions after MACS retained magnetic properties for up to at least 2 weeks of in vitro culture. The presence of nanoparticles was detected on their cell surface and intracellularly using Labeling Check reagent. These results have important consequences for procedures requiring repetitive isolation rounds after in vitro culture.Immunobiology of allogeneic stem cell transplantation and immunotherapy of hematological disease

Long‐term in vitro persistence of magnetic properties after magnetic bead‐based cell separation of T cells

Magnetic-activated cell sorting (MACS) using magnetic nanoparticles coated with specific antibodies is commonly used in immunology research. For in vitro isolation purposes, it is important to know to what extent the magnetic properties remain present in the isolated cell populations and whether it has consequences for sequential isolations. We hypothesized that only upon cell division, cells will lose their magnetic properties via dilution of the particles in/on their daughter cells. We analysed residual magnetic properties of cells that divided vs cells that did not divide after magnetic bead-based cell separation. As a model, we isolated T cells using beads targeting the non-modulating surface molecule CD45RO. Cells were labelled with the cell division tracking dye PKH and cultured under different conditions to induce variable degrees of cell division. We demonstrate that T cells that underwent no, or only minimal, cell divisions after MACS retained magnetic properties for up to at least 2 weeks of in vitro culture. The presence of nanoparticles was detected on their cell surface and intracellularly using Labeling Check reagent. These results have important consequences for procedures requiring repetitive isolation rounds after in vitro culture.Immunobiology of allogeneic stem cell transplantation and immunotherapy of hematological disease

Emerging Concepts in Immune Thrombotic Thrombocytopenic Purpura

Immune thrombotic thrombocytopenic purpura (iTTP) is an autoimmune disorder of which the etiology is not fully understood. Autoantibodies targeting ADAMTS13 in iTTP patients have extensively been studied, the immunological mechanisms leading to the breach of tolerance remain to be uncovered. This review addresses the current knowledge on genetic factors associated with the development of iTTP and the interplay between the patient’s immune system and environmental factors in the induction of autoimmunity against ADAMTS13. HLA-DRB1*11 has been identified as a risk factor for iTTP in the Caucasian population. Interestingly, HLA-DRB1*08:03 was recently identified as a risk factor in the Japanese population. Combined in vitro and in silico MHC class II peptide presentation approaches suggest that an ADAMTS13-derived peptide may bind to both HLA-DRB1*11 and HLA-DRB1*08:03 through different anchor-residues. It is apparent that iTTP is associated with the presence of infectious microorganisms, viruses being the most widely associated with development of iTTP. Infections may potentially lead to loss of tolerance resulting in the shift from immune homeostasis to autoimmunity. In the model we propose in this review, infections disrupt the epithelial barriers in the gut or lung, promoting exposure of antigen presenting cells in the mucosa-associated lymphoid tissue to the microorganisms. This may result in breach of tolerance through the presentation of microorganism-derived peptides that are homologous to ADAMTS13 on risk alleles for iTTP