Improved Peptide-MHC Interaction Predictions through Deep Generative Adversarial Networks and a Unified MHC Class I and Class II Representation
Confirmed Presenter: Michael Klausen, Evaxion Biotech A/S, Denmark
Room: 522
Format: In Person
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- Michael Klausen, Evaxion Biotech A/S, Denmark
- Christian Garde, Evaxion Biotech A/S, Denmark
- Thomas Trolle, Evaxion Biotech A/S, Denmark
- Jens Kringelum, Evaxion Biotech A/S, Denmark
Presentation Overview: Show
In this study, we address the challenge of accurately predicting peptide presentation by Major Histocompatibility Complex (MHC) molecules, a key feature in developing efficacious personalized and precision vaccines. Our approach introduces a novel deep learning framework that enhances prediction accuracy by utilizing the growing wealth of available immunopeptidomic data. Our methodology introduces three new strategies: The creation of a unified representation for both MHC class I and -II molecules, the implementation of a deep transformer encoder-decoder architecture, and the adoption of a generative adversarial network (GAN) pretraining mechanism.
The unified representation allows our model to leverage MHC binding cores across MHC classes and the deep learning architecture facilitates direct training on peptide sequences without the need for pre-processing, such as the extraction or alignment of binding cores. The GAN pretraining stabilizes the training phase and enhances overall performance by generating synthetic peptide data for training enhancement.
Our results demonstrate significant improvements in the prediction of peptide-MHC interactions, particularly for MHC class II molecules, which have historically been difficult to predict accurately. This advancement offers a more reliable and efficient tool for the design of personalized cancer immunotherapies and the development of vaccines against a wide range of pathogens. Through these technical achievements, our work contributes to the advancement of precision medicine, highlighted by a significant improvement when deployed in our AI-immunology™ platform. An improvement shown in preclinical studies and now being used in clinical trials.
TSpred: a robust prediction framework for TCR-epitope interactions using paired chain TCR sequence data
Confirmed Presenter: Ha Young Kim, Korea Advanced Institute of Science and Technology, South Korea
Room: 522
Format: In Person
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- Ha Young Kim, Korea Advanced Institute of Science and Technology, South Korea
- Sungsik Kim, GENINUS Inc., South Korea
- Woong-Yang Park, GENINUS Inc., South Korea
- Dongsup Kim, Korea Advanced Institute of Science and Technology, South Korea
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Prediction of T-cell receptor (TCR)-epitope interactions is important for many applications in biomedical research, such as cancer immunotherapy and vaccine design. Although numerous computational methods have been developed, the prediction of TCR-epitope interactions remains challenging. The prediction is known to be particularly difficult for novel epitopes, due to the scarcity of available data. Here, we propose TSpred, a new deep learning approach for the pan-specific prediction of TCR binding specificity based on paired chain TCR data. We develop a robust model that generalizes well to unseen epitopes by utilizing an ensemble model of a CNN-based model and an attention-based model. In particular, we design a reciprocal attention mechanism which is specifically designed to extract the patterns underlying TCR-epitope interactions. Upon a comprehensive evaluation of our model, we find that TSpred achieves state-of-the-art performances in both seen and unseen epitope specificity prediction tasks. Also, compared to other predictors, TSpred is more robust to bias related to peptide imbalance in the dataset. Furthermore, the reciprocal attention component of our model allows for model interpretability by capturing structurally interacting residue pairs that contribute to TCR-epitope binding. Results indicate that TSpred is a robust and reliable method for the task of TCR-epitope binding prediction.
Comprehensive neoantigen identification and prioritization using pVACtools and pVACview
Confirmed Presenter: Susanna Kiwala, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, United States
Room: 522
Format: In Person
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- Susanna Kiwala, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, United States
- Huiming Xia, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, United States
- Megan M. Richters, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, United States
- Evelyn Schmidt, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, United States
- My Hoang, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, United States
- Kartik Singhal, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, United States
- Mariam Khanfar, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, United States
- Jasreet Hundal, McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO, USA, United States
- Alexander T. Wollam, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, United States
- Joshua McMichael, McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO, USA, United States
- S. Peter Goedegebuure, Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO, United States
- Jason Walker, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA, United States
- Sherri Davies, Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO, United States
- Elaine R. Mardis, Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, OH, USA, United States
- Christopher A. Miller, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, United States
- William E. Gillanders, Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO, United States
- Obi L. Griffith, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, United States
- Malachi Griffith, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, United States
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Personalized neoantigen vaccines utilize immunogenomics and immuno-oncology strategies to combat cancer. Somatic variants in tumor cells generate neoantigens that may bind to MHC molecules and get presented on the tumor cell’s surface. Immunotherapies, such as checkpoint blockade therapies, personalized cancer vaccines and other T cell based therapies, target these neoantigens to stimulate a tumor-specific immune response.
We have developed a computational framework for neoantigen identification and prioritization, pVACtools (pVACtools.org), that integrates tumor variant and expression data (DNA- and RNA-Seq) into an end-to-end solution for design of neoantigen targeting therapies including personalized vaccines. pVACtools consists of multiple command line tools for neoantigen prediction from somatic alterations (pVACseq, pVACfuse, pVACsplice, and pVACbind), a tool for designing DNA vector–based constructs (pVACvector), as well as a web application (pVACview) for visualizing, reviewing, prioritizing, and selecting neoantigen candidates for peptide or nucleic acid vaccine manufacturing platforms.
The full pVACtools suite seamlessly allows users to: 1) Identify altered peptides from different mechanisms (i.e. point mutations, indels, gene fusions, splice site alterations, or frameshift variants). 2) Predict peptide binding affinity, elution, and immunogenicity metrics via an ensemble of MHC Class I and II algorithms. 3) Filter based on variant allele expression, read-counts, variant allele fractions, transcript support level, and peptide binding affinities. 4) Visualize results to allow further interactive neoantigen prioritization. 5) Design DNA-vector vaccines.
pVACtools rapidly and efficiently identifies potentially immunogenic neoepitopes, and is being used in both basic and translational research, as well as over 10 clinical trials on clinicialtrials.gov to date.
Immune checkpoint molecule Tim-3 regulates microglial function and the development of Alzheimer’s disease pathology.
Confirmed Presenter: Ayshwarya Subramanian, Cornell University, United States
Room: 522
Format: In Person
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- Ayshwarya Subramanian, Cornell University, United States
- Kimitoshi Kimura, Kyoto University, Japan
- Vijay Kuchroo, Harvard Medical School, United States
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Microglia are the major resident innate immune cells of the central nervous system (CNS) playing essential roles in CNS homeostasis and disease. Although strongly implicated in Alzheimer’s disease (AD) pathology, the regulatory mechanism of microglial activation remains to be fully elucidated. By combining population and single-cell (scRNA-seq) transcriptomics, IP-MS, neuroinflammation assays, and behavioral studies, we investigated the role of the AD risk gene (Wightman et al., Nat Genet, 2021) and immune checkpoint molecule HAVCR2/TIM-3 in microglial homeostasis and activation. Tim-3 (Havcr2) is highly and specifically expressed in microglia compared to other cell types in both mouse and human brain. Gene expression profiles of Tim-3 deficient microglia resemble those of phagocytic microglia, and microglia in neurodegeneration (MGnD). Mechanistically, Tim-3 enhances TGF-b signaling by promoting phosphorylation of Smad2, thus contributing to the homeostasis of microglia, in a mechanism independent of its activity in T-cells. Importantly, we report that microglia-specific Tim-3 deficiency reduced Amyloid beta (Ab) plaque load and neuronal damage, and resulted in improved cognitive function in a 5XFAD mouse model of AD. Single-nucleus and single-cell RNA sequencing identified that microglia in Havcr2-deficient 5xFAD mice are characterized by increased pro-phagocytic and anti-inflammatory gene expression together with decreased proinflammatory gene expression. Thus, Tim-3 may serve to regulate phagocytotic and inflammatory functions of activated microglia in AD. Collectively, these results hold promise for a potential new therapeutic strategy targeting the checkpoint molecule Tim-3 in AD.
Single-cell multi-omics reveals similarity between progenitor stem-cell-like CD8+ T cells and CD4+ follicular helper T cells in viral infection
Confirmed Presenter: Sarah Walker, Princeton University, United States
Room: 522
Format: In Person
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- Sarah Walker, Princeton University, United States
- Joris van der Veeken, Research Institute of Molecular Pathology, Austria
- Yuri Pritykin, Princeton University, United States
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Mechanisms of gene expression regulation in T cell activation and differentiation across lineages and functional states are incompletely understood. To address this, we generated and analyzed single-cell multi-omic scATAC+scRNA-seq data in splenic T cells (including both CD4+ and CD8+) responding to acute and chronic mouse infection with lymphocytic choriomeningitis virus (LCMV). Computational scATAC-seq data analysis is challenging due to extreme sparsity and incompletely understood statistical properties of the data, as well as high level of cell type specificity and lack of available epigenomic references. Thus, we collected a compendium of published bulk ATAC-seq datasets for mouse CD4 and CD8 T cells, and then built a comprehensive atlas of chromatin accessibility peaks and epigenomic signatures of functional T cell states. This allowed us to analyze our new scATAC-seq data at unprecedented level of detail. We were able to clearly distinguish between CD4 and CD8 T cells, as well as between naive and memory cells in both lineages. We observed that most cell states, including both effector and exhausted cells, as well as progenitor stem-cell-like Tcf1+ CD8 T cells, were found in both acute and chronic responses, though sometimes with different frequency. Interestingly, progenitor Tcf1+ CD8 T cells were most similar epigenetically and transcriptionally to CD4 follicular helper T cells. We hypothesize that similar molecular regulation, potentially driven by their direct or shared physical cell-cell interactions or shared microenvironment, may be associated with their shared regulatory program.
Optimizing CAR T cell design using quantum convolutional neural networks
Confirmed Presenter: Sara Capponi, IBM Research, IBM Almaden Research Center, San Jose, CA (USA), United States
Room: 522
Format: In Person
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- Sara Capponi, IBM Research, IBM Almaden Research Center, San Jose, CA (USA), United States
- Kahn Rhrissorrakrai, IBM Research, IBM Thomas J Watson Research Center, Yorktown Heights, NY (USA), United States
- Meltem Tolunay, IBM Quantum, IBM Almaden Research Center, San Jose, CA (USA), United States
- Tanvi Gujarati, IBM Quantum, IBM Almaden Research Center, San Jose, CA (USA), United States
- Jie Shi, IBM Research, IBM Almaden Research Center, San Jose, CA (USA), United States
- Filippo Utro, IBM Research, IBM Thomas J Watson Research Center, Yorktown Heights, NY (USA), United States
- Roshan M Regy, IBM Quantum, IBM Almaden Research Center, San Jose, CA (USA), United States
- Joseph Morrone, IBM Research, IBM Thomas J Watson Research Center, Yorktown Heights, NY (USA), United States
- Laxmi Parida, IBM Research, IBM Thomas J Watson Research Center, Yorktown Heights, NY (USA), United States
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Chimeric antigen receptor (CAR) T-cells are promising new medicines that apply to the treatment of many cancers, and potentially represent novel approaches to treat infectious diseases and autoimmunity. A central challenge in expanding and enhancing CAR T-cell functions is identifying beneficial combinations of intracellular costimulatory motifs to elicit desired phenotypes. This is due to the large motif combinatorial space and high experimental costs, in time and resources, to generate and measure CAR performance. This results in a highly data-constrained problem where developing accurate predictive models of CAR T-cell behavior is difficult. State-of-the-art machine learning (ML) models based on convolutional neural networks (CNNs) combined with long-short term memory have been shown to reach an accuracy of 70% when predicting CAR T-cell stemness and cytotoxicity. With the clear need for more accurate predictive models, we investigated the performance of quantum convolutional neural networks (QCNNs) as a novel ML model for improved predictive performance. QCNNs carry advantages over classical CNNs, including good generalization in underdetermined problems and usage of significantly fewer training parameters as these scale logarithmically with the number of qubits. QCNNs also have advantages over certain other quantum ML methods, including the absence of barren plateaus. Our study showed that QCNN matches and occasionally exceeds the performance of CNNs in classifying CAR T cells by cytotoxicity levels. Employing larger and more expressive QCNN models may further enhance performance, potentially resulting in a superior predictive tool for CAR T-cell phenotypes.
A Computational Approach to Auto-Immunity Risk Assessment: Use Cases of Molecular Mimicry Hypothesis for Viral Infections and Vaccines-Associated Adverse Events
Confirmed Presenter: Seda Arat, Pfizer, United States
Room: 522
Format: In Person
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- Seda Arat, Pfizer, United States
- Athena Mustakis, Pfizer, United States
- Dac-Trung Nguyen, Pfizer, United States
- Grigorios Koulouras, Pfizer, Greece
- Helena Qi, Pfizer, United States
- Brajesh Rai, Pfizer, United States
- Matt Martin, Pfizer, United States
Presentation Overview: Show
SARS-CoV-2 virus is a member of a large family of viruses called coronaviruses that causes a respiratory disease COVID-19. There are almost 775 million cases and more than 7 million deaths worldwide. While there are short-term effects of SARS-CoV-2 infection such as fever, fatigue, headache and loss of taste/smell, the long-term effects can be very serious, including organ damage. In some people, lasting health effects may include, heart complications, chronic kidney impairment, stroke, and Guillain-Barre syndrome (GBS). Myocarditis is also a well-known adverse event associated with both SARS-CoV-2 infection and mRNA-based COVID-19 vaccines. This study focuses on (1) building a computational pipeline based on protein sequence and 3D structure similarities, and (2) determining if these adverse events are occurring due to molecular mimicry. Initially, we identified ~2500 human proteins that contains peptides (9 and 15 amino acids) with at least 50% similarity within the SARS-CoV-2 protein sequences. These proteins were triaged to more than 50 human endogenous proteins highly expressed in the heart (for myocarditis), kidney (for chronic kidney impairment) and brain (for GBS) that could potentially lead to immune-mediated adverse events based on 3D structure analysis using Alphafold. The presentation will describe our computational approach that can be instrumental for infectious disease, vaccine and drug safety scientists for auto-immunity risk assessment.