Project description:Neoantigen discovery in pediatric brain tumors is hampered by their low mutational burden and scant tissue availability. We developed a low-input proteogenomic approach combining tumor DNA/RNA sequencing and mass spectrometry proteomics to identify tumor-restricted (neoantigen) peptides arising from multiple genomic aberrations to generate a highly target-specific, autologous, personalized T cell immunotherapy. Our data indicate that novel splice junctions are the primary source of neoantigens in medulloblastoma, a common pediatric brain tumor. Proteogenomically identified tumor-specific peptides are immunogenic and generate MHC II-based T cell responses. Moreover, polyclonal and polyfunctional T cells specific for tumor-specific peptides effectively eliminated tumor cells in vitro. Targeting novel tumor-specific antigens obviates the issue of central immune tolerance while potentially providing a safety margin favoring combination with other immune-activating therapies. These findings demonstrate the proteogenomic discovery of immunogenic tumor-specific peptides and lay the groundwork for personalized targeted T cell therapies for children with brain tumors.
Project description:Adoptive transfer of T cells expressing a transgenic T cell receptor (TCR) has the potential to revolutionize immunotherapy of infectious diseases and cancer. However, the generation of defined TCR-transgenic T cell medicinal products with predictable in vivo function still poses a major challenge and limits broader and more successful application of this ‘living drug’. Here, by studying 51 different TCRs, we show that conventional genetic engineering by viral transduction leads to variable TCR expression and functionality as a result of variable transgene copy numbers and untargeted transgene integration. In contrast, CRISPR/Cas9-mediated TCR replacement enables defined, targeted TCR transgene insertion into the TCR gene locus. Thereby, T cell products display more homogenous TCR expression similar to physiological T cells. Importantly, increased T cell product homogeneity after targeted TCR gene editing correlates with predictable in vivo T cell responses, which represents a crucial aspect for clinical application in adoptive T cell immunotherapy.
Project description:We present a pipeline, ObsERV, for the design of personalized cancer immunotherapies based on epitopes derived from endogenous retroviral elements (EVEs). We show that EVE-derived peptides are presented as antigens on tumors and can be predicted by ObsERV. Preclinical testing of ObsERV demonstrates elicitation of poly-functional CD4+ and CD8+ T-cell responses as well as long-term tumor protection and persistence of the responses.
Project description:In recent years the clinical success of T cell-based immunotherapy approaches has revolutionized treatment of solid tumors and hematological malignancies. However, still some patients do not respond to available therapies at all, others for limited time only. A promising low side-effect approach is peptide-based immunotherapy, which relies on specific immune recognition of tumor-associated human leucocyte antigen (HLA)-presented peptides. In this study, we developed a workflow for the immunopeptidome-guided design of off-the shelf warehouses for personalized peptide vaccines using the example of chronic lymphocyte leukemia (CLL). The so defined warehouses could provide the basis for different T cell-based immunotherapy approaches such as TCR-engineered T cell transfer or multi-peptide vaccinations. The warehouse approach enables a fast and cost-effective way to provide a personalized T cell-based immunotherapeutic approach. The here defined peptide warehouse is already utilized for a personalized multi-peptide vaccine trial (iVAC-XS15-CLL01, NCT04688385).
Project description:The accurate identification and prioritization of antigenic peptides presented by class-I and -II human leukocyte antigens (HLA-I and -II) recognized by autologous T cells is crucial for the development of cancer immunotherapies. While several clinical neoantigen prediction pipelines are now publicly available, none of them allows the direct integration of mass spectrometry immunopeptidomics data that can uncover antigenic peptides derived from various canonical and non-canonical sources. Therefore, we have developed and shared a unique ‘end-to-end’ clinical proteo-genomic pipeline, called NeoDisc. NeoDisc is a fast and modular computational pipeline that combines state-of-the-art publicly available and in-house software for genomics, transcriptomics, mass-spectrometry-based immunopeptidomics, and in silico tools for the identification, prediction, and prioritization of tumor-specific and immunogenic antigens from multiple sources. We demonstrated the application of NeoDisc for personalized antigen discovery, in the context of heterogenic antigenic landscape and defective cellular antigen presentation machineries, and we highlighted its clinical implementation.