Structural engineering of chimeric antigen receptors targeting HLA-restricted neoantigens.
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ABSTRACT:
SUBMITTER: Hwang MS
PROVIDER: S-EPMC8421441 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:A major limitation to understanding the associations of human leukocyte antigen (HLA) and CD8+ and CD4+ T cell receptor (TCR) genes with disease pathophysiology is the technological barrier of identifying which HLA molecules, epitopes, and TCRs form functional complexes. Here, we present a high-throughput epitope identification system that combines capture of T cell-secreted cytokines by barcoded antigen-presenting cells (APCs), cell sorting, and next-generation sequencing to identify class I- and class II-restricted epitopes starting from highly complex peptide-encoding oligonucleotide pools. We engineered APCs to express anti-cytokine antibodies, a library of DNA-encoded peptides, and multiple HLA class I or II molecules. We demonstrate that these engineered APCs link T cell activation-dependent cytokines with the DNA that encodes the presented peptide. We validated this technology by showing that we could select known targets of viral epitope-, neoepitope-, and autoimmune epitope-specific TCRs, starting from mixtures of peptide-encoding oligonucleotides. Then, starting from 10 TCRβ sequences that are found commonly in humans but lack known targets, we identified seven CD8+ or CD4+ TCR-targeted epitopes encoded by the human cytomegalovirus (CMV) genome. These included known epitopes, as well as a class I and a class II CMV epitope that have not been previously described. Thus, our cytokine capture-based assay makes use of a signal secreted by both CD8+ and CD4+ T cells and allows pooled screening of thousands of encoded peptides to enable epitope discovery for orphan TCRs. Our technology may enable identification of HLA-epitope-TCR complexes relevant to disease control, etiology, or treatment.
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Project description:Purpose: CD70 expression in normal tissues is restricted to activated lymphoid tissues. Targeting CD70 on CD70-expressing tumors could mediate "on-target, off-tumor" toxicity. This study was to evaluate the feasibility and safety of using anti-human CD70 CARs to treat cancer patients whose tumors express CD70.Experimental Design: Seven anti-human CD70 CARs with binding moieties from human CD27 combined with CD3-zeta and different costimulatory domains from CD28 and/or 41BB were constructed. In vitro functionality of these receptors was compared and in vivo treatment efficacy was evaluated in a xenograft mouse model. A homologous, all murine anti-CD70 CAR model was also used to assess treatment-related toxicities.Results: The CAR consisting of the extracellular binding portion of CD27 fused with 41BB and CD3-zeta (trCD27-41BB-zeta) conferred the highest IFN? production against CD70-expressing tumors in vitro, and NSG mice bearing established CD70-expressing human tumors could be cured by human lymphocytes transduced with this CAR. In the murine CD27-CD3-zeta CAR model, significant reduction of established tumors and prolonged survival were achieved using CAR-transduced splenocytes in a dose-dependent manner. Host preirradiation enhanced treatment efficacy but increased treatment-related toxicities such as transient weight loss and hematopoetic suppression. The treatment did not appear to block adaptive host immune responses.Conclusions: Preclinical testing supports the safety and efficacy of a CD27-containing CAR targeting CD70-expressing tumors. Clin Cancer Res; 23(9); 2267-76. ©2016 AACR.
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