Project description:Although irradiated induced-pluripotent stem cells (iPSCs) as a prophylactic cancer vaccine elicit an antitumor immune response, the therapeutic efficacy of iPSC-based cancer vaccines is not promising due to their insufficient antigenicity and the immunosuppressive tumor microenvironment. Here, we found that neoantigen-engineered iPSC cancer vaccines can trigger neoantigen-specific T cell responses to eradicate cancer cells and increase the therapeutic efficacy of RT in poorly immunogenic colorectal cancer (CRC) and triple-negative breast cancer (TNBC). We generated neoantigen-augmented iPSCs (NA-iPSCs) by engineering AAV2 vector carrying murine neoantigens and evaluated their therapeutic efficacy in combination with radiotherapy. After administration of NA-iPSC cancer vaccine and radiotherapy, we found that ~60% of tumor-bearing mice achieved a complete response in microsatellite-stable CRC model. Furthermore, splenocytes from mice treated with NA-iPSC plus RT produced high levels of IFN secretion in response to neoantigens and had a greater cytotoxicity to cancer cells, suggesting that the NA-iPSC vaccine combined with radiotherapy elicited a superior neoantigen-specific T-cell response to eradicate cancer cells. The superior therapeutic efficacy of NA-iPSCs engineered by mouse TNBC neoantigens was also observed in the syngeneic immunocompetent TNBC mouse model. We found that the risk of spontaneous lung and liver metastasis was dramatically decreased by NA-iPSCs plus RT in the TNBC animal model. Altogether, these results indicated that autologous iPSC cancer vaccines engineered by neoantigens can elicit a high neoantigen-specific T-cell response, promote tumor regression and reduce the risk of distant metastasis in combination with local radiotherapy.
Project description:Optimized polyepitope neoantigen DNA vaccines elicit neoantigen-specific immune responses in preclinical models and in clinical translation
Project description:Optimized polyepitope neoantigen DNA vaccines elicit neoantigen-specific immune responses in preclinical models and in clinical translation
Project description:The purpose of this study is 1) to evaluate the feasibility of manufacturing a patient-specific neoantigen cancer vaccine, which involves predicting the patient’s neoantigens and generating a vaccine that encodes the predicted neoantigens; and, 2) to identify and select patients who may be eligible for a shared neoantigen cancer vaccine where their tumor contains a specific shared mutation and who have the correct HLA allele capable of presenting the neoantigen derived from the tumor-specific mutation.
Project description:Neoantigen-reactive cytotoxic T lymphocytes play a vital role in precise cancer cell elimination. In this study, we demonstrate the effectiveness of personalized neoantigen-based T cell therapy in inducing tumor regression in two patients suffering from heavily-burdened metastatic ovarian cancer. Our approach involved the development of a robust pipeline for ex vivo expansion of neoantigen-reactive T lymphocytes. Neoantigen peptides were designed and synthesized based on the somatic mutations of the tumors and their predicted HLA binding affinities. These peptides were then presented to T lymphocytes through co-culture with neoantigen-loaded dendritic cells for ex vivo expansion. Subsequent to cell therapy, both patients exhibited significant reductions in tumor marker levels and experienced substantial tumor regression. One patient achieved repeated cancer regression through infusions of T cell products generated from newly identified neoantigens. Transcriptomic analyses revealed a remarkable increase in neoantigen-reactive cytotoxic lymphocytes in the peripheral blood of the patients following cell therapy. These cytotoxic T lymphocytes expressed polyclonal T cell receptors (TCR) against neoantigens, along with abundant cytotoxic proteins and pro-inflammatory cytokines. The efficacy of neoantigen targeting was significantly associated with the immunogenicity and TCR polyclonality. Notably, the neoantigen-specific TCR clonotypes persisted in the peripheral blood after cell therapy. Our findings indicate that personalized neoantigen-based T cell therapy triggers cytotoxic lymphocytes expressing polyclonal TCR against ovarian cancer, suggesting its promising potential in cancer immunotherapy.
Project description:<p>Neoantigens, which are derived from tumour-specific protein-coding mutations, are exempt from central tolerance, can generate robust immune responses and can function as bona fide antigens that facilitate tumour rejection. We demonstrated that a strategy that uses multi-epitope, personalized neoantigen vaccination, which has previously been tested in patients with high-risk melanoma, is feasible for tumours such as glioblastoma, which typically have a relatively low mutation load and an immunologically ‘cold’ tumour microenvironment. Here we conducted whole-exome sequencing of tumor and normal cells from individual patients with glioblastoma to identify tumor-specific mutations. We assessed the expression of mutated alleles by RNA-sequencing of tumor. We used personalized neoantigen-targeting vaccines to immunize patients newly diagnosed with glioblastoma following surgical resection and conventional radiotherapy in a phase I/Ib study. Patients who did not receive dexamethasone-a highly potent corticosteroid that is frequently prescribed to treat cerebral oedema in patients with glioblastoma-generated circulating polyfunctional neoantigen-specific CD4+ and CD8+ T cell responses that were enriched in a memory phenotype and showed an increase in the number of tumour-infiltrating T cells. Using single-cell T cell receptor analysis, we provide evidence that neoantigen-specific T cells from the peripheral blood can migrate into an intracranial glioblastoma tumour. Neoantigen-targeting vaccines thus have the potential to favourably alter the immune milieu of glioblastoma.</p>
Project description:In this study we report the neoantigen landscape, tumor mutational burden and tumor microenvironment of seven breast cancer patients, consisting of three Estrogen receptor (ER) positive and four Triple negative breast cancer (TNBC) subtypes.