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: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:Whole Genome Sequencing of the murine breast cancer cell line 4T1 and of the murine melanoma cell line B16-ova was carried out with the aim of identifying somatic mutations. We also ran deep Mass Spectrometry proteomics analysis on the same cell lines, aiming to determine which somatic mutations carry over to the protein expression level. Further, we tested these cancer specific protein epitopes (putative neoantigens) for immunogenicity using mouse models. Finally, the putative neoantigens that showed good immunogenic potential were used in tumor growth control experiments with mice engrafted with the two tumor cell lines. In these experiments we tested whether cancer vaccines based on individual neoantigen peptides (MHC-I) restricted the growth of the tumor compared to adequate controls. The overall aim of the project is to validate the ability of our multi-omics/bioinformatics pipeline to identify and deliver neoantigens that can be used to suppress tumor growth. File names Sample names P10859_101_S1_L001_R1_001_BHKWV3CCXY 4T1_S1_L001_R1_001_BHKWV3CCXY P10859_101_S1_L001_R2_001_BHKWV3CCXY 4T1_S1_L001_R2_001_BHKWV3CCXY P10859_101_S1_L002_R1_001_BHKWV3CCXY 4T1_S1_L002_R1_001_BHKWV3CCXY P10859_101_S1_L002_R2_001_BHKWV3CCXY 4T1_S1_L002_R2_001_BHKWV3CCXY P10859_102_S2_L003_R1_001_BHKWV3CCXY B16-OVA_S2_L003_R1_001_BHKWV3CCXY P10859_102_S2_L003_R2_001_BHKWV3CCXY B16-OVA_S2_L003_R2_001_BHKWV3CCXY P10859_102_S2_L004_R1_001_BHKWV3CCXY B16-OVA_S2_L004_R1_001_BHKWV3CCXY P10859_102_S2_L004_R2_001_BHKWV3CCXY B16-OVA_S2_L004_R2_001_BHKWV3CCXY
Project description:Background. Dendritic cell (DC)-based neoantigen vaccination holds potential as a safe and effective adjuvant therapy for patients with early-stage, resectable NSCLC, a tumor type typically characterized by high mutational loads. DCs have the unique ability to elicit robust antitumoral T-cell responses, while neoantigens are ideal targets to elicit high-affinity T cell responses with exquisite tumor specificity. Here, we present the results of a phase I clinical trial in which a novel DC vaccine targeting neoantigens was evaluated in six patients with early stage, resected NSCLC. Methods. Tumor samples were subjected to a comprehensive neoantigen identification approach encompassing genomics, transcriptomics and immunopeptidomics. Patients underwent leukapheresis for the manufacturing of monocyte-derived DCs loaded with neoantigens (Neo-mDCs) according to a four-day protocol. Neo-mDCs were injected intravenously following an intrapatient dose escalation scheme. Primary endpoint of the trial was safety. Secondary endpoints were feasibility, immunogenicity, and relapse-free survival. As a quality control, dendritic cells transfected with the mRNA-encoded neoantigen were analyzed by shotgun proteomics to validate expression of the mRNA-encoded neoantigen. Results. The vaccine was demonstrated to be feasible and safe. T cell responses were observed in 5 of 6 vaccinated patients and were dominated by CD8+ T cells, which could be detected ex vivo at high frequencies >1.5 years after the last dose. Furthermore, single cell analysis indicated that the CD8+ T cell responsive population was polyclonal and exhibited the near entire spectrum of T cell differentiation states, including a naïve-like state associated with long lasting memory. Additionally, mRNA-encoded neoantigen were detected by shotgun proteomics in four patients out of the six patients that were tested.
Project description:Background. Dendritic cell (DC)-based neoantigen vaccination holds potential as a safe and effective adjuvant therapy for patients with early-stage, resectable NSCLC. DCs have the unique ability to elicit robust antitumoral T-cell responses, while neoantigens are ideal targets to elicit high-affinity T cell responses with excellent tumor specificity. Here, we present the results of a phase I clinical trial in which a novel DC vaccine targeting neoantigens was evaluated in six patients with early stage, resected NSCLC. Methods. Autologous monocyte-derived DCs loaded with neoantigens (Neo-mDCs) were manufactured according to a 4-day protocol. Neo-mDCs were injected intravenously following an intrapatient dose escalation scheme. Primary endpoint of the trial was safety. Secondary endpoints were feasibility, immunogenicity, and relapse-free survival. Results. Vaccine manufacturing was feasible in 6 of 10 patients. Toxicity was limited to grade 1-2 adverse events. Systemic T cell responses were observed in 5 out of 6 vaccinated patients and were dominated by CD8+ T cells, which could be detected ex vivo at high frequencies >1.5 years after the last dose. Furthermore, single cell analysis indicated that the CD8+ T cell responsive population was polyclonal and exhibited the near entire spectrum of T cell differentiation states, including a naïve-like state associated with long lasting memory, but excluding exhausted cell states. Three of six vaccinated patients experienced disease relapse.Conclusion. Neo-mDC vaccination is safe, feasible and induces polyclonal populations of neoantigen-specific T-cell responses containing long lasting memory and effector cells in early-stage NSCLC patients, suggesting clinical potential.
Project description:Personalized cancer vaccines aim to activate and expand cytotoxic anti-tumor CD8+ T cells to recognize and kill tumor cells. However, the role of CD4+ T cell activation in the clinical benefit of these vaccines is not well defined. We previously established a personalized neoantigen vaccine (PancVAX) for the pancreatic cancer cell line Panc02, which activates tumor-specific CD8+ T cells but required combinatorial checkpoint modulators to achieve therapeutic efficacy. To determine the effects of neoantigen-specific CD4+ T cell activation, we generated a new vaccine (PancVAX2) targeting both MHCI- and MHCII-specific neoantigens. Tumor-bearing mice vaccinated with PancVAX2 had significantly improved control of tumor growth and long-term survival benefit without concurrent administration of checkpoint inhibitors. PancVAX2 significantly enhanced priming and recruitment of neoantigen-specific CD8+ T into the tumor with lower PD1 expression after reactivation compared to the CD8+ vaccine alone. Vaccine-induced neoantigen- specific Th1 CD4+ T cells in the tumor were associated with decreased T regulatory cells (Tregs). Consistent with this, PancVAX2 was associated with more pro-immune myeloid-derived suppressor cells and M1-like macrophages in the tumor demonstrating a less immunosuppressive tumor microenvironment. This study demonstrates the biological importance of prioritizing and including CD4 T cell-specific neoantigens for personalized cancer vaccine modalities.
Project description:The CD155/TIGIT axis can be co-opted during immune evasion in chronic viral infections and cancer. Pancreatic adenocarcinoma (PDAC) is a highly lethal malignancy, and immune-based strategies to combat this disease have been largely unsuccessful to date. We corroborate prior reports that a substantial portion of PDAC harbors predicted high affinity MHC class I-restricted neoepitopes and extend these findings to advanced/metastatic disease. Using two novel preclinical models of neoantigen-expressing PDAC, we demonstrate that intratumoral neoantigen-specific CD8+ T cells adopt multiple states of dysfunction, which are similar to tumor-infiltrating lymphocytes of human PDAC patients. Mechanistically, genetic and/or pharmacologic modulation of the CD155/TIGIT axis was sufficient to promote immune evasion in autochthonous neoantigen-expressing PDAC. Finally, we demonstrate that the CD155/TIGIT axis is critical to maintain immune evasion in PDAC and uncover a combination immunotherapy (TIGIT/PD-1 co-blockade plus CD40 agonism) that elicits profound anti-tumor responses in preclinical models, now poised for clinical evaluation.
Project description:Background. Dendritic cell (DC)-based neoantigen vaccination holds potential as a safe and effective adjuvant therapy for patients with early-stage, resectable NSCLC, a tumor type typically characterized by high mutational loads. DCs have the unique ability to elicit robust antitumoral T-cell responses, while neoantigens are ideal targets to elicit high-affinity T cell responses with exquisite tumor specificity. Here, we present the results of a phase I clinical trial in which a novel DC vaccine targeting neoantigens was evaluated in six patients with early stage, resected NSCLC. Methods. Tumor samples were subjected to a comprehensive neoantigen identification approach encompassing genomics, transcriptomics and immunopeptidomics. Using genomics and transcriptopmics data, tumor-specific antigens were identified by a bioinformatics approach. Additionally, immunopeptidomics was performed by immunoprecipitation of human MHC class I molecule followed by immunopeptides enrichment and LC-MS/MS analysis. Two immunopeptidomics screens were performed. In the first immunopeptidomics screen, patient-derived tumors were analyzed to uncover neoepitopes specific for the patient. In the second, screen, patient-derived EBV-immortilized B cell lines overexpressing the selected neoepitopes were analyzed to verify that the predicted neoepitopes can bind to the HLA haplotypes of the patients. For anti-tumor vaccination, patients underwent leukapheresis for the manufacturing of monocyte-derived DCs loaded with neoantigens (Neo-mDCs) according to a four-day protocol. Neo-mDCs were injected intravenously following an intrapatient dose escalation scheme. Primary endpoint of the trial was safety. Secondary endpoints were feasibility, immunogenicity, and relapse-free survival. Results. In the first immunopeptidomics screen, one neoepitopes derived was identified from the tumor of one patient. In the second immunopeptidomics screen, several predicted neoepitopes were confirmed to be presented on the HLA haplotypes of the patients by analyzing the patient-derived EBV-immortilized B cell lines. Additionally, the vaccine was demonstrated to be feasible and safe. T cell responses were observed in 5 of 6 vaccinated patients and were dominated by CD8+ T cells, which could be detected ex vivo at high frequencies >1.5 years after the last dose. Furthermore, single cell analysis indicated that the CD8+ T cell responsive population was polyclonal and exhibited the near entire spectrum of T cell differentiation states, including a naïve-like state associated with long lasting memory but excluding exhausted cell states. Three of six vaccinated patients experienced disease relapse. Conclusion. Neo-mDC vaccination is safe and feasible. Vaccination induces large populations of neoantigen-specific T-cell responses containing long lasting memory and effector cells in early-stage NSCLC patients, suggesting clinical potential.
Project description:Upon chronic antigen exposure, CD8+ T cells become exhausted acquiring a dysfunctional state correlated with the inability to control infection or tumor. In contrast to exhausted T cells, stem-like CD8+ T progenitors maintain the ability to promote and sustain effective immunity. Adenovirus (Ad) vectored vaccines encoding tumor neoantigens have been shown to eradicate large tumors when combined with anti-Programmed cell death protein 1 (αPD-1) in murine models, however the mechanisms and translational potential have not yet been elucidated. Here, we show that gorilla Ad vaccine targeting tumor neoepitopes enhance responses to αPD-1 therapy, by improving immunogenicity and anti-tumor efficacy. Single cell RNA-seq demonstrated that the combination of Ad vaccine and αPD-1 increased the number of murine polyfunctional neoantigen specific CD8+ T cells over αPD-1 monotherapy, with an accumulation of Tcf1+ stem-like progenitors in draining lymph nodes and effector CD8+T cells in tumors. Combined TCR sequencing analysis highlighted a broader spectrum of neoantigen specific CD8+ T cells upon vaccination compared to αPD-1 monotherapy. The translational relevance of these data is supported by results obtained in the first 12 patients with metastatic deficient mismatch repair (dMMR) tumors vaccinated with an Ad vaccine encoding shared neoantigens. Expansion and diversification of TCRs was observed in post-treatment biopsies of patients with clinical response, as well as an increase in tumor infiltrating T cells with an effector memory signature. These findings indicate a promising mechanism to overcome resistance to PD-1 blockade, by promoting immunogenicity and broadening the spectrum and magnitude of neoantigen-specific T cells infiltrating tumors.