The stimulation of the immune system using oncolytic adenoviruses (OAds) has attracted significant interest and several studies suggested that OAds immunogenicity might be important for their efficacy. Therefore, we developed a versatile and rapid system to adsorb tumor-specific major histocompatibility complex class I (MHC-I) peptides onto the viral surface to drive the immune response toward the tumor epitopes. By studying the model epitope SIINFEKL, we demonstrated that the peptide-coated OAd (PeptiCRAd) retains its infectivity and the cross presentation of the modified-exogenous epitope on MHC-I is not hindered. We then showed that the SIINFEKL-targeting PeptiCRAd achieves a superior antitumor efficacy and increases the percentage of antitumor CD8+ T cells and mature epitope-specific dendritic cells in vivo. PeptiCRAds loaded with clinically relevant tumor epitopes derived from tyrosinase-related protein 2 (TRP-2) and human gp100 could reduce the growth of primary-treated tumors and secondary-untreated melanomas, promoting the expansion of antigen-specific T-cell populations. Finally, we tested PeptiCRAd in humanized mice bearing human melanomas. In this model, a PeptiCRAd targeting the human melanoma-associated antigen A1 (MAGE-A1) and expressing granulocyte and macrophage colony-stimulating factor (GM-CSF) was able to eradicate established tumors and increased the human MAGE-A1-specific CD8+ T cell population. Herein, we show that the immunogenicity of OAds plays a key role in their efficacy and it can be exploited to direct the immune response system toward exogenous tumor epitopes. This versatile and rapid system overcomes the immunodominance of the virus and elicits a tumor-specific immune response, making PeptiCRAd a promising approach for clinical testing.
A subset of MHC-associated self-peptides presented by the recipient's cells and immunologically foreign to the donor can induce an allogeneic immune response after hematopoietic stem cell transplantation (HSCT). These immunogenic peptides originate from the genomic polymorphisms and are known as minor histocompatibility antigens (MiHA). MiHA mismatches trigger the post-transplant immune response, which could manifest in both the deleterious “graft-vs.-host” disease and the beneficial “graft-vs.-leukemia” effect. Importantly, some MiHAs are considered to be promising targets for posttransplant T-cell immunotherapy of hematopoietic malignancies. This creates a demand for a robust and fast approach to genotyping MiHA-encoding polymorphisms. We report a multiplex real-time PCR method for the genotyping of 20 polymorphisms that are encoding HLA-A * 02:01-restricted MiHAs. This method uses allele-specific primers and gene-specific hydrolysis probes. In 1 h it allows for the detection of MiHA mismatches in a donor-recipient pair without the need for electrophoresis, sequencing, or other time-consuming techniques. We validated the method with Sanger and NGS sequencing and demonstrated good performance over a wide range of DNA concentrations. We propose our protocol as a fast and accurate method of identifying mismatched MiHAs. The information on the MiHA mismatches is useful for studying the allogeneic immune response following HSCT and for selecting the targets for post-transplant T-cell therapy.
CanCer -Immunotherapy, CanCer VaCCInes I vaccines further. IL-12 has shown to drive cellular immune responses by aiding the priming and expansion of CD8 T cells. We have previously demonstrated that a highly optimized engineered DNA vaccine targeting HPV 16 and 18 E6/E7 (pGX3001 and pGX3002) elicited potent TH1 and cytotoxic cellular immune responses in a Phase I clinical trial. Here, we sought to determine whether the HPV vaccine-induced antitumor immunity could be further enhanced by the addition of IL12 as an adjuvant.We first demonstrated that IL-12 could enhance HPV16 E6 and E7-specific cellular responses measured by ELISpot in mice (average of 1037 vs 504 SFU/106 splenocytes). Then we performed an in vivo tumor therapy study to determine whether IL-12 could enhance the therapeutic efficacy of pGX3001 in TC-1 tumor bearing C57BL/6 mice. The results induced that mice immunized with pGX3001+IL-12 exhibited smaller tumors compared to those in the no adjuvant group. Thirty days post tumor transplantation, 9 out of 10 mice in the pGX3100+IL-12 group showed complete tumor regression, while there were only 4 out of 10 mice in the pGX3001 group that showed complete tumor regression, indicating that the addition of plasmid-based mouse IL-12 enhanced the vaccine-induced antitumor immunity in a murine model. Furthermore, an additional study in a more relevant, non-human primate model was performed to ensure that the vaccine-induced cellular immune responses could also be augmented by using a rhesus macaque IL-12 plasmid. The data indicated that the addition of IL-12 increased the magnitude of vaccine-induced cellular immune responses about two fold post third immunization (average of 2711 SFU vs 1400 SFU/106 PBMCs as measured by ELISpot). The HPV antigen-specific memory responses in the HPV+IL-12 group were increased more than four-fold compared to the responses in the unadjuvanted group (average of 2570 vs 577 SFU/106 PBMCs). Flow cytometric analysis revealed the induction of both HPV-specific CD4 and CD8 T cells that efficiently increased IFN-ɤ responses. Both adjuvant and unadjuvanted groups showed an increase in effector and central memory CD8 T cells after immunization, while the IL-12 group exhibited stronger effector memory CD8 T cell responses. Taken together, these data support the further development of this HPV DNA vaccine in combination with IL12 as a cancer immunotherapy candidate.
Background.Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is being widely applied as a therapy for hematological malignancies. The long-term outcome of allo-HSCT depends directly on the ability of cytotoxic T-lymphocytes to recognize and eliminate the residual tumor. CTLA-4 is one of the regulatory proteins that provide control over the development of the immune response. Polymorphisms in the CTLA4 gene can affect its function and the efficiency of the antitumor response.The objective:to study the effect of non-synonymous single nucleotide polymorphism (nsSNP) c.49A>G in the donor CTLA4 gene on tumor control in the recipient of allogeneic hematopoietic stem cells (HSC).Materials and methods.Donors of HSC were genotyped for nsSNP c.49A>G in the CTLA4 gene by the real-time polymerase chain reaction using the allele-specific primers. Genotyping data was validated by Sanger’s sequencing of 22 randomly selected samples. The overall survival, the event-free survival and relapse probability were calculated using the Kaplan–Mayer method. A log-rank test was used to assess the statistical significance of group disparities. A p-value of 0.05 was considered as significant.Results.The frequencies of the CTLA4 gene c.49A>G polymorphism alleles in the observed population (102 healthy donors of HSC) correspond to the frequencies obtained by the “1000 genomes” project for the European population. The effect of the donor CTLA4 polymorphism on the tumor control was evaluated on the cohort of patients with acute leukemia after human leukocyte antigen (HLA) matched HSCT from an unrelated donor. It was shown, the three-year relapse-free survival was significantly lower for those patients who received grafts from a donor with the homozygous A/A state of nsSNP c.49A>G (p = 0.01), it was 12.7 % versus 62,8 % in group with c.49A>G G/G and A/G donor genotypes. The incidence of relapse was also significantly different for the group with A/A genotype and for the group with G/G or A/G genotypes of the nsSNP and equaled to 83.7 and 29.3 % respectively (p = 0.03).Conclusion.Patients with acute leukemia, who underwent allo-HSCT from unrelated completely HLA-matched donors with c.49A>G G/G or A/G genotypes have the significantly lower risk of relapse than patients whose donors had the A/A genotype. These results suggest practicability of the nsSNP genotyping for the optimal donor selection.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.