Project description:Adoptive cell transfer (ACT) using neoantigen-specific T cells is an effective immunotherapeutic strategy. However, the difficulty in identifying and screening neoantigen-specific T cells limits its widespread application. Here, we prepared neoantigen-reactive T cells (NRTs) after immunization with a tumor lysate-loaded dendritic cell (DC) vaccine (OCDC) for ACT. Our results demonstrated that the OCDC vaccine could induce a neoantigen-specific immune response, and it was feasible to prepare NRTs by loading immunogenic neoantigens onto DCs and coculturing them with spleen lymphocytes from mice immunized with the OCDC vaccine. We then transferred these NRTs back to the LL/2 tumor-bearing mice after OCDC vaccine immunization and found that OCDC vaccine and NRTs adoptive transfer combination treatment could induce a stronger antitumor response. Furthermore, we found that infused NRTs could migrate into the tumor microenvironment to exert antitumor effects. Our research provides a new and convenient method of preparing NRTs for ACT. The clinical translation of this approach has the potential to increase ACT efficacy.
Project description:Adoptive cell transfer (ACT) using neoantigen-specific T cells is an effective immunotherapeutic strategy. However, the difficulty in identifying and screening neoantigen-specific T cells limits its widespread application. Here, we prepared neoantigen-reactive T cells (NRTs) after immunization with a tumor lysate-loaded dendritic cell (DC) vaccine (OCDC) for ACT. Our results demonstrated that the OCDC vaccine could induce a neoantigen-specific immune response, and it was feasible to prepare NRTs by loading immunogenic neoantigens onto DCs and coculturing them with spleen lymphocytes from mice immunized with the OCDC vaccine. We then transferred these NRTs back to the LL/2 tumor-bearing mice after OCDC vaccine immunization and found that OCDC vaccine and NRTs adoptive transfer combination treatment could induce a stronger antitumor response. Furthermore, we found that infused NRTs could migrate into the tumor microenvironment to exert antitumor effects. Our research provides a new and convenient method of preparing NRTs for ACT. The clinical translation of this approach has the potential to increase ACT efficacy.
Project description:In this study, we show that passive transfer of purified antibodies from vaccinated macaques can protect naïve animals against SIVmac251 challenges. The protective signature included multiple antibody functions and correlated with upregulation of interferon pathways in the vaccinated animals. Adoptive transfer of purified IgG from the vaccinated animals with the most robust protective signatures provided partial protection against SIVmac251 challenges in naïve recipient rhesus macaques. These data demonstrate the protective efficacy of purified vaccine-elicited antiviral antibodies, even in the absence of virus neutralization.
Project description:We have shown that DC vaccine is superior to peptide vaccine in terms of priming and expansion of antigen-specific CD8+ T cells. DC vaccine-primed pmel-1 cells displayed better effecter functions than cells by peptide-primed cells in terms of cytokine production and externalization of cytotoxic granules. Furthermore DC vaccine-primed cells were metabolically distinct from peptide-primed cells. To confirm these findings, we performed a microarray analysis using splenic pmel-1 T cells from mice immunized with hgp100 peptide vaccine or DC vaccine. We also used splenic naïve pmel-1 T cells as a control.
Project description:The purpose of this study was to identify the molecular signatures of antigen-encountering T cells, we established the adoptive transfer murine heterotopic heart transplantation model and isolated TEa cells from spleens for RNA sequencing.
Project description:Effector CD8+ T cell (TE) proliferation and cytokine production depends on enhanced glucose metabolism. However, circulating T cells continuously adapt to glucose fluctuations caused by diet and inter-organ metabolite exchange. Here we show that transient glucose restriction (TGR) in activated CD8+ TE metabolically primes effector functions and enhances tumour clearance in mice. Tumor-specific TGR CD8+ TE co-cultured with tumor spheroids in replete conditions display enhanced effector molecule expression, and adoptive transfer of these cells in a murine lymphoma model leads to greater numbers of immunologically functional circulating donor cells and complete tumor clearance. Mechanistically, TGR TE undergo metabolic remodelling that upon glucose re-exposure supports enhanced glucose uptake, increased carbon allocation to the pentose phosphate pathway (PPP), and a cellular redox shift toward a more reduced state, all indicators of a more anabolic program to support their enhanced functionality. Thus, metabolic conditioning could be utilized to promote efficiency of T cell products for adoptive cellular therapy.
Project description:Transgenic T-cell receptor (TCR) adoptive cell therapies recognizing tumor antigens are associated with robust initial response rates, but frequent disease relapse. This usually occurs in the setting of poor long-term persistence of cells expressing the transgenic TCR, generated using murine stem cell virus (MSCV) -retroviral vectors. Analysis of clinical transgenic adoptive cell therapy products in vivo revealed that despite strong persistence of the transgenic TCR DNA sequence over time, its expression was profoundly decreased over time at the RNA and protein levels. Patients with the greatest degrees of expression suppression displayed significant increases in DNA methylation over time within the MSCV promoter region, as well as progressive increases in DNA methylation within the entire MSCV vector over time. These increases in vector methylation occurred independently of its integration site within the host genomes. These results have significant implications for the design of future viral-vector gene engineered adoptive cell transfer therapies.
Project description:The failure to date of all S. aureus vaccine trials has been a conundrum and underlines fundamental flaws in current translational models. A major difference between humans and laboratory animals is the early and frequent exposure of humans to S. aureus compared to animals, which is not accounted for in vaccine studies. In recapitulating the failed IsdB human vaccine trial, we showed that mice previously infected with S. aureus do not mount a protective vaccine antibody response, unlike naïve mice. S. aureus infection induces robust but non-neutralizing anti-IsdB antibodies that target different but overlapping IsdB epitopes compared to IsdB vaccine. In the setting of prior S. aureus infection, however, IsdB vaccine recalls the non-protective humoral response which further competes and reduces efficacy of protective vaccine-generated specific antibodies. Vaccination against the heme-binding domain of IsdB or select IsdB epitope can overcome interference by S. aureus infection. Using an adoptive transfer model, we showed that human serum antibodies against IsdB and another vaccine target, ClfA, are also non-protective and blocked anti-staphylococcal immunity conferred by passive immunizations. Overall, our study demonstrates proof of concept that failure of anti-S. aureus active and passive immunizations could be explained by non-protective imprint of prior host-pathogen interaction.