NitraTh epitope-based neoantigen vaccines for effective tumor immunotherapy.

Neoantigen vaccines represent an emerging and promising strategy in the field of tumor immunotherapy. Despite their potential, designing an effective neoantigen vaccine remains a challenge due to the current limitations in predicting CD4+ T cell epitopes with high accuracy. Here, we introduce a novel approach to neoantigen vaccine design that does not rely on computational prediction of CD4+ T cell epitopes. Utilizing nitrated helper T cell epitope containing p-nitrophenylalanine, termed "NitraTh epitope," we have successfully engineered a series of tumor neoantigen vaccines capable of eliciting robust neoantigen-specific immune responses. With the help of NitraTh epitope, even mutations with low predicted affinity for MHC class I molecules were successfully induced to elicit neoantigen-specific responses. In H22 cell allograft and patient-derived xenograft (PDX) liver cancer mouse models, the NitraTh epitope-based neoantigen vaccines significantly suppressed tumor progression. More strikingly, through single-cell sequencing we found that the NitraTh epitope-based neoantigen vaccines regulate macrophage reprogramming and modulate macrophages to decrease the levels of the immunosuppressive molecule prostaglandin E2 (PGE2), which in turn reshapes the tumor immunosuppressive microenvironment. In summary, NitraTh epitope-based neoantigen vaccines possess the dual effects of potently activating neoantigen-specific immunity and alleviating immunosuppression, potentially providing a new paradigm for the design of tumor neoantigen vaccines.

Altered epitopes enhance macrophage-mediated anti-tumour immunity to low-immunogenic tumour mutations.

Personalized neoantigen therapy has shown long-term and stable efficacy in specific patient populations. However, not all patients have sufficient levels of neoantigens for treatment. Although somatic mutations are commonly found in tumours, a significant portion of these mutations do not trigger an immune response. Patients with low mutation burdens continue to exhibit unresponsiveness to this treatment. We propose a design paradigm for neoantigen vaccines by utilizing the highly immunogenic unnatural amino acid p-nitrophenylalanine (pNO2Phe) for sequence alteration of somatic mutations that failed to generate neoepitopes. This enhances the immunogenicity of the mutations and transforms it into a suitable candidate for immunotherapy. The nitrated altered epitope vaccines designed according to this paradigm is capable of activating circulating CD8+ T cells and inducing immune cross-reactivity against autologous mutated epitopes in different MHC backgrounds (H-2Kb, H-2Kd, and human HLA-A02:01), leading to the elimination of tumour cells carrying the mutation. After immunization with the altered epitopes, tumour growth was significantly inhibited. It is noteworthy that nitrated epitopes induce tumour-infiltrating macrophages to differentiate into the M1 phenotype, surprisingly enhancing the MHC II molecule presenting pathway of macrophages. Nitrated epitope-treated macrophages have the potential to cross-activate CD4+ and CD8+ T cells, which may explain why pNO2Phe can enhance the immunogenicity of epitopes. Meanwhile, the immunosuppressive microenvironment of the tumour is altered due to the activation of macrophages. The nitrated neoantigen vaccine strategy enables the design of vaccines targeting non-immunogenic tumour mutations, expanding the pool of potential peptides for personalized and shared novel antigen therapy. This approach provides treatment opportunities for patients previously ineligible for new antigen vaccine therapy.

Sodium Alginate Hydrogel-Mediated Cancer Immunotherapy for Postoperative In Situ Recurrence and Metastasis.

With the development of technology, adjuvant immunotherapy has become a promising strategy for prevention of postoperative tumor regression and metastasis by stimulating the host immune response. However, the therapeutic effects are still unsatisfactory due to the lack of synergy between different methods. In this study, an efficient synergistic immunotherapy system based on injectable sodium alginate hydrogels was designed to inhibit in situ recurrence and metastasis at the same time. On the one hand, an injectable sodium alginate (SA) hydrogel microsystem loaded with toll-like receptor (TLR) agonists (CpG ODNs) was synthesized for inhibiting in situ recurrence, and then carcinoembryonic antigen (CEA) probe was also added to detect CEA based on fluorescence resonance energy transfer (FRET) technology to monitor the occurrence and development of tumor recurrence. On the other hand, an anti-programmed cell death 1 ligand 1 antibody (anti-PD-L1)-modified SA nanogel loaded with indocyanine green (ICG@SA-anti-PD-L1 nanogel) was prepared for diagnosing and inhibiting lung metastasis by assisting orthotopic tumor therapy. In vitro and in vivo results demonstrated that this SA micro/nanosystem could monitor and inhibit postoperative recurrence and metastasis. We hope that this micro/nano-synergistic system will become an effective strategy for postoperative adjuvant immunotherapy.

A Logic AND-Gated Sonogene Nanosystem for Precisely Regulating the Apoptosis of Tumor Cells.

To date, many methods have been developed for inducing tumor cell death, such as using chemical drugs and radiation. However, all of them have a common problem, a lack of mechanisms for precisely regulating the death of tumor cells. It often leads to nonspecific death and systemic side effects. Therefore, the efficacy and further application of these traditional methods are limited. In this paper, a logic AND-gated sonogene nanosystem was designed for precisely regulating the apoptosis of tumor cells. The running of this system required two essential parts, MscL I92L channel protein and ultrasound. Ultrasound could open the MscL I92L protein channel which when expressed on cells triggers the influx and outflux of small molecules through the channel. When the channel is kept open for a long time, Ca2+ influx becomes excessive which in turn activates the Ca2+ apoptosis pathway of cells. The expression of MscL I92L protein and the applying of ultrasound constituted the logic AND gate which could implement the precise regulation to apoptosis. This strategy would help reduce nonspecific triggers and side effects. In this system, cationic nanoliposomes were prepared as the carrier for effectively delivering MscL I92L plasmids to tumor cells in vivo. We investigated the apoptosis-promoting effect of this system in different tumor cell lines (HeLa, B16, and 4T1). The results demonstrated that the apoptosis rate was highest in the B16 cell line (the early apoptosis rate was 11.9% and the late apoptosis rate was 59.1%) when the cells were subjected to consistent ultrasound (6 MHz, 15 W) for 30 min. This logic AND-gated sonogene nanosystem is expected to provide a new strategy and development direction for tumor therapy.