Tumor Antigen-Based Nanovaccines for Cancer Immunotherapy: A Review

Cancer Nanovaccines: Mechanisms, Design Principles, and Clinical Translation

Cancer immunotherapy has transformed the landscape of oncological treatment by employing various strategies to teach the immune system to eliminate tumors. Among these, cancer nanovaccines are an emerging strategy that utilizes nanotechnology to enhance immune activation in response to tumor antigens. This review addresses the principles behind the different technologies in this field aimed at generating a robust and effective immune response. The diversity of strategies adopted for the design of nanovaccines is discussed, including the types of active agents, nanocarriers, their functionalizations, and the incorporation of adjuvants. Furthermore, strategies to optimize nanoparticle formulations to enhance the antigen presentation, target immune cells, and organs and promote strong and durable antitumor responses are explored. Finally, we analyze the current state of clinical application, highlighting ongoing clinical trials and the future potential of cancer nanovaccines. The insights presented in this review aim to guide future research and development efforts in the field, contributing to the advancement of more effective and targeted nanovaccines in the fight against cancer.

Nano-Oncologic Vaccine for Boosting Cancer Immunotherapy: The Horizons in Cancer Treatment

Nano-oncologic vaccines represent a groundbreaking approach in the field of cancer immunotherapy, leveraging the unique advantages of nanotechnology to enhance the effectiveness and specificity of cancer treatments. These vaccines utilize nanoscale carriers to deliver tumor-associated antigens and immunostimulatory adjuvants, facilitating targeted immune activation and promoting robust antitumor responses. By improving antigen presentation and localizing immune activation within the tumor microenvironment, nano-oncologic vaccines can significantly increase the efficacy of cancer immunotherapy, particularly when combined with other treatment modalities. This review highlights the mechanisms through which nano-oncologic vaccines operate, their potential to overcome existing limitations in cancer treatment, and ongoing advancements in design. Additionally, it discusses the targeted delivery approach, such as EPR effects, pH response, ultrasonic response, and magnetic response. The combination therapy effects with photothermal therapy, radiotherapy, or immune checkpoint inhibitors are also discussed. Overall, nano-oncologic vaccines hold great promise for changing the landscape of cancer treatment and advancing personalized medicine, paving the way for more effective therapeutic strategies tailored to individual patient needs.

JR, Xu Z, Wang S. Ultrasound-Guided Histotripsy Triggers the Release of Tumor-Associated Antigens from Breast Cancers

Background/Objectives: There is increasing evidence to indicate that histotripsy treatment can enhance the host anti-tumor immune responses both locally at the targeting tumor site as well as systemically from abscopal effects. Histotripsy is a non-invasive ultrasound ablation technology that mechanically disrupts target tissue via cavitation. A key factor contributing to histotripsy-induced abscopal effects is believed to be the release of tumor-specific antigens (TSAs) or tumor-associated antigens (TAAs) that induce a systemic immune response. In this study, we studied the effect of histotripsy treatment on the release of HER2, a well-defined TAA target for cancer immunotherapy. Methods: A range of doses of histotripsy administered to HER2-postive mammary tumor cells in an in vitro cell culture system and an ex vivo tumor were applied. In addition, a single dose of histotripsy was used for an in vivo murine tumor model. The released proteins, and specifically HER2, in both tumor cell-free supernatants and tumor cell pellets were analyzed by a BCA protein assay, an ultra-performance liquid chromatography (UPLC) assay, and Western blot. Results: Our results showed that histotripsy could significantly trigger the release of HER2 proteins in the current study. The level of HER2 proteins was actually higher in tumor cell-free supernatants than in tumor cell pellets, suggesting that HER2 was released from the intracellular domain into the extracellular compartment. Furthermore, proportionally more HER2 protein was released at higher histotripsy doses, indicating free HER2 was histotripsy-dose-dependent. Conclusions: In conclusion, we have qualitatively and quantitatively demonstrated that histotripsy treatment triggers the release of HER2 from the tumor cells into the extracellular compartment. The histotripsy-mediated release of HER2 antigens provides important insights into the mechanism underlying its immunostimulation and suggests the potential of TSA/TAA-based immunotherapies in numerous cancer types.

Application of biomimetic nanovaccines in cancer immunotherapy: A useful strategy to help combat immunotherapy resistance

Breakthroughs in actual clinical applications have begun through vaccine-based cancer immunotherapy, which uses the body's immune system, both humoral and cellular, to attack malignant cells and fight diseases. However, conventional vaccine approaches still face multiple challenges eliciting effective antigen-specific immune responses, resulting in immunotherapy resistance. In recent years, biomimetic nanovaccines have emerged as a promising alternative to conventional vaccine approaches by incorporating the natural structure of various biological entities, such as cells, viruses, and bacteria. Biomimetic nanovaccines offer the benefit of targeted antigen-presenting cell (APC) delivery, improved antigen/adjuvant loading, and biocompatibility, thereby improving the sensitivity of immunotherapy. This review presents a comprehensive overview of several kinds of biomimetic nanovaccines in anticancer immune response, including cell membrane-coated nanovaccines, self-assembling protein-based nanovaccines, extracellular vesicle-based nanovaccines, natural ligand-modified nanovaccines, artificial antigen-presenting cells-based nanovaccines and liposome-based nanovaccines. We also discuss the perspectives and challenges associated with the clinical translation of emerging biomimetic nanovaccine platforms for sensitizing cancer cells to immunotherapy.

Nucleic acid-based vaccine for ovarian cancer cells; bench to bedside

Ovarian cancer continues to be a difficult medical issue that affects millions of individuals worldwide. Important platforms for cancer immunotherapy include checkpoint inhibitors, chimeric antigen receptor T cells, bispecific antibodies, cancer vaccines, and other cell-based treatments. To avoid numerous infectious illnesses, conventional vaccinations based on synthetic peptides, recombinant subunit vaccines, and live attenuated and inactivated pathogens are frequently utilized. Vaccine manufacturing processes, however, are not entirely safe and carry a significant danger of contaminating living microorganisms. As a result, the creation of substitute vaccinations is required for both viral and noninfectious illnesses, including cancer. Recently, there has been testing of nucleic acid vaccines, or NAVs, as a cancer therapeutic. Tumor antigens (TAs) are genetically encoded by DNA and mRNA vaccines, which the host uses to trigger immune responses against ovarian cancer cells that exhibit the TAs. Despite being straightforward, safe, and easy to produce, NAVs are not currently thought to be an ideal replacement for peptide vaccines. Some obstacles to this strategy include selecting the appropriate therapeutic agents (TAs), inadequate immunogenicity, and the immunosuppressive characteristic of ovarian cancer. We focus on strategies that have been employed to increase NAVs' effectiveness in the fight against ovarian cancer in this review.

Nanovaccines: An effective therapeutic approach for cancer therapy

Cancer vaccines hold considerable promise for the immunotherapy of solid tumors. Nanomedicine offers several strategies for enhancing vaccine effectiveness. In particular, molecular or (sub) cellular vaccines can be delivered to the target lymphoid tissues and cells by nanocarriers and nanoplatforms to increase the potency and durability of antitumor immunity and minimize negative side effects. Nanovaccines use nanoparticles (NPs) as carriers and/or adjuvants, offering the advantages of optimal nanoscale size, high stability, ample antigen loading, high immunogenicity, tunable antigen presentation, increased retention in lymph nodes, and immunity promotion. To induce antitumor immunity, cancer vaccines rely on tumor antigens, which are administered in the form of entire cells, peptides, nucleic acids, extracellular vesicles (EVs), or cell membrane-encapsulated NPs. Ideal cancer vaccines stimulate both humoral and cellular immunity while overcoming tumor-induced immune suppression. Herein, we review the key properties of nanovaccines for cancer immunotherapy and highlight the recent advances in their development based on the structure and composition of various (including synthetic and semi (biogenic) nanocarriers. Moreover, we discuss tumor cell-derived vaccines (including those based on whole-tumor-cell components, EVs, cell membrane-encapsulated NPs, and hybrid membrane-coated NPs), nanovaccine action mechanisms, and the challenges of immunocancer therapy and their translation to clinical applications.

A novel fluoropolymer as a protein delivery vector with robust adjuvant effect for cancer immunotherapy

The inefficient treatment using protein-based nanovaccines is largely attributed to their inadequate immunogenicity. Herein, we developed a novel fluoropolymer (PF) via ring-opening polymerization and constructed a fluoropolymer-based nanovaccine for tumor immunotherapy. Due to the existence of fluoroalkyl chains, PF not only played a crucial role in tumor antigen delivery but also exhibited a remarkable adjuvant effect in enhancing the immunogenicity of nanovaccines. The nanovaccines formed by mixing PF with a model antigen ovalbumin (OVA) enhanced the uptake of antigen proteins by dendritic cells (DCs) and promoted the maturation and antigen presentation of DCs. Compared with free OVA, PF/OVA showed better efficacy in both pre-cancer prevention and tumor treatment. Furthermore, the proportion of CD4+ T and CD8+ T cells was significantly increased in lymph nodes and tumors of mice immunized with PF/OVA. Additionally, there was a great enhancement in the levels of key anti-tumor cytokines (TNF-α and IFN-γ) in the serum of the PF/OVA immunized mice. Our research has shown that fluoropolymer PF applied as a protein vector and adjuvant has great potential for the development of nanovaccines with robust immunogenicity.

Next-Generation Vaccines: Nanovaccines in the Fight against SARS-CoV-2 Virus and beyond SARS-CoV-2

The virus responsible for the coronavirus viral pandemic is the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Emerging SARS-CoV-2 variants caused by distinctive mutations within the viral spike glycoprotein of SARS-CoV-2 are considered the cause for the rapid spread of the disease and make it challenging to treat SARS-CoV-2. The manufacturing of appropriate efficient vaccines and therapeutics is the only option to combat this pandemic. Nanomedicine has enabled the delivery of nucleic acids and protein-based vaccines to antigen-presenting cells to produce protective immunity against the coronavirus. Nucleic acid-based vaccines, particularly mRNA nanotechnology vaccines, are the best prevention option against the SARS-CoV-2 pandemic worldwide, and they are effective against the novel coronavirus and its multiple variants. This review will report on progress made thus far with SARS-CoV-2 vaccines and beyond employing nanotechnology-based nucleic acid vaccine approaches.

Analysis of the Clinical Value of MAGE-A9 Expressions in Cervical Cancer Tissues and PBMC

Objective

The aim of this study is to explore the expressions and clinical significance of melanoma-associated antigen-A9 (MAGE-A9) in cervical cancer tissues and peripheral blood mononuclear cells (PBMC).

Methods

108 patients who were scheduled to undergo cervical conization or extensive hysterectomy between March 2019 and January 2021 due to cervical lesions were selected by convenient sampling. According to postoperative pathological results, the patients were divided into a cervical cancer group (n = 64) and cervical intraepithelial neoplasia (CIN) group (n = 44). The expression levels of MAGE-A9 mRNA in cervical lesion tissues and PBMC were detected by real-time fluorescence quantitative PCR, and the expression of MAGE-A9 protein in lesion tissues was detected by immunohistochemistry. The correlation between MAGE-A9 mRNA expressions in cancer tissues and PBMC and serum tumor markers in patients with cervical cancer and the relationship between MAGE-A9 protein expression in cancer tissues and clinicopathological characteristics were analyzed, and a receiver operating characteristic curve (ROC curve) was drawn to explore the diagnostic value of MAGE-A9 mRNA expressions in cancer tissues and PBMC on cervical cancer.

Results

The expression levels of MAGE-A9 mRNA in cervical lesion tissues and PBMC in the cervical cancer group were significantly higher than those in the CIN group (P < 0.05), and the levels of serum SCC-Ag, CA-125, and CEA were significantly higher than those in the CIN group (P < 0.05). The positive rate of the MAGE-A9 protein expression in cervical lesion tissues in the cervical cancer group was significantly higher than that in the CIN group (P < 0.05). The expression levels of MAGE-A9 mRNA in cancer tissues and PBMC of patients with cervical cancer were positively correlated with serum SCC-Ag, CA-125, and CEA (P < 0.05). The positive rate of the MAGE-A9 protein expression in cervical cancer tissues was related to FIGO stage, tumor diameter, degree of differentiation, lymph node metastasis, and high-risk HPV infection (P < 0.05) and was not correlated with age and pathological type (P > 0.05). The areas under the ROC curves of MAGE-A9 mRNA in lesion tissue and MAGE-A9 mRNA in PBMC were 0.925 and 0.900 in the diagnosis of cervical cancer (P < 0.05).

Conclusion

The expressions of MAGE-A9 in cancer tissues and PBMC of patients with cervical cancer are upregulated, which is related to the levels of serum tumor markers and the progression of disease. MAGE-A9 is expected to become an important marker for the diagnosis of early cervical cancer.

Experimental Study on Antitumor Activity of Gold Nanoparticles-Assisted Delivery of PD-L1 SiRNA in Non-Small Cell Lung Cancer

Objective: By delivering PD-L1 siRNA to A549 cells using nano-gold we tried to enhance the lymphocytes’ ability to inhibit the growth of non-small-cell lung cancer. Methods: In a one-step reaction, gold nanoparticles and PD-L1 siRNA were combined to form gold nanoparticles and PD-L1 siRNA complexes. After incubation with A549 cells, PD-1 was detected by quantitative polymerase chain reaction (qPCR) as well as immunohistochemical staining. Mouse xenografts were used to test the anti-tumor activity. It was found that using a gold nanoparticle-siRNA complex, we were able to successfully reduce the expression of PD-L1 in A549 cells. The nano-gold-siRNA complex outperformed free siRNA after co-incubation with tumor cells. In vivo experiments show that nano-gold-siRNA is more effective at targeting tumor tissue and increasing T cells’ ability to inhibit the A549 tumor than free siRNA. For this study, we found that the delivery of siRNA to tumors using a nano-gold nanoparticle enhances the ability of the siRNA to aggregate in tumors, which in turn enhances the ability of T lymphocytes to combat non-small cell lung cancer by enhancing their anti-tumor activity. This nano-gold-PD-L1-siRNA complex may be a promising treatment for non-small cell lung cancer, according to preliminary results.

The Application of Sensitive Nano-Confined Nanoparticle System Using siRNA Targeting Extracellular Signal-Regulated Kinase (ERK)/Mitogen-Activated Protein Kinase (MAPK) Pathway in Gastrointestinal Cancer

In this study we tried to develop a Sensitive Nano-Confined Nanoparticles (S-NCN) system using siRNA against Programmed death-ligand 1 (PDL-1) and Polo Like Kinase 1 (Plk1) to treat gastrointestinal cancer. In this regard, we first synthesized the corresponding materials, prepared the S-NCN system, and verified its functionality. Subsequently, we demonstrated in vitro that S-NCN delivery of siPlk1 could effectively downregulate the expression of Plk1 gene in GC1436 cells and lead to significant apoptosis of tumor cells. Xenografted gastrointestinal cancer model mice were used to evaluate the in vivo efficacy of the nanoparticle. We have demonstrated that the developed S-NCN system can efficiently bind siRNA and deliver it into target tumor cells, solving the main obstacle of siRNA delivery in vivo and effectively silencing target genes with a very potential delivery option.