Antitumour dendritic cell vaccination in a priming and boosting approach

mRNA vaccines contribute to innate and adaptive immunity to enhance immune response in vivo

Messenger RNA (mRNA) therapeutics have been widely employed as strategies for the treatment and prevention of diseases. Amid the global outbreak of COVID-19, mRNA vaccines have witnessed rapid development. Generally, in the case of mRNA vaccines, the initiation of the innate immune system serves as a prerequisite for triggering subsequent adaptive immune responses. Critical cells, cytokines, and chemokines within the innate immune system play crucial and beneficial roles in coordinating tailored immune reactions towards mRNA vaccines. Furthermore, immunostimulators and delivery systems play a significant role in augmenting the immune potency of mRNA vaccines. In this comprehensive review, we systematically delineate the latest advancements in mRNA vaccine research, present an in-depth exploration of strategies aimed at amplifying the immune effectiveness of mRNA vaccines, and offer some perspectives and recommendations regarding the future advancements in mRNA vaccine development.

Personalized cancer T-cell therapy takes the stage, mirroring vaccine success

Personalized T-cell therapy is emerging as a pivotal treatment of cancer care by tailoring cellular therapies to individual genetic and antigenic profiles, echoing the exciting success of personalized vaccines. We describe here the parallel evolution and analogies of cancer vaccines and T-cell therapies.

Identification of immune-related tumor antigens and immune subtypes in osteosarcoma

Purpose

The development of tumor vaccines has become a hot topic in immunotherapy for osteosarcoma (OS); however, more tumor antigens with stronger immunogenicity need to be identified.

Methods

We downloaded six sets of gene expression profile data from online databases. The overexpressed genes were analyzed, intersected, and used to calculate the immune infiltration abundance in the TARGET OS dataset based on their expression matrix. Potential tumor antigen genes were identified based on whether they exhibited a high correlation with the antigen-presenting cells (APCs). A total of 1330 immune-related genes (IRGs) from the ImmPort website were retrieved based on their expression, and the Consensus Cluster method was used to obtain immune subtypes of the OS samples. Prognosis, immune microenvironment, and sensitivity to drugs were compared among the immune subtypes.

Results

In total, 680 genes were overexpressed in at least two datasets, of which TREM2, TNFRSF12A, and THY1 were positively correlated with different APCs. Based on the expression matrix of 1330 IRGs in TARGET-OS, two immune subtypes, IS1 and IS2, were identified. The prognosis of the IS1 subtype was better than that of IS2, the expression of immune checkpoint (ICP)-related genes was higher in patients with the IS1 subtype, and immune cell infiltration and sensitivity to 16 drugs were generally higher in IS1 subtype patients.

Conclusion

We identified three APC-correlated genes that can be considered to code for potential novel tumor antigens for OS vaccines. Two immune subtypes in patients with OS were identified to implement personalized treatments using mRNA vaccines.

Phase and Defect Engineering of MoSe2 Nanosheets for Enhanced NIR-II Photothermal Immunotherapy

Inducing immunogenic cell death (ICD) during photothermal therapy (PTT) has the potential to effectively trigger photothermal immunotherapy (PTI). However, ICD induced by PTT alone is often limited by inefficient PTT, low immunogenicity of tumor cells, and a dysregulated redox microenvironment. Herein, we develop MoSe2 nanosheets with high-percentage metallic 1T phase and rich exposed active Mo centers through phase and defect engineering of MoSe2 as an effective nanoagent for PTI. The metallic 1T phase in MoSe2 nanosheets endows them with strong PTT performance, and the abundant exposed active Mo centers endow them with high activity for glutathione (GSH) depletion. The MoSe2-mediated high-performance PTT synergizing with efficient GSH depletion facilitates the release of tumor-associated antigens to induce robust ICD, thus significantly enhancing checkpoint blockade immunotherapy and activating systemic immune response in mouse models of colorectal cancer and triple-negative metastatic breast cancer.

Factor of time in dendritic cell (DC) maturation: short-term activation of DCs significantly improves type 1 cytokine production and T cell responses

Dendritic cells (DCs) have been intensively studied in correlation to tumor immunology and for the development DC-based cancer vaccines. Here, we present the significance of the temporal aspect of DC maturation for the most essential subsequent timepoint, namely at interaction with responding T cells or after CD40-Ligand restimulation. Mostly, DC maturation is still being achieved by activation processes which lasts 24 h to 48 h. We hypothesized this amount of time is excessive from a biological standpoint and could be the underlying cause for functional exhaustion. Indeed, shorter maturation periods resulted in extensive capacity of monocyte-derived DCs to produce inflammatory cytokines after re-stimulation with CD40-Ligand. This effect was most evident for the primary type 1 polarizing cytokine, IL-12p70. This capacity reached peak at 6 h and dropped sharply with longer exposure to initial maturation stimuli (up to 48 h). The 6 h maturation protocol reflected superiority in subsequent functionality tests. Namely, DCs displayed twice the allostimulatory capacity of 24 h- and 48 h-matured DCs. Similarly, type 1 T cell response measured by IFN-γ production was 3-fold higher when CD4+ T cells had been stimulated with shortly matured DC and over 8-fold greater in case of CD8+ T cells, compared to longer matured DCs. The extent of melanoma-specific CD8+ cytotoxic T cell induction was also greater in case of 6 h DC maturation. The major limitation of the study is that it lacks in vivo evidence, which we aim to examine in the future. Our findings show an unexpectedly significant impact of temporal exposure to activation signals for subsequent DC functionality, which we believe can be readily integrated into existing knowledge on in vitro/ex vivo DC manipulation for various uses. We also believe this has important implications for DC vaccine design for future clinical trials.

Polydopamine nanoparticles cross-linked hyaluronic acid photothermal hydrogel with cascading immunoinducible effects for in situ antitumor vaccination

Tumor vaccine, which can effectively prevent tumor recurrence and metastasis, is a promising tool in tumor immunotherapy. However, heterogeneity of tumors and the inability to achieve a cascade effect limit the therapeutic effects of most developing tumor vaccine. We have developed a cascading immunoinducible in-situ mannose-functionalized polydopamine loaded with imiquimod phenylboronic hyaluronic acid nanocomposite gel vaccine (M/P-PDA@IQ PHA) through a boronic ester-based reaction. This reaction utilizes mannose-functionalized polydopamine loaded with imiquimod (M/P-PDA@IQ NAs) as a cross-linking agent to react with phenylboronic-grafted hyaluronic acid. Under near-infrared light irradiation, the M/P-PDA@IQ PHA caused local hyperthermia to trigger immunogenic cell death of tumor cells and tumor-associated antigens (TAAs) releasing. Subsequently, the M/P-PDA@IQ NAs which were gradually released by the pH/ROS/GSH-triggered degradation of M/P-PDA@IQ PHA, could capture and deliver these TAAs to lymph nodes. Finally, the M/P-PDA@IQ NAs facilitated maturation and cross-presentation of dendritic cells, as well as activation of cytotoxic T lymphocytes. Overall, the M/P-PDA@IQ PHA could serve as a novel in situ vaccine to stimulate several key nodes including TAAs release and capture, targeting lymph nodes and enhanced dendritic cells uptake and maturation as well as T cells activation. This cascading immune activation strategy can effectively elicit antitumor immune response.

Engineered dendritic cells-derived exosomes harboring HIV-1 Nefmut-Tat fusion protein and heat shock protein 70: A promising HIV-1 safe vaccine candidate

Antigen presenting cells (APCs)-derived exosomes are nano-vesicles that can induce antigen-specific T cell responses, and possess therapeutic effects in clinical settings. Moreover, dendritic cells (DCs)-based vaccines have been developed to combat human immunodeficiency virus-1 (HIV-1) infection in preclinical and clinical trials. We investigated the immunostimulatory effects (B- and T-cells activities) of DCs- and exosomes-based vaccine constructs harboring HIV-1 Nefmut-Tat fusion protein as an antigen candidate and heat shock protein 70 (Hsp70) as an adjuvant in mice. The modified DCs and engineered exosomes harboring Nefmut-Tat protein or Hsp70 were prepared using lentiviral vectors compared to electroporation, characterized and evaluated by in vitro and in vivo immunological tests. Our data indicated that the engineered exosomes induced high levels of total IgG, IgG2a, IFN-γ, TNF-α and Granzyme B. Moreover, co-injection of exosomes harboring Hsp70 could significantly increase the secretion of antibodies, cytokines and Granzyme B. The highest levels of IFN-γ and TNF-α were observed in exosomes harboring Nefmut-Tat combined with exosomes harboring Hsp70 (Exo-Nefmut-Tat + Exo-Hsp70) regimen after single-cycle replicable (SCR) HIV-1 exposure. Generally, Exo-Nefmut-Tat + Exo-Hsp70 regimen can be considered as a promising safe vaccine candidate due to high T-cells (Th1 and CTL) activity and its maintenance against SCR HIV-1 exposure.

Engineered Bacteriophage-Based In Situ Vaccine Remodels a Tumor Microenvironment and Elicits Potent Antitumor Immunity

In situ vaccines (ISVs) utilize the localized delivery of chemotherapeutic agents or radiotherapy to stimulate the release of endogenous antigens from tumors, thereby eliciting systemic and persistent immune activation. Recently, a bioinspired ISV strategy has attracted tremendous attention due to its features such as an immune adjuvant effect and genetic plasticity. M13 bacteriophages are natural nanomaterials with intrinsic immunogenicity, genetic flexibility, and cost-effectiveness for large-scale production, demonstrating the potential for application in cancer vaccines. In this study, we propose an ISV based on the engineered M13 bacteriophage targeting CD40 (M13CD40) for dendritic cell (DC)-targeted immune stimulation, named H-GM-M13CD40. We induce immunogenic cell death and release tumor antigens through local delivery of (S)-10-hydroxycamptothecin (HCPT), followed by intratumoral injection of granulocyte-macrophage colony stimulating factor (GM-CSF) and M13CD40 to enhance DC recruitment and activation. We demonstrate that this ISV strategy can result in significant accumulation and activation of DCs at the tumor site, reversing the immunosuppressive tumor microenvironment. In addition, H-GM-M13CD40 can synergize with the PD-1 blockade and induce abscopal effects in cold tumor models. Overall, our study verifies the immunogenicity of the engineered M13CD40 bacteriophage and provides a proof of concept that the engineered M13CD40 phage can function as an adjuvant for ISVs.

Chiral coordination polymer nanowires boost radiation-induced in situ tumor vaccination

Radiation-induced in situ tumor vaccination alone is very weak and insufficient to elicit robust antitumor immune responses. In this work, we address this issue by developing chiral vidarabine monophosphate-gadolinium nanowires (aAGd-NWs) through coordination-driven self-assembly. We elucidate the mechanism of aAGd-NW assembly and characterize their distinct features, which include a negative surface charge, ultrafine topography, and right-handed chirality. Additionally, aAGd-NWs not only enhance X-ray deposition but also inhibit DNA repair, thereby enhancing radiation-induced in situ vaccination. Consequently, the in situ vaccination induced by aAGd-NWs sensitizes radiation enhances CD8+ T-cell-dependent antitumor immunity and synergistically potentiates the efficacy immune checkpoint blockade therapies against both primary and metastatic tumors. The well-established aAGd-NWs exhibit exceptional therapeutic capacity and biocompatibility, offering a promising avenue for the development of radioimmunotherapy approaches.

Cell membrane coated nanoparticles as a biomimetic drug delivery platform for enhancing cancer immunotherapy

Cancer immunotherapy, a burgeoning modality for cancer treatment, operates by activating the autoimmune system to impede the growth of malignant cells. Although numerous immunotherapy strategies have been employed in clinical cancer therapy, the resistance of cancer cells to immunotherapeutic medications and other apprehensions impede the attainment of sustained advantages for most patients. Recent advancements in nanotechnology for drug delivery hold promise in augmenting the efficacy of immunotherapy. However, the efficacy is currently constrained by the inadequate specificity of delivery, low rate of response, and the intricate immunosuppressive tumor microenvironment. In this context, the investigation of cell membrane coated nanoparticles (CMNPs) has revealed their ability to perform targeted delivery, immune evasion, controlled release, and immunomodulation. By combining the advantageous features of natural cell membranes and nanoparticles, CMNPs have demonstrated their unique potential in the realm of cancer immunotherapy. This review aims to emphasize recent research progress and elucidate the underlying mechanisms of CMNPs as an innovative drug delivery platform for enhancing cancer immunotherapy. Additionally, it provides a comprehensive overview of the current immunotherapeutic strategies involving different cell membrane types of CMNPs, with the intention of further exploration and optimization.

Construction of lymph nodes-targeting tumor vaccines by using the principle of DNA base complementary pairing to enhance anti-tumor cellular immune response

Tumor vaccines, a crucial immunotherapy, have gained growing interest because of their unique capability to initiate precise anti-tumor immune responses and establish enduring immune memory. Injected tumor vaccines passively diffuse to the adjacent draining lymph nodes, where the residing antigen-presenting cells capture and present tumor antigens to T cells. This process represents the initial phase of the immune response to the tumor vaccines and constitutes a pivotal determinant of their effectiveness. Nevertheless, the granularity paradox, arising from the different requirements between the passive targeting delivery of tumor vaccines to lymph nodes and the uptake by antigen-presenting cells, diminishes the efficacy of lymph node-targeting tumor vaccines. This study addressed this challenge by employing a vaccine formulation with a tunable, controlled particle size. Manganese dioxide (MnO2) nanoparticles were synthesized, loaded with ovalbumin (OVA), and modified with A50 or T20 DNA single strands to obtain MnO2/OVA/A50 and MnO2/OVA/T20, respectively. Administering the vaccines sequentially, upon reaching the lymph nodes, the two vaccines converge and simultaneously aggregate into MnO2/OVA/A50-T20 particles through base pairing. This process enhances both vaccine uptake and antigen delivery. In vitro and in vivo studies demonstrated that, the combined vaccine, comprising MnO2/OVA/A50 and MnO2/OVA/T20, exhibited robust immunization effects and remarkable anti-tumor efficacy in the melanoma animal models. The strategy of controlling tumor vaccine size and consequently improving tumor antigen presentation efficiency and vaccine efficacy via the DNA base-pairing principle, provides novel concepts for the development of efficient tumor vaccines.

Neoantigen Identification and Dendritic Cell-Based Vaccines for Lung Cancer Immunotherapy

Immunotherapies can treat many cancers, including difficult-to-treat cases such as lung cancer. Due to its tolerability, long-lasting therapeutic responses, and efficacy in a wide spectrum of patients, immunotherapy can also help to treat lung cancer, which has few treatment choices. Tumor-specific antigens (TSAs) for cancer vaccinations and T-cell therapies are difficult to discover. Neoantigens (NeoAgs) from genetic mutations, irregular RNA splicing, protein changes, or viral genetic sequences in tumor cells provide a solution. NeoAgs, unlike TSAs, are non-self and can cause an immunological response. Next-generation sequencing (NGS) and bioinformatics can swiftly detect and forecast tumor-specific NeoAgs. Highly immunogenic NeoAgs provide personalized or generalized cancer immunotherapies. Dendritic cells (DCs), which originate and regulate T-cell responses, are widely studied potential immunotherapeutic therapies for lung cancer and other cancers. DC vaccines are stable, reliable, and safe in clinical trials. The purpose of this article is to evaluate the current status, limitations, and prospective clinical applications of DC vaccines, as well as the identification and selection of major histocompatibility complex (MHC) class I and II genes for NeoAgs. Our goal is to explain DC biology and activate DC manipulation to help researchers create extremely potent cancer vaccines for patients.

Targeting Dendritic Cell Dysfunction to Circumvent Anti-PD1 Resistance in Head and Neck Cancer

PURPOSE

Neoadjuvant anti-PD1 (aPD1) therapies are being explored in surgically resectable head and neck squamous cell carcinoma (HNSCC). Encouraging responses have been observed, but further insights into the mechanisms underlying resistance and approaches to improve responses are needed.

EXPERIMENTAL DESIGN

We integrated data from syngeneic mouse oral carcinoma (MOC) models and neoadjuvant pembrolizumab HNSCC patient tumor RNA-sequencing data to explore the mechanism of aPD1 resistance. Tumors and tumor-draining lymph nodes (DLN) from MOC models were analyzed for antigen-specific priming. CCL5 expression was enforced in an aPD1-resistant model.

RESULTS

An aPD1-resistant mouse model showed poor priming in the tumor DLN due to type 1 conventional dendritic cell (cDC1) dysfunction, which correlated with exhausted and poorly responsive antigen-specific T cells. Tumor microenvironment analysis also showed decreased cDC1 in aPD1-resistant tumors compared with sensitive tumors. Following neoadjuvant aPD1 therapy, pathologic responses in patients also positively correlated with baseline transcriptomic cDC1 signatures. In an aPD1-resistant model, intratumoral cDC1 vaccine was sufficient to restore aPD1 response by enhancing T-cell infiltration and increasing antigen-specific responses with improved tumor control. Mechanistically, CCL5 expression significantly correlated with neoadjuvant aPD1 response and enforced expression of CCL5 in an aPD1-resistant model, enhanced cDC1 tumor infiltration, restored antigen-specific responses, and recovered sensitivity to aPD1 treatment.

CONCLUSIONS

These data highlight the contribution of tumor-infiltrating cDC1 in HNSCC aPD1 response and approaches to enhance cDC1 infiltration and function that may circumvent aPD1 resistance in patients with HNSCC.

Dismantlable Coronated Nanoparticles for Coupling the Induction and Perception of Immunogenic Cell Death

Therapy-induced immunogenic cell death (ICD) can initiate both innate and adaptive immune responses for amplified anti-tumor efficacy. However, dying cell-released ICD signals are prone to being sequestered by the TIM-3 receptors on dendritic cell (DC) surfaces, preventing immune surveillance. Herein, dismantlable coronated nanoparticles (NPs) are fabricated as a type of spatiotemporally controlled nanocarriers for coupling tumor cell-mediated ICD induction to DC-mediated immune sensing. These NPs are loaded with an ICD inducer, mitoxantrone (MTO), and wrapped by a redox-labile anti-TIM-3 (αTIM-3) antibody corona, forming a separable core-shell structure. The antibody corona disintegrates under high levels of extracellular reactive oxygen species in the tumor microenvironment, exposing the MTO-loaded NP core for ICD induction and releasing functional αTIM-3 molecules for DC sensitization. Systemic administration of the coronated NPs augments DC maturation, promotes cytotoxic T cell recruitment, enhances tumor susceptibility to immune checkpoint blockade, and prevents the side effects of MTO. This study develops a promising nanoplatform to unleash the potential of host immunity in cancer therapy.

Hit-and-run vaccine system that overcomes limited neoantigen epitopes for efficient broad antitumor response

Neoantigen cancer vaccines have been envisioned as one of the most promising means for cancer therapies. However, identifying neoantigens for tumor types with low tumor mutation burdens continues to limit the effectiveness of neoantigen vaccines. Herein, we proposed a "hit-and-run" vaccine strategy which primes T cells to attack tumor cells decorated with exogenous "neo-antigens". This vaccine strategy utilizes a peptide nanovaccine to elicit antigen-specific T cell responses after tumor-specific decoration with a nanocarrier containing the same peptide antigens. We demonstrated that a poly(2-oxazoline)s (POx) conjugated with OVA257-264 peptide through a matrix metalloprotease 2 (MMP-2) sensitive linker could efficiently and selectively decorate tumor cells with OVA peptides in vivo. Then, a POx-based nanovaccine containing OVA257-264 peptides to elicit OVA-specific T cell responses was designed. In combination with this hit-and-run vaccine system, an effective vaccine therapy was demonstrated across tumor types even without OVA antigen expression. This approach provides a promising and uniform vaccine strategy against tumors with a low tumor mutation burden.

Myeloid Cell-Triggered In Situ Cell Engineering for Robust Vaccine-Based Cancer Treatment

Following the success of the dendritic cell (DC) vaccine, the cell-based tumor vaccine shows its promise as a vaccination strategy. Except for DC cells, targeting other immune cells, especially myeloid cells, is expected to address currently unmet clinical needs (e.g., tumor types, safety issues such as cytokine storms, and therapeutic benefits). Here, it is shown that an in situ injected macroporous myeloid cell adoptive scaffold (MAS) not only actively delivers antigens (Ags) that are triggered by scaffold-infiltrating cell surface thiol groups but also releases granulocyte-macrophage colony-stimulating factor and other adjuvant combos. Consequently, this promotes cell differentiation, activation, and migration from the produced monocyte and DC vaccines (MASVax) to stimulate antitumor T-cell immunity. Neoantigen-based MASVax combined with immune checkpoint blockade induces rejection of established tumors and long-term immune protection. The combined depletion of immunosuppressive myeloid cells further enhances the efficacy of MASVax, indicating the potential of myeloid cell-based therapies for immune enhancement and normalization treatment of cancer.

The future of cancer vaccines against colorectal cancer

INTRODUCTION

Colorectal cancer (CRC) is the second most lethal malignancy worldwide. Immune checkpoint inhibitors (ICIs) benefit only 15% of patients with mismatch repair-deficient/microsatellite instability (dMMR/MSI) CRC. The majority of patients are not suitable due to insufficient immune infiltration. Cancer vaccines are a potential approach for inducing tumor-specific immunity within the solid tumor microenvironment.

AREA COVERED

In this review, we have provided an overview of the current progress in CRC vaccines over the past three years and briefly depict promising directions for further exploration.

EXPERT OPINION

Cancer vaccines are certainly a promising field for the antitumor treatment against CRC. Compared to monotherapy, cancer vaccines are more appropriate as adjuvants to standard treatment, especially in combination with ICI blockade, for microsatellite stable patients. Improved vaccine construction requires neoantigens with sufficient immunogenicity, satisfactory HLA-binding affinity, and an ideal delivery platform with perfect lymph node retention and minimal off-target effects. Prophylactic vaccines that potentially prevent CRC carcinogenesis are also worth investigating. The exploration of appropriate biomarkers for cancer vaccines may benefit prognostic prediction analysis and therapeutic response prediction in patients with CRC. Although many challenges remain, CRC vaccines represent an exciting area of research that may become an effective addition to current guidelines.

The rising roles of exosomes in the tumor microenvironment reprogramming and cancer immunotherapy

Exosomes are indispensable for intercellular communications. Tumor microenvironment (TME) is the living environment of tumor cells, which is composed of various components, including immune cells. Based on TME, immunotherapy has been recently developed for eradicating cancer cells by reactivating antitumor effect of immune cells. The communications between tumor cells and TME are crucial for tumor development, metastasis, and drug resistance. Exosomes play an important role in mediating these communications and regulating the reprogramming of TME, which affects the sensitivity of immunotherapy. Therefore, it is imperative to investigate the role of exosomes in TME reprogramming and the impact of exosomes on immunotherapy. Here, we review the communication role of exosomes in regulating TME remodeling and the efficacy of immunotherapy, as well as summarize the underlying mechanisms. Furthermore, we also introduce the potential application of the artificially modified exosomes as the delivery systems of antitumor drugs. Further efforts in this field will provide new insights on the roles of exosomes in intercellular communications of TME and cancer progression, thus helping us to uncover effective strategies for cancer treatment.

Treatment of a MyD88 inhibitor alleviates rejection and inflammation in xenotransplantation by inhibiting dendritic cells activation and trained immunity in macrophages

BACKGROUND

Acute vascular rejection (AVR) and systemic inflammation in xenograft recipients (SIXR) negatively impact the xenografts survival, and novel immunosuppressants are required to improve survival outcomes. We previously reported that TJ-M2010-5, a myeloid differentiation factor 88 (MyD88) inhibitor, exerts excellent anti-rejection effects in allogeneic transplantation. The aim of the present study was to evaluate the efficacy of TJ-M2010-5 in preventing AVR and SIXR and to investigate whether combined treatment of TJ-M2010-5 with anti-CD154 antibody (MR1) could prolong xenograft survival furthermore.

METHODS

A model involving heart transplantation from Sprague-Dawley rats to BALB/c mice was established in vivo, and the xenografts developed typical AVR. Bone marrow-derived dendritic cells and macrophages were cultured to study the underlying mechanisms induced by rat cardiomyocyte lysate stimulation in vitro.

RESULTS

TJ-M2010-5 monotherapy prolonged xenograft survival, although combination treatment with MR1 further enhanced the anti-AVR and anti-SIXR effects with about 21 days graft survival, compared to monotherapy. TJ-M2010-5 reduced dendritic cell and macrophage activation induced by xenotransplantation, downregulated CD80/CD86 expression, suppressed B-cell activation and anti-donor antibody generation, reduced pro-inflammatory cytokine production and tissue factor expression, and attenuated epigenetic modifications underlying interleukin-6 and tumor necrosis factor-α production in macrophages by inhibiting nuclear factor kappa B nuclear translocation.

CONCLUSIONS

TJ-M2010-5 attenuated AVR and SIXR and contributed to xenograft survival by inhibiting dendritic cell and macrophage activation. A dual-system inhibition strategy combining TJ-M2010-5 with anti-CD154 antibody achieved better results in xenotransplantation.

Unlocking the power of nanomedicine: Cell membrane-derived biomimetic cancer nanovaccines for cancer treatment

Over the past decades, nanomedicine researchers have dedicated their efforts to developing nanoscale platforms capable of more precisely delivering drug payloads to attack tumors. Cancer nanovaccines are exhibiting a distinctive capability in inducing tumor-specific antitumor responses. Nevertheless, there remain numerous challenges that must be addressed for cancer nanovaccines to evoke sufficient therapeutic effects. Cell membrane-derived nanovaccines are an emerging class of cancer vaccines that comprise a synthetic nanoscale core camouflaged by naturally derived cell membranes. The specific cell membrane has a biomimetic nanoformulation with several distinctive abilities, such as immune evasion, enhanced biocompatibility, and tumor targeting, typically associated with a source cell. Here, we discuss the advancements of cell membrane-derived nanovaccines and how these vaccines are used for cancer therapeutics. Translational endeavors are currently in progress, and additional research is also necessary to effectively address crucial areas of demand, thereby facilitating the future successful translation of these emerging vaccine platforms.

Immune Specific and Tumor-Dependent mRNA Vaccines for Cancer Immunotherapy: Reprogramming Clinical Translation into Tumor Editing Therapy

Extensive research into mRNA vaccines for cancer therapy in preclinical and clinical trials has prepared the ground for the quick development of immune-specific mRNA vaccines during the COVID-19 pandemic. Therapeutic cancer vaccines based on mRNA are well tolerated, and are an attractive choice for future cancer immunotherapy. Ideal personalized tumor-dependent mRNA vaccines could stimulate both humoral and cellular immunity by overcoming cancer-induced immune suppression and tumor relapse. The stability, structure, and distribution strategies of mRNA-based vaccines have been improved by technological innovations, and patients with diverse tumor types are now being enrolled in numerous clinical trials investigating mRNA vaccine therapy. Despite the fact that therapeutic mRNA-based cancer vaccines have not yet received clinical approval, early clinical trials with mRNA vaccines as monotherapy and in conjunction with checkpoint inhibitors have shown promising results. In this review, we analyze the most recent clinical developments in mRNA-based cancer vaccines and discuss the optimal platforms for the creation of mRNA vaccines. We also discuss the development of the cancer vaccines' clinical research, paying particular attention to their clinical use and therapeutic efficacy, which could facilitate the design of mRNA-based vaccines in the near future.

Harnessing innate immune pathways for therapeutic advancement in cancer

The innate immune pathway is receiving increasing attention in cancer therapy. This pathway is ubiquitous across various cell types, not only in innate immune cells but also in adaptive immune cells, tumor cells, and stromal cells. Agonists targeting the innate immune pathway have shown profound changes in the tumor microenvironment (TME) and improved tumor prognosis in preclinical studies. However, to date, the clinical success of drugs targeting the innate immune pathway remains limited. Interestingly, recent studies have shown that activation of the innate immune pathway can paradoxically promote tumor progression. The uncertainty surrounding the therapeutic effectiveness of targeted drugs for the innate immune pathway is a critical issue that needs immediate investigation. In this review, we observe that the role of the innate immune pathway demonstrates heterogeneity, linked to the tumor development stage, pathway status, and specific cell types. We propose that within the TME, the innate immune pathway exhibits multidimensional diversity. This diversity is fundamentally rooted in cellular heterogeneity and is manifested as a variety of signaling networks. The pro-tumor effect of innate immune pathway activation essentially reflects the suppression of classical pathways and the activation of potential pro-tumor alternative pathways. Refining our understanding of the tumor's innate immune pathway network and employing appropriate targeting strategies can enhance our ability to harness the anti-tumor potential of the innate immune pathway and ultimately bridge the gap from preclinical to clinical application.

Nanocatalytic Anti-Tumor Immune Regulation

Immunotherapy has brought a new dawn for human being to defeat cancer. Although existing immunotherapy regimens (CAR-T, etc.) have made breakthroughs in the treatments of hematological cancer and few solid tumors such as melanoma, the therapeutic efficacy on most solid tumors is still far from being satisfactory. In recent years, the researches on tumor immunotherapy based on nanocatalytic materials are under rapid development, and significant progresses have been made. Nanocatalytic medicine has been demonstrated to be capable of overcoming the limitations of current clinicnal treatments by using toxic chemodrugs, and exhibits highly attractive advantages over traditional therapies, such as the enhanced and sustained therapeutic efficacy based on the durable catalytic activity, remarkably reduced harmful side-effects without using traditional toxic chemodrugs, and so on. Most recently, nanocatalytic medicine has been introduced in the immune-regulation for disease treatments, especially, in the immunoactivation for tumor therapies. This article presents the most recent progresses in immune-response activations by nanocatalytic medicine-initiated chemical reactions for tumor immunotherapy, and elucidates the mechanism of nanocatalytic medicines in regulating anti-tumor immunity. By reviewing the current research progress in the emerging field, this review will further highlight the great potential and broad prospects of nanocatalysis-based anti-tumor immune-therapeutics.

Advances in immunotherapy for biliary tract cancers

ABSTRACT

Biliary tract cancers (BTC), a heterogeneous disease with poor prognosis, including gallbladder cancer (GBC), intrahepatic cholangiocarcinoma (ICC), and extrahepatic cholangiocarcinoma (ECC). Although surgery is currently the primary regimen to treat BTC, most BTC patients are diagnosed at an advanced stage and miss the opportunity of surgical eradication. As a result, non-surgical therapy serves as the main intervention for advanced BTC. In recent years, immunotherapy has emerged as one of the most promising therapies in a number of solid cancers, and it includes immune checkpoint inhibitors (ICIs) monotherapy or combined therapy, tumor vaccines, oncolytic virus immunotherapy, adoptive cell therapy (ACT), and cytokine therapy. However, these therapies have been practiced in limited clinical settings in patients with BTC. In this review, we focus on the discussion of latest advances of immunotherapy in BTC and update the progress of multiple current clinical trials with different immunotherapies.

Development of novel HPV therapeutic vaccine constructs based on engineered exosomes and tumor cell lysates

AIMS

Human papillomavirus (HPV) infections are highly prevalent globally. While preventive HPV vaccines exist, therapeutic vaccines are needed to treat existing HPV lesions and malignancies. This study evaluated the immunostimulatory and anti-tumor effects of three therapeutic vaccine candidates based on the recombinant protein, tumor cell lysate (TCL), and engineered exosome (Exo) harboring the heat shock protein 27 (Hsp27)-E7 fusion construct in mouse model.

MAIN METHODS

At first, the recombinant Hsp27-E7 protein was generated in E. coli expression system. Then, tumor cell lysates-based and engineered exosomes-based vaccine constructs harboring green fluorescent protein (GFP) and Hsp27-E7 were produced using lentiviral system. Finally, their immunological and antitumor effects were investigated in both prophylactic and therapeutic experiments.

KEY FINDINGS

Our data showed that the recombinant Hsp27-E7 protein, TCL-Hsp27-E7 and Exo-Hsp27-E7 regimens can induce the highest level of IFN-γ, TNF-α and Granzyme B, respectively. The percentage of tumor-free mice was identical for three vaccine strategies (survival rate: 75 %) in both prophylactic and therapeutic experiments. Generally, the TCL-Hsp27-E7, Exo-Hsp27-E7 and recombinant Hsp27-E7 protein regimens induced effective immune responses toward Th1 and CTL activity, and subsequently antitumor effects in mouse model.

SIGNIFICANCE

Regarding to higher Granzyme B secretion, lower tumor growth and more safety, the Exo-Hsp27-E7 regimen can be considered as the most promising HPV vaccination strategy.

Impaired monocyte-derived dendritic cell phenotype in prostate cancer patients: A phenotypic comparison with healthy donors

BACKGROUND

Dendritic cells (DCs) play a crucial role in immunity. Research on monocyte-derived DCs (Mo-DCs) cancer vaccines is in progress despite limited success in clinical trials. This study focuses on Mo-DCs generated from prostate cancer (PCA) patients, comparing them with DCs from healthy donors (HD-DCs).

METHODS

Mo-DCs were isolated from PCA patient samples, and their phenotype was compared to HD-DCs. Key parameters included monocyte count, CD14 expression, and the levels of maturation markers (HLA-DR, CD80, CD86) were assessed.

RESULTS

PCA samples exhibited a significantly lower monocyte count and reduced CD14 expression compared to healthy samples (p ⟨ 0.0001). Additionally, PCA-DCs expressed significantly lower levels of maturation markers, including HLA-DR, CD80, and CD86, when compared to HD-DCs (p = 0.123, p = 0.884, and p = 0.309, respectively).

CONCLUSION

The limited success of DC vaccines could be attributed to impaired phenotypic characteristics. These observations suggest that suboptimal characteristics of Mo-DCs generated from cancer patient blood samples might contribute to the limited success of DC vaccines. Consequently, this study underscores the need for alternative strategies to enhance the features of Mo-DCs for more effective cancer immunotherapies.

Designing nanodiscs as versatile platforms for on-demand therapy

Nowadays, there has been an increasing utilization of nanomedicines for disease treatment. Nanodiscs (NDs) have emerged as a novel platform technology that garners significant attention in biomedical research and drug discovery. NDs are nanoscale phospholipid bilayer discs capable of incorporating membrane proteins and lipids within a native-like environment. They are assembled using amphiphilic biomacromolecular materials, such as apolipoprotein A1 or membrane scaffold proteins (MSPs), peptides, and styrene-maleic acid polymers (SMAs). NDs possess well-defined sizes and shapes, offering a stable, homogeneous, and biologically relevant environment for studying membrane proteins and lipids. Their unique properties have made them highly desirable for diverse applications, including cancer immunotherapy, vaccine development, antibacterial and antiviral therapy, and treating Alzheimer's disease (AD) and diabetes-related conditions. This review discusses the classifications, advantages, and applications of NDs in disease therapy.

A critical time window for leukapheresis product transportation to manufacture clinical-grade dendritic cells with optimal anti-tumor activities

BACKGROUND AIMS

Dendritic cell (DC)-based immunotherapy is a promising approach to treat cancer. However, key aspects governing the reproducible manufacturing of high-quality DC remain incompletely defined. Here, we show that the time window between leukapheresis and DC manufacturing is critical.

METHODS

Transcriptomic profiling by RNA-seq was used to unbiasedly characterize cellular states during each step of DC manufacturing process, and functional assays were used to determine the anti-tumor activities of DC.

RESULTS

During preclinical development of a DC-based cytotherapy platform, CUD-002 (NCT05270720), we found that DC quality varied among different batches, even though commonly used DC maturation markers CD80, CD83 and CD86 were indistinguishable. Multivariate analysis indicated that DC quality was negatively associated with the shipping time from the leukapheresis site to the manufacturing center. To investigate the potential effect of shipping time, we stored leukapheresis materials from three donors for 0, 1, 2 or 3 days before DC manufacturing. For each step, we carried out RNA-seq analysis to unbiasedly characterize cellular states. Integrated bioinformatic analyses indicated that longer storage time reduced the expression of several transcription factors to attenuate interferon pathways.

CONCLUSIONS

Consistently, we found that 3-day storage of leukapheresis materials significantly lowered the efficiency to generate DC but also impaired DC responses to inflammatory signals, resulting in inferior antigen-presentation and cytotoxic T-cell activities. Thus, we recommend using leukapheresis materials within 48 h to manufacture therapeutic DCs.

Cytokine-armed dendritic cell progenitors for antigen-agnostic cancer immunotherapy

Dendritic cells (DCs) are antigen-presenting myeloid cells that regulate T cell activation, trafficking and function. Monocyte-derived DCs pulsed with tumor antigens have been tested extensively for therapeutic vaccination in cancer, with mixed clinical results. Here, we present a cell-therapy platform based on mouse or human DC progenitors (DCPs) engineered to produce two immunostimulatory cytokines, IL-12 and FLT3L. Cytokine-armed DCPs differentiated into conventional type-I DCs (cDC1) and suppressed tumor growth, including melanoma and autochthonous liver models, without the need for antigen loading or myeloablative host conditioning. Tumor response involved synergy between IL-12 and FLT3L and was associated with natural killer and T cell infiltration and activation, M1-like macrophage programming and ischemic tumor necrosis. Antitumor immunity was dependent on endogenous cDC1 expansion and interferon-γ signaling but did not require CD8+ T cell cytotoxicity. Cytokine-armed DCPs synergized effectively with anti-GD2 chimeric-antigen receptor (CAR) T cells in eradicating intracranial gliomas in mice, illustrating their potential in combination therapies.

Mechanisms of Melanoma Progression and Treatment Resistance: Role of Cancer Stem-like Cells

Melanoma is the third most common type of skin cancer, characterized by its heterogeneity and propensity to metastasize to distant organs. Melanoma is a heterogeneous tumor, composed of genetically divergent subpopulations, including a small fraction of melanoma-initiating cancer stem-like cells (CSCs) and many non-cancer stem cells (non-CSCs). CSCs are characterized by their unique surface proteins associated with aberrant signaling pathways with a causal or consequential relationship with tumor progression, drug resistance, and recurrence. Melanomas also harbor significant alterations in functional genes (BRAF, CDKN2A, NRAS, TP53, and NF1). Of these, the most common are the BRAF and NRAS oncogenes, with 50% of melanomas demonstrating the BRAF mutation (BRAFV600E). While the successful targeting of BRAFV600E does improve overall survival, the long-term efficacy of available therapeutic options is limited due to adverse side effects and reduced clinical efficacy. Additionally, drug resistance develops rapidly via mechanisms involving fast feedback re-activation of MAPK signaling pathways. This article updates information relevant to the mechanisms of melanoma progression and resistance and particularly the mechanistic role of CSCs in melanoma progression, drug resistance, and recurrence.

Radiotherapy-Triggered In Situ Tumor Vaccination Boosts Checkpoint Blockaded Immune Response via Antigen-Capturing Nanoadjuvants

In situ vaccination (ISV) formed with the aid of intratumorally injected adjuvants has shed bright light on enhancing the abscopal therapeutic effects of radiotherapy. However, the limited availability of antigens resulting from the radiotherapy-induced immunogenic cell death largely hampers the clinical outcome of ISV. To maximally utilize the radiotherapy-induced antigen, we herein developed a strategy by capturing the radiotherapy-induced antigen in situ with a nanoadjuvant comprised of CpG-loaded Fe3O4 nanoparticles. The highly efficient click reaction between the maleimide residue on the nanoadjuvant and sulfhydryl group on the antigen maximized the bioavailability of autoantigens and CpG adjuvant in vivo. Importantly, combined immune checkpoint blockade can reverse T cell exhaustion after treatment with radiotherapy-induced ISV, thereby largely suppressing the treated and distant tumor. Mechanistically, metabolomics reveals the intratumorally injected nanoadjuvants disrupt redox homeostasis in the tumor microenvironment, further inducing tumor ferroptosis after radiotherapy. Overall, the current study highlights the immense potential of the innovative antigen-capturing nanoadjuvants for synergistically enhancing the antitumor effect.

Click-Chemistry-Mediated Cell Membrane Glycopolymer Engineering to Potentiate Dendritic Cell Vaccines

Dendritic cell vaccine (DCV) holds great potential in tumor immunotherapy owing to its potent ability in eliciting tumor-specific immune responses. Aiming at engineering enhanced DCV, we report the first effort to construct a glycopolymer-engineered DC vaccine (G-DCV) via metabolicglycoengineering and copper-free click-chemistry. Model G-DCV was prepared by firstly delivering tumor antigens, ovalbumin (OVA) into dendritic cells (DC) with fluoroalkane-grafted polyethyleneimines, followed by conjugating glycopolymers with a terminal group of dibenzocyclooctyne (DBCO) onto dendritic cells. Compared to unmodified DCV, our G-DCV could induce stronger T cell activation due to the enhanced adhesion between DCs and T cells. Notably, such G-DCV could more effectively inhibit the growth of the mouse B16-OVA (expressing OVA antigen) tumor model after adoptive transfer. Moreover, by combination with an immune checkpoint inhibitor, G-DCV showed further increased anti-tumor effects in treating different tumor models. Thus, our work provides a novel strategy to enhance the therapeutic effectiveness of DC vaccines.

Dendritic cells: the yin and yang in disease progression

Dendritic cells (DCs) are antigen presenting cells that link innate and adaptive immunity. DCs have been historically considered as the most effective and potent cell population to capture, process and present antigens to activate naïve T cells and originate favorable immune responses in many diseases, such as cancer. However, in the last decades, it has been observed that DCs not only promote beneficial responses, but also drive the initiation and progression of some pathologies, including inflammatory bowel disease (IBD). In line with those notions, different therapeutic approaches have been tested to enhance or impair the concentration and role of the different DC subsets. The blockade of inhibitory pathways to promote DCs or DC-based vaccines have been successfully assessed in cancer, whereas the targeting of DCs to inhibit their functionality has proved to be favorable in IBD. In this review, we (a) described the general role of DCs, (b) explained the DC subsets and their role in immunogenicity, (c) analyzed the role of DCs in cancer and therapeutic approaches to promote immunogenic DCs and (d) analyzed the role of DCs in IBD and therapeutic approaches to reduced DC-induced inflammation. Therefore, we aimed to highlight the "yin-yang" role of DCs to improve the understand of this type of cells in disease progression.

Molecular determinants of immunogenic cell death elicited by radiation therapy

Cancer cells undergoing immunogenic cell death (ICD) can initiate adaptive immune responses against dead cell-associated antigens, provided that (1) said antigens are not perfectly covered by central tolerance (antigenicity), (2) cell death occurs along with the emission of immunostimulatory cytokines and damage-associated molecular patterns (DAMPs) that actively engage immune effector mechanisms (adjuvanticity), and (3) the microenvironment of dying cells is permissive for the initiation of adaptive immunity. Finally, ICD-driven immune responses can only operate and exert cytotoxic effector functions if the microenvironment of target cancer cells enables immune cell infiltration and activity. Multiple forms of radiation, including non-ionizing (ultraviolet) and ionizing radiation, elicit bona fide ICD as they increase both the antigenicity and adjuvanticity of dying cancer cells. Here, we review the molecular determinants of ICD as elicited by radiation as we critically discuss strategies to reinforce the immunogenicity of cancer cells succumbing to clinically available radiation strategies.

Photodynamic Modulation of Endoplasmic Reticulum and Mitochondria Network Boosted Cancer Immunotherapy

Immunogenic cell death (ICD) represents a promising approach for enhancing tumor therapy efficacy by inducing antitumor immune response. However, current ICD inducers often have insufficient endoplasmic reticulum (ER) enrichment and ineffectiveness in tumor immune escape caused by ER-mitochondria interaction. In this study, a kind of photoactivatable probe, THTTPy-PTSA, which enables sequential targeting of the ER and mitochondria is developed. THTTPy-PTSA incorporates p-Toluenesulfonamide (PTSA) for ER targeting, and upon light irradiation, the tetrahydropyridine group undergoes a photo oxidative dehydrogenation reaction, transforming into a pyridinium group that acts as a mitochondria-targeting moiety. The results demonstrate that THTTPy-PTSA exhibits exceptional subcellular translocation from the ER to mitochondria upon light irradiation treatment, subsequently triggers a stronger ER stress response through a cascade-amplification effect. Importantly, the augmented ER stress leads to substantial therapeutic efficacy in a 4T1 tumor model by eliciting the release of numerous damage-associated molecular patterns, thereby inducing evident and widespread ICD, consequently enhancing the antitumor immune efficacy. Collectively, the findings emphasize the pivotal role of photodynamic modulation of the ER-mitochondria network, facilitated by THTTPy-PTSA with precise spatial and temporal regulation, in effectively bolstering the antitumor immune response. This innovative approach presents a promising alternative for addressing the challenges associated with cancer immunotherapy.

Lipoproteins are key immunostimulatory components of Bacillus species for dendritic cell maturation and activation

Dendritic cells (DCs) play an important role in immunity by sensing and responding to invasive microbes. Bacillus species are rod-shaped sporulating bacteria that include the pathogenic Bacillus cereus and commensal Bacillus subtilis. Although the interaction between DC and these two Bacillus species has been studied, their key structural component that prompts DC activation is poorly understood. Here, we investigated the two Bacillus species in DC activation by whole cells and their representative microbe-associated molecular patterns (MAMPs). MAMPs including lipoteichoic acid (LTA), lipoprotein (LPP), and peptidoglycan (PGN) were purified from the two Bacillus species. Among the MAMPs, LPP from both species most potently induced the maturation and activation of DCs while PGN, but not LTA, moderately stimulated DCs. LPPs from both Bacillus species enhanced the expression of DC maturation markers including CCR7, CD40, CD80, CD83, CD86, CD205, MHC-I, and MHC-II. Among the MAMPs from B. cereus, PGN most considerably lowered the endocytic capacity of DCs implying DC maturation whereas PGN from B. subtilis lowered it to a similar degree to its LPP. Furthermore, DCs sensitized with LPPs from both Bacillus species and PGN from B. subtilis moderately induced TNF-α and IL-6 production. Notably, a combination of MAMPs did not show any synergistic effect on DC activation. Taken together, our results demonstrate that LPP is the key structural component in B. cereus and B. subtilis that leads to DC activation.

Harnessing the innate immune system by revolutionizing macrophage-mediated cancer immunotherapy

Immunotherapy is a promising and safer alternative to conventional cancer therapies. It involves adaptive T-cell therapy, cancer vaccines, monoclonal antibodies, immune checkpoint blockade (ICB), and chimeric antigen receptor (CAR) based therapies. However, most of these modalities encounter restrictions in solid tumours owing to a dense, highly hypoxic and immune-suppressive microenvironment as well as the heterogeneity of tumour antigens. The elevated intra-tumoural pressure and mutational rates within fastgrowing solid tumours present challenges in efficient drug targeting and delivery. The tumour microenvironment is a dynamic niche infiltrated by a variety of immune cells, most of which are macrophages. Since they form a part of the innate immune system, targeting macrophages has become a plausible immunotherapeutic approach. In this review, we discuss several versatile approaches (both at pre-clinical and clinical stages) such as the direct killing of tumour-associated macrophages, reprogramming pro-tumour macrophages to anti-tumour phenotypes, inhibition of macrophage recruitment into the tumour microenvironment, novel CAR macrophages, and genetically engineered macrophages that have been devised thus far. These strategies comprise a strong and adaptable macrophage-toolkit in the ongoing fight against cancer and by understanding their significance, we may unlock the full potential of these immune cells in cancer therapy.

Augmenting Immunotherapy via Bioinspired MOF-Based ROS Homeostasis Disruptor with Nanozyme-Cascade Reaction

Despite its remarkable clinical breakthroughs, immune checkpoint blockade (ICB) therapy remains limited by the insufficient immune response in the "cold" tumor. Nanozyme-based antitumor catalysis is associated with precise immune activation in the tumor microenvironment (TME). In this study, a cascade-augmented nanoimmunomodulator (CMZM) with multienzyme-like activities, which includes superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and glutathione oxidase (GSHOx), that dissociates under an acidic and abundant GSH TME, is proposed for multimodal imaging-guided chemodynamic therapy (CDT)/photodynamic therapy (PDT) enhanced immunotherapy. Vigorous multienzyme-like activities can not only produce O2 to alleviate hypoxia and promote the polarization of M2 to M1 macrophages, but also generate ROS (•OH and 1 O2 ) and deplete GSH in the TME to expose necrotic cell fragments and reverse immunosuppressive TME by eliciting the maturation of dendritic cells and infiltration of cytotoxic T lymphocytes (CTLs) in tumors. Therefore, inhibitory effects on both primary and distant tumors are achieved through synergy with an α-PD-L1 blocking antibody. This cascade multienzyme-based nanoplatform provides a smart strategy for highly efficient ICB immunotherapy against "cold" tumors by revising immunosuppressive TME.

Application of Engineered Dendritic Cell Vaccines in Cancer Immunotherapy: Challenges and Opportunities

OPINION STATEMENT

The primary objective of this study is to evaluate the effectiveness of cancer vaccines containing genetically modified dendritic cells (DCs) in inducing transformational immune responses. This paper sheds considerable light on DCs' function in advancing treatment techniques. This objective is achieved by thoroughly analyzing the many facets of DCs and their strategic integration into cancer treatment. Due to their role as immune response regulators, DCs can potentially enhance cancer treatment strategies. DCs have the potential to revolutionize immunotherapy, as shown by a comprehensive analysis of their numerous characteristics. The review deftly transitions from examining the fundamentals of preclinical research to delving into the complexities of clinical implementation while acknowledging the inherent challenges in translating DC vaccine concepts into tangible progress. The analysis also emphasizes the potential synergistic outcomes that can be achieved by combining DC vaccines with established pharmaceuticals, thereby emphasizing the importance of employing a holistic approach to enhance treatment efficacy. Despite the existence of transformative opportunities, advancement is hindered by several obstacles. The exhaustive analysis of technical complexities, regulatory dynamics, and upcoming challenges provides valuable insights for overcoming obstacles requiring strategic navigation to incorporate DC vaccines successfully. This document provides a comprehensive analysis of the developments in DC-based immunotherapy, concentrating on its potential to transform cancer therapy radically.

"Closed-Loop" O2-Economizer Induced In Situ Therapeutic Vaccine against Hypoxic Tumors

Therapeutic tumor vaccines, which use tumor antigens to stimulate a cancer patient's immune system to eventually kill the tumor tissues, have emerged as one of the most attractive strategies in anticancer research. Especially, exploring in situ vaccines has become a potential field in cancer immunotherapy. However, due to the hypoxic tumor microenvironment, the generation of tumor antigens is always mild and not sufficient. Hence, in this study, we designed a closed-loop mitochondrial oxygen-economizer (TPCA) to induce enhanced phototherapy-driven in situ vaccines. The O2-economizer was developed by the integration of the photosensitizer CyI and the mitochondrial inhibitor atovaquone into the PAMAM dendrimer. In vitro and in vivo studies showed that TPCA could enter the mitochondria through (3-propylcarboxyl) triphenylphosphine bromide (TPP) and effectively restrict the respiration of tumor cells to reduce tumor hypoxia, thus providing continuous oxygen for enhanced iodinated cyanine dye mediated photodynamic therapy, which could further induce in situ vaccines for ablating the primary tumor directly and inhibiting the tumor metastasis and recurrence. Furthermore, the antitumor mechanism revealed that O2-economizer-based oxygen-boosted PDT elicited immunogenic cancer cell death with enhanced exposure and release of DAMPs and altered the immunosuppressive tumor microenvironment with increased recruitment of T cells in tumors, thereby inducing in situ vaccines and provoking the systematic antitumor responses against CT26 tumors. This study will provide innovative approaches for local, abscopal, and metastatic tumor treatment.

Close the cancer-immunity cycle by integrating lipid nanoparticle-mRNA formulations and dendritic cell therapy

Effective cancer immunotherapy is usually blocked by immunosuppressive factors in the tumour microenvironment, resulting in tumour promotion, metastasis and recurrence. Here we combine lipid nanoparticle-mRNA formulations and dendritic cell therapy (named CATCH) to boost the cancer-immunity cycle via progressive steps to overcome the immunosuppressive tumour microenvironment. Multiple types of sugar-alcohol-derived lipid nanoparticles are conceived to modulate the cancer-immunity cycle. First, one type of lipid nanoparticle containing CD40 ligand mRNA induces robust immunogenic cell death in tumoural tissues, leading to the release of tumour-associated antigens and the expression of CD40 ligand. Next, dendritic cells engineered by another type of lipid nanoparticle encapsulating CD40 mRNA are adoptively transferred, which are then activated by the CD40 ligand molecules in tumoural tissues. This promotes the secretion of multiple cytokines and chemokines, and the upregulation of co-stimulatory molecules on dendritic cells, which are crucial for reprogramming the tumour microenvironment and priming the T-cell responses. After dendritic cells present tumour-associated antigens to T cells, all the above stepwise events contribute to boosting a potent tumour-specific T-cell immunity that eradicates established tumours, suppresses distal lesions and prevents tumour rechallenge.

Potentiating cancer vaccination by adjuvant-loaded cryo-shocked tumor cells

Cancer vaccine holds vast promise in potentiating tumor immunotherapy. Here, we developed a simple cancer vaccine based on the liquid nitrogen-treated cells (LNT cells) that engineered by one-shot shocking of the live tumor cells in liquid nitrogen. In this vaccine, the obtained LNT cells served as both tumor antigens and delivery vehicles to load the adjuvant imiquimod (R837). This design could achieve efficient co-uptake of antigen/adjuvant by antigen presenting cells (APCs) and prolong in vivo retention of tumor antigens and adjuvants. This adjuvant-loaded LNT cells augmented in vivo antitumor responses and enhanced survival in melanoma-bearing mouse model compared with conventional whole-cell vaccine of the mixture of tumor lysis and adjuvant.

Liquid nitrogen frozen cells for chemotherapy drug delivery and vaccination of melanoma

PURPOSE

Cancer vaccine (CV) has thrived as a promising tool for cancer prevention and treatment. However, how to maintain the integrity and diversity of individualized vaccine antigens and activate the adaptive immune system is still challenging.

METHODS

Herein, a preventive and therapeutic vaccine platform for in situ effective multi-model synergistic therapy is developed. In our study, we process B16F10 cells by liquid nitrogen frozen (LNF) to obtain LNF cells, the characterization of LNF cells were conducted. Moreover,  the anti-tumor effect and immune activation ability were studied, and the role as a CV were investigated.

RESULTS

The LNF cells preserve intact cellular structure and tumor-associated self-antigen gp100. Moreover, LNF cells have the ability of loading and releasing doxorubicin (DOX). Except for the anti-tumor effect of chemotherapy brought by DOX, the LNF cells can promote the maturation of dendritic cells (DCs) and induce immune response by activating CD4+ and CD8+ T cells, particularly with the existence of adjuvant, R848. Specifically, the CD8+ T cells of mice in LNF-DOX/R848 group are 6 times of that in PBS group in tumor microenvironment, and twice in spleen. Therefore, LNF cells can also be utilized as a CV. Vaccination with LNF/R848 cells effectively suppress the tumor growth in mice by fivefold as compared to the control group.

CONCLUSION

In this work, we obtain the LNF cells with a simple procedure. The LNF cells not only provides a tumor cells-based multi-modal system for cancer therapy but inspires new insights into future development of individualized CVs strategies. This study processes live B16F10 cells by liquid nitrogen frozen to obtain LNF cells, which preserve cell integrity and homologous targeting ability. The LNF cells can load and deliver drug and can serve as tumor vaccine. Results demonstrated the LNF cells have effective prophylactic ability, and ideal anti-tumor ability with the loaded drug and adjuvant.

High WFDC3 gene expression is associated with poor prognosis and reduced immune cells infiltration in pancreatic adenocarcinoma: A study using the TCGA database and bioinformatics analysis

Whey-acidic-protein (WAP) four-disulfide core domain protein 3 (WFDC3) is one of the WAP family proteins. This protein family is associated with the development of solid tumors and affects the tumor immunological microenvironment. However, the prognostic value of WFDC3 in pancreatic adenocarcinoma (PAAD) and its effect on the tumor immune microenvironment is yet to be clarified. The Cancer Genome Atlas database and Genotype-Tissue Expression database were used to analyze the differential expression of WFDC3 between the tumor and adjacent tissues. The clinical significance of WFDC3 was analyzed in The Cancer Genome Atlas and International Cancer Genome Consortium database using WFDC3 transcripts and clinical information. In order to elucidate the underlying mechanisms, gene set enrichment analysis was conducted to determine potential activated pathways. Immune score evaluation and publicly available pharmacogenomics database [the Genomics of Drug Sensitivity in Cancer] were utilized to quantify immune cell infiltration and the effect on chemotherapeutic drug sensitivity. WFDC3 levels were higher in PAAD tissues than in normal pancreatic tissues. High levels of WFDC3 expression progressively increased as PAAD tumor stages progressed. Patients with elevated WFDC3 expression showed a poor prognosis. The gene set enrichment analysis analysis revealed that glutamate, arginine, and proline, and histidine metabolism levels were elevated in patients with a high WFDC3 expression phenotype. B, CD4+ T, and CD8+ T cell infiltration was diminished in PAAD tissues with elevated WFDC3 expression. According to pharmacogenomics, PAAD tissues with high WFDC3 expression are susceptible to gemcitabine. WFDC3 is highly expressed in PAAD, and patients with a high level of WFDC3 expression have a shorter overall survival time, indicating a poorer prognosis. High expression of WFDC3 may lead to the development of PAAD by affecting the amino acid metabolism and the tumor immunological microenvironment. WFDC3 may serve as a potential diagnostic and prognostic biomarker for PAAD patients.

Oncolytic virus M1 functions as a bifunctional checkpoint inhibitor to enhance the antitumor activity of DC vaccine

Although promising, dendritic cell (DC) vaccines still provide limited clinical benefits, mainly due to the immunosuppressive tumor microenvironment (TME) and the lack of tumor-associated antigens (TAAs). Oncolytic virus therapy is an ideal strategy to overcome immunosuppression and expose TAAs; therefore, they may work synergistically with DC vaccines. In this study, we demonstrate that oncolytic virus M1 (OVM) can enhance the antitumor effects of DC vaccines across diverse syngeneic mouse tumor models by increasing the infiltration of CD8+ effector T cells in the TME. Mechanically, we show that tumor cells counteract DC vaccines through the SIRPα-CD47 immune checkpoint, while OVM can downregulate SIRPα in DCs and CD47 in tumor cells. Since OVM upregulates PD-L1 in DCs, combining PD-L1 blockade with DC vaccines and OVM further enhances antitumor activity. Overall, OVM strengthens the antitumor efficacy of DC vaccines by targeting the SIRPα-CD47 axis, which exerts dominant immunosuppressive effects on DC vaccines.

The nexus of dynamic T cell states and immune checkpoint blockade therapy in the periphery and tumor microenvironment

Immune checkpoint blockade (ICB) therapies, that is, using monoclonal antibodies to reinvigorate tumor-reactive, antigen-specific T cells from the inhibitory effects of CTLA-4, PD-1 and PD-L1 immune checkpoints, have revolutionized the therapeutic landscape of modern oncology. However, only a subset of patients can benefit from the ICB therapy. Biomarkers associated with ICB response, resistance and prognosis have been subjected to intensive research in the past decade. Early studies focused on the analysis of tumor specimens and their residing microenvironment. However, biopsies can be challenging to obtain in clinical practice, and do not reflect the dynamic changes of immunological parameters during the ICB therapy. Recent studies have investigated profiles of antigen-specific T cells derived from the peripheral compartment using multi-omics approaches. By tracking the clonotype and diversity of tumor-reactive T cell receptor repertoire, these studies collectively establish that de novo priming of antigen-specific T cells in peripheral blood occurs throughout the course of ICB, whereas preexisting T cells prior to ICB are exhausted to various degrees. Here, we review what is known about ICB-induced T cell phenotypic and functional changes in cancer patients both within the tumor microenvironment and in the peripheral compartment. A better understanding of parameters influencing the response to ICBs will provide rationales for developing novel diagnostics and combinatorial therapeutic strategies to maximize the clinical efficacies of ICB therapies.

Resistance to immune checkpoint therapies by tumour-induced T-cell desertification and exclusion: key mechanisms, prognostication and new therapeutic opportunities

Immune checkpoint therapies (ICT) can reinvigorate the effector functions of anti-tumour T cells, improving cancer patient outcomes. Anti-tumour T cells are initially formed during their first contact (priming) with tumour antigens by antigen-presenting cells (APCs). Unfortunately, many patients are refractory to ICT because their tumours are considered to be 'cold' tumours-i.e., they do not allow the generation of T cells (so-called 'desert' tumours) or the infiltration of existing anti-tumour T cells (T-cell-excluded tumours). Desert tumours disturb antigen processing and priming of T cells by targeting APCs with suppressive tumour factors derived from their genetic instabilities. In contrast, T-cell-excluded tumours are characterised by blocking effective anti-tumour T lymphocytes infiltrating cancer masses by obstacles, such as fibrosis and tumour-cell-induced immunosuppression. This review delves into critical mechanisms by which cancer cells induce T-cell 'desertification' and 'exclusion' in ICT refractory tumours. Filling the gaps in our knowledge regarding these pro-tumoral mechanisms will aid researchers in developing novel class immunotherapies that aim at restoring T-cell generation with more efficient priming by APCs and leukocyte tumour trafficking. Such developments are expected to unleash the clinical benefit of ICT in refractory patients.

Single-cell sequencing and bulk RNA data reveal the tumor microenvironment infiltration characteristics of disulfidptosis related genes in breast cancer

BACKGROUND

Immunotherapy, represented by immune checkpoint inhibitors, has made significant progress in the treatment of cancer. Numerous studies have demonstrated that antitumor therapies targeting cell death exhibit synergistic effects with immunotherapy. Disulfidptosis is a recently discovered form of cell death, and its potential influence on immunotherapy, similar to other regulated cell death processes, requires further investigation. The prognostic value of disulfidptosis in breast cancer and its role in the immune microenvironment has not been investigated.

METHODS

High dimensional weighted gene coexpression network analysis (hdWGCNA) and Weighted co-expression network analysis (WGCNA) methods were employed to integrate breast cancer single-cell sequencing data and bulk RNA data. These analyses aimed to identify genes associated with disulfidptosis in breast cancer. Risk assessment signature was constructed using Univariate Cox and least absolute shrinkage and selection operator (LASSO) analyses.

RESULTS

In this study, we constructed a risk signature by disulfidptosis-related genes to predict overall survival and immunotherapy response in BRCA patients. The risk signature demonstrated robust prognostic power and accurately predicted survival compared to traditional clinicopathological features. It also effectively predicted the response to immunotherapy in patients with breast cancer. Through cell communication analysis in additional single-cell sequencing data, we identified TNFRSF14 as a key regulatory gene. Combining TNFRSF14 targeting and immune checkpoint inhibition to induce disulfidptosis in tumor cells could potentially suppress tumor proliferation and enhance survival in patients with BRCA.

A Multivalent Personalized Vaccine Orchestrating Two-Signal Activation Rebuilds the Bridge Between Innate and Adaptive Antitumor Immunity

Personalized vaccines capable of circumventing tumor heterogeneity have exhibited compelling prospects. However, their therapeutic benefit is greatly hindered by the limited antigen repertoire and poor response of CD8+ T-cell immunity. Here, a double-signal coregulated cross-linking hydrogel-based vaccine (Bridge-Vax) is engineered to rebuild the bridge between innate and adaptive immunity for activating CD8+ T-cells against full repertoire of tumor antigens. Mechanistically, unlike prominent CD4+ T-cell responses in most cases, administration of Bridge-Vax encapsulated with granulocyte-macrophage colony-stimulating factor concentrates a wave of dendritic cells (DCs), which further promotes DCs activation with costimulatory signal by the self-adjuvanted nature of polysaccharide hydrogel. Simultaneously, synergy with the increased MHC-I epitopes by codelivered simvastatin for cross-presentation enhancement, Bridge-Vax endows DCs with necessary two signals for orchestrating CD8+ T-cell activation. Bridge-Vax elicits potent antigen-specific CD8+ T-cell responses in vivo, which not only shows efficacy in B16-OVA model but confers specific immunological memory to protect against tumor rechallenge. Moreover, personalized multivalent Bridge-Vax tailored by leveraging autologous tumor cell membranes as antigens inhibits postsurgical B16F10 tumor recurrence. Hence, this work provides a facile strategy to rebuild the bridge between innate and adaptive immunity for inducing potent CD8+ T-cell immunity and would be a powerful tool for personalized cancer immunotherapy.