Dendritic Cell-based Vaccines Research Articles

Dendritic Cell Immunotherapy for Ovarian Cancer: An Overview of Our Achievements

Epithelial ovarian carcinoma (EOC) is the fifth leading cause of cancer-related death in women, largely reflecting the early dissemination of this malignant disease to the peritoneum. Due to its immunological features, EOC has poor response to immune checkpoint inhibitors (ICIs), including a limited tumor mutational burden (TMB), poor infiltration by immune cells, and active immunosuppression. Thus, novel strategies are needed to overcome the frequent lack of pre-existing immunity in patients with EOC. We developed and tested an autologous dendritic cell (DC)-based vaccine (DCVAC), which has recently been shown to be safe and to significantly improve progression-free survival (PFS) in two independent randomized phase II clinical trials enrolling patients with EOC (SOV01, NCT02107937; SOV02, NCT02107950). In addition, our exploratory data analyses suggest that the clinical benefits of the DCVAC were more pronounced in patients with EOC with lower-than-median TMBs and reduced CD8+ T cell infiltration. Thus, the DC-based vaccine stands out as a promising clinical tool to jumpstart anticancer immunity in patients with immunologically “cold” EOC. Our findings underscore the need for personalized immunotherapy and the clinical relevance of potential tumor-related biomarkers within the immunotherapy field. Additional clinical trials are needed to address these strategies as well as the potential value of the TMB and immune infiltration at baseline as biomarkers for guiding the clinical management of EOC.

Development of Cell Technologies Based on Dendritic Cells for Immunotherapy of Oncological Diseases.

Immunotherapy using dendritic cell-based vaccination is a natural approach using the capabilities and functions inherent in the patient's immune system to eliminate tumor cells. The development of dendritic cell-based cell technologies evolved as the disorders of dendritic cell differentiation and function in cancer were studied; some of these functions are antigen presentation, priming of cytotoxic T-lymphocytes and induction of antigen-specific immune responses. At the initial stage of technology development, it was necessary to develop protocols for the in vitro generation of functionally mature dendritic cells that were capable of capturing tumor antigens and processing and presenting them in complex with MHC to T-lymphocytes. To achieve this, various forms of tumor-associated antigen delivery systems were tested, including lysates, tumor cell proteins (peptides), and DNA and RNA constructs, and it was shown that the use of DNA and RNA constructs was the most effective method, as it made it possible not only to deliver the most immunogenic epitopes of tumor-associated antigens to dendritic cells, but also to enhance their ability to induce antigen-specific cytotoxic T-lymphocytes. Currently, cell therapy based on dendritic cells is a modern basis for antigen-specific immunotherapy of cancer due to the simplicity of creating DNA and RNA constructs encoding information about both target tumor antigens and regulatory molecules. The potential development of cell technologies based on dendritic cells aims to obtain antigen-specific cytotoxic T-lymphocytes induced by dendritic cells, study their functional activity and develop cell-based therapy.

The Interaction of Immune System in Tumour Microenvironment and Possible Role of Cancer Cell Immnunosensitization for Better Treatment Efficacy: A Review

Unlike haematologic malignant cells which express cell surface common antigens uniformly and are susceptible to targeted cancer immunotherapy, solid tumours either lack such antigens or have been mutated due to chemotherapy or other therapeutic interventions. Moreover, rapidly dividing tumour cells present complex and dynamic tumour metabolism, which hampers immune cells' reactivity against the tumour cells. Hence solid tumours other than immune-sensitive cancers such as melanoma and renal cell carcinoma are less responsive towards current cellular immunotherapy strategies, including cytokine therapy, dendritic cell-based vaccines, and immune-activating antibodies. Nonetheless, emerging evidence supports combined approaches that target immunosuppressive or antiapoptotic molecules, involving sensitization of the cancer cells by immunosensitizing drugs to express specific ligands that will be recognized by the immune cells via trafficking. This review highlights the immune system's involvement in the tumour microenvironment and the potential significance of cancer cell immunosensitization for improved treatment outcomes.

PERSPECTIVE FOR APPLYING ANTITUMOR VACCINES

One of the promising areas in immunotherapy are tumour-specific vaccines based on immunocompromised cells. DC-based personalized neoantigenic cellular vaccines have promising antitumor effects in clinical practice. Dendritic cell-based vaccines have a number of advantages, one example being the ability to engage both innate and adaptive immunity, as well as to develop long-term immunological memory against tumor recurrence. DCs are the most professional and consistent antigens and are more effective in activating resting T cells. The review provides the most up-to-date information on cancer vaccines, as well as an analysis of the types of cancer vaccines from domestic and foreign sources. The conclusion of this brief review is the wide variety of types of tumor-specific vaccines and their rapid improvement.

Unlocking Dendritic Cell-Based Vaccine Efficacy through Genetic Modulation-How Soon Is Now?

The dendritic cell (DC) vaccine anti-cancer strategy involves tumour-associated antigen loading and maturation of autologous ex vivo cultured DCs, followed by infusion into the cancer patient. This strategy stemmed from the idea that to induce a robust anti-tumour immune response, it was necessary to bypass the fundamental immunosuppressive mechanisms of the tumour microenvironment that dampen down endogenous innate immune cell activation and enable tumours to evade immune attack. Even though the feasibility and safety of DC vaccines have long been confirmed, clinical response rates remain disappointing. Hence, the full potential of DC vaccines has yet to be reached. Whether this cellular-based vaccination approach will fully realise its position in the immunotherapy arsenal is yet to be determined. Attempts to increase DC vaccine immunogenicity will depend on increasing our understanding of DC biology and the signalling pathways involved in antigen uptake, maturation, migration, and T lymphocyte priming to identify amenable molecular targets to improve DC vaccine performance. This review evaluates various genetic engineering strategies that have been employed to optimise and boost the efficacy of DC vaccines.

Advances in immunotherapy for osteosarcoma: a review of emerging treatment strategies

Advances in immunotherapy for osteosarcoma have shown promising results, with the use of monoclonal antibodies and immune checkpoint inhibitors. These strategies are aimed at targeting specific molecules and pathways involved in tumour immune evasion and promoting anti-tumour immune responses. Other emerging immunotherapeutic approaches include autophagy and pyroptosis induction, chimeric antigen receptor T-cell therapy, gadolinium-bisphosphonate nanoparticles and dendritic cell-based vaccines. Continued research into these emerging treatment strategies is essential for developing effective therapies for patients with high-grade osteosarcoma.

Dendritic cell-based vaccine prepared with recombinant Lactococcus lactis enhances antigen cross-presentation and antitumor efficacy through ROS production.

Lactococcus lactis (L.L) is safe and can be used as vehicle. In this study, the immunoregulatory effect of L.L on dendritic cell (DC) activation and mechanism were investigated. The immune responses and antigen cross-presentation mechanism of DC-based vaccine prepared with OVA recombinant L.L were explored. Confocal microscopy and flow cytometry were used to analyze the mechanism of L.L promoting DC maturation, phagosome membrane rupture and antigen presentation. The antitumor effect of DC vaccine prepared with L.L-OVA was assessed in the B16-OVA tumor mouse model. L.L significantly promoted DC maturation, which was partially dependent on TLR2 and downstream MAPK and NF-κB signaling pathways. L.L was internalized into DCs by endocytosis and did not co-localized with lysosome. OVA recombinant L.L enhanced antigen cross-presentation of DCs through the phagosome-to-cytosol pathway in a reactive oxygen species (ROS)- and proteasome-dependent manner. In mouse experiments, L.L increased the migration of DCs to draining lymph node and DC vaccine prepared with OVA recombinant L.L induced strong antigen-specific Th1 and cytotoxic T lymphocyte responses, which significantly inhibited B16-OVA tumor growth. This study demonstrated that recombinant L.L as an antigen delivery system prepared DC vaccine can enhance the antigen cross-presentation and antitumor efficacy.

Advances in Immunotherapeutics in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) accounts for up to 95% of all pancreatic cancer cases and is the seventh-leading cause of cancer death. Poor prognosis is a result of late presentation, a lack of screening tests and the fact some patients develop resistance to chemotherapy and radiotherapy. Novel therapies like immunotherapeutics have been of recent interest in pancreatic cancer. However, this field remains in its infancy with much to unravel. Immunotherapy and other targeted therapies have yet to yield significant progress in treating PDAC, primarily due to our limited understanding of the disease immune mechanisms and its intricate interactions with the tumour microenvironment (TME). In this review we provide an overview of current novel immunotherapies which have been studied in the field of pancreatic cancer. We discuss their mechanisms, evidence available in pancreatic cancer as well as the limitations of such therapies. We showcase the potential role of combining novel therapies in PDAC, postulate their potential clinical implications and the hurdles associated with their use in PDAC. Therapies discussed with include programmed death checkpoint inhibitors, Cytotoxic T-lymphocyte-associated protein 4, Chimeric Antigen Receptor-T cell therapy, oncolytic viral therapy and vaccine therapies including KRAS vaccines, Telomerase vaccines, Gastrin Vaccines, Survivin-targeting vaccines, Heat-shock protein (HSP) peptide complex-based vaccines, MUC-1 targeting vaccines, Listeria based vaccines and Dendritic cell-based vaccines.

A Comprehensive Review on Cancer Vaccines and Vaccine Strategies in Hepatocellular Carcinoma.

HCC, the most prevalent form of primary liver cancer, presents a substantial global health challenge due to its high mortality and limited therapeutic options. This review delves into the potential of cancer vaccines as a novel therapeutic avenue for HCC. We examine the various categories of cancer vaccines, including peptide-based, dendritic cell-based, viral vector-based, DNA, and mRNA vaccines, and their potential application in HCC management. This review also addresses the inherent challenges in vaccine development, such as tumor heterogeneity and the need for identifying tumor-specific antigens. We underscore the role of cancer vaccines in reshaping the immune environment within HCC, fostering durable immune memory, and their potential in combination therapies. The review also evaluates clinical trials and emphasizes the necessity for more extensive research to optimize vaccine design and patient selection criteria. We conclude with future perspectives, highlighting the significance of personalized therapies, innovative antigen delivery platforms, immune modulatory agents, and predictive biomarkers in revolutionizing HCC treatment. Simple Summary: This review explores the potential of cancer vaccines as a promising therapeutic strategy for hepatocellular carcinoma (HCC), a prevalent and deadly liver cancer. The authors discuss various types of cancer vaccines, their challenges, and their role in modulating the immune response within HCC. They also highlight clinical trials and future perspectives, emphasizing the importance of personalized therapies, novel antigen delivery platforms, and predictive biomarkers. The findings from this research could significantly impact the research community by providing a comprehensive understanding of the current state of cancer vaccines for HCC, thereby guiding future research and potentially transforming HCC treatment strategies.

Irreversible Electroporation Combined With Dendritic Cell-based Vaccines for the Treatment of Osteosarcoma.

Osteosarcoma is the most common primary bone malignancy, and surgical resection combined with neoadjuvant chemotherapy is the gold-standard treatment for affected patients. Although the overall survival rates for patients with osteosarcoma currently range from 60% to 70%, outcomes remain disappointing for patients with recurrent, metastatic, or unresectable disease. Irreversible electroporation (IRE) is a novel ablation technique with the potential to elicit an immune response in solid tumors. Dendritic cell (DC)-based tumor vaccines have shown promising therapeutic efficacy in preclinical studies focused on osteosarcoma; however, only limited therapeutic efficacy has been observed in clinical trials. Thus, there is considerable potential therapeutic value in developing combination osteosarcoma treatments that involve IRE and DC-based tumor vaccines. In this review, we discuss recent advances in preclinical and clinical DC-based immunotherapies, as well as potential combinations of DC-based vaccines and IRE, that may improve therapeutic outcomes for patients with osteosarcoma.

Potential of Personalized Dendritic Cell-Based Immunohybridoma Vaccines to Treat Prostate Cancer.

Prostate cancer (PCa) is the most commonly diagnosed cancer and the second most common cause of death due to cancer. About 30% of patients with PCa who have been castrated develop a castration-resistant form of the disease (CRPC), which is incurable. In the last decade, new treatments that control the disease have emerged, slowing progression and spread and prolonging survival while maintaining the quality of life. These include immunotherapies; however, we do not yet know the optimal combination and sequence of these therapies with the standard ones. All therapies are not always suitable for every patient due to co-morbidities or adverse effects of therapies or both, so there is an urgent need for further work on new therapeutic options. Advances in cancer immunotherapy with an immune checkpoint inhibition mechanism (e.g., ipilimumab, an anti-CTLA-4 inhibitor) have not shown a survival benefit in patients with CRPC. Other immunological approaches have also not given clear results, which has indirectly prevented breakthrough for this type of therapeutic strategy into clinical use. Currently, the only approved form of immunotherapy for patients with CRPC is a cell-based medicine, but it is only available to patients in some parts of the world. Based on what was gained from recently completed clinical research on immunotherapy with dendritic cell-based immunohybridomas, the aHyC dendritic cell vaccine for patients with CRPC, we highlight the current status and possible alternatives that should be considered in the future.

825-P: Novel Autologous Dendritic Cell Therapy AVT001 for Type 1 Diabetes

Studies in several animal models and of humans with type 1 diabetes (T1D) have suggested that Qa-1/HLA-E restricted CD8+ T regulatory cells (Tregs) are important in maintaining self-tolerance and a defect thereof playing a key role in T1D pathogenesis. To evaluate the safety and efficacy of targeting this pathway in T1D we undertook a first in human, phase 1/2 study of AVT001, an investigational autologous dendritic cell-based vaccine designed to address this immunologic mechanism. This double-blind, randomized (2:1 treated vs placebo) trial enrolled individuals (n=25) who were 16 years and older, within 1 year of clinical diagnosis of T1D, and with an ex-vivo correctable defect in the function of HLA-E-restricted CD8+ Tregs. All participants underwent leukapheresis, the first step in the generation of AVT001. AVT001 treatment (n=16) or placebo (n=9) was delivered as a series of three-monthly intravenous infusions. The primary endpoint of the study was safety/tolerability at day 150. AVT001 was safe and well tolerated with all participants completing treatment, no peri-infusion reactions noted, and adverse events reported as being mild or moderate in the AVT001 treated group, with rates similar to placebo. A pre-specified efficacy endpoint was change from baseline in C-peptide area under the curve (AUC) during a 4-hour mixed meal tolerance test utilizing a mixed-effect model for repeated measurements (MMRM). The baseline mean (SD) AUCs were treated 0.531 (0.363) and placebo 0.611 (0.178) nmol/L. At day 150, the C-peptide AUCs were significantly different between groups, namely 0.518 (0.430) and 0.472 (0.134) respectively. Per MMRM, the least square mean difference between AVT001 and placebo at day 150, is estimated to be 0.172 (p=<.0001). There was an increase in AUC or no change for 6 (37.5%) in the AVT001 treated group and 1 (11.1%) in the placebo group. These results indicate that AVT001 treatment was safe and well tolerated with evidence of significant preservation of endogenous insulin secretion. Disclosure J.L.Gaglia: Advisory Panel; Dompé, Consultant; Vertex Pharmaceuticals Incorporated, Abata Therapeutics, Avotres Inc., Current Health, Research Support; Avotres Inc., Dompé, Imcyse, Stock/Shareholder; Vertex Pharmaceuticals Incorporated. J.Ritz: Advisory Panel; Novartis, Taleris, AvroBio, Clade Therapeutics, LifeVault Bio, Smart Immune, Garuda, Tscan, Research Support; Gilead Sciences, Inc., Novartis. H.Jiang: Employee; Avotres Inc. M.Mackey: None. H.L.Daley: None. N.Bryant: None. D.Y.Kim: None. T.Dong: Employee; Avotres Inc., Novartis. E.E.Fan: None. J.Vora: Other Relationship; Avotres Inc., Glyscend Inc. J.S.Skyler: Advisory Panel; Adocia, Altheia Sciences, Arecor, Avotres Inc., Bayer Inc., COUR Pharmaceuticals, Dance Biopharm/Aerami, Diasome, Enthera, Immnomolecular Therapeutics, Kriya Therapeutics, Oramed Pharmaceuticals, Orgenesis Inc., Precigen, Inc., ViaCyte, Inc., Board Member; Applied Therapeutics Inc., Dexcom, Inc., Consultant; Novo Nordisk, Sanofi, Signos, 4Immune, Other Relationship; Imcyse, Provention Bio, Inc. Funding Avotres Inc.

CAR T cells and dendritic cells: vaccinomics perspectives

Immunotherapy has revolutionized cancer treatment with Chimeric Antigen Receptor (CAR) T cells and dendritic cell-based vaccines showing remarkable efficacy in certain malignancies. This review provides an integrative overview of recent advances and future directions in vaccinomics. A critical aspect of improving efficacy is the integration of CAR T cells and dendritic cell-based therapies to leverage synergistic effects. Personalization of cancer treatment, facilitated by strategies such as HLA typing and antigen selection, is essential for targeting specific tumor antigens and evading immune resistance. The tumor microenvironment plays a crucial role in modulating immune responses and can be targeted to enhance therapy efficacy. Novel adjuvants and immune modulators, such as Toll-like receptor agonists and checkpoint inhibitors, can further improve efficacy and safety. Predictive biomarkers and patient stratification strategies are essential for optimizing candidate selection. Future research should focus on optimizing CAR T cell and dendritic cell-based therapies, developing novel combinational strategies, and advancing gene editing and manufacturing techniques. Expansion to non-cancerous diseases could greatly broaden the impact on public health. Addressing challenges and limitations associated with these therapies can unlock their full potential and revolutionize the treatment of various malignancies and other medical conditions.

Tubeimuside I improves the efficacy of a therapeutic Fusobacterium nucleatum dendritic cell-based vaccine against colorectal cancer.

Fusobacterium nucleatum (F. nucleatum) infection has been confirmed to be associated with the development, chemoresistance, and immune evasion of colorectal cancer (CRC). The complex relationship between the microorganism, host cells, and the immune system throughout all stages of CRC progression, which makes the development of new therapeutic methods difficult. We developed a new dendritic cell (DC) vaccine to investigate the antitumor efficacy of CRC immunotherapy strategies. By mediating a specific mode of interaction between the bacteria, tumor, and host, we found a new plant-derived adjuvant, tubeimuside I (TBI), which simultaneously improved the DC vaccine efficacy and inhibited the F. nucleatum infection. Encapsulating TBI in a nanoemulsion greatly improved the drug efficacy and reduced the drug dosage and administration times. The nanoemulsion encapsulated TBI DC vaccine exhibited an excellent antibacterial and antitumor effect and improved the survival rate of CRC mice by inhibiting tumor development and progression. In this study, we provide a effective strategy for developing a DC-based vaccine against CRC and underlies the importance of further understanding the mechanism of CRC processes caused by F. nucleatum.

Cancer vaccines based on whole-tumor lysate or neoepitopes with validated HLA binding outperform those with predicted HLA-binding affinity.

Antigen selection and prioritization represent crucial determinants of vaccines' efficacy. Here, we compare two personalized dendritic cell-based vaccination strategies using whole-tumor lysate or neoantigens. Data in mouse and in cancer patients demonstrate that peptide vaccines using neoantigens predicted on the sole basis of in silico peptide-major histocompatibility complex (MHC) binding affinity underperform relative to whole-tumor-lysate vaccines. In contrast, effective invitro peptide-MHC binding affinity and peptide immunogenicity significantly improve the prioritization of tumor-rejecting neoepitopes and result in more efficacious vaccines.

ARE DENDRITIC CELLS A POTENTIAL TOOL FOR MASTITIS VACCINE DEVELOPMENT?

Mastitis is one of the main disease causing big economic losses to dairy farmers. This disease is caused mainly by bacteria. Because of not efficient vaccines, there are necessary to develop new immunotherapy of vaccination strategy to reduce this disease in dairy farms. Dendritic cells are antigen-presenting cells which are able to present antigen to lymphocytes. They are able to induce activation of T naïve lymphocytes. Dendritic cells were used for development of dendritic cell-based anti-tumor vaccines. Development of vaccines against bovine mastitis has many limitations as high number of various pathogens that are able to cause inflammation of mammary gland in cattle; absence of mucus barrier in mammary gland; reduced phagocytic efficiency because of casein and fat globules etc. To this day, it is not available vaccine against bovine mastitis with high efficiency. Development of new immunotherapy or vaccine against mastitis would be very desirable. In this mini review, we are considering possibilities for development of new dendritic cell-based vaccine against bovine mastitis.

IFNα and 5-Aza-2'-deoxycytidine combined with a dendritic-cell targeting DNA vaccine alter tumor immune cell infiltration in the B16F10 melanoma model.

DNA vaccines containing a fusion of the gene encoding chemokine MIP-3α (CCL20), the ligand for CCR6 on immature dendritic cells (DCs), to melanoma-associated antigen genes have enhanced anti-tumor immunity and efficacy compared to those lacking the chemokine gene. Previous work has shown that type-I interferon (IFNα or IFN) and 5-Aza-2'-deoxycytidine (5Aza) significantly enhance the therapeutic benefit of DNA vaccines as measured by reduced tumor burden and improved mouse survival. Here, we explored mouse intratumoral immune correlates underlying the therapeutic benefit of this combination regimen (vaccine, IFN, and 5Aza) as compared to vaccine alone and IFN and 5Aza without vaccine, focusing on chemokine mRNA expression by qRT-PCR and inflammatory cellular infiltration into the tumor microenvironment (TME) by flow cytometry and immunohistochemistry (IHC). The combination group significantly upregulated intratumoral mRNA expression of key immune infiltration chemokines XCL1 and CXCL10. Flow cytometric analyses of tumor suspensions exhibited greater tumor infiltration of CD8+ DCs, CCR7+ DCs, and NK cells in the combination group, as well as reduced levels of myeloid-derived suppressor cells (MDSCs) in vaccinated groups. The mice receiving combination therapy also had greater proportions of effector/memory T-cells (Tem), in addition to showing an enhanced infiltration of Tem and central memory CD8+ T-cells, (Tcm). Tem and Tcm populations both correlated with smaller tumor size. Immunohistochemical analysis of tumors confirmed that CD8+ cells were more abundant overall and especially in the tumor parenchyma with combination therapy. Efficient targeting of antigen to immature DCs with a chemokine-fusion vaccine offers a potential alternative approach to classic and dendritic cell-based vaccines. Combining this approach with IFNα and 5Aza treatments significantly improved vaccine efficacy. This treatment creates an environment of increased inflammatory chemokines that facilitates the trafficking of CD8+ DCs, NK cells, and CD8+ T-cells, especially memory cells, while reducing the number of MDSCs. Importantly, in the combination group, CD8+ cells were more able to penetrate the tumor mass in addition to being more numerous. Further analysis of the pathways engaged by our combination therapy is expected to provide additional insights into melanoma pathogenesis and facilitate the development of novel treatment strategies.

A New Plasmacytoid Dendritic Cell-Based Vaccine in Combination with Anti-PD-1 Expands the Tumor-Specific CD8+ T Cells of Lung Cancer Patients.

The purpose of immune checkpoint inhibitor (ICI)-based therapies is to help the patient's immune system to combat tumors by restoring the immune response mediated by CD8+ cytotoxic T cells. Despite impressive clinical responses, most patients do not respond to ICIs. Therapeutic vaccines with autologous professional antigen-presenting cells, including dendritic cells, do not show yet significant clinical benefit. To improve these approaches, we have developed a new therapeutic vaccine based on an allogeneic plasmacytoid dendritic cell line (PDC*line), which efficiently activates the CD8+ T-cell response in the context of melanoma. The goal of the study is to demonstrate the potential of this platform to activate circulating tumor-specific CD8+ T cells in patients with lung cancer, specifically non-small-cell lung cancer (NSCLC). PDC*line cells loaded with peptides derived from tumor antigens are used to stimulate the peripheral blood mononuclear cells of NSCLC patients. Very interestingly, we demonstrate an efficient activation of specific T cells for at least two tumor antigens in 69% of patients irrespective of tumor antigen mRNA overexpression and NSCLC subtype. We also show, for the first time, that the antitumor CD8+ T-cell expansion is considerably improved by clinical-grade anti-PD-1 antibodies. Using PDC*line cells as an antigen presentation platform, we show that circulating antitumor CD8+ T cells from lung cancer patients can be activated, and we demonstrate the synergistic effect of anti-PD-1 on this expansion. These results are encouraging for the development of a PDC*line-based vaccine in NSCLC patients, especially in combination with ICIs.

Neutrophils in Dendritic Cell-Based Cancer Vaccination: The Potential Roles of Neutrophil Extracellular Trap Formation.

Neutrophils have conflicting roles in the context of cancers, where they have been associated with contributing to both anti-tumor and pro-tumor responses. Their functional heterogenicity is plastic and can be manipulated by environmental stimuli, which has fueled an area of research investigating therapeutic strategies targeting neutrophils. Dendritic cell (DC)-based cancer vaccination is an immunotherapy that has exhibited clinical promise but has shown limited clinical efficacy. Enhancing our understanding of the communications occurring during DC cancer vaccination can uncover opportunities for enhancing the DC vaccine platform. There have been observed communications between neutrophils and DCs during natural immune responses. However, their crosstalk has been poorly studied in the context of DC vaccination. Here, we review the dual functionality of neutrophils in the context of cancers, describe the crosstalk between neutrophils and DCs during immune responses, and discuss their implications in DC cancer vaccination. This discussion will focus on how neutrophil extracellular traps can influence immune responses in the tumor microenvironment and what roles they may play in promoting or hindering DC vaccine-induced anti-tumor efficacy.

Dendritic Cell-Based Vaccines Recruit Neutrophils to the Local Draining Lymph Nodes to Prime Natural Killer Cell Responses

Dendritic cell (DC)-based cancer vaccines are a form of immunotherapy that activates the innate and adaptive immune systems to combat cancers. Neutrophils contribute to cancer biology and have the potential to be exploited by immunotherapeutic platforms to enhance anti-tumor immune responses. We previously showed that DC vaccines elicit the expansion of mouse interferon (IFN)γ-producing mature natural killer (NK) cells to elevate anti-tumor responses. Here, we demonstrate the rapid recruitment of neutrophils to the draining lymph nodes of DC-vaccinated mice. This was accompanied by an increase in the total number of NK cells producing IFNγ and expressing CD107a, a marker of degranulation that demonstrates NK cell functional activity. Furthermore, the depletion of neutrophils in DC-immunized mice resulted in decreased numbers of NK cells in draining lymph nodes compared to the controls. Interestingly, the increased number of IFNγ- and CD107a-expressing NK cells in DC-immunized mice was not detected in mice depleted of neutrophils. Further investigations showed that DC vaccines induced IFNγ- and TNFα-producing CD8+ T cells that also expressed CD107a, but depletion of neutrophils did not have any impact on the CD8+ T cell population. Our findings suggest that neutrophil-mediated anti-tumor immunity induced by a DC vaccine platform could be targeted to provide innovative strategies to enhance its clinical efficacy.