In Vivo Administration of Recombinant Human Granulocyte Colony-Stimulating Factor Increases the Immune Effectiveness of Dendritic Cell-Based Cancer Vaccination

Viral vector- and virus-like particle-based vaccines against infectious diseases: A minireview

To overcome the limitations of conventional vaccines, new platforms for vaccine design have emerged such as those based on viral vectors and virus-like particles (VLPs). Viral vector vaccines are highly efficient and the onset of protection is quick. Many recombinant vaccine candidates for humans are based on viruses belonging to different families such as Adenoviridae, Retroviridae, Paramyxoviridae, Rhabdoviridae, and Parvoviridae. Also, the first viral vector vaccine licensed for human vaccination was the Japanese encephalitis virus vaccine. Since then, several viral vectors have been approved for vaccination against the viruses of Lassa fever, Ebola, hepatitis B, hepatitis E, SARS-CoV-2, and malaria. VLPs are nanoparticles that mimic viral particles formed from the self-assembly of structural proteins and VLP-based vaccines against hepatitis B and E viruses, human papillomavirus, and malaria have been commercialized. As evidenced by the accelerated production of vaccines against COVID-19, these new approaches are important tools for vaccinology and for generating rapid responses against pathogens and emerging pandemic threats.

Attitudes, expectations, and lived experiences of cancer patients receiving dendritic cell vaccine therapy in Japan

Objective

Immunotherapeutic approaches to cancer, such as dendritic cell vaccine therapy, promise to improve survival rate but may present unique challenges to patients. However, there is no research on the lived experiences of cancer patients receiving dendritic cell vaccine therapy. The aim of this study was to explore the attitudes, expectations, and experiences of cancer patients receiving dendritic cell vaccine therapy in Japan.

Methods

This was an exploratory qualitative study. A descriptive phenomenological approach was used to investigate the experiences of eight advanced-stage cancer patients (median age: 59.5 years). Data were collected between July 2018 and March 2020 using in-depth semi-structured interviews. Data were analyzed according to Colaizzi's seven-step phenomenological strategy, and EQUATOR's Consolidated Criteria for Reporting Qualitative Research (COREQ) guidelines for qualitative studies were followed.

Results

Four themes emerged from the data analysis: strong concerns about chemotherapy, faith in dendritic cell vaccine therapy, motivation to succeed, and physical and mental changes. The first two themes related to pretreatment attitudes and expectations. The latter two themes expressed participants' experiences during and after therapy.

Conclusions

Dendritic cell vaccine therapy patients expressed fears about the effects of standard treatment, and hope and uncertainty regarding immunotherapy treatment decisions and efficacy. The findings suggest that such patients require nursing care that includes prevention and reduction of chemotherapy side effects, careful observation of patients' well-being, management of patients' expectations and uncertainty, formation of patient-health care practitioner partnerships, and team medicine.

Cancer Immunotherapy Using Bioengineered Micro/Nano Structured Hydrogels

Hydrogels, a class of materials with a 3D network structure, are widely used in various applications of therapeutic delivery, particularly cancer therapy. Micro and nanogels as miniaturized structures of the bioengineered hydrogels may provide extensive benefits over the common hydrogels in encapsulation and controlled release of small molecular drugs, macromolecular therapeutics, and even cells. Cancer immunotherapy is rapidly developing, and micro/nanostructured hydrogels have gained wide attention regarding their engineered payload release properties that enhance systemic anticancer immunity. Additionally, they are a great candidate due to their local administration properties with a focus on local immune cell manipulation in favor of active and passive immunotherapies. Although applied locally, such micro/nanostructured can also activate systemic antitumor immune responses by releasing nanovaccines safely and effectively inhibiting tumor metastasis and recurrence. However, such hydrogels are mostly used as locally administered carriers to stimulate the immune cells by releasing tumor lysate, drugs, or nanovaccines. In this review, the latest developments in cancer immunotherapy are summarized using micro/nanostructured hydrogels with a particular emphasis on their function depending on the administration route. Moreover, the potential for clinical translation of these hydrogel-based cancer immunotherapies is also discussed.

Different In Vitro-Generated MUTZ-3-Derived Dendritic Cell Types Secrete Dexosomes with Distinct Phenotypes and Antigen Presentation Potencies

Human dendritic cell (DC) dexosomes were evaluated for their function and preclinical validation for vaccines. Dexosomes are small DC-secreted vesicles that contain absorbing immune signals. Vaccine manufacturing requires a significant number of monocyte-derived DCs (Mo-DCs) from donor blood; thus, Mo-DC dexosomes are expected to serve as novel materials for cancer vaccination. In this study, we characterized a potential dexosome model using immature and mature MUTZ3-derived DCs (M-imIL-4-DC, M-imIFN-DC, M-mIL-4-DC, and M-mIFN-DC) and their dexosomes (M-imIL-4-Dex, M-imIFN-Dex, M-mIL4-Dex, and M-mIFN-Dex). Despite the lack of significant differences in viability, M-mIFN-DC showed a significantly higher level of yield and higher levels of maturation surface markers, such as CD86 and HLA-ABC, than M-mIL-4-DC. In addition, M-mIFN-Dex expressed a higher level of markers, such as HLA-ABC, than M-mIL-4-Dex. Furthermore, M-mIFN-Dex exhibited a higher level of antigen presentation potency, as evaluated using a MART-1 system, than either M-imIFN-Dex or M-mIL-4-Dex. We found that M-mIFN-Dex is one of the four types of MUTZ3-derived DCs that harbor potential immunogenicity, suggesting that DC dexosomes could be useful resources in cancer immunotherapy.

Dendritic cell differentiation from human induced pluripotent stem cells: challenges and progress

Dendritic cells (DCs) are the major antigen-presenting cells of the immune system responsible for initiating and coordinating immune responses. These abilities provide potential for several clinical applications, such as the development of immunogenic vaccines. However, difficulty in obtaining DCs from conventional sources, such as bone marrow (BM), peripheral blood (PBMC), and cord blood (CB), is a significantly hinders routine application. The use of human induced pluripotent stem cells (hiPSCs) is a valuable alternative for generating sufficient numbers of DCs to be used in basic and pre-clinical studies. Despite the many challenges that must be overcome to achieve an efficient protocol for obtaining the major DC types from hiPSCs, recent progress has been made. Here we review the current state of developing DCs from hiPSCs, as well as the key elements required to enable the routine use of hiPSC-derived DCs in pre-clinical and clinical assays.

Optimizing leukapheresis product yield and purity for blood cell-based gene and immune effector cell therapy

PURPOSE OF REVIEW

A critical common step for blood-based ex-vivo gene and immune effector cell (IEC) therapies is the collection of target cells for further processing and manufacturing, often accomplished through a leukapheresis procedure to collect mononuclear cells (MNCs). The purpose of this review is to describe strategies to optimize the apheresis product cell yield and purity for gene and IEC therapies. Relevant data from the conventional bone marrow transplant literature is described where applicable.

RECENT FINDINGS

Product yield is affected by three main factors: the peripheral blood concentration of the target cell, optimized by mobilizing agents, donor interventions or donor selection; the volume of peripheral blood processed, tailored to the desired product yield using prediction algorithms; and target cell collection efficiency, optimized by a variety of device and donor-specific considerations. Factors affecting product purity include characteristics of the donor, mobilizing agent, device, and device settings.

SUMMARY

Strategies to optimize product yield and purity for gene and IEC therapies are important to consider because of loss of target cell numbers or function with downstream steps and detrimental effects of nontarget cells on further manufacturing and patient outcome.

Quality Verification with a Cluster-Controlled Manufacturing System to Generate Monocyte-Derived Dendritic Cells

Dendritic cell (DC) vaccines for cancer immunotherapy have been actively developed to improve clinical efficacy. In our previous report, monocyte−derived DCs induced by interleukin (IL)−4 with a low−adherence dish (low−adherent IL-4−DCs: la−IL-4−DCs) improved the yield and viability, as well as relatively prolonged survival in vitro, compared to IL-4−DCs developed using an adherent culture protocol. However, la−IL-4−DCs exhibit remarkable cluster formation and display heterogeneous immature phenotypes. Therefore, cluster formation in la−IL-4−DCs needs to be optimized for the clinical development of DC vaccines. In this study, we examined the effects of cluster control in the generation of mature IL-4−DCs, using cell culture vessels and measuring spheroid formation, survival, cytokine secretion, and gene expression of IL-4−DCs. Mature IL-4−DCs in cell culture vessels (cluster−controlled IL-4−DCs: cc−IL-4−DCs) displayed increased levels of CD80, CD86, and CD40 compared with that of la−IL-4−DCs. cc−IL-4−DCs induced antigen−specific cytotoxic T lymphocytes (CTLs) with a human leukocyte antigen (HLA)−restricted melanoma antigen recognized by T cells 1 (MART−1) peptide. Additionally, cc−IL-4−DCs produced higher levels of IFN−γ, possessing the CTL induction. Furthermore, DNA microarrays revealed the upregulation of BCL2A1, a pro−survival gene. According to these findings, the cc−IL-4−DCs are useful for generating homogeneous and functional IL-4−DCs that would be expected to promote long−lasting effects in DC vaccines.

G-CSF in tumors: Aggressiveness, tumor microenvironment and immune cell regulation

Granulocyte colony-stimulating factor (G-CSF) is a cytokine most well-known for maturation and mobilization of bone marrow neutrophils. Although it is used therapeutically to treat chemotherapy induced neutropenia, it is also highly expressed in some tumors. Case reports suggest that tumors expressing high levels of G-CSF are aggressive, more difficult to treat, and present with poor prognosis and high mortality rates. Research on this topic suggests that G-CSF has tumor-promoting effects on both tumor cells and the tumor microenvironment. G-CSF has a direct effect on tumor cells to promote tumor stem cell longevity and overall tumor cell proliferation and migration. Additionally, it may promote pro-tumorigenic immune cell phenotypes such as M2 macrophages, myeloid-derived suppressor cells, and regulatory T cells. Overall, the literature suggests a plethora of pro-tumorigenic activity that should be balanced with the therapeutic use. In this review, we present an overview of the multiple complex roles of G-CSF and G-CSFR in tumors and their microenvironment and discuss how clinical advances and strategies may open new therapeutic avenues.

Interferon-α-Induced Dendritic Cells Generated with Human Platelet Lysate Exhibit Elevated Antigen Presenting Ability to Cytotoxic T Lymphocytes

Given the recent advancements of immune checkpoint inhibitors, there is considerable interest in cancer immunotherapy provided through dendritic cell (DC)-based vaccination. Although many studies have been conducted to determine the potency of DC vaccines against cancer, the clinical outcomes are not yet optimal, and further improvement is necessary. In this study, we evaluated the potential ability of human platelet lysate (HPL) to produce interferon-α-induced DCs (IFN-DCs). In the presence of HPL, IFN-DCs (HPL-IFN-DCs) displayed high viability, yield, and purity. Furthermore, HPL-IFN-DCs displayed increased CD14, CD56, and CCR7 expressions compared with IFN-DCs produced without HPL; HPL-IFN-DCs induced an extremely higher number of antigen-specific cytotoxic T lymphocytes (CTLs) than IFN-DCs, which was evaluated with a human leukocyte antigen (HLA)-restricted melanoma antigen recognized by T cells 1 (MART-1) peptide. Additionally, the endocytic and proteolytic activities of HPL-IFN-DCs were increased. Cytokine production of interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-α was also elevated in HPL-IFN-DCs, which may account for the enhanced CTL, endocytic, and proteolytic activities. Our findings suggest that ex-vivo-generated HPL-IFN-DCs are a novel monocyte-derived type of DC with high endocytic and proteolytic activities, thus highlighting a unique strategy for DC-based immunotherapies.

Dendritic Cells Pre-Pulsed with Wilms' Tumor 1 in Optimized Culture for Cancer Vaccination

With recent advances in cancer vaccination therapy targeting tumor-associated antigens (TAAs), dendritic cells (DCs) are considered to play a central role as a cell-based drug delivery system in the bioactive immune environment. Ex vivo generation of monocyte-derived DCs has been conventionally applied in adherent manufacturing systems with separate loading of TAAs before clinical use. We developed DCs pre-pulsed with Wilms’ tumor (WT1) peptides in low-adhesion culture maturation (WT1-DCs). Quality tests (viability, phenotype, and functions) of WT1-DCs were performed for process validation, and findings were compared with those for conventional DCs (cDCs). In comparative analyses, WT1-DCs showed an increase in viability and recovery of the DC/monocyte ratio, displaying lower levels of IL-10 (an immune suppressive cytokine) and a similar antigen-presenting ability in an in vitro cytotoxic T lymphocytes (CTLs) assay with cytomegalovirus, despite lower levels of CD80 and PD-L2. A clinical study revealed that WT1-specific CTLs (WT1-CTLs) were detected upon using the WT1-DCs vaccine in patients with cancer. A DC vaccine containing TAAs produced under an optimized manufacturing protocol is a potentially promising cell-based drug delivery system to induce acquired immunity.