An autologous dendritic cell vaccine polarizes a Th-1 response which is tumoricidal to patient-derived breast cancer cells

Advances in dendritic cell-based therapeutic tumor vaccines

Dendritic cell-based therapeutic tumor vaccines are an active immunotherapy that has been commonly tried in the clinic,traditional treatment modalities for malignant tumors, such as surgery, radiotherapy and chemotherapy, have the disadvantages of high recurrence rates and side effects. The dendritic cell vaccination destroys cells from tumors by means of the patient's own system of immunity, a very promising treatment. However, due to the suppression of the tumor immune microenvironment, the difficulty of screening for optimal specific antigens, and the high technical difficulty of vaccine production. Most tumor vaccines currently available in the clinic have failed to produce significant clinical therapeutic effects. In this review, the fundamentals of therapeutic dendritic cells vaccine therapy are briefly outlined, with a focus on the progress of therapeutic Dendritic cells vaccine research in the clinic and the initiatives undertaken to enhance dendritic cell vaccinations' anti-tumor effectiveness. It is believed that through the continuous exploration of novel therapeutic strategies, therapeutic dendritic cells vaccines can play a greater role in improving tumor treatment for tumor patients.

Novel strategies in breast cancer management: From treatment to long-term remission

Breast cancer (BC) is the most common malignancy among women and a leading cause of cancer-related mortality worldwide. Although improvements in early detection and therapy have been made, metastatic breast cancer (mBC) continues to be an incurable disease. Although existing treatments can prolong survival and enhance quality of life, they do not provide a definitive cure. Targeted therapies have significantly improved outcomes, particularly for subtypes such as human epidermal growth factor receptor 2 (HER2)-positive and hormone receptor (HR)-positive (HR+) BC. Key innovations include antibodydrug conjugates (ADCs) and next-generation endocrine therapies. ADCs combine monoclonal antibodies with cytotoxic agents, allowing targeted delivery to tumor cells while minimizing systemic toxicity. Immunotherapy is emerging as a promising approach for aggressive subtypes, such as triple-negative breast cancer (TNBC). Strategies under investigation include chimeric antigen receptor T-cell (CAR-T) therapy, tumor-infiltrating lymphocyte (TIL) therapies, and natural killer (NK) cell treatments, all aimed at enhancing the ability of the immune system to target and eliminate resistant tumor cells. Tissue engineering, particularly hydrogel-based delivery systems, offers the potential for localized treatment. These systems enable the controlled release of therapeutic agents or immune cells directly to the tumor site, supporting tissue regeneration and enhancing immune surveillance to reduce recurrence. Despite these advancements, challenges remain, including treatment resistance, the immunosuppressive tumor microenvironment, and high costs. Overcoming these barriers requires further innovation in drug delivery systems and a deeper understanding of tumor biology.

The Application of Dendritic Cells Vaccines in Tumor Therapy and Their Combination with Biomimetic Nanoparticles

Dendritic cells (DCs) act as a bridge between innate and adaptive immunity by presenting antigens to effector immune cells and have shown broad application potential in tumor immunotherapy. However, the clinical translation of DC vaccines encounters significant challenges, such as the immunosuppressive tumor microenvironment (TME) and the sub-optimal DC function and vaccine efficacy in vivo. In this review, our investigation has uncovered the latest developments in DC vaccines and their potential in cancer immunotherapy, with a special emphasis on the integration of nanotechnology. Several types of nanomaterials, including protein cage nanoparticles (NPs), biomimetic NPs, and targeted multifunctional NPs, have been developed to enhance the antigen presentation ability of DCs and their stimulatory effects on T cells. In addition, we have also summarized the synergistic anti-cancer effects of DC vaccines with immune checkpoint inhibitors, chemotherapy, and radiotherapy. In addition, recent advances in nanotechnology have made it possible to develop novel biomarkers that can enhance the antigen presentation capacity of DCs and stimulate T cells. These biomarkers not only improve the accuracy and precision of DC vaccine design but also provide new insights into understanding the mechanisms of the DC-mediated immune response. Despite challenges pertaining to technical complexities and individual adaptation in the design and production of DC vaccines, personalized immunotherapy based on DCs is expected to become an important part of cancer treatment with rapid developments in biotechnology and immunology. This review provides new perspectives and potential solutions for the optimal design and application of DC vaccines in cancer therapy.

Autologous Human Dendritic Cells from XDR-TB Patients Polarize a Th1 Response Which Is Bactericidal to Mycobacterium tuberculosis

Extensively drug-resistant tuberculosis (XDR-TB) is a public health concern as drug resistance is outpacing the drug development pipeline. Alternative immunotherapeutic approaches are needed. Peripheral blood mononuclear cells (PBMCs) were isolated from pre-XDR/XDR-TB (n = 25) patients and LTBI (n = 18) participants. Thereafter, monocytic-derived dendritic cells (mo-DCs) were co-cultured with M. tb antigens, with/without a maturation cocktail (interferon-γ, interferon-α, CD40L, IL-1β, and TLR3 and TLR7/8 agonists). Two peptide pools were evaluated: (i) an ECAT peptide pool (ESAT6, CFP10, Ag85B, and TB10.4 peptides) and (ii) a PE/PPE peptide pool. Sonicated lysate of the M. tb HN878 strain served as a control. Mo-DCs were assessed for DC maturation markers, Th1 cytokines, and the ability of the DC-primed PBMCs to restrict the growth of M. tb-infected monocyte-derived macrophages. In pre-XDR/XDR-TB, mo-DCs matured with M. tb antigens (ECAT or PE/PPE peptide pool, or HN878 lysate) + cocktail, compared to mo-DCs matured with M. tb antigens only, showed higher upregulation of co-stimulatory molecules and IL-12p70 (p < 0.001 for both comparisons). The matured mo-DCs had enhanced antigen-specific CD8+ T-cell responses to ESAT-6 (p = 0.05) and Ag85B (p = 0.03). Containment was higher with mo-DCs matured with the PE/PPE peptide pool cocktail versus mo-DCs matured with the PE/PPE peptide pool (p = 0.0002). Mo-DCs matured with the PE/PPE peptide pool + cocktail achieved better containment than the ECAT peptide pool + cocktail [50%, (IQR:39-75) versus 46%, (IQR:15-62); p = 0.02]. In patients with pre-XDR/XDR-TB, an effector response primed by mo-DCs matured with an ECAT or PE/PPE peptide pool + cocktail was capable of restricting the growth of M. tb in vitro.

Anti-Tumor Immunity to Patient-Derived Breast Cancer Cells by Vaccination with Interferon-Alpha-Conditioned Dendritic Cells (IFN-DC)

BACKGROUND

Breast cancer represents one of the leading causes of death among women. Surgery can be effective, but once breast cancer has metastasized, it becomes extremely difficult to treat. Conventional therapies are associated with substantial toxicity and poor efficacy due to tumor heterogeneity, treatment resistance and disease relapse. Moreover, immune checkpoint blockade appears to offer limited benefit in breast cancer. The poor tumor immunogenicity and the immunosuppressive tumor microenvironment result in scarce T-cell infiltration, leading to a low response rate. Thus, there is considerable interest in the development of improved active immunotherapies capable of sensitizing a patient's immune system against tumor cells.

METHODS

We evaluated the in vitro anti-tumor activity of a personalized vaccine based on dendritic cells generated in the presence of interferon (IFN)-α and granulocyte-macrophage colony-stimulating factor (IFN-DC) and loaded with an oxidized lysate from autologous tumor cells expanded as 3D organoid culture maintaining faithful tumor antigenic profiles.

RESULTS

Our findings demonstrate that stimulation of breast cancer patients' lymphocytes with autologous IFN-DC led to efficient Th1-biased response and the generation in vitro of potent cytotoxic activity toward the patients' own tumor cells.

CONCLUSIONS

This approach can be potentially applied in association with checkpoint blockade and chemotherapy in the design of new combinatorial therapies for breast cancer.

The Potential of Photodynamic Therapy Using Solid Lipid Nanoparticles with Aluminum Phthalocyanine Chloride as a Nanocarrier for Modulating Immunogenic Cell Death in Murine Melanoma In Vitro

Photodynamic therapy (PDT) uses a photosensitizer to generate reactive oxygen species (ROS) that kill target cells. In cancer treatments, PDT can potentially induce immunogenic cell death (ICD), which is characterized by a well-controlled exposure of damage-associated molecular patterns (DAMPs) that activate dendritic cells (DCs) and consequently modulate the immune response in the tumor microenvironment. However, PDT still has limitations, such as the activity of photosensitizers in aqueous media and poor bioavailability. Therefore, a new photosensitizer system, SLN-AlPc, has been developed to improve the therapeutic efficacy of PDT. In vitro experiments showed that the light-excited nanocarrier increased ROS production in murine melanoma B16-F10 cells and modulated the profile of DCs. PDT induced cell death accompanied by the exposure of DAMPs and the formation of autophagosomes. In addition, the DCs exposed to PDT-treated B16-F10 cells exhibited morphological changes, increased expression of MHCII, CD86, CD80, and production of IL-12 and IFN-γ, suggesting immune activation towards an antitumor profile. These results indicate that the SLNs-AlPc protocol has the potential to improve PDT efficacy by inducing ICD and activating DCs.

Leptin/lipopolysaccharide-treated dendritic cell vaccine improved cellular immune responses in an animal model of breast cancer

PURPOSE

In dendritic cells (DCs), leptin as an immune-regulating hormone, increases the IL-12 generation whereas it reduces the IL-10 production, thus contributing to TH1 cell differentiation. Using a murine model of breast cancer (BC), we evaluated the impacts of the Leptin and/or lipopolysaccharide (LPS)-treated DC vaccine on various T-cell-related immunological markers.

MATERIALS AND METHODS

Tumors were established in mice by subcutaneously injecting 7 × 105 4T1 cells into the right flank. Mice received the DC vaccines pretreated with Leptin, LPS, and both Leptin/LPS, on days 12 and 19 following tumor induction. The animals were sacrificed on day 26 and after that the frequency of the splenic cytotoxic T lymphocytes (CTLs) and TH1 cells; interferon gamma (IFN-γ), interleukin 12 (IL-12) and tumor growth factor beta (TGF-β) generation by tumor lysate-stimulated spleen cells, and the mRNA expression of T-bet, FOXP3 and Granzyme B in the tumors were measured with flow cytometry, ELISA and real-time PCR methods, respectively.

RESULTS

Leptin/LPS-treated mDC group was more efficient in blunting tumor growth (p = .0002), increasing survival rate (p = .001), and preventing metastasis in comparison with the untreated tumor-bearing mice (UT-control). In comparison to the UT-control group, treatment with Leptin/LPS-treated mDC also significantly increased the splenic frequencies of CTLs (p < .001) and TH1 cells (p < .01); promoted the production of IFN-γ (p < .0001) and IL-12 (p < .001) by splenocytes; enhanced the T-bet (p < .05) and Granzyme B (p < .001) expression, whereas decreased the TGF-β and FOXP3 expression (p < .05).

CONCLUSION

Compared to the Leptin-treated mDC and LPS-treated mDC vaccines, the Leptin/LPS-treated mDC vaccine was more effective in inhibiting BC development and boosting immune responses against tumor.

Polysaccharides regulate Th1/Th2 balance: A new strategy for tumor immunotherapy

T helper (Th) cells have received extensive attention owing to their indispensable roles in anti-tumor immune responses. Th1 and Th2 cells are two key subsets of Th cells that exist in relative equilibrium through the secretion of cytokines that suppress their respective immune response. When the type of cytokine in the tumor microenvironment is altered, this equilibrium may be disrupted, leading to a shift from Th1 to Th2 immune response. Th1/Th2 imbalance is one of the decisive factors in the development of malignant tumors. Therefore, focusing on the balance of Th1/Th2 anti-tumor immune responses may enable future breakthroughs in cancer immunotherapy. Polysaccharides can regulate the imbalance between Th1 and Th2 cells and their characteristic cytokine profiles, thereby improving the tumor immune microenvironment. To our knowledge, this study is the most comprehensive assessment of the regulation of the tumor Th1/Th2 balance by polysaccharides. Herein, we systematically summarized the intrinsic molecular mechanisms of polysaccharides in the regulation of Th1 and Th2 cells to provide a new perspective and potential target drugs for improved anti-tumor immunity and delayed tumor progression.

Cancer stem cells: a target for overcoming therapeutic resistance and relapse

Cancer stem cells (CSCs) are a small subset of cells in cancers that are thought to initiate tumorous transformation and promote metastasis, recurrence, and resistance to treatment. Growing evidence has revealed the existence of CSCs in various types of cancers and suggested that CSCs differentiate into diverse lineage cells that contribute to tumor progression. We may be able to overcome the limitations of cancer treatment with a comprehensive understanding of the biological features and mechanisms underlying therapeutic resistance in CSCs. This review provides an overview of the properties, biomarkers, and mechanisms of resistance shown by CSCs. Recent findings on metabolic features, especially fatty acid metabolism and ferroptosis in CSCs, are highlighted, along with promising targeting strategies. Targeting CSCs is a potential treatment plan to conquer cancer and prevent resistance and relapse in cancer treatment.

TL-532, a novel specific Toll-like receptor 3 agonist rationally designed for targeting cancers: discovery process and biological characterization

Toll-like receptor 3 (TLR3) is an innate immune receptor that recognizes double-stranded RNA (dsRNA) and induces inflammation in immune and normal cells to initiate anti-microbial responses. TLR3 acts also as a death receptor only in cancer cells but not in their normal counterparts, making it an attractive target for cancer therapies. To date, all of the TLR3-activating dsRNAs used at preclinical or clinical stages have major drawbacks such as structural heterogeneity, toxicity, and lack of specificity and/or efficacy. We conducted the discovery process of a new family of TLR3 agonists that are chemically manufactured on solid-phase support and perfectly defined in terms of sequence and size. A stepwise discovery process was performed leading to the identification of TL-532, a 70 base pair dsRNA that is potent without transfection reagent and is highly specific for TLR3 without activating other innate nucleic sensors such as RIG-I/MDA5, TLR7, TLR8, and TLR9. TL-532 induces inflammation in murine RAW264.7 myeloid macrophages, in human NCI-H292 lung cancer cells, and it promotes immunogenic apoptosis in tumor cells in vitro and ex vivo without toxicity towards normal primary cells. In conclusion, we identified a novel TLR3 agonist called TL-532 that has promising anticancer properties.

Vaccination with celecoxib-treated dendritic cells improved cellular immune responses in an animal breast cancer model

PURPOSE

Prostaglandin E2 (PGE2), a product of cyclooxygenase (COX) pathway of arachidonic acid, exerts inhibitory impacts on dendritic cell (DC) activity to repress anti-tumor immune responses. Therefore, targeting COX during DC vaccine generation may enhance DC-mediated antitumor responses. We aimed to investigate the impacts of DC vaccine treated with celecoxib (CXB), a selective COX2 inhibitor, on some T cell-related parameters.

MATERIALS AND METHODS

Breast cancer (BC) was induced in BALB/c mice, and then they received DC vaccine treated with lipopolysaccharide (LPS-mDCs), LPS with a 5 ​μM dose of CXB (LPS/CXB5-mDCs) and LPS with a 10 ​μM dose of CXB (LPS/CXB10-mDCs). The frequency of splenic Th1 and Treg cells and amounts of IFN-γ, IL-12 and TGF-β production by splenocytes, as well as, the expression of Granzyme-B, T-bet and FOXP3 in tumors were determined using flow cytometry, ELISA, and real-time PCR, respectively.

RESULTS

Compared with untreated tumor group (T-control), treatment with LPS/CXB5-mDCs and LPS/CXB10-mDCs decreased tumor growth (P ​= ​0.009 and P ​< ​0.0001), escalated survival rate (P ​= ​0.002), increased the frequency of splenic Th1 cells (P ​= ​0.0872, and P ​= ​0.0155), increased the IFN-γ (P ​= ​0.0003 and P ​= ​0.0061) and IL-12 (P ​= ​0.001 and P ​= ​0.0009) production by splenocytes, upregulated T-bet (P ​= ​0.062 and P ​< ​0.0001) and Granzyme-B (P ​= ​0.0448 and P ​= ​0.4485), whereas decreased the number of Treg cells (P ​= ​0.0014, and P ​= ​0.0219), reduced the amounts of TGF-β production by splenocytes (P ​= ​0.0535 and P ​= ​0.0169), and reduced the expression of FOXP3 (P ​= ​0.0006 and P ​= ​0.0057) in comparison with T-control group.

CONCLUSIONS

Our findings show that LPS/CXB-treated DC vaccine potently modulated antitumor immune responses in a mouse BC model.

Biomimetic nanoparticles for tumor immunotherapy

Currently, tumor treatment research still focuses on the cancer cells themselves, but the fact that the immune system plays an important role in inhibiting tumor development cannot be ignored. The activation of the immune system depends on the difference between self and non-self. Unfortunately, cancer is characterized by genetic changes in the host cells that lead to uncontrolled cell proliferation and evade immune surveillance. Cancer immunotherapy aims to coordinate a patient's immune system to target, fight, and destroy cancer cells without destroying the normal cells. Nevertheless, antitumor immunity driven by the autoimmune system alone may be inadequate for treatment. The development of drug delivery systems (DDS) based on nanoparticles can not only promote immunotherapy but also improve the immunosuppressive tumor microenvironment (ITM), which provides promising strategies for cancer treatment. However, conventional nano drug delivery systems (NDDS) are subject to several limitations in clinical transformation, such as immunogenicity and the potential toxicity risks of the carrier materials, premature drug leakage at off-target sites during circulation and drug load content. In order to address these limitations, this paper reviews the trends and progress of biomimetic NDDS and discusses the applications of each biomimetic system in tumor immunotherapy. Furthermore, we review the various combination immunotherapies based on biomimetic NDDS and key considerations for clinical transformation.

Pan-Cancer Analysis of the Prognostic and Immunotherapeutic Value of MITD1

Microtubule-interacting and trafficking domain containing 1 (MITD1) is associated with abscission during cytokinesis. However, systematic investigation into its role in cancer is lacking. Therefore, we explored the pan-cancer role of MITD1 using multiple databases. Expression and clinical survival, immunological, and enrichment analyses were performed using R packages and online tools. For breast cancer, single-cell level analysis, immunochemistry, and in vitro experiments were performed to explore the mechanism of MITD1. A nomogram was established to predict the prognosis of patients with breast cancer and evaluate the immunotherapy biomarker based on two datasets. In some cancers, high MITD1 expression was associated with a more favorable prognosis. For instance, it inhibited tumor cell proliferation and migration in breast cancer. MITD1 may regulate cancer development by altering the tumor microenvironment, and MITD1 expression may predict the response to immune checkpoint blockade, platinum, and poly ADP-ribose polymerase inhibitor therapies. Our nomogram was used to determine the prognosis of patients with breast cancer. MITD1 can also predict the response to immunotherapy. Our first pan-cancer study of MITD1 has shown that it plays different roles in cancer development and therapy. In breast cancer, MITD1 inhibited cell proliferation and migration and serves as a new biomarker.

The modulatory role of dendritic cell-T cell cross-talk in breast cancer: Challenges and prospects

Antigen recognition and presentation are highlighted as the first steps in developing specialized antigen responses. Dendritic cells (DCs) are outstanding professional antigen-presenting cells (APCs) responsible for priming cellular immunity in pathological states, including cancer. However, the diminished or repressed function of DCs is thought to be a substantial mechanism through which tumors escape from the immune system. In this regard, DCs obtained from breast cancer (BC) patients represent a notably weakened potency to encourage specific T-cell responses. Additionally, impaired DC-T-cell cross-talk in BC facilitates the immune evade of cancer cells and is connected with tumor advancement, immune tolerance, and adverse prognosis for patients. In this review we aim to highlight the available knowledge on DC-T-cell interactions in BC aggressiveness and show its therapeutic potential in BC treatment.

Stability Program in Dendritic Cell Vaccines: A “Real-World” Experience in the Immuno-Gene Therapy Factory of Romagna Cancer Center

Advanced therapy medical products (ATMPs) are rapidly growing as innovative medicines for the treatment of several diseases. Hence, the role of quality analytical tests to ensure consistent product safety and quality has become highly relevant. Several clinical trials involving dendritic cell (DC)-based vaccines for cancer treatment are ongoing at our institute. The DC-based vaccine is prepared via CD14+ monocyte differentiation. A fresh dose of 10 million DCs is administered to the patient, while the remaining DCs are aliquoted, frozen, and stored in nitrogen vapor for subsequent treatment doses. To evaluate the maintenance of quality parameters and to establish a shelf life of frozen vaccine aliquots, a stability program was developed. Several parameters of the DC final product at 0, 6, 12, 18, and 24 months were evaluated. Our results reveal that after 24 months of storage in nitrogen vapor, the cell viability is in a range between 82% and 99%, the expression of maturation markers remains inside the criteria for batch release, the sterility tests are compliant, and the cell costimulatory capacity unchanged. Thus, the data collected demonstrate that freezing and thawing do not perturb the DC vaccine product maintaining over time its functional and quality characteristics.

LncRNA PCAT6 activated by SP1 facilitates the progression of breast cancer by the miR-326/LRRC8E axis

Breast cancer is an aggressive malignancy with high morbidity in females worldwide. Extensive studies reveal that long noncoding RNAs (lncRNAs) are abnormally expressed and act as key regulators in various cancers, including breast cancer. In this work, we investigated the role and regulatory mechanism of lncRNA prostate cancer-associated transcript 6 (PCAT6) in breast cancer progression. Our findings revealed that PCAT6 was overexpressed in breast cancer tissues and cell lines. Furthermore, elevation of PCAT6 reflected an adverse prognosis of patients. Functional experiments indicated that PCAT6 knockdown hampered cell proliferation, facilitated apoptosis and cell cycle arrest in vitro, and inhibited tumor growth in vivo. We also found that the transcription factor SP1 could bind to the PCAT6 promoter and promoted its expression. Subsequently, it was verified that PCAT6 was a molecular sponge for microRNA-326 (miR-326), and the leucine-rich repeat containing the eight family member E (LRRC8E) was a direct target of miR-326. Rescue assays revealed that LRRC8E overexpression attenuated the suppressive effect of PCAT6 knockdown on cellular progression of breast cancer. In summary, this study demonstrated that SP1-activated PCAT6 promoted the malignant behaviors of breast cancer cells by regulating the miR-326/LRRC8E axis.

A recombinant oncolytic Newcastle virus expressing MIP-3α promotes systemic antitumor immunity

BACKGROUND

The oncolytic Newcastle disease virus (NDV) is inherently able to trigger the lysis of tumor cells and induce the immunogenic cell death (ICD) of tumor cells and is also an excellent gene-engineering vector. The macrophage inflammatory protein-3α (MIP-3α) is a specific chemokine for dendritic cells (DCs). Thus, we constructed a recombinant NDV expressing MIP-3α (NDV-MIP3α) as an in vivo DC vaccine for amplifying antitumor immunities.

METHODS

The recombinant NDV-MIP3α was constructed by the insertion of MIP-3α cDNA between the P and M genes. Western blotting assay and ELISA were used to detect MIP-3α, HMGB1, IgG, and ATP in the supernatant and sera. The chemotaxis of DCs was examined by Transwell chambers. The phenotypes of the immune cells (eg, DCs) were analyzed by flow cytometry. The antitumor efficiency of NDV-MIP3α was observed in B16 and CT26 tumor-bearing mice. Immunofluorescence and immunohistochemistry were applied to observe the ecto-calreticulin (CRT) and intratumoral attraction of DCs. Adoptive transfer of splenocytes and antibodies and depletion of T-cell subsets were used to evaluate the relationship between antitumor immunities and the role of the T-cell subtype.

RESULTS

The findings show that NDV-MIP3α has almost the same capabilities of tumor lysis and induction of ICD as the wild-type NDV (NDV-WT). MIP-3α secreted by NDV-MIP3α could successfully attract DCs in vitro and in vivo. Both B16 and CT26 cells infected with NDV-MIP3α could strongly promote DC maturation and activation. Compared with NDV-WT, intratumoral injection of NDV-MIP3α and the adoptive transfer of T lymphocytes from mice injected with NDV-MIP3α resulted in a significant suppression of B16 and CT26 tumor growth. The NDV-MIP3α-induced production of tumor-specific cellular and humoral immune responses was dependent on CD8⁺ T cells and partially on CD4⁺ T cells. A significant reversion of tumor microenvironments was found in the mice injected with NDV-MIP3α.

CONCLUSIONS

Compared with NDV-WT, the recombinant NDV-MIP3α as an in vivo DC vaccine demonstrates enhanced antitumor activities through the induction of stronger system immunities and modulation of the tumor microenvironment. This strategy may be a potential approach for the generation of an in vivo DC vaccine.

CELF2 is a candidate prognostic and immunotherapy biomarker in triple-negative breast cancer and lung squamous cell carcinoma: A pan-cancer analysis

CUGBP Elav-like family member 2(CELF2) plays crucial roles in the development and activation of T cell. However, the impacts of CELF2 on tumour-infiltrating immune cells (TIICs) and clinical outcomes of tumours remain unclear. In this study, we found that elevated CELF2 expression was markedly correlated with prolonged survival in multiple tumours, particularly in breast and lung cancers. Notably, CELF2 only impacted the prognosis of triple-negative breast cancer (TNBC) with lymph node metastasis. Further investigation showed CELF2 expression was positively correlated with the infiltration abundance of dendritic cells (DCs), CD8+ T cells and neutrophils in breast invasive carcinoma (BRCA) and DCs in lung squamous cell carcinoma (LUSC). CELF2 also had strong correlations with markers of diverse TIICs such as T cells, tumour-associated macrophages and DCs in BRCA and LUSC. Importantly, CELF2 was significantly associated with plenty of immune checkpoint molecules (ICMs) and outperformed five prevalent biomarkers including PD-1, PD-L1, CTLA-4, CD8 and tumour mutation burden in predicting immunotherapeutic responses. Immunohistochemistry also revealed lower protein levels of CELF2 in TNBC and LUSC compared to normal tissues, and patients with high expression showed significantly prolonged prognosis. In conclusion, we demonstrated that increased CELF2 expression was closely related to better prognosis and superior TIIC infiltration and ICM expression, particularly in BRCA and LUSC. CELF2 also performed well in evaluating the immunotherapeutic efficacy, suggesting CELF2 might be a promising biomarker.

TLR3 agonists: RGC100, ARNAX, and poly-IC: a comparative review

Toll-like receptors 3 (TLR3) have been broadly studied among all TLRs over the last few decades together with its agonists due to their contribution to cancer regression. These agonists undeniably have some shared characteristics such as mimicking dsRNA but pathways through which they exhibit antitumor properties are relatively diverse. In this review, three widely studied agonists RGC100, ARNAX, and poly-IC are discussed along with their structural and physiochemical differences including the signaling cascades through which they exert their actions. Comparison has been made to identify the finest agonist with maximum effectivity and the least side effect profile.

Immunotherapy in breast cancer: A clinician's perspective

Globally over 2 million women are diagnosed with breast cancer each year despite major advances in detection and treatment of the disease. Breast cancer is comprised of several distinct subtypes and understanding the heterogeneity of the disease has become crucial for treatment planning. Therapeutic strategies span from a hormone therapy-based focus for women with estrogen receptor positive breast cancer to targeting human epidermal growth factor (HER2) by small molecules, antibody-drug-conjugates (ADC) and monoclonal antibodies in those with HER2 overexpression. Other novel treatment strategies for select subgroups of patients include the cyclin-dependent kinase 4/6 (CDK4/6) inhibitors for women with estrogen receptor positive tumors, the poly ADP ribose polymerase (PARP) inhibitors for those with BRCA mutations, and phosphoinositide 3-kinase (PI3K) inhibitors for women with tumors harboring phophatidylinositol-4,5-bisphosphate 3 kinase catalytic subunit alpha (PIK3CA) mutations. In contrast, the treatment for women with triple negative breast cancer has until recently been solely limited to chemotherapy. The profound impact of immunotherapy on cancer treatment in general has created much hope for its potential in breast cancer. This review will focus on the current advances and the research of immunotherapy in breast cancer, particularly on immune checkpoint inhibitors, adoptive cell transfer and cancer vaccines.

Mannosylated gelatin nanoparticles enhanced inactivated PRRSV targeting dendritic cells and increased T cell immunity

The objective of the present work was to evaluate the efficacy of a novel antigen carrier using mannosylated gelatin nanoparticles with entrapped inactivated porcine reproductive and respiratory syndrome virus (PRRSV) in inducing T cell mediated immunity in vitro. Gelatin nanoparticles (GNP) were modified with mannose to form mannosylated gelatin nanoparticles (MnGNP), which can efficiently and specifically target monocyte derived dendritic cells (MoDCs). The inactivated PRRSV was encapsulated in the MnGNP and GNP, referred to as MnGNP-PRRSV and GNP-PRRSV, respectively. All these prepared nanometer particles were characterized for size, surface charge, drug encapsulation efficiency, and drug release. The efficacy of MnGNP in targeting MoDCs was investigated, as well as the subsequent MoDCs maturation and T cell mediated cytotoxicity. The developed MnGNP-PRRSV particle was characterized with a nanometric size of 302.67 ± 3.2 nm, surface charge of 23.81 ± 1.26 mV, and PRRSV encapsulation efficiency of 63.2 ± 1.85 %. The maximum uptake of MnGNP in MoDCs in vitro was 15.5 times higher than GNP with a shorter reaction time that peaked 4 h earlier. The uptake of MnGNP-PRRSV induced maturation of MoDCs and significantly enhanced expression of SWC-3a, CD80, CD1, SLA I, SLA II on MoDCs, compared to PRRSV (p < 0.001). The cytokine secretion of IL-1β, IL-6, IL-10, and IL-12 was also increased in MoDCs when treated with MnGNP-PRRSV, compared to PRRSV (p < 0.05). The matured MoDCs triggered T lymphocytes in autologous peripheral blood mononuclear cells (PBMCs) activation, proliferation, and differentiation into effector cytotoxic T lymphocyte, suggesting increased amount of activated T cells after MnGNP-PRRSV treatment. Additionally, the function of T cells to kill PRRSV infected cells was 83.98 ± 2.62 % when triggered by MnGNP-PRRSV, compared to 60 ± 4.7 % in PRRSV group (p < 0.001). These results indicate that MnGNP with entrapped inactivated PRRSV can effectively and specifically target dendritic cells for maturation and activation, and subsequently improve T cell activation, proliferation and function to kill PRRSV infected cells.

Antitumour dendritic cell vaccination in a priming and boosting approach

Mobilizing antitumour immunity through vaccination potentially constitutes a powerful anticancer strategy but has not yet provided robust clinical benefits in large patient populations. Although major hurdles still exist, we believe that currently available strategies for vaccines that target dendritic cells or use them to present antitumour antigens could be integrated into existing clinical practice using prime-boost approaches. In the priming phase, these approaches capitalize on either standard treatment modalities to trigger in situ vaccination and release tumour antigens or vaccination with dendritic cells loaded with tumour lysates or patient-specific neoantigens. In a second boost phase, personalized synthetic vaccines specifically boost T cells that were triggered during the priming phase. This immunotherapy approach has been enabled by the substantial recent improvements in dendritic cell vaccines. In this Perspective, we discuss these improvements, highlight how the prime-boost approach can be translated into clinical practice and provide solutions for various anticipated hurdles.

Trial watch: TLR3 agonists in cancer therapy

Toll-like receptor 3 (TLR3) is a pattern recognition receptor that senses exogenous (viral) as well as endogenous (mammalian) double-stranded RNA in endosomes. On activation, TLR3 initiates a signal transduction pathway that culminates with the secretion of pro-inflammatory cytokines including type I interferon (IFN). The latter is essential not only for innate immune responses to infection but also for the initiation of antigen-specific immunity against viruses and malignant cells. These aspects of TLR3 biology have supported the development of various agonists for use as stand-alone agents or combined with other therapeutic modalities in cancer patients. Here, we review recent preclinical and clinical advances in the development of TLR3 agonists for oncological disorders.

Abbreviations

cDC, conventional dendritic cell; CMT, cytokine modulating treatment; CRC, colorectal carcinoma; CTL, cytotoxic T lymphocyte; DC, dendritic cell; dsRNA, double-stranded RNA; FLT3LG, fms-related receptor tyrosine kinase 3 ligand; HNSCC, head and neck squamous cell carcinoma; IFN, interferon; IL, interleukin; ISV, in situ vaccine; MUC1, mucin 1, cell surface associated; PD-1, programmed cell death 1; PD-L1, programmed death-ligand 1; polyA:U, polyadenylic:polyuridylic acid; polyI:C, polyriboinosinic:polyribocytidylic acid; TLR, Toll-like receptor.

Dendritic Cells and Their Role in Immunotherapy

Despite significant advances in the field of cancer immunotherapy, the majority of patients still do not benefit from treatment and must rely on traditional therapies. Dendritic cells have long been a focus of cancer immunotherapy due to their role in inducing protective adaptive immunity, but cancer vaccines have shown limited efficacy in the past. With the advent of immune checkpoint blockade and the ability to identify patient-specific neoantigens, new vaccines, and combinatorial therapies are being evaluated in the clinic. Dendritic cells are also emerging as critical regulators of the immune response within tumors. Understanding how to augment the function of these intratumoral dendritic cells could offer new approaches to enhance immunotherapy, in addition to improving the cytotoxic and targeted therapies that are partially dependent upon a robust immune response for their efficacy. Here we will discuss the role of specific dendritic cell subsets in regulating the anti-tumor immune response, as well as the current status of dendritic cell-based immunotherapies, in order to provide an overview for future lines of research and clinical trials.

HER2-Positive Breast Cancer Immunotherapy: A Focus on Vaccine Development

Clinical progress in the field of HER2-positive breast cancer therapy has been dramatically improved by understanding of the immune regulatory mechanisms of tumor microenvironment. Passive immunotherapy utilizing recombinant monoclonal antibodies (mAbs), particularly trastuzumab and pertuzumab has proved to be an effective strategy in HER2-positive breast cancer treatment. However, resistance to mAb therapy and relapse of disease are still considered important challenges in clinical practice. There are increasing reports on the induction of cellular and humoral immune responses in HER2-positive breast cancer patients. More recently, increasing efforts are focused on using HER2-derived peptide vaccines for active immunotherapy. Here, we discuss the development of various HER2-derived vaccines tested in animal models and human clinical trials. Different formulations and strategies to improve immunogenicity of the antigens in animal studies are also discussed. Furthermore, other immunotherapeutic approaches to HER2 breast cancer including, CTLA-4 inhibitors, immune checkpoint inhibitors, anti PD-1/PD-L1 antibodies are presented.

Dendritic Cells Therapy with Cytokine-Induced Killer Cells and Activated Cytotoxic T Cells Attenuated Th2 Bias Immune Response

THE AIM OF THIS STUDY

The purpose of this study is to investigate whether the DC cells combined with CIK cells (DC/CIK) and DC activated cytotoxic T cells (DC-ACT) treatment can promote antitumor response and change the immune indicators by targeting the heterogeneous tumor cell populations at a system level.

METHODS

In this study, 112 patients with cancer were assigned to the DC/CIK treatment and 116 patients received the DC-ACT therapy. We detected the lymphocyte subsets and other immune indicators pre- and post-treatment to evaluate the changes of patient's immunity and compare the differences in immune status between two adoptive cellular immunotherapies.

RESULTS

DC/CIK therapy elevated the percentage of CD3+ HLA-DR+ T cells, NK cells and several serological cytokines such as IL-2, IL-6 after cell infusion (p < .05). DC-ACT therapy could increase the total CD3 + T cells, CD8 + T cells, CD3+ HLA-DR+ cells and IL-12 cytokines after cell infusion (p < .05). The levels of IL-4/IFN-γ, IL-4/IL-12 and IL-6/IL-12 were reduced significantly in the DC-ACT group compared with DC/CIK group. These observations suggested that DC-ACT therapy has more dominance to induce Th1 cytokine response instead of skewing toward the Th2 cytokine profile based on the immunomodulatory properties.

CONCLUSIONS

These results indicated that DC, CIK, and DC-ACT cells exert anti-tumor activity through the different pathways. Thus, this work may provide valuable insights into the clinical curative effect evaluation of immunocyte therapy and the design of combined immunotherapeutic strategies for malignant tumors.

PKHB1 Tumor Cell Lysate Induces Antitumor Immune System Stimulation and Tumor Regression in Syngeneic Mice with Tumoral T Lymphoblasts

Acute lymphocytic leukemia (ALL) is the most common pediatric cancer. Currently, treatment options for patients with relapsed and refractory ALL mostly rely on immunotherapies. However, hematological cancers are commonly associated with a low immunogenicity and immune tolerance, which may contribute to leukemia relapse and the difficulties associated with the development of effective immunotherapies against this disease. We recently demonstrated that PKHB1, a TSP1-derived CD47 agonist peptide, induces immunogenic cell death (ICD) in T cell ALL (T-ALL). Cell death induced by PKHB1 on T-ALL cell lines and their homologous murine, L5178Y-R (T-murine tumor lymphoblast cell line), induced damage-associated molecular patterns (DAMPs) exposure and release. Additionally, a prophylactic vaccination with PKHB1-treated L5178Y-R cells prevented tumor establishment in vivo in all the cases. Due to the immunogenic potential of PKHB1-treated cells, in this study we assessed their ability to induce antitumor immune responses ex vivo and in vivo in an established tumor. We first confirmed the selectivity of cell death induced by PKBH1 in tumor L5178Y-R cells and observed that calreticulin exposure increased when cell death increased. Then, we found that the tumor cell lysate (TCL) obtained from PKHB1-treated L5178YR tumor cells (PKHB1-TCL) was able to induce, ex vivo, dendritic cells maturation, cytokine production, and T cell antitumor responses. Finally, our results show that in vivo, PKHB1-TCL treatment induces tumor regression in syngeneic mice transplanted with L5178Y-R cells, increasing their overall survival and protecting them from further tumor establishment after tumor rechallenge. Altogether our results highlight the immunogenicity of the cell death induced by PKHB1 activation of CD47 as a potential therapeutic tool to overcome the low immunogenicity and immune tolerance in T-ALL.