Combination therapy with dendritic cell vaccine and IL-2 encapsulating polymeric micelles enhances intra-tumoral accumulation of antigen-specific CTLs

IL-2 based cancer immunotherapies: an evolving paradigm

Discovered over 4 decades ago in the supernatants of activated T cells, interleukin-2 (IL-2) is a potent pleiotropic cytokine involved in the regulation of immune responses. It is required for effector T cell expansion and differentiation as well as for peripheral tolerance induced by regulatory T cells. High-dose IL-2 treatment was the first FDA-approved immunotherapy for renal cell carcinoma and melanoma, achieving single agent complete and durable responses, albeit only in a small proportion of patients. The therapeutic potential of wild type IL-2 is clinically limited by its short half-life and severe vascular toxicity. Moreover, the activation of regulatory T cells and the terminal differentiation of effector T cells on IL-2 pose additional restrictions. To overcome the toxicity of IL-2 in order to realize its full potential for patients, several novel engineering strategies are being developed and IL-2 based immunotherapy for cancer has emerged as a burgeoning field of clinical and experimental research. In addition, combination of IL-2 with PD-1/L1 pathway blockade shows vastly improved anti-tumor efficacy over either monotherapy in preclinical tumor models. In this review we discuss the biological characteristics of IL-2 and its receptors, as well as its efficacy and treatment limiting toxicities in cancer patients. We also explore the efforts aimed at developing novel and safer IL-2 therapies to harness the full therapeutic potential of this cytokine.

Advancements in dendritic cell vaccination: enhancing efficacy and optimizing combinatorial strategies for the treatment of glioblastoma

Glioblastomas (GBM) are highly invasive, malignant primary brain tumors. The overall prognosis is poor, and management of GBMs remains a formidable challenge, necessitating novel therapeutic strategies such as dendritic cell vaccinations (DCVs). While many early clinical trials demonstrate an induction of an antitumoral immune response, outcomes are mixed and dependent on numerous factors that vary between trials. Optimization of DCVs is essential; the selection of GBM-specific antigens and the utilization of 18F-fludeoxyglucose Positron Emission Tomography (FDG-PET) may add significant value and ultimately improve outcomes for patients undergoing treatment for glioblastoma. This review provides an overview of the mechanism of DCV, assesses previous clinical trials, and discusses future strategies for the integration of DCV into glioblastoma treatment protocols. To conclude, the review discusses challenges associated with the use of DCVs and highlights the potential of integrating DCV with standard therapies.

Enhancing Skin Cancer Immunotheranostics and Precision Medicine through Functionalized Nanomodulators and Nanosensors: Recent Development and Prospects

Skin cancers, especially melanomas, present a formidable diagnostic and therapeutic challenge to the scientific community. Currently, the incidence of melanomas shows a high increase worldwide. Traditional therapeutics are limited to stalling or reversing malignant proliferation, increased metastasis, or rapid recurrence. Nonetheless, the advent of immunotherapy has led to a paradigm shift in treating skin cancers. Many state-of-art immunotherapeutic techniques, namely, active vaccination, chimeric antigen receptors, adoptive T-cell transfer, and immune checkpoint blockers, have achieved a considerable increase in survival rates. Despite its promising outcomes, current immunotherapy is still limited in its efficacy. Newer modalities are now being explored, and significant progress is made by integrating cancer immunotherapy with modular nanotechnology platforms to enhance its therapeutic efficacy and diagnostics. Research on targeting skin cancers with nanomaterial-based techniques has been much more recent than other cancers. Current investigations using nanomaterial-mediated targeting of nonmelanoma and melanoma cancers are directed at augmenting drug delivery and immunomodulation of skin cancers to induce a robust anticancer response and minimize toxic effects. Many novel nanomaterial formulations are being discovered, and clinical trials are underway to explore their efficacy in targeting skin cancers through functionalization or drug encapsulation. The focus of this review rivets on theranostic nanomaterials that can modulate immune mechanisms toward protective, therapeutic, or diagnostic approaches for skin cancers. The recent breakthroughs in nanomaterial-based immunotherapeutic modulation of skin cancer types and diagnostic potentials in personalized immunotherapies are discussed.

Dendritic cell transfer for cancer immunotherapy

Dendritic cells (DCs) play a major role in cancer immunosurveillance as they bridge innate and adaptive immunity by detecting tumor-associated antigens and presenting them to T lymphocytes. The adoptive transfer of antigen loaded DCs has been proposed as an immunotherapeutic approach for the treatment of various types of cancer. Nevertheless, despite promising preclinical data, the therapeutic efficacy of DC transfer is still deceptive in cancer patients. Here we summarize recent findings in DC biology with a special focus on the development of actionable therapeutic strategies and discuss experimental and clinical approaches that aim at improving the efficacy of DC-based immunotherapies, including, but not limited to, optimized DC production and antigen loading, stimulated maturation, the co-treatment with additional immunotherapies, as well as the inhibition of DC checkpoints.

Electroporation-Based ex Vivo Gene Delivery into Dendritic Cells by Anionic Polymer-Coated Versatile Nuclear Localization Signal/pDNA Complex

In this study, we focused on a nuclear localization signal (NLS)-based versatile peptide vector, designed by us, combined with electroporation (EP) to establish an efficient gene delivery system to non-dividing or slow growing dendritic cells. We determined the intranuclear transport, gene expression, and cell viability in JAWS II mouse dendritic cells transfected with the green fluorescent protein (GFP) expression plasmid DNA alone (naked pEGFP); positive charged complex of NLS derivative STR-CH2SV40H2C, and pEGFP (binary complex); or negative charged complex of the binary complex with a biocompatible polyanion, γ-polyglutamic acid (ternary complex) combined with or without EP application. Although the binary complex showed higher nuclear transport and GFP expression in the absence of EP than those for naked pEGFP, the combination of EP significantly decreased the cell viability and did not improve the efficiency of compared gene expression. However, in the ternary complex, the intranuclear transport and GFP expression efficiency were significantly higher than those of naked pEGFP and the binary complex when combined with EP, and there was no decrease in cell viability. The results suggest that polyanion-coated ternary complex with EP is useful for non-viral gene delivery system into non-dividing cells for ex vivo gene/cell therapy.

Polymeric Micelles in Cancer Immunotherapy

Cancer immunotherapies have generated some miracles in the clinic by orchestrating our immune system to combat cancer cells. However, the safety and efficacy concerns of the systemic delivery of these immunostimulatory agents has limited their application. Nanomedicine-based delivery strategies (e.g., liposomes, polymeric nanoparticles, silico, etc.) play an essential role in improving cancer immunotherapies, either by enhancing the anti-tumor immune response, or reducing their systemic adverse effects. The versatility of working with biocompatible polymers helps these polymeric nanoparticles stand out as a key carrier to improve bioavailability and achieve specific delivery at the site of action. This review provides a summary of the latest advancements in the use of polymeric micelles for cancer immunotherapy, including their application in delivering immunological checkpoint inhibitors, immunostimulatory molecules, engineered T cells, and cancer vaccines.

Combination antitumor therapy with targeted dual-nanomedicines

Combination therapy is one of the important treatment strategies for cancer at present. However, the outcome of current combination therapy based on the co-administration of conventional dosage forms is suboptimal, due to the short half-lives of chemodrugs, their deficient tumor selectivity and so forth. Nanotechnology-based targeted delivery systems show great promise in addressing the associated problems and providing superior therapeutic benefits. In this review, we focus on the combination of therapeutic strategies between different nanomedicines or drug-loaded nanocarriers, rather than the co-delivery of different drugs via a single nanocarrier. We introduce the general concept of various targeting strategies of nanomedicines, present the principles of combination antitumor therapy with dual-nanomedicines, analyze their advantages and limitations compared with co-delivery strategies, and overview the recent advances of combination therapy based on targeted nanomedicines. Finally, we reviewed the challenges and future perspectives regarding the selection of therapeutic agents, targeting efficiency and the gap between the preclinical and clinical outcome.

Immunotherapy against metastatic bladder cancer by combined administration of granulocyte macrophage-colony stimulating factor and interleukin-2 surface modified MB49 bladder cancer stem cells vaccine

In previous studies, it has been shown that the granulocyte macrophage‐colony stimulating factor (GM‐CSF) or interleukin‐2 (IL‐2) surface modified MB49 bladder cancer stem cells (MCSCs) vaccine could induce a specific antitumor immunity and against bladder cancer in mice model respectively. However, whether combined administration of GM‐CSF and IL‐2 could produce specific immune responses to cancer stem cells (CSCs) was uncertain. MCSCs were established and characterized. GM‐CSF and IL‐2 MCSCs vaccines were prepared and bioactivity was evaluated. The therapeutic, protective, specific, and memorial immune response animal experiments were designed. Tumor‐specific cytotoxic T lymphocytes assay, enzyme linked immunosorbent assay, flow cytometry assay were performed to indentify whether vaccine caused an antitumor immunity. Streptavidin (SA)‐GM‐CSF and SA‐IL‐2 MCSCs vaccines were prepared successfully. Such vaccines inhibited the volume of tumor and prolonged the survival of the mice in animal experiments. The express of IgG or IFN‐c, the portion of dendritic cells, CD8⁺ and CD4⁺ T cells were highest in the combined vaccines group than the SA‐GM‐CSF vaccine group, the SA‐IL‐2 vaccine group, the MCSCs group and the PBS group. The combined of GM‐CSF and IL‐2 vaccines could induce better antitumor immunity than a vaccine alone.

Antibody-Based Cancer Therapy: Successful Agents and Novel Approaches

Since their discovery, antibodies have been viewed as ideal candidates or "magic bullets" for use in targeted therapy in the fields of cancer, autoimmunity, and chronic inflammatory disorders. A wave of antibody-dedicated research followed, which resulted in the clinical approval of a first generation of monoclonal antibodies for cancer therapy such as rituximab (1997) and cetuximab (2004), and infliximab (2002) for the treatment of autoimmune diseases. More recently, the development of antibodies that prevent checkpoint-mediated inhibition of T cell responses invigorated the field of cancer immunotherapy. Such antibodies induced unprecedented long-term remissions in patients with advanced stage malignancies, most notably melanoma and lung cancer, that do not respond to conventional therapies. In this review, we will recapitulate the development of antibody-based therapy, and detail recent advances and new functions, particularly in the field of cancer immunotherapy. With the advent of recombinant DNA engineering, a number of rationally designed molecular formats of antibodies and antibody-derived agents have become available, and we will discuss various molecular formats including antibodies with improved effector functions, bispecific antibodies, antibody-drug conjugates, antibody-cytokine fusion proteins, and T cells genetically modified with chimeric antigen receptors. With these exciting advances, new antibody-based treatment options will likely enter clinical practice and pave the way toward more successful control of malignant diseases.

Co-delivery of doxorubicin and interleukin-2 via chitosan based nanoparticles for enhanced antitumor efficacy

In order to reduce toxicity and improve antitumor therapeutic effects of doxorubicin (DOX) and recombinant human interleukin-2 (rhIL-2), we developed a hydrophilic cationic polymer (N,N,N-trimethyl chitosan, TMC) based nanocomplexes (FTCD/rhIL-2) which could efficiently mediate systemic co-delivery of hydrophobic DOX and water-soluble rhIL-2 to achieve the purpose of combination therapy. DOX was covalently conjugated to TMC through cis-aconitic anhydride (CA) which endowed nanocomplexes a pH-sensitive release of DOX, while rhIL-2 was loaded through electrostatic adsorption without compromise of bioactivity. The resultant nanocomplexes exhibited sub-spherical shape (∼200nm) and positive charge (>20mV). Folate (FA) modification was utilized with the intention of active targeting, which was however correlated with weakened tumor growth inhibition, emphasizing the importance of balance in overcoming diverse delivery barriers for efficacious antitumor therapy. Compared with free drugs, FTCD/rhIL-2 nanocomplexes significantly delayed tumor growth, increased the serum immunoglobulin G (IgG) level and the amount of tumor infiltrated cytotoxic T lymphocytes. These results indicated that the combinational administration of DOX and rhIL-2 based on polymer nanoparticles could serve as an effective strategy in antitumor therapy.

STATEMENT OF SIGNIFICANCE

Combined administration of doxorubicin (DOX) and recombinant human interleukin-2 (rhIL-2) has been utilized for the treatment of tumors. However the traditional administration brought to severe side effects, and the efficiency of current delivery systems were unsatisfactory. Herein we developed a hydrophilic cationic polymer based nanoparticle delivery system which facilitated simultaneous and systemic co-delivery of hydrophobic DOX and water-soluble rhIL-2. This system achieved pH-sensitive release of DOX and sustained release of rhIL-2 in vitro, meanwhile, improved anti-tumor efficacy and reduced side-effect in vivo. Thus, our study provided a solution for combinational administration of DOX and rhIL-2 and could serve as an effective strategy in antitumor therapy.

Micro and Nano Material Carriers for Immunomodulation

Modulation of the immune system through the use of micro and nano carriers offers opportunities in transplant tolerance, autoimmunity, infectious disease, and cancer. In particular, polymeric, lipid, and inorganic materials have been used as carriers of proteins, nucleic acids, and small drug molecules to direct the immune system toward either suppressive or stimulatory states. Current technologies have focused on the use of particulates or scaffolds, the modulation of materials properties, and the delivery of biologics or small drug molecules to achieve a desired response. Discussed are relevant immunology concepts, the types of biomaterial carriers used for immunomodulation highlighting their benefits and drawbacks, the material properties influencing immune responses, and recent examples in the field of transplant tolerance.

The double-edge role of B cells in mediating antitumor T-cell immunity: Pharmacological strategies for cancer immunotherapy

Emerging evidence reveals the controversial role of B cells in antitumor immunity, but the underlying mechanisms have to be explored. Three latest articles published in the issue 521 of Nature in 2015 reconfirmed the puzzling topic and put forward some explanations of how B cells regulate antitumor T-cell responses both positively and negatively. This paper attempts to demonstrate that different B-cell subpopulations have distinct immunological properties and that they are involved in either antitumor responses or immunosuppression. Recent studies supporting the positive and negative roles of B cells in tumor development were summarized comprehensively. Several specific B-cell subpopulations, such as IgG(+), IgA(+), IL-10(+), and regulatory B cells, were described in detail. The mechanisms underlying the controversial B-cell effects were mainly attributed to different B-cell subpopulations, different B-cell-derived cytokines, direct B cell-T cell interaction, different cancer categories, and different malignant stages, and the immunological interaction between B cells and T cells is mediated by dendritic cells. Promising B-cell-based antitumor strategies were proposed and novel B-cell regulators were summarized to present interesting therapeutic targets. Future investigations are needed to make sure that B-cell-based pharmacological strategies benefit cancer immunotherapy substantially.

Strategies and developments of immunotherapies in osteosarcoma

Osteosarcoma (OS) is a frequently observed primary malignant tumor. Current therapy for osteosarcoma consists of comprehensive treatment. The long-term survival rate of patients exhibiting nonmetastatic OS varies between 65-70%. However, a number of OS cases have been observed to be resistant to currently used therapies, leading to disease recurrence and lung metastases, which are the primary reasons leading to patient mortality. In the present review, a number of pieces of evidence provide support for the potential uses of immunotherapy, including immunomodulation and vaccine therapy, for the eradication of tumors via upregulation of the immune response. Adoptive T-cell therapy and oncolytic virotherapy have been used to treat OS and resulted in objective responses. Immunologic checkpoint blockade and targeted therapy are also potentially promising therapeutic tools. Immunotherapy demonstrates significant promise with regard to improving the outcomes for patients exhibiting OS.

Common gamma chain cytokines in combinatorial immune strategies against cancer

Common γ chain (γC) cytokines, namely IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21 are important for the proliferation, differentiation, and survival of lymphocytes that display antitumor activity, thus stimulating considerable interest for the use of cytokines in cancer immunotherapy. In this review, we will focus on the γC cytokines that demonstrate the greatest potential for immunotherapy, IL-2, IL-7, IL-15, and IL-21. We will briefly cover their biological function, potential applications in cancer therapy, and update on their use in combinatorial immune strategies for eradicating tumors and hematopoietic malignancies.