A Magnetic Nanovaccine Enhances Cancer Immunotherapy

Covalent LYTAC Enabled by DNA Aptamers for Immune Checkpoint Degradation Therapy

Immune checkpoint blockade (ICB) therapy, while achieving tremendous clinical successes, still suffers from a low objective response rate in clinical cancer treatment. As a proof-of-concept study, we propose a new immune checkpoint degradation (ICD) therapy relying on lysosome-targeting chimera (LYTAC) to deplete immune checkpoint programmed death ligand-1 (PD-L1) on the tumor cell surface. Our designed chimeric aptamer on one side targets lysosome-trafficking receptor, and on the other side allows biorthogonal covalent-conjugation-reinforced specific binding of PD-L1. This covalent LYTAC is able to hijack PD-L1 for lysosomal degradation with greatly improved efficiency over its noncovalent counterpart in complex in vivo environment. Beyond abolishing the PD-1/PD-L1 axis associated immune resistance, we demonstrate for the first time that LYTAC-triggered PD-L1 degradation could directly cause immunogenic apoptosis of tumor cells to elicit tumor-specific immune responses, offering unparalleled advantages over ICB antibody therapy. Remarkably, ICD therapy with covalent LYTAC achieves comparable or higher antitumor efficacy while causing significantly less inflammatory injury compared to antibody-based ICB therapy. Moreover, covalent LYTAC can serve as a general platform for specifically degrading other membrane-associated proteins, making it a promising tool for future applications. Our work presents a novel molecular tool for effective LYTAC in complex environments, offering valuable insights in pushing DNA-based LYTAC drugs toward in vivo and clinical applications.

Combined Cancer Immunotheranostic Nanomedicines: Delivery Technologies and Therapeutic Outcomes

Cancer is among the main causes of mortality all over the world. The delayed diagnosis is directly related to the decrease in survival rate. The use of immunotherapy has dramatically changed the treatment outcomes of different types of cancers. However, many patients still do not respond to immunotherapies, and many also suffer from severe immune-related side effects. Recent advances in the fields of nanomedicine bioengineering and in particular imaging offered new approaches which can enhance not only the safety but also the efficacy of immunotherapy. Theranostics has showed great progress as a branch of medicine which integrates both diagnosis and therapy in a single system. The outcomes from animal studies demonstrated an improvement in the diagnostic and immunotherapeutic potential of nanoparticles within the theranostic framework. Herein, we discuss the most recent developments in the application of nanotheranostics for combining tumor imaging and cancer immunotherapies.

In-depth review of delivery carriers associated with vaccine adjuvants: current status and future perspectives

INTRODUCTION

Vaccines are powerful tools for controlling microbial infections and preventing epidemics. To enhance the immune response to antigens, effective subunit vaccines or mRNA vaccines often require the combination of adjuvants or delivery carriers. In recent years, with the rapid development of immune mechanism research and nanotechnology, various studies based on the optimization of traditional adjuvants or various novel carriers have been intensified, and the construction of vaccine adjuvant delivery systems (VADS) with both adjuvant activity and antigen delivery has become more and more important in vaccine research.

AREAS COVERED

This paper reviews the common types of vaccine adjuvant delivery carriers, classifies the VADS according to their basic carrier types, introduces the current research status and future development trend, and emphasizes the important role of VADS in novel vaccine research.

EXPERT OPINION

As the number of vaccine types increases, conventional aluminum adjuvants show limitations in effectively stimulating cellular immune responses, limiting their use in therapeutic vaccines for intracellular infections or tumors. In contrast, the use of conventional adjuvants as VADS to carry immunostimulatory molecules or deliver antigens can greatly enhance the immune boosting effect of classical adjuvants. A comprehensive understanding of the various delivery vehicles will further facilitate the development of vaccine adjuvant research.

In vivo fate and intracellular trafficking of vaccine delivery systems

With the pandemic of severe acute respiratory syndrome coronavirus 2, vaccine delivery systems emerged as a core technology for global public health. Given that antigen processing takes place inside the cell, the intracellular delivery and trafficking of a vaccine antigen will contribute to vaccine efficiency. Investigations focusing on the in vivo behavior and intracellular transport of vaccines have improved our understanding of the mechanisms relevant to vaccine delivery systems and facilitated the design of novel potent vaccine platforms. In this review, we cover the intracellular trafficking and in vivo fate of vaccines administered via various routes and delivery systems. To improve immune responses, researchers have used various strategies to modulate vaccine platforms and intracellular trafficking. In addition to progress in vaccine trafficking studies, the challenges and future perspectives for designing next-generation vaccines are discussed.

Nanovaccine: an emerging strategy

INTRODUCTION

Vaccination is so far the most effective way of eradicating infections. Rapidly emerging drug resistance against infectious diseases and chemotherapy-related toxicities in cancer warrant immediate vaccine development to save mankind. Subunit vaccines alone, however, fail to elicit sufficiently strong and long-lasting protective immunity against deadly pathogens. Nanoparticle (NP)-based delivery vehicles like microemulsions, liposomes, virosomes, nanogels, micelles and dendrimers offer promising strategies to overcome limitations of traditional vaccine adjuvants. Nanovaccines can improve targeted delivery, antigen presentation, stimulation of body's innate immunity, strong T cell response combined with safety to combat infectious diseases and cancers. Further, nanovaccines can be highly beneficial to generate effective immutherapeutic formulations against cancer.

AREAS COVERED

This review summarizes the emerging nanoparticle strategies highlighting their success and challenges in preclinical and clinical trials in infectious diseases and cancer. It provides a concise overview of current nanoparticle-based vaccines, their adjuvant potential and their cellular delivery mechanisms.

EXPERT OPINION

The nanovaccines (50-250 nm in size) are most efficient in terms of tissue targeting, prolonged circulation and preferential uptake by the professional APCs chiefly due to their small size. More rational designing, improved antigen loading, extensive functionalization and targeted delivery are some of the future goals of ideal nanovaccines.

Magnetic Nanostructures as Emerging Therapeutic Tools to Boost Anti-Tumour Immunity

Cancer immunotherapy has shown remarkable results in various cancer types through a range of immunotherapeutic approaches, including chimeric antigen receptor-T cell (CAR-T) therapy, immune checkpoint blockade (ICB), and therapeutic vaccines. Despite the enormous potential of cancer immunotherapy, its application in various clinical settings has been limited by immune evasion and immune suppressive mechanisms occurring locally or systemically, low durable response rates, and severe side effects. In the last decades, the rapid advancement of nanotechnology has been aiming at the development of novel synthetic nanocarriers enabling precise and enhanced delivery of immunotherapeutics, while improving drug stability and effectiveness. Magnetic nanostructured formulations are particularly intriguing because of their easy surface functionalization, low cost, and robust manufacturing procedures, together with their suitability for the implementation of magnetically-guided and heat-based therapeutic strategies. Here, we summarize and discuss the unique features of magnetic-based nanostructures, which can be opportunely designed to potentiate classic immunotherapies, such as therapeutic vaccines, ICB, adoptive cell therapy (ACT), and in situ vaccination. Finally, we focus on how multifunctional magnetic delivery systems can facilitate the anti-tumour therapies relying on multiple immunotherapies and/or other therapeutic modalities. Combinatorial magnetic-based therapies are indeed offering the possibility to overcome current challenges in cancer immunotherapy.