An anti-CD103 antibody-drug conjugate prolongs the survival of pancreatic islet allografts in mice

Spotlight on ideal target antigens and resistance in antibody-drug conjugates: Strategies for competitive advancement

Antibody-drug conjugates (ADCs) represent a novel and promising approach in targeted therapy, uniting the specificity of antibodies that recognize specific antigens with payloads, all connected by the stable linker. These conjugates combine the best targeted and cytotoxic therapies, offering the killing effect of precisely targeting specific antigens and the potent cell-killing power of small molecule drugs. The targeted approach minimizes the off-target toxicities associated with the payloads and broadens the therapeutic window, enhancing the efficacy and safety profile of cancer treatments. Within precision oncology, ADCs have garnered significant attention as a cutting-edge research area and have been approved to treat a range of malignant tumors. Correspondingly, the issue of resistance to ADCs has gradually come to the fore. Any dysfunction in the steps leading to the ADCs' action within tumor cells can lead to the development of resistance. A deeper understanding of resistance mechanisms may be crucial for developing novel ADCs and exploring combination therapy strategies, which could further enhance the clinical efficacy of ADCs in cancer treatment. This review outlines the brief historical development and mechanism of ADCs and discusses the impact of their key components on the activity of ADCs. Furthermore, it provides a detailed account of the application of ADCs with various target antigens in cancer therapy, the categorization of potential resistance mechanisms, and the current state of combination therapies. Looking forward, breakthroughs in overcoming technical barriers, selecting differentiated target antigens, and enhancing resistance management and combination therapy strategies will broaden the therapeutic indications for ADCs. These progresses are anticipated to advance cancer treatment and yield benefits for patients.

Sequential immunotherapy: towards cures for autoimmunity

Despite major progress in the treatment of autoimmune diseases in the past two decades, most therapies do not cure disease and can be associated with increased risk of infection through broad suppression of the immune system. However, advances in understanding the causes of autoimmune disease and clinical data from novel therapeutic modalities such as chimeric antigen receptor T cell therapies provide evidence that it may be possible to re-establish immune homeostasis and, potentially, prolong remission or even cure autoimmune diseases. Here, we propose a 'sequential immunotherapy' framework for immune system modulation to help achieve this ambitious goal. This framework encompasses three steps: controlling inflammation; resetting the immune system through elimination of pathogenic immune memory cells; and promoting and maintaining immune homeostasis via immune regulatory agents and tissue repair. We discuss existing drugs and those in development for each of the three steps. We also highlight the importance of causal human biology in identifying and prioritizing novel immunotherapeutic strategies as well as informing their application in specific patient subsets, enabling precision medicine approaches that have the potential to transform clinical care.

Activation of cancer immunotherapy by nanomedicine

Cancer is one of the most difficult diseases to be treated in the world. Immunotherapy has made great strides in cancer treatment in recent years, and several tumor immunotherapy drugs have been approved by the U.S. Food and Drug Administration. Currently, immunotherapy faces many challenges, such as lacking specificity, cytotoxicity, drug resistance, etc. Nanoparticles have the characteristics of small particle size and stable surface function, playing a miraculous effect in anti-tumor treatment. Nanocarriers such as polymeric micelles, liposomes, nanoemulsions, dendrimers, and inorganic nanoparticles have been widely used to overcome deficits in cancer treatments including toxicity, insufficient specificity, and low bioavailability. Although nanomedicine research is extensive, only a few nanomedicines are approved to be used. Either Bottlenecks or solutions of nanomedicine in immunotherapy need to be further explored to cope with challenges. In this review, a brief overview of several types of cancer immunotherapy approaches and their advantages and disadvantages will be provided. Then, the types of nanomedicines, drug delivery strategies, and the progress of applications are introduced. Finally, the application and prospect of nanomedicines in immunotherapy and Chimeric antigen receptor T-cell therapy (CAR-T) are highlighted and summarized to address the problems of immunotherapy the overall goal of this article is to provide insights into the potential use of nanomedicines and to improve the efficacy and safety of immunotherapy.

One-step fabrication of lidocaine/CalliSpheres® composites for painless transcatheter arterial embolization

BACKGROUND

Transcatheter arterial embolization (TAE) is one of the first-line treatments for advanced hepatocellular cancer. The pain caused by TAE is a stark complication, which remains to be prevented by biomedical engineering methods.

METHODS

Herein, a commercial embolic agent CalliSpheres^® bead (CB) was functionally modified with lidocaine (Lid) using an electrostatic self-assembly technique. The products were coded as CB/Lid-n (n = 0, 5, 10, corresponding to the relative content of Lid). The chemical compositions, morphology, drug-loading, and drug-releasing ability of CB/Lid-n were comprehensively investigated. The biocompatibility was determined by hemolysis assay, live/dead cell staining assay, CCK8 assay, immunofluorescence (IHC) staining assay and quantitative real-time PCR. The thermal withdrawal latency (TWL) and edema ratio (ER) were performed to evaluate the analgesia of CB/Lid-n using a plantar inflammation model. A series of histological staining, including immunohistochemistry (IL-6, IL-10, TGF-β and Navi1.7) and TUNEL were conducted to reveal the underlying mechanism of anti-tumor effect of CB/Lid-n on a VX2-tumor bearing model.

RESULTS

Lid was successfully loaded onto the surface of CalliSpheres^® bead, and the average diameter of CalliSpheres^® bead increased along with the dosage of Lid. CB/Lid-n exhibited desirable drug-loading ratio, drug-embedding ratio, and sustained drug-release capability. CB/Lid-n had mild toxicity towards L929 cells, while triggered no obvious hemolysis. Furthermore, CB/Lid-n could improve the carrageenan-induced inflammation response micro-environment in vivo and in vitro. We found that CB/Lid-10 could selectively kill tumor by blocking blood supply, inhibiting cell proliferation, and promoting cell apoptosis. CB/Lid-10 could also release Lid to relieve post-operative pain, mainly by remodeling the harsh inflammation micro-environment (IME).

CONCLUSIONS

In summary, CB/Lid-10 has relatively good biocompatibility and bioactivity, and it can serve as a promising candidate for painless transcatheter arterial embolization.

The SKI proto-oncogene restrains the resident CD103+CD8+ T cell response in viral clearance

Acute viral infection causes illness and death. In addition, an infection often results in increased susceptibility to a secondary infection, but the mechanisms behind this susceptibility are poorly understood. Since its initial identification as a marker for resident memory CD8⁺ T cells in barrier tissues, the function and regulation of CD103 integrin (encoded by ITGAE gene) have been extensively investigated. Nonetheless, the function and regulation of the resident CD103⁺CD8⁺ T cell response to acute viral infection remain unclear. Although TGFβ signaling is essential for CD103 expression, the precise molecular mechanism behind this regulation is elusive. Here, we reveal a TGFβ-SKI-Smad4 pathway that critically and specifically directs resident CD103⁺CD8⁺ T cell generation for protective immunity against primary and secondary viral infection. We found that resident CD103⁺CD8⁺ T cells are abundant in both lymphoid and nonlymphoid tissues from uninfected mice. CD103 acts as a costimulation signal to produce an optimal antigenic CD8⁺ T cell response to acute viral infection. There is a reduction in resident CD103⁺CD8⁺ T cells following primary infection that results in increased susceptibility of the host to secondary infection. Intriguingly, CD103 expression inversely and specifically correlates with SKI proto-oncogene (SKI) expression but not R-Smad2/3 activation. Ectopic expression of SKI restricts CD103 expression in CD8⁺ T cells in vitro and in vivo to hamper viral clearance. Mechanistically, SKI is recruited to the Itgae loci to directly suppress CD103 transcription by regulating histone acetylation in a Smad4-dependent manner. Our study therefore reveals that resident CD103⁺CD8⁺ T cells dictate protective immunity during primary and secondary infection. Interfering with SKI function may amplify the resident CD103⁺CD8⁺ T cell response to promote protective immunity.

Inhibition of Dectin-1 on Dendritic Cells Prevents Maturation and Prolongs Murine Islet Allograft Survival

Introduction

The ability of dendritic cells (DCs) to initiate an immune response or induce immune tolerance depends on their maturation status. Dendritic-cell-associated C-type lectin 1 (Dectin-1) plays a key role in the differentiation, activation, and maturation of DCs. Therefore, we hypothesized that inhibition of Dectin-1 could prevent DC maturation and induce immune tolerance of transplanted organs.

Methods

DCs were transduced with a recombinant lentiviral vector to inhibit Dectin-1 and then were injected into a murine recipient before islet transplantation. C57BL/6 mice (H-2b) were treated with lentiviral vector-Dectin-1-RNAi-DC (DC-Dectin-1-RNAi group), lentiviral vector-GFP DCs (DC-GFP group), and PBS (control group). Pancreatic islet transplantation was performed and graft survival was recorded. The proportions of regulatory T cells, Th1 cells, and Th17 cells in the spleen and draining lymph nodes, and serum levels of interleukin (IL)-10, IL-17, and interferon (INF)-γ were measured.

Results

The inhibition of Dectin-1 resulted in low expression of MHC-II and costimulatory molecules in DCs. Murine recipients treated with DC-Dectin-1-RNAi had longer islet allograft survival time, a reduction in the levels of Th1 and Th17 cells and secreted cytokines, and an increase of Treg cells.

Conclusion

The inhibition of Dectin-1 by recombinant lentiviral vector Dectin-1-RNAi inhibits the maturation and activation of DCs, affects the differentiation of T cell subsets, and prolongs allograft survival.