Collagen-binding IL-12 enhances tumour inflammation and drives the complete remission of established immunologically cold mouse tumours

A natural adhesive-based nanomedicine initiates photothermal-directed in situ immunotherapy with durability and maintenance

Tumor immunotherapies have emerged as a promising frontier in the realm of cancer treatment. However, challenges persist in achieving localized, durable immunostimulation while counteracting the tumor's immunosuppressive environment. Here, we develop a natural mussel foot protein-based nanomedicine with spatiotemporal control for tumor immunotherapy. In this nanomedicine, an immunoadjuvant prodrug and a photosensitizer are integrated, which is driven by their dynamic bonding and non-covalent assembling with the protein carrier. Harnessing the protein carrier's bioadhesion, this nanomedicine achieves a drug co-delivery with spatiotemporal precision, by which it not only promotes tumor photothermal ablation but also broadens tumor antigen repertoire, facilitating in situ immunotherapy with durability and maintenance. This nanomedicine also modulates the tumor microenvironment to overcome immunosuppression, thereby amplifying antitumor responses against tumor progression. Our strategy underscores a mussel foot protein-derived design philosophy of drug delivery aimed at refining combinatorial immunotherapy, offering insights into leveraging natural proteins for cancer treatment.

Integrating IL-12 mRNA nanotechnology with SBRT eliminates T cell exhaustion in preclinical models of pancreatic cancer

Pronounced T cell exhaustion characterizes immunosuppressive tumors, with the tumor microenvironment (TME) employing multiple mechanisms to elicit this suppression. Traditional immunotherapies, such as immune checkpoint blockade, often fail due to their focus primarily on T cells. To overcome this, we utilized a proinflammatory cytokine, interleukin (IL)-12, that re-wires the immunosuppressive TME by inducing T cell effector function while also repolarizing immunosuppressive myeloid cells. Due to toxicities observed with systemic administration of this cytokine, we utilized lipid nanoparticles encapsulating mRNA encoding IL-12 for intratumoral injection. This strategy has been proven safe and tolerable in early clinical trials for solid malignancies. We report an unprecedented loss of exhausted T cells and the emergence of an activated phenotype in murine pancreatic ductal adenocarcinoma (PDAC) treated with stereotactic body radiation therapy (SBRT) and IL-12mRNA. Our mechanistic findings reveal that each treatment modality contributes to the T cell response differently, with SBRT expanding the T cell receptor repertoire and IL-12mRNA promoting robust T cell proliferation and effector status. This distinctive T cell signature mediated marked growth reductions and long-term survival in local and metastatic PDAC models. This is the first study of its kind combining SBRT with IL-12mRNA and provides a promising new approach for treating this aggressive malignancy.

Prognostic Impact of Acute and Chronic Inflammatory Interleukin Signatures in the Tumor Microenvironment of Early Breast Cancer

Interleukins play dual roles in breast cancer, acting as both promoters and inhibitors of tumorigenesis within the tumor microenvironment, shaped by their inflammatory functions. This study analyzed the subtype-specific prognostic significance of an acute inflammatory versus a chronic inflammatory interleukin signature using microarray-based gene expression analysis. Correlations between these interleukin signatures and immune cell markers (CD8, IgKC, and CD20) and immune checkpoints (PD-1) were also evaluated. This study investigated the prognostic significance of an acute inflammatory IL signature (IL-12, IL-21, and IFN-γ) and a chronic inflammatory IL signature (IL-4, IL-5, IL-10, IL-13, IL-17, and CXCL1) for metastasis-free survival (MFS) using Kaplan-Meier curves and Cox regression analyses in a cohort of 461 patients with early breast cancer. Correlations were analyzed using the Spearman-Rho correlation coefficient. Kaplan-Meier curves revealed that the prognostic significance of the acute inflammatory IL signature was specifically pronounced in the basal-like subtype (p = 0.004, Log Rank). This signature retained independent prognostic significance in multivariate Cox regression analysis (HR 0.463, 95% CI 0.290-0.741; p = 0.001). A higher expression of the acute inflammatory IL signature was associated with longer MFS. The chronic inflammatory IL signature showed a significant prognostic effect in the whole cohort, with higher expression associated with shorter MFS (p = 0.034). Strong correlations were found between the acute inflammatory IL signature and CD8 expression (ρ = 0.391; p < 0.001) and between the chronic inflammatory IL signature and PD-1 expression (ρ = 0.627; p < 0.001). This study highlights the complex interaction between acute and chronic inflammatory interleukins in breast cancer progression and prognosis. These findings provide insight into the prognostic relevance of interleukin expression patterns in breast cancer and may inform future therapeutic strategies targeting the immune-inflammatory axis.

Interleukin-12 Delivery Strategies and Advances in Tumor Immunotherapy

Interleukin-12 (IL-12) is considered to be a promising cytokine for enhancing an antitumor immune response; however, recombinant IL-12 has shown significant toxicity and limited efficacy in early clinical trials. Recently, many strategies for delivering IL-12 to tumor tissues have been developed, such as modifying IL-12, utilizing viral vectors, non-viral vectors, and cellular vectors. Previous studies have found that the fusion of IL-12 with extracellular matrix proteins, collagen, and immune factors is a way to enhance its therapeutic potential. In addition, studies have demonstrated that viral vectors are a good platform, and a variety of viruses such as oncolytic viruses, adenoviruses, and poxviruses have been used to deliver IL-12-with testing previously conducted in various cancer models. The local expression of IL-12 in tumors based on viral delivery avoids systemic toxicity while inducing effective antitumor immunity and acting synergistically with other therapies without compromising safety. In addition, lipid nanoparticles are currently considered to be the most mature drug delivery system. Moreover, cells are also considered to be drug carriers because they can effectively deliver therapeutic substances to tumors. In this article, we will systematically discuss the anti-tumor effects of IL-12 on its own or in combination with other therapies based on different delivery strategies.

Structure and assembly of the human IL-12 signaling complex

Interleukin (IL)-12 is a heterodimeric pro-inflammatory cytokine. Our cryoelectron microscopy structure determination of human IL-12 in complex with IL-12Rβ1 and IL-12Rβ2 at a resolution of 3.75 Å reveals that IL-12Rβ2 primarily interacts with the IL-12p35 subunit via its N-terminal Ig-like domain, while IL-12Rβ1 binds to the p40 subunit with its N-terminal fibronectin III domain. This binding mode of IL-12 with its receptors is similar to that of IL-23 but shows notable differences with other cytokines. Through structural information and biochemical assays, we identified Y62, Y189, and K192 as key residues in IL-12p35, which bind to IL-12Rβ2 with high affinity and mediate IL-12 signal transduction. Furthermore, structural comparisons reveal two distinctive conformational states and structural plasticity of the heterodimeric interface in IL-12. As a result, our study advances our understanding of IL-12 signal initiation and opens up new opportunities for the engineering and therapeutic targeting of IL-12.

Interleukin-12 treatment reduces tumor growth and modulates the expression of CASKA and MIR-203 in athymic mice bearing tumors induced by the HGC-27 gastric cancer cell line

Gastric cancer (GC) is one of the most common malignant tumors in the digestive system and due to its poor prognosis, there is an increase in the demand for more effective anticancer therapies. Interleukins are potential anticancer agents which can modulate expression of cancer related genes and have therapeutic effects. Interleukin 12 (IL-12) exhibits potent anti-tumor, anti-angiogenic and anti-metastatic activities and represents the ideal candidate for tumor immunotherapy, due to its ability to activate both innate and adaptive immunities. The aim of this study was to evaluate the effect of IL-12 administration on GC tumor growth induced in the cancer xenograft nude mouse model. Tumor development was analyzed weekly and after 8 weeks, the animals were sacrificed for cytokine analysis (IL-4, TNF-alfa, IL-2, INF-gamma, IL-12, IL-10, TGF-beta) by ELISA. The tumor cells in the implanted areas of the animals that developed solid growth of the tumor (anatomopathological analysis was performed). We have also evaluated CASK and miR203 expression, two related cell invasion factors, in the induced tumors after administration of 6 n/kg IL-12. The development of tumor masses was observed in all groups of animals inoculated with HGC-27 neoplastic cells. In animals treated with 6 n/kg IL-12, there was no tumor development confirmed by anatomopathological analysis. Changes in the levels of pro and anti-inflammatory cytokines were also observed. Our results indicated that miR203 expression was elevated while CASK was downregulated. These results suggest that IL-12 treatment repress the tumor growth by induction of miR203 expression which in turn repress CASK expression.

Nanoenabled IL-15 Superagonist via Conditionally Stabilized Protein-Protein Interactions Eradicates Solid Tumors by Precise Immunomodulation

Protein complexes are crucial structures that control many biological processes. Harnessing these structures could be valuable for therapeutic therapy. However, their instability and short lifespans need to be addressed for effective use. Here, we propose an innovative approach based on a functional polymeric cloak that coordinately anchors different domains of protein complexes and assembles them into a stabilized nanoformulation. As the polymer-protein association in the cloak is pH sensitive, the nanoformulation also allows targeting the release of the protein complexes to the acidic microenvironment of tumors for aiding their therapeutic performance. Building on this strategy, we developed an IL-15 nanosuperagonist (Nano-SA) by encapsulating the interleukin-15 (IL-15)/IL-15 Receptor α (IL-15Rα) complex (IL-15cx) for fostering synergistic transpresentation in tumors. Upon intravenous administration, Nano-SA stably circulated in the bloodstream, safeguarding the integrity of IL-15cx until reaching the tumor site, where it selectively released the active complex. Thus, Nano-SA significantly amplified the antitumor immune signals while diminishing systemic off-target effects. In murine colon cancer models, Nano-SA achieved potent immunotherapeutic effects, eradicating tumors without adverse side effects. These findings highlight the transformative potential of nanotechnology for advancing protein complex-based therapies.

Local delivery of cell surface-targeted immunocytokines programs systemic antitumor immunity

Systemically administered cytokines are potent immunotherapeutics but can cause severe dose-limiting toxicities. To overcome this challenge, cytokines have been engineered for intratumoral retention after local delivery. However, despite inducing regression of treated lesions, tumor-localized cytokines often elicit only modest responses at distal untreated tumors. In the present study, we report a localized cytokine therapy that safely elicits systemic antitumor immunity by targeting the ubiquitous leukocyte receptor CD45. CD45-targeted immunocytokines have lower internalization rates relative to wild-type counterparts, leading to sustained downstream cis and trans signaling between lymphocytes. A single intratumoral dose of αCD45-interleukin (IL)-12 followed by a single dose of αCD45-IL-15 eradicated treated tumors and untreated distal lesions in multiple syngeneic mouse tumor models without toxicity. Mechanistically, CD45-targeted cytokines reprogrammed tumor-specific CD8+ T cells in the tumor-draining lymph nodes to have an antiviral transcriptional signature. CD45 anchoring represents a broad platform for protein retention by host immune cells for use in immunotherapy.

Tumor-Localized Interleukin-2 and Interleukin-12 Combine with Radiation Therapy to Safely Potentiate Regression of Advanced Malignant Melanoma in Pet Dogs

PURPOSE

Cytokines IL2 and IL12 exhibit potent anticancer activity but suffer a narrow therapeutic window due to off-tumor immune cell activation. Engineering cytokines with the ability to bind and associate with tumor collagen after intratumoral injection potentiated response without toxicity in mice and was previously safe in pet dogs with sarcoma. Here, we sought to test the efficacy of this approach in dogs with advanced melanoma.

PATIENTS AND METHODS

This study examined 15 client-owned dogs with histologically or cytologically confirmed malignant melanoma that received a single 9-Gy fraction of radiotherapy, followed by six cycles of combined collagen-anchored IL2 and IL12 therapy every 2 weeks. Cytokine dosing followed a 3 + 3 dose escalation design, with the initial cytokine dose chosen from prior evaluation in canine sarcomas. No exclusion criteria for tumor stage or metastatic burden, age, weight, or neuter status were applied for this trial.

RESULTS

Median survival regardless of the tumor stage or dose level was 256 days, and 10/13 (76.9%) dogs that completed treatment had CT-measured tumor regression at the treated lesion. In dogs with metastatic disease, 8/13 (61.5%) had partial responses across their combined lesions, which is evidence of locoregional response. Profiling by NanoString of treatment-resistant dogs revealed that B2m loss was predictive of poor response to this therapy.

CONCLUSIONS

Collectively, these results confirm the ability of locally administered tumor-anchored cytokines to potentiate responses at regional disease sites when combined with radiation. This evidence supports the clinical translation of this approach and highlights the utility of comparative investigation in canine cancers.

A laponite-based immunologically active gel delivery system for long-acting tumor vaccine

Traditional bolus vaccines typically require multiple doses, which complicates the vaccination process and may cause missed shots, leading to sub-optimal immunity and reduced vaccine effectiveness. Herein, a gel-based long-acting vaccine system with self-adjuvant properties based on laponite was constructed to simplify vaccination procedures and improve vaccine effectiveness. Firstly, the gel system could recruit multiple types of immune cells to form immune niches. Secondly, it could achieve sustained delivery of antigens to lymph nodes by active transport and passive drainage. Then, the gel system triggered the formation of a large number of germinal centers, which elicited enhanced and durable humoral immune responses, as well as strong cellular immune responses. As a result, it eventually showed good prophylactic and therapeutic effects in a variety of tumor models including melanoma, colorectal cancer and peritoneal metastasis models. By further combining the immunoadjuvant CpG ODN and cytokine IL-12, the effect of the gel-vaccine could be further enhanced. In a murine peritoneal metastasis model of colorectal carcinoma, a single administration of the gel-vaccine resulted in complete tumor eradication in 8/9 mice. In summary, this study developed an immunologically active gel-vaccine system. And as a robust and versatile vaccine platform, by loading different antigens and adjuvants, this gel-vaccine system is expected to realize its better therapeutic potential.

Exploiting protein domain modularity to enable synthetic control of engineered cells

The ability to precisely control cellular function in response to external stimuli can enhance the function and safety of cell therapies. In this review, we will detail how the modularity of protein domains has been exploited for cellular control applications, specifically through design of multifunctional synthetic constructs and controllable split moieties. These advances, which build on techniques developed by biologists, protein chemists and drug developers, harness natural evolutionary tendencies of protein domain fusion and fission. In this light, we will highlight recent advances towards the development of novel immunoreceptors, base editors, and cytokines that have achieved intriguing therapeutic potential by taking advantage of well-known protein evolutionary phenomena and have helped cells learn new tricks via synthetic biology. In general, protein modularity, i.e., the relatively facile separation or (re)assembly of functional single protein domains or subdomains, is becoming an enabling phenomenon for cellular engineering by allowing enhanced control of phenotypic responses.

High-Affinity Superantigen-Based Trifunctional Immune Cell Engager Synergizes NK and T Cell Activation for Tumor Suppression

The development of immune cell engagers (ICEs) can be limited by logistical and functional restrictions associated with fusion protein designs, thus limiting immune cell recruitment to solid tumors. Herein, a high affinity superantigen-based multivalent ICE is developed for simultaneous activation and recruitment of NK and T cells for tumor treatment. Yeast library-based directed evolution is adopted to identify superantigen variants possessing enhanced binding affinity to immunoreceptors expressed on human T cells and NK cells. High-affinity superantigens exhibiting improved immune-stimulatory activities are then incorporated into a superantigen-based tri-functional yeast-display-enhanced multivalent immune cell engager (STYMIE), which is functionalized with a nanobody, a Neo-2/15 cytokine, and an Fc domain for tumor targeting, immune stimulation, and prolonged circulation, respectively. Intravenous administration of STYMIE enhances NK and T cell recruitment into solid tumors, leading to enhanced inhibition in multiple tumor models. The study offers design principles for multifunctional ICEs.

Reversibly photoswitchable protein assemblies with collagen affinity for in vivo photoacoustic imaging of tumors

Recent advancements in photoacoustic (PA) imaging have leveraged reversibly photoswitchable chromophores, known for their dual absorbance states, to enhance imaging sensitivity through differential techniques. Yet, their deployment in tumor imaging has faced obstacles in achieving targeted delivery with high efficiency and specificity. Addressing this challenge, we introduce innovative protein assemblies, DrBphP-CBD, by genetically fusing a photosensory module from Deinococcus radiodurans bacterial phytochrome (DrBphP) with a collagen-binding domain (CBD). These protein assemblies form sub-100-nanometer structures composed of 24 DrBphP dimers and 12 CBD trimers, presenting 24 protein subunits. Their affinity for collagens, combined with impressive photoswitching contrast, markedly improves PA imaging precision. In various tumor models, intravenous administration of DrBphP-CBD has demonstrated enhanced tumor targeting and retention, augmenting contrast in PA imaging by minimizing background noise. This strategy underscores the clinical potential of DrBphP-CBD as PA contrast agents, propelling photoswitchable chromoproteins to the forefront of precise cancer diagnosis.

RNA nanotherapeutics with fibrosis overexpression and retention for MASH treatment

Metabolic dysfunction-associated steatohepatitis (MASH) poses challenges for targeted delivery and retention of therapeutic proteins due to excess extracellular matrix (ECM). Here we present a new approach to treat MASH, termed "Fibrosis overexpression and retention (FORT)". In this strategy, we design (1) retinoid-derivative lipid nanoparticle (LNP) to enable enhanced mRNA overexpression in fibrotic regions, and (2) mRNA modifications which facilitate anchoring of therapeutic proteins in ECM. LNPs containing carboxyl-retinoids, rather than alcohol- or ester-retinoids, effectively deliver mRNA with over 10-fold enhancement of protein expression in fibrotic livers. The carboxyl-retinoid rearrangement on the LNP surface improves protein binding and membrane fusion. Therapeutic proteins are then engineered with an endogenous collagen-binding domain. These fusion proteins exhibit increased retention in fibrotic lesions and reduced systemic toxicity. In vivo, fibrosis-targeting LNPs encoding fusion proteins demonstrate superior therapeutic efficacy in three clinically relevant male-animal MASH models. This approach holds promise in fibrotic diseases unsuited for protein injection.

DNA nanodevice as a multi-module co-delivery platform for combination cancer immunotherapy

A major challenge in combining cancer immunotherapy is the efficient delivery of multiple types of immunological stimulators to elicit a robust anti-tumor immune response and reprogram the immunosuppressive tumor microenvironment (TME). Here, we developed a DNA nanodevice that was generated by precisely assembling three types of immunological stimulators. The doxorubicin (Dox) component induced immunogenic cell death (ICD) in tumor cells and enhanced phagocytosis of antigen-presenting cells (APCs). Exogenous double-stranded DNA (dsDNA) could act as a molecular adjuvant to activate the stimulator of interferon genes (STING) signaling in APCs by engulfing dying tumor cells. Interleukin (IL)-12 and small hairpin programmed cell death-ligand 1 (shPD-L1) transcription templates were designed to regulate TME. Additionally, for targeted drug delivery, multiple cyclo[Arg-Gly-Asp-(d-Phe)-Cys] (cRGD) peptide units on DNA origami were employed. The incorporation of disulfide bonds allowed the release of multiple modules in response to intracellular glutathione (GSH) in tumors. The nanodevice promoted the infiltration of CD8+ and CD4+ cells into the tumor and generated a highly inflamed TME, thereby enhancing the effectiveness of cancer immunotherapy. Our research results indicate that the nanodevice we constructed can effectively inhibit tumor growth and prevent lung metastasis without obvious systemic toxicity, providing a promising strategy for cancer combination treatment.

CLN-617 Retains IL2 and IL12 in Injected Tumors to Drive Robust and Systemic Immune-Mediated Antitumor Activity

Despite clinical evidence of antitumor activity, the development of cytokine therapies has been hampered by a narrow therapeutic window and limited response rates. Two cytokines of high interest for clinical development are interleukin 2 (IL2) and interleukin 12 (IL12), which potently synergize to promote the activation and proliferation of T cells and NK cells. However, the only approved human IL2 therapy, Proleukin, is rarely used in the clinic due to systemic toxicities, and no IL12 product has been approved to date due to severe dose-limiting toxicities. Here, we describe CLN-617, a first-in-class therapeutic for intratumoral (IT) injection that co-delivers IL2 and IL12 on a single molecule in a safe and effective manner. CLN-617 is a single-chain fusion protein comprised of IL2, leukocyte-associated immunoglobulin-like receptor 2 (LAIR2), human serum albumin (HSA), and IL12. LAIR2 and HSA function to retain CLN-617 in the treated tumor by binding collagen and increasing molecular weight, respectively. We found that IT administration of a murine surrogate of CLN-617, mCLN-617, eradicated established treated and untreated tumors in syngeneic models, significantly improved response to anti-PD1 checkpoint therapy, and generated a robust abscopal response dependent on cellular immunity and antigen cross-presentation. CLN-617 is being evaluated in a clinical trial in patients with advanced solid tumors (NCT06035744).

Stimulating the Antitumor Immune Response Using Immunocytokines: A Preclinical and Clinical Overview

Cytokines are immune modulators which can enhance the immune response and have been proven to be an effective class of immunotherapy. Nevertheless, the clinical use of cytokines in cancer treatment has faced several challenges associated with poor pharmacokinetic properties and the occurrence of adverse effects. Immunocytokines (ICKs) have emerged as a promising approach to overcome the pharmacological limitations observed with cytokines. ICKs are fusion proteins designed to deliver cytokines in the tumor microenvironment by taking advantage of the stability and specificity of immunoglobulin-based scaffolds. Several technological approaches have been developed. This review focuses on ICKs designed with the most impactful cytokines in the cancer field: IL-2, TNFα, IL-10, IL-12, IL-15, IL-21, IFNγ, GM-CSF, and IFNα. An overview of the pharmacological effects of the naked cytokines and ICKs tested for cancer therapy is detailed. A particular emphasis is given on the immunomodulatory effects of ICKs associated with their technological design. In conclusion, this review highlights active ways of development of ICKs. Their already promising results observed in clinical trials are likely to be improved with the advances in targeting technologies such as cytokine/linker engineering and the design of multispecific antibodies with tumor targeting and immunostimulatory functional properties.

Treatment of intracranial inflammatory myofibroblastic tumor with PD-L1 inhibitor and novel oncolytic adenovirus Ad-TD-nsIL12: a case report and literature review

Inflammatory myofibroblastic tumor (IMT) is a rare pathological entity first described in 1939. This lesion is most commonly found in the lungs, but cases involving other systems, such as the central nervous system known as intracranial IMT (IIMT), have also been reported. Diagnosis currently relies on pathological results due to the lack of characteristic imaging changes. Surgical resection is an effective treatment, though the disease is invasive and may recur. Previous literature has reported a high level of programmed death 1 (PD-1) expression in IMT tissues, suggesting that immunotherapy may be effective for this condition. In this case report, we present a middle-aged male who received PD-1 inhibitor and oncolytic adenovirus (Ad-TD-nsIL12) treatment after IIMT resection surgery. This successful approach provides a new direction for the treatment of IIMT.

Lipid-based nanosystems: the next generation of cancer immune therapy

Immunotherapy has become an important part of the oncotherapy arsenal. Its applicability in various cancer types is impressive, as well as its use of endogenous mechanisms to achieve desired ends. However, off-target or on-target-off-tumor toxicity, limited activity, lack of control in combination treatments and, especially for solid tumors, low local accumulation, have collectively limited clinical use thereof. These limitations are partially alleviated by delivery systems. Lipid-based nanoparticles (NPs) have emerged as revolutionary carriers due to favorable physicochemical characteristics, with specific applications and strengths particularly useful in immunotherapeutic agent delivery. The aim of this review is to highlight the challenges faced by immunotherapy and how lipid-based NPs have been, and may be further utilized to address such challenges. We discuss recent fundamental and clinical applications of NPs in a range of areas and provide a detailed discussion of the main obstacles in immune checkpoint inhibition therapies, adoptive cellular therapies, and cytokine therapies. We highlight how lipid-based nanosystems could address these through either delivery, direct modulation of the immune system, or targeting of the immunosuppressive tumor microenvironment. We explore advanced and emerging liposomal and lipid nanoparticle (LNP) systems for nucleic acid delivery, intrinsic and extrinsic stimulus-responsive formulations, and biomimetic lipid-based nanosystems in immunotherapy. Finally, we discuss the key challenges relating to the clinical use of lipid-based NP immunotherapies, suggesting future research directions for the near term to realize the potential of these innovative lipid-based nanosystems, as they become the crucial steppingstone towards the necessary enhancement of the efficacy of immunotherapy.

Nanoplatform-Based In Vivo Gene Delivery Systems for Cancer Therapy

Gene therapy uses modern molecular biology methods to repair disease-causing genes. As a burgeoning therapeutic, it has been widely applied for cancer therapy. Since 1989, there have been numerous clinical gene therapy cases worldwide. However, a few are successful. The main challenge of clinical gene therapy is the lack of efficient and safe vectors. Although viral vectors show high transfection efficiency, their application is still limited by immune rejection and packaging capacity. Therefore, the development of non-viral vectors is overwhelming. Nanoplatform-based non-viral vectors become a hotspot in gene therapy. The reasons are mainly as follows. 1) Non-viral vectors can be engineered to be uptaken by specific types of cells or tissues, providing effective targeting capability. 2) Non-viral vectors can protect goods that need to be delivered from degradation. 3) Nanoparticles can transport large-sized cargo such as CRISPR/Cas9 plasmids and nucleoprotein complexes. 4) Nanoparticles are highly biosafe, and they are not mutagenic in themselves compared to viral vectors. 5) Nanoparticles are easy to scale preparation, which is conducive to clinical conversion and application. Here, an overview of the categories of nanoplatform-based non-viral gene vectors, the limitations on their development, and their applications in cancer therapy.

Synergistic Anti-Tumor Efficacy Achieved by Reversing Drug Resistance through the Regulation of the Tumor Immune Microenvironment with IL-12 and Osimertinib Combination Therapy

The objective of this study was to investigate the role of IL-12 in enhancing the anti-tumor efficacy of the small molecule targeted drug osimertinib in resistant tumor models and reversing resistance mechanisms. We utilized paired non-small cell lung cancer H1975 tumor tissues, establishing mouse tumor models with diverse tumor immune microenvironments. Analytical methods including immunohistochemistry and immunofluorescence were employed to compare immune cell infiltration, cytokines, effector molecules, and protein changes in resistant signaling pathways in tumor tissues, shedding light on IL-12's mechanism of action in enhancing osimertinib efficacy and reversing resistance. Results showed that osimertinib monotherapy had limited tumor suppression, whereas IL-12 exhibited more significant anti-tumor effects. Combination therapy groups demonstrated even greater tumor suppression with increased immune cell infiltration, elevated immune-related factor secretion, reduced immunosuppressive MDSCs, and decreased resistance-related signaling pathway markers. In conclusion, IL-12 enhances anti-tumor efficacy and reverses osimertinib resistance through various mechanisms, including increased immune cell infiltration, reduced immunosuppressive MDSCs, enhanced immune cell granzyme and IFN-γ release, decreased PDL-1 expression, improved tumor microenvironment, restored immune surveillance, and heightened cancer cell sensitivity to osimertinib.

Anti-PD-1 cis-delivery of low-affinity IL-12 activates intratumoral CD8+T cells for systemic antitumor responses

Immune checkpoint blockade (ICB) therapies function by alleviating immunosuppression on tumor-infiltrating lymphocytes (TILs) but are often insufficient to fully reactivate these dysfunctional TILs. Although interleukin 12 (IL-12) has been used in combination with ICB to improve efficacy, this remains limited by severe toxicity associated with systemic administration of this cytokine. Here, we engineer a fusion protein composed of an anti-PD-1 antibody and a mouse low-affinity IL-12 mutant-2 (αPD1-mIL12mut2). Systemic administration of αPD1-mIL12mut2 displays robust antitumor activities with undetectable toxicity. Mechanistically, αPD1-mIL12mut2 preferentially activates tumor-infiltrating PD-1+CD8+T cells via high-affinity αPD-1 mediated cis-binding of low-affinity IL-12. Additionally, αPD1-mIL12mut2 treatment exerts an abscopal effect to suppress distal tumors, as well as metastasis. Collectively, αPD1-mIL12mut2 treatment induces robust systemic antitumor responses with reduced side effects.

Thiolation-Based Protein-Protein Hydrogels for Improved Wound Healing

The limitations of protein-based hydrogels, including their insufficient mechanical properties and restricted biological functions, arise from the highly specific functions of proteins as natural building blocks. A potential solution to overcome these shortcomings is the development of protein-protein hydrogels, which integrate structural and functional proteins. In this study, a protein-protein hydrogel formed by crosslinking bovine serum albumin (BSA) and a genetically engineered intrinsically disordered collagen-like protein (CLP) through Ag─S bonding is introduced. The approach involves thiolating lysine residues of BSA and crosslinking CLP with Ag+ ions, utilizing thiolation of BSA and the free-cysteines of CLP. The resulting protein-protein hydrogels exhibit exceptional properties, including notable plasticity, inherent self-healing capabilities, and gel-sol transition in response to redox conditions. In comparison to standalone BSA hydrogels, these protein-protein hydrogels demonstrate enhanced cellular viability, and improved cellular migration. In vivo experiments provide conclusive evidence of accelerated wound healing, observed not only in murine models with streptozotocin (Step)-induced diabetes but also in zebrafish models subjected to UV-burn injuries. Detailed mechanistic insights, combined with assessments of proinflammatory cytokines and the expression of epidermal differentiation-related proteins, robustly validate the protein-protein hydrogel's effectiveness in promoting wound repair.

Mesothelin CAR-T cells expressing tumor-targeted immunocytokine IL-12 yield durable efficacy and fewer side effects

Chimeric antigen receptor (CAR)-modified T cell therapy has achieved remarkable efficacy in treating hematological malignancies, but it confronts many challenges in treating solid tumors, such as the immunosuppressive microenvironment of the solid tumors. These factors reduce the antitumor activity of CAR-T cells in clinical trials. Therefore, we used the immunocytokine interleukin-12 (IL-12) to enhance the efficacy of CAR-T cell therapy. In this study, we engineered CAR-IL12R54 T cells that targeted mesothelin (MSLN) and secreted a single-chain IL-12 fused to a scFv fragment R54 that recognized a different epitope on mesothelin. The evaluation of the anti-tumor activity of the CAR-IL12R54 T cells alone or in combination with anti-PD-1 antibody in vitro and in vivo was followed by the exploration of the functional mechanism by which the immunocytokine IL-12 enhanced the antitumor activity. CAR-IL12R54 T cells had potency to lyse mesothelin positive tumor cells in vitro. In vivo studies demonstrated that CAR-IL12R54 T cells were effective in controlling the growth of established tumors in a xenograft mouse model with fewer side effects than CAR-T cells that secreted naked IL-12. Furthermore, combination of PD-1 blockade antibody with CAR-IL12R54 T cells elicited durable anti-tumor responses. Mechanistic studies showed that IL12R54 enhanced Interferon-γ (IFN-γ) production and dampened the activity of regulatory T cells (Tregs). IL12R54 also upregulated CXCR6 expression in the T cells through the NF-κB pathway, which facilitated T cell infiltration and persistence in the tumor tissues. In summary, the studies provide a good therapeutic option for the clinical treatment of solid tumors.

Controlled Refolding of Denatured IL-12 Using In Situ Antigen-Capturing Nanochaperone Remarkably Reduces the Systemic Toxicity and Enhances Cancer Immunotherapy

Cytokines are powerful in cancer immunotherapy, however, their therapeutic potential is limited by the severe systemic toxicity. Here a potent strategy to reduce the toxicity of systemic cytokine therapy by delivering its denatured form using a finely designed nanochaperone, is described. It is demonstrated that even if the denatured protein cargos are occasionally released under normal physiological conditions they are still misfolded, while can effectively refold into native states and release to function in tumor microenvironment. Consequently, the systemic toxicity of cytokines is nearly completely overcome. Moreover, an immunogenic cell death (ICD)-inducing chemotherapeutic is further loaded and delivered to tumor using this nanochaperone to trigger the release of tumor-associated antigens (TAAs) that are subsequently captured in situ by nanochaperone and then reflows into lymph nodes (LNs) to promote antigen cross-presentation. This optimized personalized nanochaperone-vaccine demonstrates unprecedented suppressive effects against large, advanced tumors, and in combination with immune checkpoint blockade (ICB) therapy results in a significant abscopal effect and inhibition of postoperative tumor recurrence and metastasis. Hence, this approach provides a simple and universal delivery strategy to reduce the systemic toxicities of cytokines, as well as provides a robust personalized cancer vaccination platform, which may find wide applications in cancer immunotherapy.

Understanding the matrix: collagen modifications in tumors and their implications for immunotherapy

Tumors are highly complex and heterogenous ecosystems where malignant cells interact with healthy cells and the surrounding extracellular matrix (ECM). Solid tumors contain large ECM deposits that can constitute up to 60% of the tumor mass. This supports the survival and growth of cancerous cells and plays a critical role in the response to immune therapy. There is untapped potential in targeting the ECM and cell-ECM interactions to improve existing immune therapy and explore novel therapeutic strategies. The most abundant proteins in the ECM are the collagen family. There are 28 different collagen subtypes that can undergo several post-translational modifications (PTMs), which alter both their structure and functionality. Here, we review current knowledge on tumor collagen composition and the consequences of collagen PTMs affecting receptor binding, cell migration and tumor stiffness. Furthermore, we discuss how these alterations impact tumor immune responses and how collagen could be targeted to treat cancer.

T cell cascade regulation initiates systemic antitumor immunity through living drug factory of anti-PD-1/IL-12 engineered probiotics

Immune checkpoint blockade (ICB) has revolutionized cancer therapy but only works in a subset of patients due to the insufficient infiltration, persistent exhaustion, and inactivation of T cells within a tumor. Herein, we develop an engineered probiotic (interleukin [IL]-12 nanoparticle Escherichia coli Nissle 1917 [INP-EcN]) acting as a living drug factory to biosynthesize anti-PD-1 and release IL-12 for initiating systemic antitumor immunity through T cell cascade regulation. Mechanistically, INP-EcN not only continuously biosynthesizes anti-PD-1 for relieving immunosuppression but also effectively cascade promote T cell activation, proliferation, and infiltration via responsive release of IL-12, thus reaching a sufficient activation threshold to ICB. Tumor targeting and colonization of INP-EcNs dramatically increase local drug accumulations, significantly inhibiting tumor growth and metastasis compared to commercial inhibitors. Furthermore, immune profiling reveals that anti-PD-1/IL-12 efficiently cascade promote antitumor effects in a CD8+ T cell-dependent manner, clarifying the immune interaction of ICB and cytokine activation. Ultimately, such engineered probiotics achieve a potential paradigm shift from T cell exhaustion to activation and show considerable promise for antitumor bio-immunotherapy.

XTX301, a Tumor-Activated Interleukin-12 Has the Potential to Widen the Therapeutic Index of IL12 Treatment for Solid Tumors as Evidenced by Preclinical Studies

IL12 is a proinflammatory cytokine, that has shown promising antitumor activity in humans by promoting the recruitment and activation of immune cells in tumors. However, the systemic administration of IL12 has been accompanied by considerable toxicity, prompting interest in researching alternatives to drive preferential IL12 bioactivity in the tumor. Here, we have generated XTX301, a tumor-activated IL12 linked to the human Fc protein via a protease cleavable linker that is pharmacologically inactivated by an IL12 receptor subunit beta 2 masking domain. In vitro characterization demonstrates multiple matrix metalloproteases, as well as human primary tumors cultured as cell suspensions, can effectively activate XTX301. Intravenous administration of a mouse surrogate mXTX301 demonstrated significant tumor growth inhibition (TGI) in inflamed and non-inflamed mouse models without causing systemic toxicities. The superiority of mXTX301 in mediating TGI compared with non-activatable control molecules and the greater percentage of active mXTX301 in tumors versus other organs further confirms activation by the tumor microenvironment-associated proteases in vivo. Pharmacodynamic characterization shows tumor selective increases in inflammation and upregulation of immune-related genes involved in IFNγ cell signaling, antigen processing, presentation, and adaptive immune response. XTX301 was tolerated following four repeat doses up to 2.0 mg/kg in a nonhuman primate study; XTX301 exposures were substantially higher than those at the minimally efficacious dose in mice. Thus, XTX301 has the potential to achieve potent antitumor activity while widening the therapeutic index of IL12 treatment and is currently being evaluated in a phase I clinical trial.

Adoptive cell therapy for solid tumors beyond CAR-T: Current challenges and emerging therapeutic advances

Adoptive cellular immunotherapy using immune cells expressing chimeric antigen receptors (CARs) is a highly specific anti-tumor immunotherapy that has shown promise in the treatment of hematological malignancies. However, there has been a slow progress toward the treatment of solid tumors owing to the complex tumor microenvironment that affects the localization and killing ability of the CAR cells. Solid tumors with a strong immunosuppressive microenvironment and complex vascular system are unaffected by CAR cell infiltration and attack. To improve their efficacy toward solid tumors, CAR cells have been modified and upgraded by "decorating" and "pruning". This review focuses on the structure and function of CARs, the immune cells that can be engineered by CARs and the transformation strategies to overcome solid tumors, with a view to broadening ideas for the better application of CAR cell therapy for the treatment of solid tumors.

Dynamic monitoring of the fibrosis disease by a collagen targeting near infrared probe

The deposition of the extracellular matrix, especially collagen, and the elevated expression levels of reactive oxygen species, including H2O2, are the main features of fibrosis. Fibrosis can occur in many tissues, such as tumor and liver tissues. The deposition of collagen in the location of lesions not only leads to immunological rejection and supports liver fibrosis and tumor progression, but also provides unique physiological signals with the progression of fibrosis and tumor. However, at present, the detection of fibrosis, especially real time detection, is greatly difficult, making it important to develop noninvasive probes for the dynamic monitoring of fibrosis progression. Herein, we propose a H2O2 responsive macromolecular probe for collagen imaging with high sensitivity and specificity. This probe consists of a collagen-targeting peptide and a H2O2-sensitive and near-infrared (NIR)-emitting macromolecular optical probe, which could effectively bind to collagen both in vitro and in vivo in the region of tumor or fibrotic liver tissues, allowing for high sensitivity and noninvasive visualization of fibrotic tissues and real time monitoring of collagen degradation after anti-fibrotic drug treatment.

Engineered Bacterial Biomimetic Vesicles Reprogram Tumor-Associated Macrophages and Remodel Tumor Microenvironment to Promote Innate and Adaptive Antitumor Immune Responses

Tumor-associated macrophages (TAMs) are among the most abundant infiltrating leukocytes in the tumor microenvironment (TME). Reprogramming TAMs from protumor M2 to antitumor M1 phenotype is a promising strategy for remodeling the TME and promoting antitumor immunity; however, the development of an efficient strategy remains challenging. Here, a genetically modified bacterial biomimetic vesicle (BBV) with IFN-γ exposed on the surface in a nanoassembling membrane pore structure was constructed. The engineered IFN-γ BBV featured a nanoscale structure of protein and lipid vesicle, the existence of rich pattern-associated molecular patterns (PAMPs), and the costimulation of introduced IFN-γ molecules. In vitro, IFN-γ BBV reprogrammed M2 macrophages to M1, possibly through NF-κB and JAK-STAT signaling pathways, releasing nitric oxide (NO) and inflammatory cytokines IL-1β, IL-6, and TNF-α and increasing the expression of IL-12 and iNOS. In tumor-bearing mice, IFN-γ BBV demonstrated a targeted enrichment in tumors and successfully reprogrammed TAMs into the M1 phenotype; notably, the response of antigen-specific cytotoxic T lymphocyte (CTL) in TME was promoted while the immunosuppressive myeloid-derived suppressor cell (MDSC) was suppressed. The tumor growth was found to be significantly inhibited in both a TC-1 tumor and a CT26 tumor. It was indicated that the antitumor effects of IFN-γ BBV were macrophage-dependent. Further, the modulation of TME by IFN-γ BBV produced synergistic effects against tumor growth and metastasis with an immune checkpoint inhibitor in an orthotopic 4T1 breast cancer model which was insensitive to anti-PD-1 mAb alone. In conclusion, IFN-γ-modified BBV demonstrated a strong capability of efficiently targeting tumor and tuning a cold tumor hot through reprogramming TAMs, providing a potent approach for tumor immunotherapy.

Molecular Masking of Synthetic Immunomodulator Evokes Antitumor Immunity With Reduced Immune Tolerance and Systemic Toxicity by Temporal Activity Recovery and Sustained Stimulation

Activation of the innate immune system counteracts tumor-induced immunosuppression. Hence, small molecule-based toll-like receptor 7/8 agonists (TLR7/8a), which can modulate immunosuppression in the tumor microenvironment along with the activation of innate immunity, are emerging as essential components of cancer immunotherapy. However, the clinical application of synthetic TLR7/8a therapies is limited by systemic immune-associated toxicity and immune tolerance induced by uncontrolled stimulatory activities and repeated treatments. To address these limitations, a dynamic immunomodulation strategy incorporating masking and temporal recovery of the activity of TLR7/8a through prodrug-like TLR7/8a (pro-TLR7/8a) at the molecular level and a sustained and controlled release of active TLR7/8a from nanoliposome (pro-TLR7/8a) (NL(pro-TLR7/8)) in a macroscale depot are designed. Immunization with cationic NL(pro-TLR7/8) and anionic antigens triggers robust activation of innate immune cells as well as antigen-specific T cell responses, eliciting reprogramming of immunosuppressive cells into tumor-suppressive cells, with decreased systemic adverse effects and immune tolerance. Combination treatment with NL(pro-TLR7/8a) and immune checkpoint inhibitors (anti-CTLA-4 plus anti-PD-L1) or nanoliposomes (Doxorubicin) has synergistic effects on antitumor immunity in various tumor models. The concept of pro-TLR7/8a suggested herein may facilitate the advancement of small-molecule-based immunomodulators for clinical translation and safe and effective cancer immunotherapy.

CD8+ T cell priming that is required for curative intratumorally anchored anti-4-1BB immunotherapy is constrained by Tregs

Although co-stimulation of T cells with agonist antibodies targeting 4-1BB (CD137) improves antitumor immune responses in preclinical studies, clinical success has been limited by on-target, off-tumor activity. Here, we report the development of a tumor-anchored ɑ4-1BB agonist (ɑ4-1BB-LAIR), which consists of a ɑ4-1BB antibody fused to the collagen-binding protein LAIR. While combination treatment with an antitumor antibody (TA99) shows only modest efficacy, simultaneous depletion of CD4+ T cells boosts cure rates to over 90% of mice. Mechanistically, this synergy depends on ɑCD4 eliminating tumor draining lymph node regulatory T cells, resulting in priming and activation of CD8+ T cells which then infiltrate the tumor microenvironment. The cytotoxic program of these newly primed CD8+ T cells is then supported by the combined effect of TA99 and ɑ4-1BB-LAIR. The combination of TA99 and ɑ4-1BB-LAIR with a clinically approved ɑCTLA-4 antibody known for enhancing T cell priming results in equivalent cure rates, which validates the mechanistic principle, while the addition of ɑCTLA-4 also generates robust immunological memory against secondary tumor rechallenge. Thus, our study establishes the proof of principle for a clinically translatable cancer immunotherapy.

Tumor-localized interleukin-2 and interleukin-12 combine with radiation therapy to safely potentiate regression of advanced malignant melanoma in pet dogs

The clinical use of interleukin-2 and -12 cytokines against cancer is limited by their narrow therapeutic windows due to on-target, off-tumor activation of immune cells when delivered systemically. Engineering IL-2 and IL-12 to bind to extracellular matrix collagen allows these cytokines to be retained within tumors after intralesional injection, overcoming these clinical safety challenges. While this approach has potentiated responses in syngeneic mouse tumors without toxicity, the complex tumor-immune interactions in human cancers are difficult to recapitulate in mouse models of cancer. This has driven an increased role for comparative oncology clinical trials in companion (pet) dogs with spontaneous cancers that feature analogous tumor and immune biology to human cancers. Here, we report the results from a dose-escalation clinical trial of intratumoral collagen-binding IL-2 and IL-12 cytokines in pet dogs with malignant melanoma, observing encouraging local and regional responses to therapy that may suggest human clinical benefit with this approach.

Immunostimulatory gene therapy combined with checkpoint blockade reshapes tumor microenvironment and enhances ovarian cancer immunotherapy

Immune evasion has made ovarian cancer notorious for its refractory features, making the development of immunotherapy highly appealing to ovarian cancer treatment. The immune-stimulating cytokine IL-12 exhibits excellent antitumor activities. However, IL-12 can induce IFN-γ release and subsequently upregulate PDL-1 expression on tumor cells. Therefore, the tumor-targeting folate-modified delivery system F-DPC is constructed for concurrent delivery of IL-12 encoding gene and small molecular PDL-1 inhibitor (iPDL-1) to reduce immune escape and boost anti-tumor immunity. The physicochemical characteristics, gene transfection efficiency of the F-DPC nanoparticles in ovarian cancer cells are analyzed. The immune-modulation effects of combination therapy on different immune cells are also studied. Results show that compared with non-folate-modified vector, folate-modified F-DPC can improve the targeting of ovarian cancer and enhance the transfection efficiency of pIL-12. The underlying anti-tumor mechanisms include the regulation of T cells proliferation and activation, NK activation, macrophage polarization and DC maturation. The F-DPC/pIL-12/iPDL-1 complexes have shown outstanding antitumor effects and low toxicity in peritoneal model of ovarian cancer in mice. Taken together, our work provides new insights into ovarian cancer immunotherapy. Novel F-DPC/pIL-12/iPDL-1 complexes are revealed to exert prominent anti-tumor effect by modulating tumor immune microenvironment and preventing immune escape and might be a promising treatment option for ovarian cancer treatment.

Enhancing drug penetration in solid tumors via nanomedicine: Evaluation models, strategies and perspectives

Effective tumor treatment depends on optimizing drug penetration and accumulation in tumor tissue while minimizing systemic toxicity. Nanomedicine has emerged as a key solution that addresses the rapid clearance of free drugs, but achieving deep drug penetration into solid tumors remains elusive. This review discusses various strategies to enhance drug penetration, including manipulation of the tumor microenvironment, exploitation of both external and internal stimuli, pioneering nanocarrier surface engineering, and development of innovative tactics for active tumor penetration. One outstanding strategy is organelle-affinitive transfer, which exploits the unique properties of specific tumor cell organelles and heralds a potentially transformative approach to active transcellular transfer for deep tumor penetration. Rigorous models are essential to evaluate the efficacy of these strategies. The patient-derived xenograft (PDX) model is gaining traction as a bridge between laboratory discovery and clinical application. However, the journey from bench to bedside for nanomedicines is fraught with challenges. Future efforts should prioritize deepening our understanding of nanoparticle-tumor interactions, re-evaluating the EPR effect, and exploring novel nanoparticle transport mechanisms.

Engineering Anticytokine Antibodies for Immune Modulation

The delicate balance of immune homeostasis is regulated by the interactions between cytokines and their cognate cell surface signaling receptors. There is intensive interest in harnessing cytokines as drugs for diseases such as cancer and autoimmune disorders. However, the multifarious and often contradictory activities of cytokines, coupled with their short serum half-lives, limit clinical performance and result in dangerous toxicities. There is thus growing emphasis on manipulating natural cytokines to enhance their selectivity, safety, and durability through various strategies. One strategy that has gained traction in recent years is the development of anticytokine Abs that not only extend the circulation half-life of cytokines but also specifically bias their immune activities through multilayered molecular mechanisms. Although Abs are notorious for their antagonistic activities, this review focuses on anticytokine Abs that selectively agonize the activity of the target protein. This approach has potential to help realize the clinical promise of cytokine-based therapies.

Preclinical and clinical studies of a tumor targeting IL-12 immunocytokine

The clinical success of immune checkpoint inhibitors (ICIs) has demonstrated the promise and challenges of cancer immunotherapy. There is an unmet need to develop novel cancer therapies that can provide clinical benefit for most patients with solid malignancies, which harbor innate or acquired resistance to ICIs. Interleukin-12 (IL-12) is a promising cytokine for cancer therapy given its direct stimulatory effects on innate and adaptive immunity. However, unfavorable pharmacokinetics and a narrow therapeutic index render recombinant IL-12 (rIL-12) less attractive as a cancer therapy. NHS-IL12 is a fusion protein of IL-12 and NHS76 (human IgG1) antibody engineered to target single and double stranded DNA present in necrotic areas solid tumors. In preclinical tumor models, NHS-IL12 elicited significant Th1 immune activation and tumor suppressive effects, primarily mediated by NK and CD8+ T lymphocytes, with engagement of myeloid immunity. NHS-IL12 is currently being evaluated clinically in combination with various therapeutic modalities, including chemotherapy, radiation therapy, immune checkpoint inhibition, vaccines, and epigenetic modulation. Here we review the preclinical and clinical studies involving NHS-IL12 for the treatment of solid malignancies.

Collagen Anchoring Protein-Nucleic Acid Chimeric Probe for In Situ In Vivo Mapping of a Tumor-Specific Protease

In situ analysis of biomarkers in the tumor microenvironment (TME) is important to reveal their potential roles in tumor progression and early diagnosis of tumors but remains a challenge. In this work, a bottom-up modular assembly strategy was proposed for a multifunctional protein-nucleic chimeric probe (PNCP) for in situ mapping of cancer-specific proteases. PNCP, containing a collagen anchoring module and a target proteolysis-responsive isothermal amplification sensor module, can be anchored in the collagen-rich TME and respond to the target protease in situ and generate amplified signals through rolling cycle amplification of tandem fluorescent RNAs. Taking matrix metalloproteinase 2 (MMP-2), a tumor-associated protease, as the model, the feasibility of PNCP was demonstrated for the in situ detection of MMP-2 activity in 3D tumor spheroids. Moreover, in situ in vivo mapping of MMP-2 activity was also achieved in a metastatic solid tumor model with high sensitivity, providing a useful tool for evaluating tumor metastasis and distinguishing highly aggressive forms of tumors.

Intratumoral aluminum hydroxide-anchored IL-12 drives potent antitumor activity by remodeling the tumor microenvironment

IL-12 is a potent cytokine that can promote innate and adaptive anticancer immunity, but its clinical development has been limited by toxicity when delivered systemically. Intratumoral (i.t.) administration can expand the therapeutic window of IL-12 and other cytokines but is in turn limited by rapid drug clearance from the tumor, which reduces efficacy, necessitates frequent administration, and increases systemic accumulation. To address these limitations, we developed an anchored IL-12 designated ANK-101, composed of an engineered IL-12 variant that forms a stable complex with the FDA-approved vaccine adjuvant aluminum hydroxide (Alhydrogel). Following i.t. administration of murine ANK-101 (mANK-101) in early intervention syngeneic mouse tumors, the complex formed a depot that was locally retained for weeks as measured by IVIS or SPECT/CT imaging, while unanchored protein injected i.t. was cleared within hours. One or 2 i.t. injections of mANK-101 induced single-agent antitumor activity across a diverse range of syngeneic tumors, including models resistant to checkpoint blockade at doses where unanchored IL-12 had no efficacy. Local treatment with mANK-101 further induced regressions of noninjected lesions, especially when combined with systemic checkpoint blockade. Antitumor activity was associated with remodeling of the tumor microenvironment, including prolonged IFN-γ and chemokine expression, recruitment and activation of T and NK cells, M1 myeloid cell skewing, and increased antigen processing and presentation. Subcutaneous administration of ANK-101 in cynomolgus macaques was well tolerated. Together, these data demonstrate that ANK-101 has an enhanced efficacy and safety profile and warrants future clinical development.

Engineered IL-7 synergizes with IL-12 immunotherapy to prevent T cell exhaustion and promote memory without exacerbating toxicity

Cancer immunotherapy is moving toward combination regimens with agents of complementary mechanisms of action to achieve more frequent and robust efficacy. However, compared with single-agent therapies, combination immunotherapies are associated with increased overall toxicity because the very same mechanisms also work in concert to enhance systemic inflammation and promote off-tumor toxicity. Therefore, rational design of combination regimens that achieve improved antitumor control without exacerbated toxicity is a main objective in combination immunotherapy. Here, we show that the combination of engineered, tumor matrix-binding interleukin-7 (IL-7) and IL-12 achieves remarkable anticancer effects by activating complementary pathways without inducing any additive immunotoxicity. Mechanistically, engineered IL-12 provided effector properties to T cells, while IL-7 prevented their exhaustion and boosted memory formation as assessed by tumor rechallenge experiments. The dual combination also rendered checkpoint inhibitor (CPI)-resistant genetically engineered melanoma model responsive to CPI. Thus, our approach provides a framework of evaluation of rationally designed combinations in immuno-oncology and yields a promising therapy.

Revitalizing Cytokine-Based Cancer Immunotherapy through Advanced Delivery Systems

Cytokines can coordinate robust immune responses, holding great promise as therapeutics against infections, autoimmune diseases, and cancers. In cancer treatment, numerous pro-inflammatory cytokines have displayed promising efficacy in preclinical studies. However, their clinical application is hindered by poor pharmacokinetics, significant toxicity and unsatisfactory anticancer efficacy. Thus, while IFN-α and IL-2 are approved for specific cancer treatments, other cytokines still remain subject of intense investigation. To accelerate the application of cytokines as cancer immunotherapeutics, strategies need to be directed to improve their safety and anticancer performance. In this regard, delivery systems could be used to generate innovative therapies by targeting the cytokines or nucleic acids, such as DNA and mRNA, encoding the cytokines to tumor tissues. This review centers on these innovative delivery strategies for cytokines, summarizing key approaches, such as gene delivery and protein delivery, and critically examining their potential and challenges for clinical translation.

A Mild Hyperthermia Hollow Carbon Nanozyme as Pyroptosis Inducer for Boosted Antitumor Immunity

The immune checkpoint blockade (ICB) antibody immunotherapy has demonstrated clinical benefits for multiple cancers. However, the efficacy of immunotherapy in tumors is suppressed by deficient tumor immunogenicity and immunosuppressive tumor microenvironments. Pyroptosis, a form of programmed cell death, can release tumor antigens, activate effective tumor immunogenicity, and improve the efficiency of ICB, but efficient pyroptosis for tumor treatment is currently limited. Herein, we show a mild hyperthermia-enhanced pyroptosis-mediated immunotherapy based on hollow carbon nanozyme, which can specifically amplify oxidative stress-triggered pyroptosis and synchronously magnify pyroptosis-mediated anticancer responses in the tumor microenvironment. The hollow carbon sphere modified with iron and copper atoms (HCS-FeCu) with multiple enzyme-mimicking activities has been engineered to induce cell pyroptosis via the radical oxygen species (ROS)-Tom20-Bax-Caspase 3-gasdermin E (GSDME) signaling pathway under light activation. Both in vitro and in vivo antineoplastic results confirm the superiority of HCS-FeCu nanozyme-induced pyroptosis. Moreover, the mild photothermal-activated pyroptosis combining anti-PD-1 can enhance antitumor immunotherapy. Theoretical calculations further indicate that the mild photothermal stimulation generates high-energy electrons and enhances the interaction between the HCS-FeCu surface and adsorbed oxygen, facilitating molecular oxygen activation, which improves the ROS production efficiency. This work presents an approach that effectively transforms immunologically "cold" tumors into "hot" ones, with significant implications for clinical immunotherapy.

An engineered immunocytokine with collagen affinity improves the tumor bioavailability, tolerability, and therapeutic efficacy of IL-2

The clinical utility of human interleukin-2 (hIL-2) is limited by its short serum half-life, preferential activation of regulatory T (TReg) over immune effector cells, and dose-limiting toxicities. We previously engineered F10 immunocytokine (IC), an intramolecularly assembled cytokine/antibody fusion protein that linked hIL-2 to an anti-IL-2 antibody (denoted F10) that extended IL-2 half-life and augmented the immune effector to TReg ratio. Here, we leveraged molecular engineering to improve the anti-tumor therapeutic efficacy and tolerability of F10 IC by developing an iteration, denoted F10 IC-CBD (collagen binding domain), designed for intratumoral administration and in situ retention based on collagen affinity. F10 IC-CBD retained IL-2 bioactivity exclusively in the tumor and eliminated IL-2-associated toxicities. Furthermore, F10 IC exhibited potent single-agent therapeutic efficacy and synergy with systemic immune checkpoint blockade and elicited an abscopal response in mouse tumors models. This engineered fusion protein presents a prototype for the design of intratumoral therapies.

A collagen-immobilized nanodevice for in situ ratiometric imaging of cancer biomarkers in the tumor microenvironment

Monitoring the spatiotemporal dynamics of cancer biomarkers within the tumor microenvironment (TME) is critical to understanding their roles in tumorigenesis. Here, we reported a multifunctional fusion protein (collagen-binding domain and duck circovirus tag fused to mCherry, CBD-mCherry-DCV) capable of binding collagen with high affinity and covalently binding specific nucleic acids with exceptional efficiency. We then constructed a chimeric protein-nucleic acid nanodevice (CPNN) using CBD-mCherry-DCV and an aptamer-based sensing module to enable spatially controlled ratiometric imaging of cancer biomarkers in the TME. The collagen-anchoring module CBD-mCherry-DCV allowed specific immobilization of CPNN on 3D multicellular tumor spheroids, enabling the sensing module to achieve "off-on" fluorescence imaging of cancer biomarkers upon specific target recognition by an aptamer. Taking advantage of the constant fluorescence signal of mCherry and the activatable fluorescence response of Cy5 to specific cancer biomarkers, the detection sensitivity and reliability of CPNN were improved by self-calibrating the signal intensity. Specifically, CPNN enabled ratiometric fluorescence imaging of varying concentrations of exogenous PDGF-BB and ATP in tumor spheroids with a high signal-to-background ratio. Furthermore, it allowed the visual monitoring of endogenous PDGF-BB and ATP released from cells. Overall, this study demonstrates the potential of the nanodevice as a versatile approach for the visualization and imaging of cancer biomarkers in the TME.

In vitro modelling of local gene therapy with IL-15/IL-15Rα and a PD-L1 antagonist in melanoma reveals an interplay between NK cells and CD4+ T cells

Blockade of the immune checkpoint axis consisting of programmed death-1 (PD-1) and its ligand PD-L1 alleviates the functional inhibition of tumor-infiltrating lymphoid cells yet weakly induces their expansion. Exogenous cytokines could further expand lymphoid cells and thus synergize with αPD-L1 therapy. However, systemic delivery of most cytokines causes severe toxicity due to unspecific expansion of immune cells in the periphery. Here, we modelled local delivery of cytokines and αPD-L1 therapeutics to immune cell-containing in vitro melanoma tumors. Three-dimensional tumor models consisting of 624-MEL cells were co-cultured with human peripheral blood lymphoid cells (PBLs) in presence of the cytokines IL-2, IL-7, IL-15, IL-21 and IFN-γ. To model local gene therapy, melanoma tumors were modified with lentiviral vectors encoding IL-15 fused to IL-15Rα (IL-15/IL-15Rα) and K2-Fc, a fusion of a human PD-L1 specific single domain antibody to immunoglobulin (Ig)G1 Fc. To evaluate the interplay between PBL fractions, NK cells, CD4+ T cells or CD8+ T cells were depleted. Tumor cell killing was followed up using real time imaging and immune cell expansion and activation was evaluated with flow cytometry. Among the tested cytokines, IL-15 was the most potent cytokine in stimulating tumor cell killing and expanding both natural killer (NK) cells and CD8+ T cells. Gene-based delivery of IL-15/IL-15Rα to tumor cells, shows expansion of NK cells, activation of NK cells, CD4+ and CD8+ T cells, and killing of tumor spheroids. Both NK cells and CD8+ T cells are necessary for tumor cell killing and CD4+ T-cell activation was reduced without NK cells. Co-delivery of K2-Fc improved tumor cell killing coinciding with increased activation of NK cells, which was independent of bystander T cells. CD4+ or CD8+ T cells were not affected by the co-delivery of K2-Fc even though NK-cell activation impacted CD4+ T-cell activation. This study demonstrates that gene-based delivery of IL-15/IL-15Rα to tumor cells effectively mediates anti-tumor activity and sensitizes the tumor microenvironment for therapy with αPD-L1 therapeutics mainly by impacting NK cells. These findings warrant further investigation of gene-based IL-15 and K2-Fc delivery in vivo.

A collagen-binding SIRPαFc fusion protein for targeted cancer immunotherapy

Collagen is abundant but exposed in tumor due to the abnormal tumor blood vessels, thus is considered as a tumor-specific target. The A3 domain of von Willebrand factor (vWF A3) is a kind of collagen-binding domain (CBD) which could bind collagen specifically. Previously we reported a chemosynthetic CBD-SIRPαFc conjugate, which could block CD47 and derived tumor-targeting ability by CBD. CBD-SIRPαFc conjugate represented improved anti-tumor efficacy with increased MHC II+ M1 macrophages, but the uncertain coupling ratio remained a problem. Herein, we produced a vWF A3-SIRPαFc fusion protein through eukaryotic expression system. It was examined at both molecular and cellular levels with its collagen affinity, uninfluenced original affinity to targets and phagocytosis-promoting function compared to unmodified SIRPαFc. Living imaging showed that vWF A3-SIRPαFc fusion protein derived the improved accumulation and retention in tumor than SIRPαFc. In the MC38 allograft model, vWF A3-SIRPαFc demonstrated a superior tumor-suppressing effect, characterized by increased MHC II+ M1 macrophages and T cells (particularly CD4+ T cells). These results revealed that vWF A3-SIRPαFc fusion protein derived tumor-targeting ability, leading to improved anti-tumor immunotherapeutic efficacy compared to SIRPαFc. Altogether, vWF A3 improved the anti-tumor efficacy and immune-activating function of SIRPαFc, supporting targeting tumor collagen as a possible targeted strategy.

Spatiotemporally programming cytokine immunotherapies through protein engineering

Cytokines have long been considered promising cancer immunotherapy agents due to their endogenous role in activating and proliferating lymphocytes. However, since the initial FDA approvals of Interleukin-2 (IL-2) and Interferon-ɑ (IFNɑ) for oncology over 30 years ago, cytokines have achieved little success in the clinic due to narrow therapeutic windows and dose-limiting toxicities. This is attributable to the discrepancy between the localized, regulated manner in which cytokines are deployed endogenously versus the systemic, untargeted administration used to date in most exogenous cytokine therapies. Furthermore, cytokines' ability to stimulate multiple cell types, often with paradoxical effects, may present significant challenges for their translation into effective therapies. Recently, protein engineering has emerged as a tool to address the shortcomings of first-generation cytokine therapies. In this perspective, we contextualize cytokine engineering strategies such as partial agonism, conditional activation and intratumoral retention through the lens of spatiotemporal regulation. By controlling the time, place, specificity, and duration of cytokine signaling, protein engineering can allow exogenous cytokine therapies to more closely approach their endogenous exposure profile, ultimately moving us closer to unlocking their full therapeutic potential.

Collagen code in tumor microenvironment: Functions, molecular mechanisms, and therapeutic implications

The tumor microenvironment (TME) is crucial in cancer progression, and the extracellular matrix (ECM) is an important TME component. Collagen is a major ECM component that contributes to tumor cell infiltration, expansion, and distant metastasis during cancer progression. Recent studies reported that collagen is deposited in the TME to form a collagen wall along which tumor cells can infiltrate and prevent drugs from working on the tumor cells. Collagen-tumor cell interaction is complex and requires the activation of multiple signaling pathways for biochemical and mechanical signaling interventions. In this review, we examine the effect of collagen deposition in the TME on tumor progression and discuss the interaction between collagen and tumor cells. This review aims to illustrate the functions and mechanisms of collagen in tumor progression in the TME and its role in tumor therapy. The findings indicated collagen in the TME appears to be a better target for cancer therapy.

Targeting collagen in tumor extracellular matrix as a novel targeted strategy in cancer immunotherapy

Collagen, the most abundant protein in mammal, is widely expressed in tissues and organs, as well as tumor extracellular matrix. Tumor collagen mainly accumulates in tumor stroma or beneath tumor blood vessel endothelium, and is exposed due to the fragmentary structure of tumor blood vessels. Through the blood vessels with enhanced permeability and retention (EPR) effect, collagen-binding macromolecules could easily bind to tumor collagen and accumulate within tumor, supporting tumor collagen to be a potential tumor-specific target. Recently, numerous studies have verified that targeting collagen within tumor extracellular matrix (TEM) would enhance the accumulation and retention of immunotherapy drugs at tumor, significantly improving their anti-tumor efficacy, as well as avoiding severe adverse effects. In this review, we would summarize the known collagen-binding domains (CBD) or proteins (CBP), their mechanism and application in tumor-targeting immunotherapy, and look forward to future development.