Cell membrane-anchored and tumor-targeted IL-12 (attIL12)-T cell therapy for eliminating large and heterogeneous solid tumors

Future perspectives on engineered T cells for cancer

Chimeric antigen receptor (CAR) T cell therapy has emerged as a revolutionary treatment for hematological malignancies, but its adaptation to solid tumors is impeded by multiple challenges, particularly T cell dysfunction and exhaustion. The heterogeneity and inhospitableness of the solid tumor microenvironment (TME) contribute to diminished CAR T cell efficacy exhibited by reduced cytotoxicity, proliferation, cytokine secretion, and the upregulation of inhibitory receptors, similar to the phenotype of tumor-infiltrating lymphocytes (TILs). In this review, we highlight recent advances in T cell therapy for solid tumors, particularly brain cancer. Innovative strategies, including locoregional delivery and 'armoring' CAR T cells with cytokines such as interleukin (IL)-18, are under investigation to improve efficacy and safety. We also highlight emerging issues with toxicity management of CAR T cell adverse events. This review discusses the obstacles associated with CAR T cell therapy in the context of solid tumors and outlines current and future strategies to overcome these challenges.

Modular chimeric cytokine receptors with leucine zippers enhance the antitumour activity of CAR T cells via JAK/STAT signalling

The limited availability of cytokines in solid tumours hinders maintenance of the antitumour activity of chimeric antigen receptor (CAR) T cells. Cytokine receptor signalling pathways in CAR T cells can be activated by transgenic expression or injection of cytokines in the tumour, or by engineering the activation of cognate cytokine receptors. However, these strategies are constrained by toxicity arising from the activation of bystander cells, by the suboptimal biodistribution of the cytokines and by downregulation of the cognate receptor. Here we show that replacement of the extracellular domains of heterodimeric cytokine receptors in T cells with two leucine zipper motifs provides optimal Janus kinase/signal transducer and activator of transcription signalling. Such chimeric cytokine receptors, which can be generated for common γ-chain receptors, interleukin-10 and -12 receptors, enabled T cells to survive cytokine starvation without induction of autonomous cell growth, and augmented the effector function of CAR T cells in vitro in the setting of chronic antigen exposure and in human tumour xenografts in mice. As a modular design, leucine zippers can be used to generate constitutively active cytokine receptors in effector immune cells.

Hydrogel-mediated tumor T cell infiltration and immune evasion to reinforce cancer immunotherapy

Cancer immunotherapy has received increasing attention in tumor therapy. However, insufficient infiltration of T cells and over-expressed PD-L1 checkpoint in tumor cells severely impede cancer immunotherapy. Here, an injectable hydrogel was designed to reinforce T cell infiltration and inactivate PD-L1 for powerful cancer immunotherapy. The hydrogel was created by sodium alginate (SA) as the gelator, where linagliptin particles and BMS-202 particles were present in hydrogel micropores. After gelation in the tumor site, the linagliptin powerfully suppressed chemokine CXCL10 degradation, enabling the introduced CXCL10 to realize sustainable chemotaxis towards strong T cell infiltration. Meanwhile, the BMS-202 inactivated PD-L1 of tumor cells, thereby eliminating the PD-L1-governed immune evasion. Therefore, the hydrogel in combination with CXCL10 demonstrated powerful cancer immunotherapy against primary and distant tumors, along with efficient inhibition of lung metastasis. Our study not only offers a potent platform against tumors, but also provides a conceptually new approach to reinforce cancer immunotherapy.

Cell membrane-anchored and tumor-targeted IL-12 T-cell therapy destroys cancer-associated fibroblasts and disrupts extracellular matrix in heterogenous osteosarcoma xenograft models

BACKGROUND

The extracellular matrix (ECM) and cancer-associated fibroblasts (CAFs) play major roles in tumor progression, metastasis, and the poor response of many solid tumors to immunotherapy. CAF-targeted chimeric antigen receptor-T cell therapy cannot infiltrate ECM-rich tumors such as osteosarcoma.

METHOD

In this study, we used RNA sequencing to assess whether the recently invented membrane-anchored and tumor-targeted IL-12-armed (attIL12) T cells, which bind cell-surface vimentin (CSV) on tumor cells, could destroy CAFs to disrupt the ECM. We established an in vitro model of the interaction between osteosarcoma CAFs and attIL12-T cells to uncover the underlying mechanism by which attIL12-T cells penetrate stroma-enriched osteosarcoma tumors.

RESULTS

RNA sequencing demonstrated that attIL12-T cell treatment altered ECM-related gene expression. Immunohistochemistry staining revealed disruption or elimination of high-density CAFs and ECM in osteosarcoma xenograft tumors following attIL12-T cell treatment, and CAF/ECM density was inversely correlated with T-cell infiltration. Other IL12-armed T cells, such as wild-type IL-12-targeted or tumor-targeted IL-12-T cells, did not disrupt the ECM because this effect depended on the engagement between CSV on the tumor cell and its ligand on the attIL12-T cells. Mechanistic studies found that attIL12-T cell treatment elevated IFNγ production on interacting with CSV+ tumor cells, suppressing transforming growth factor beta secretion and in turn upregulating FAS-mediated CAF apoptosis. CAF destruction reshaped the tumor stroma to favor T-cell infiltration and tumor inhibition.

CONCLUSIONS

This study unveiled a novel therapy-attIL12-T cells-for targeting CAFs/ECM. These findings are highly relevant to humans because CAFs are abundant in human osteosarcoma.

Antigen-dependent IL-12 signaling in CAR T cells promotes regional to systemic disease targeting

Chimeric antigen receptor (CAR) T cell therapeutic responses are hampered by limited T cell trafficking, persistence, and durable anti-tumor activity in solid tumors. However, these challenges can be largely overcome by relatively unconstrained synthetic engineering strategies. Here, we describe CAR T cells targeting tumor-associated glycoprotein-72 (TAG72), utilizing the CD28 transmembrane domain upstream of the 4-1BB co-stimulatory domain as a driver of potent anti-tumor activity and IFNγ secretion. CAR T cell-mediated IFNγ production facilitated by IL-12 signaling is required for tumor cell killing, which is recapitulated by engineering an optimized membrane-bound IL-12 (mbIL12) molecule in CAR T cells. These T cells show improved antigen-dependent T cell proliferation and recursive tumor cell killing in vitro, with robust in vivo efficacy in human ovarian cancer xenograft models. Locoregional administration of mbIL12-engineered CAR T cells promotes durable anti-tumor responses against both regional and systemic disease in mice. Safety and efficacy of mbIL12-engineered CAR T cells is demonstrated using an immunocompetent mouse model, with beneficial effects on the immunosuppressive tumor microenvironment. Collectively, our study features a clinically-applicable strategy to improve the efficacy of locoregionally-delivered CAR T cells engineered with antigen-dependent immune-modulating cytokines in targeting regional and systemic disease.

Bispecific GPC3/PD‑1 CAR‑T cells for the treatment of HCC

Constantly stimulated by the tumor microenvironment (TME), programmed death 1 (PD‑1) is elevated, and it interacts with PD ligand 1 (PD‑L1), rendering chimeric antigen receptor (CAR)‑T cells dysfunctional. Hence, CAR‑T cells immune to PD‑1‑induced immunosuppression were constructed to improve the function of CAR‑T cells in hepatocellular carcinoma (HCC). Double‑target CAR‑T cells, targeting glypican‑3 (GPC3) [a tumour-associated antigen (TAA)] and hindering PD‑1‑PD‑L1 binding, were established. The expression of GPC3, PD‑L1, and inhibitory receptors was measured using flow cytometry. The cytotoxicity, cytokine release, and differentiation level of CAR‑T cells were determined using lactate dehydrogenase release assay, enzyme‑linked immunosorbent assay, and flow cytometry, respectively. HCC cells were targeted and eliminated by double‑target CAR‑T cells. These double‑target CAR‑T cells limit PD‑1‑PD‑L1 binding and sustain cytotoxicity to PD‑L1⁺ HCC cells. The relatively low IR expression and differentiation level in double‑target CAR‑T cells in tumour tissues induced tumour‑suppression and extended survival in PD‑L1⁺ HCC TX models, as opposed to their single‑target counterparts. The results of the present study suggested that the newly constructed double‑target CAR‑T cells exhibit stronger tumour‑suppressing effects in HCC than their single‑target counterparts, which are common, suggesting the potential of strengthening CAR‑T cell activity in HCC treatment.

Role and Potential of Different T Helper Cell Subsets in Adoptive Cell Therapy

Historically, CD8⁺ T cells have been considered the most relevant effector cells involved in the immune response against tumors and have therefore been the focus of most cancer immunotherapy approaches. However, CD4⁺ T cells and their secreted factors also play a crucial role in the tumor microenvironment and can orchestrate both pro- and antitumoral immune responses. Depending on the cytokine milieu to which they are exposed, CD4⁺ T cells can differentiate into several phenotypically different subsets with very divergent effects on tumor progression. In this review, we provide an overview of the current knowledge about the role of the different T helper subsets in the immune system, with special emphasis on their implication in antitumoral immune responses. Furthermore, we also summarize therapeutic applications of each subset and its associated cytokines in the adoptive cell therapy of cancer.

Managing the immune microenvironment of osteosarcoma: the outlook for osteosarcoma treatment

Osteosarcoma, with poor survival after metastasis, is considered the most common primary bone cancer in adolescents. Notwithstanding the efforts of researchers, its five-year survival rate has only shown limited improvement, suggesting that existing therapeutic strategies are insufficient to meet clinical needs. Notably, immunotherapy has shown certain advantages over traditional tumor treatments in inhibiting metastasis. Therefore, managing the immune microenvironment in osteosarcoma can provide novel and valuable insight into the multifaceted mechanisms underlying the heterogeneity and progression of the disease. Additionally, given the advances in nanomedicine, there exist many advanced nanoplatforms for enhanced osteosarcoma immunotherapy with satisfactory physiochemical characteristics. Here, we review the classification, characteristics, and functions of the key components of the immune microenvironment in osteosarcoma. This review also emphasizes the application, progress, and prospects of osteosarcoma immunotherapy and discusses several nanomedicine-based options to enhance the efficiency of osteosarcoma treatment. Furthermore, we examine the disadvantages of standard treatments and present future perspectives for osteosarcoma immunotherapy.

Antigen-dependent IL-12 signaling in CAR T cells promotes regional to systemic disease targeting

Chimeric antigen receptor (CAR) T cell therapeutic responses are hampered by limited T cell trafficking, persistence, and durable anti-tumor activity in solid tumor microenvironments. However, these challenges can be largely overcome by relatively unconstrained synthetic engineering strategies, which are being harnessed to improve solid tumor CAR T cell therapies. Here, we describe fully optimized CAR T cells targeting tumor-associated glycoprotein-72 (TAG72) for the treatment of solid tumors, identifying the CD28 transmembrane domain upstream of the 4-1BB co-stimulatory domain as a driver of potent anti-tumor activity and IFNγ secretion. These findings have culminated into a phase 1 trial evaluating safety, feasibility, and bioactivity of TAG72-CAR T cells for the treatment of patients with advanced ovarian cancer ( NCT05225363 ). Preclinically, we found that CAR T cell-mediated IFNγ production facilitated by IL-12 signaling was required for tumor cell killing, which was recapitulated by expressing an optimized membrane-bound IL-12 (mbIL12) molecule on CAR T cells. Critically, mbIL12 cell surface expression and downstream signaling was induced and sustained only following CAR T cell activation. CAR T cells with mbIL12 demonstrated improved antigen-dependent T cell proliferation and potent cytotoxicity in recursive tumor cell killing assays in vitro and showed robust in vivo anti-tumor efficacy in human xenograft models of ovarian cancer peritoneal metastasis. Further, locoregional administration of TAG72-CAR T cells with antigen-dependent IL-12 signaling promoted durable anti-tumor responses against both regional and systemic disease in mice and was associated with improved systemic T cell persistence. Our study features a clinically-applicable strategy to improve the overall efficacy of locoregionally-delivered CAR T cells engineered with antigen-dependent immune-modulating cytokines in targeting both regional and systemic disease.

Splenic-targeting biomimetic nanovaccine for elevating protective immunity against virus infection

BACKGROUND

The prevalence of viral infectious diseases has become a serious threat to public safety, economic and social development. Vaccines have been served as the most effective platform to prevent virus transmission via the activation of host immune responses, while the low immunogenicity or safety, the high cost of production, storage, transport limit their effective clinical application. Therefore, there is a need to develop a promising strategy to improve the immunogenicity and safety of vaccines.

METHODS

We developed a splenic-targeting biomimetic nanovaccine (NV) that can boost protective humoral and cellular immunity against african swine fever virus (ASFV) infection. The universal PLGA nanoparticles (CMR-PLGA/p54 NPs) coated with mannose and CpG (TLR9 agonist) co-modified red blood cell (RBC) membrane were prepared, which comprised a viral antigen (p54) and can be served as a versatile nanovaccine for elevating protective immunity.

RESULTS

CMR-PLGA/p54 NVs could be effectively uptaken by BMDC and promoted BMDC maturation in vitro. After subcutaneous immunization, antigen could be effectively delivered to the splenic dendritic cells (DCs) due to the splenic homing ability of RBC and DC targeting capacity of mannose, which promoted antigen presentation and DCs maturation, and further elicited higher levels of cytokines secretion and specific IgG titers, CD4⁺ and CD8⁺ T cells activation and B maturation. Moreover, NVs demonstrated notable safety during the immunization period.

CONCLUSIONS

This study demonstrates the high potential of CMR-PLGA NPs as vaccine delivery carriers to promote humoral and cellular immune responses, and it provides a promising strategy to develop safe and effective vaccines against viral infectious diseases.

Antitumor Activities of Interleukin-12 in Melanoma

Melanoma is the most common and serious malignant tumor among skin cancers. Although more and more studies have revolutionized the systematic treatment of advanced melanoma in recent years, access to innovative drugs for melanoma is still greatly restricted in many countries. IL-12 produced mainly by antigen-presenting cells regulates the immune response and affects the differentiation of T cells in the process of antigen presentation. However, the dose-limited toxicity of IL-12 limits its clinical application. The present review summarizes the basic biological functions and toxicity of IL-12 in the treatment of melanoma and discusses the clinical application of IL-12, especially the combination of IL-12 with immune checkpoint inhibitors, cytokines and other therapeutic drugs. We also summarize several promising technological approaches such as carriers that have been developed to improve the pharmacokinetics, efficacy and safety of IL-12 or IL-12 encoding plasmid application.

Immune checkpoint inhibitors in osteosarcoma: A hopeful and challenging future

Osteosarcoma (OS), the most common malignant tumor in the musculoskeletal system, mainly occurs in adolescents. OS results in high mortality and disability rates due to a fatal metastatic tendency and subsequent iatrogenic damage caused by surgery, radiotherapy and chemotherapy. Recently, immunotherapies have resulted in promising prognoses with reduced side effects compared with traditional therapies. Immune checkpoint inhibitors (ICIs), which are a representative immunotherapy for OS, enhance the antitumor effects of immune cells. ICIs have shown satisfactory outcomes in other kinds of malignant tumors, especially hemopoietic tumors. However, there is still a high percentage of failures or severe side effects associated with the use of ICIs to treat OS, leading to far worse outcomes. To reveal the underlying mechanisms of drug resistance and side effects, recent studies elucidated several possible reasons, including the activation of other inhibitory immune cells, low immune cell infiltration in the tumor microenvironment, different immune properties of OS subtypes, and the involvement of osteogenesis and osteolysis. According to these mechanisms, researchers have developed new methods to overcome the shortcomings of ICIs. This review summarizes the recent breakthroughs in the use of ICIs to treat OS. Although numerous issues have not been solved yet, ICIs are still the most promising treatment options to cure OS in the long run.

Metal-Cyclic Dinucleotide Nanomodulator-Stimulated STING Signaling for Strengthened Radioimmunotherapy of Large Tumor

Combined treatment of immunotherapy and radiotherapy shows promising therapeutic effects for the regression of a variety of cancers. However, even multi-modality therapies often fail to antagonize the regression of large tumors due to the extremely immunosuppressive tumor microenvironment (TME). Here, a radioimmunotherapeutic paradigm based on stimulator of interferon genes (STING)-dependent signaling is applied to preclude large tumor progression by utilizing the metal-cyclic dinucleotide (CDN) nanoplatform, which integrates STING agonist c-di-AMP and immunomodulating microelement manganese (II) within the tannic acid nanostructure (TMA-NPs). As observed by magnetic resonance imaging, the localized administration of TMA-NPs effectively relieves hypoxia within TME and causes radical oxygen species overproduction and apoptosis in cancer cells after exposure to X-ray irradiation. The DNA fragments released from the apoptotic cells after the combined treatment augment the production of endogenous CDNs in cancer cells, hence significantly activating the STING-mediated pathway for stronger anti-tumor immunity. The localized therapy of TMA-NPs + X-ray not only inhibits the primary large tumor progression but also retards distant tumor growth by promoting dendritic cell maturation and activating cytotoxic immune cells whil suppressing immunosuppressive cells. Therefore, this work represents the combinatorial potency of TMA-NPs and X-rays on large tumor regression through strengthened STING-mediated radioimmunotherapeutics.

IL12 immune therapy clinical trial review: Novel strategies for avoiding CRS-associated cytokines

Interleukin 12 (IL-12) is a naturally occurring cytokine that plays a key role in inducing antitumor immune responses, including induction of antitumor immune memory. Currently, no IL-12-based therapeutic products have been approved for clinical application because of its toxicities. On the basis of this review of clinical trials using primarily wild-type IL-12 and different delivery methods, we conclude that the safe utilization of IL-12 is highly dependent on the tumor-specific localization of IL-12 post administration. In this regard, we have developed a cell membrane-anchored and tumor-targeted IL-12-T (attIL12-T) cell product for avoiding toxicity from both IL-12 and T cells-induced cytokine release syndrome in peripheral tissues. A phase I trial using this product which seeks to avoid systemic toxicity and boost antitumor efficacy is on the horizon. Of note, this product also boosts the impact of CAR-T or TCR-T cell efficacy against solid tumors, providing an alternative approach to utilize CAR-T to overcome tumor resistance.

The Evolution of Chimeric Antigen Receptor T-Cell Therapy in Children, Adolescents and Young Adults with Acute Lymphoblastic Leukemia

Chimeric antigen receptor T-cell (CAR T) therapy is a revolutionary treatment for pediatric, adolescent and young adult patients (AYA) with relapsed/refractory B-cell acute lymphoblastic leukemia. While the landscape of immunotherapy continues to rapidly evolve, widespread use of CAR T therapy is limited and many questions remain regarding the durability of CAR T therapy, methods to avoid CAR T therapy resistance and the role of consolidative stem cell transplant. Modified strategies to develop effective and persistent CAR T cells at lower costs and decreased toxicities are warranted. In this review we present current indications, limitations and future directions of CAR T therapy for ALL in the pediatric and AYA population.

Membrane-Anchored and Tumor-Targeted IL12 (attIL12)-PBMC Therapy for Osteosarcoma

PURPOSE

Chimeric antigen receptor (CAR) T-cell therapy has shown great promise for treating hematologic malignancies but requires a long duration of T-cell expansion, is associated with severe toxicity, and has limited efficacy for treating solid tumors. We designed experiments to address those challenges.

EXPERIMENTAL DESIGN

We generated a cell membrane-anchored and tumor-targeted IL12 (attIL12) to arm peripheral blood mononuclear cells (PBMC) instead of T cells to omit the expansion phase for required CAR T cells.

RESULTS

This IL12-based attIL12-PBMC therapy showed significant antitumor efficacy in both heterogeneous osteosarcoma patient-derived xenograft tumors and metastatic osteosarcoma tumors with no observable toxic effects. Mechanistically, attIL12-PBMC treatment resulted in tumor-restricted antitumor cytokine release and accumulation of attIL12-PBMCs in tumors. It also induced terminal differentiation of osteosarcoma cells into bone-like cells to impede tumor growth.

CONCLUSIONS

In summary, attIL12-PBMC therapy is safe and effective against osteosarcoma. Our goal is to move this treatment into a clinical trial. Owing to the convenience of the attIL12-PBMC production process, we believe it will be feasible.

Secretory co-factors in next-generation cellular therapies for cancer

Since chimeric antigen receptor (CAR) T-cell therapies for hematologic malignancies were approved by the U.S. Food and Drug Administration, numerous "next-generation" CAR T cells have been developed to improve their safety, efficacy, and applicability. Although some of these novel therapeutic strategies are promising, it remains difficult to apply these therapies to solid tumors and to control adverse effects, such as cytokine release syndrome and neurotoxicity. CAR T cells are generated using highly scalable genetic engineering techniques. One of the major strategies for producing next-generation CAR T cells involves the integration of useful co-factor(s) into the artificial genetic design of the CAR gene, resulting in next-generation CAR T cells that express both CAR and the co-factor(s). Many soluble co-factors have been reported for CAR T cells and their therapeutic effects and toxicity have been tested by systemic injection; therefore, CAR T cells harnessing secretory co-factors could be close to clinical application. Here, we review the various secretory co-factors that have been reported to improve the therapeutic efficacy of CAR T cells and ameliorate adverse events. In addition, we discuss the different co-factor expression systems that have been used to optimize their beneficial effects. Altogether, we demonstrate that combining CAR T cells with secretory co-factors will lead to next-generation CAR T-cell therapies that can be used against broader types of cancers and might provide advanced tools for more complicated synthetic immunotherapies.

Acute or chronic inflammation role in gastrointestinal oncology

The following letter to the editor highlights the review titled “Inflammatory bowel disease-related colorectal cancer: Past, present and future perspectives” in World J Gastrointest Oncol 2022 March 15; 14(3): 547-567. It is necessary to explore the role of inflammation in promoting tumorigenesis and development of gastrointestinal cancers.