IL-13Rα2 humanized scFv-based CAR-T cells exhibit therapeutic activity against glioblastoma

Suppressive immune microenvironment and CART therapy for glioblastoma: Future prospects and challenges

Glioblastoma, a highly malignant intracranial tumor, has acquired slow progress in treatment. Previous clinical trials involving targeted therapy and immune checkpoint inhibitors have shown no significant benefits in treating glioblastoma. This ineffectiveness is largely due to the complex immunosuppressive environment of glioblastoma. Glioblastoma cells exhibit low immunogenicity and strong heterogeneity and the immune microenvironment is replete with inhibitory cytokines, numerous immunosuppressive cells, and insufficient effective T cells. Fortunately, recent Phase I clinical trials of CART therapy for glioblastoma have confirmed its safety, with a small subset of patients achieving survival benefits. However, CART therapy continues to face challenges, including blood-brain barrier obstruction, antigen loss, and an immunosuppressive tumor microenvironment (TME). This article provides a detailed examination of glioblastoma's immune microenvironment, both from intrinsic and extrinsic tumor cell factors, reviews current clinical and basic research on multi-targets CART treatment, and concludes by outlining the key challenges in using CART cells for glioblastoma therapy.

B cells enhance EphA2 chimeric antigen receptor T cells cytotoxicity against glioblastoma via improving persistence

Chimeric antigen receptor (CAR) T cell therapy is a powerful adoptive immunotherapy against blood cancers, but the therapeutic effect was not efficient enough on solid tumors. B cells have been reported to play a critical role in regulating memory T differentiation and cytotoxic T development. However, as of yet the influence of such B cells on CAR T cells has not been discussed. In this study, using ephrin type-A receptor 2 (EphA2) specific CAR T cells, we cultured B cells successfully to stimulate CAR T cells in vitro, and investigated the cell differentiation and anti-tumor efficiency. We observed that EphA2-CAR T cells stimulated by B cells performed increased interferon γ (IFN γ) production and upregulated OX40 expression, as well as the enhanced anti-tumor activity and reduced PD-1 expression. The persistence of CAR T cells was enhanced after B cells stimulation for more than 7 days with the increased subset of central memory T cells (TCM). In addition, next generation sequencing was performed to explore the underlying mechanisms. The up-regulated genes clustered in, immune response activation, chemokine signaling pathway, calcium signaling pathway, cGMP-PKG signaling pathway and et al. which contributed to the upregulated anti-glioblastoma (GBM) activity of CAR T cells stimulated by B cell. Furthermore, MEF2C, CD40, SYK and TNFRSF13B were upregulated in CAR T cells after co-culturing with B cells. These genes functionally enriched in promoting lymphocytes proliferation and may contribute to the enhanced persistence of CAR T cells. In conclusion, these results indicated the critical role of B cells in prolonging CAR T cells longevity and enhancing anti-tumor activity, which paves the way for the therapeutic exploitation of EphA2-CAR T cells against GBM in the future.

Understanding the immunosuppressive microenvironment of glioma: mechanistic insights and clinical perspectives

Glioblastoma (GBM), the predominant and primary malignant intracranial tumor, poses a formidable challenge due to its immunosuppressive microenvironment, thereby confounding conventional therapeutic interventions. Despite the established treatment regimen comprising surgical intervention, radiotherapy, temozolomide administration, and the exploration of emerging modalities such as immunotherapy and integration of medicine and engineering technology therapy, the efficacy of these approaches remains constrained, resulting in suboptimal prognostic outcomes. In recent years, intensive scrutiny of the inhibitory and immunosuppressive milieu within GBM has underscored the significance of cellular constituents of the GBM microenvironment and their interactions with malignant cells and neurons. Novel immune and targeted therapy strategies have emerged, offering promising avenues for advancing GBM treatment. One pivotal mechanism orchestrating immunosuppression in GBM involves the aggregation of myeloid-derived suppressor cells (MDSCs), glioma-associated macrophage/microglia (GAM), and regulatory T cells (Tregs). Among these, MDSCs, though constituting a minority (4-8%) of CD45+ cells in GBM, play a central component in fostering immune evasion and propelling tumor progression, angiogenesis, invasion, and metastasis. MDSCs deploy intricate immunosuppressive mechanisms that adapt to the dynamic tumor microenvironment (TME). Understanding the interplay between GBM and MDSCs provides a compelling basis for therapeutic interventions. This review seeks to elucidate the immune regulatory mechanisms inherent in the GBM microenvironment, explore existing therapeutic targets, and consolidate recent insights into MDSC induction and their contribution to GBM immunosuppression. Additionally, the review comprehensively surveys ongoing clinical trials and potential treatment strategies, envisioning a future where targeting MDSCs could reshape the immune landscape of GBM. Through the synergistic integration of immunotherapy with other therapeutic modalities, this approach can establish a multidisciplinary, multi-target paradigm, ultimately improving the prognosis and quality of life in patients with GBM.

Chimeric Antigen Receptor T Cell and Chimeric Antigen Receptor NK Cell Therapy in Pediatric and Adult High-Grade Glioma-Recent Advances

High-grade gliomas (HGG) account for approximately 10% of central nervous system (CNS) tumors in children and 25% of CNS tumors in adults. Despite their rare occurrence, HGG are a significant clinical problem. The standard therapeutic procedure in both pediatric and adult patients with HGG is the surgical resection of the tumor combined with chemotherapy and radiotherapy. Despite intensive treatment, the 5-year overall survival in pediatric patients is below 20-30%. This rate is even lower for the most common HGG in adults (glioblastoma), at less than 5%. It is, therefore, essential to search for new therapeutic methods that can extend the survival rate. One of the therapeutic options is the use of immune cells (T lymphocytes/natural killer (NK) cells) expressing a chimeric antigen receptor (CAR). The objective of the following review is to present the latest results of preclinical and clinical studies evaluating the efficacy of CAR-T and CAR-NK cells in HGG therapy.

Gastrodin synergistically increases migration of interleukin-13 receptor α2 chimeric antigen receptor T cell to the brain against glioblastoma multiforme: A preclinical study

Therapy with chimeric antigen receptor T (CAR-T) cells involves using reformative T lymphocytes that have three domains, antigen recognition, transmembrane, and costimulating to achieve the therapeutic purpose. CAR-T therapy on malignant hematologic has been successful; however, its effectiveness in patients with solid tumors is still limited. Few studies exist confirming the efficacy of natural products on the function of CAR-T cells. The purpose of this study is to assess the effect of gastrodin (GAS) on CAR-T cells that target interleukin-13 receptor α2 antigen (IL-13Rα2 CAR-T) in the brain against glioblastoma multiforme. Migration of IL-13Rα2 CAR-T was evaluated using the Transwell assay. The effects of GAS on IL-13Rα2 CAR-T cells were assessed both in vitro and situ glioblastoma models. The cytoskeleton was stained with Fluorescein 5-isothiocyanate (FITC)-phalloidin. Cytokines expression in cells was determined by flow cytometry and ELISA assay. Western blotting was used to detect the S1P1 expression, and quantitative PCR assay was used to determine the IL-13Rα2 gene level. GAS increased the migratory and destructive capacity of IL-13Rα2 CAR-T cells with no effect on cytokine release. By increasing the expression of S1P1, GAS encouraged the entry of CAR-T cells into the brain and bone marrow. Transcriptomic analysis revealed that genes related to skeletal migration such as add2 and gng8 showed increased expression in GAS-treated CAR-T cells. We found that GAS synergistically improves the mobility of IL-13Rα2 CAR-T, enhancing their ability to recognize the tumor antigen of glioblastoma, which could be advantageous for the application of CAR-T for the treatment of solid tumors.

Immunotherapy in glioblastoma treatment: Current state and future prospects

Glioblastoma remains as the most common and aggressive malignant brain tumor, standing with a poor prognosis and treatment prospective. Despite the aggressive standard care, such as surgical resection and chemoradiation, median survival rates are low. In this regard, immunotherapeutic strategies aim to become more attractive for glioblastoma, considering its recent advances and approaches. In this review, we provide an overview of the current status and progress in immunotherapy for glioblastoma, going through the fundamental knowledge on immune targeting to promising strategies, such as Chimeric antigen receptor T-Cell therapy, immune checkpoint inhibitors, cytokine-based treatment, oncolytic virus and vaccine-based techniques. At last, it is discussed innovative methods to overcome diverse challenges, and future perspectives in this area.

Gene Targets of CAR-T Cell Therapy for Glioblastoma

Glioblastoma (GBM) is an aggressive primary brain tumor with a poor prognosis following conventional therapeutic interventions. Moreover, the blood-brain barrier (BBB) severely impedes the permeation of chemotherapy drugs, thereby reducing their efficacy. Consequently, it is essential to develop novel GBM treatment methods. A novel kind of pericyte immunotherapy known as chimeric antigen receptor T (CAR-T) cell treatment uses CAR-T cells to target and destroy tumor cells without the aid of the antigen with great specificity and in a manner that is not major histocompatibility complex (MHC)-restricted. It has emerged as one of the most promising therapy techniques with positive clinical outcomes in hematological cancers, particularly leukemia. Due to its efficacy in hematologic cancers, CAR-T cell therapy could potentially treat solid tumors, including GBM. On the other hand, CAR-T cell treatment has not been as therapeutically effective in treating GBM as it has in treating other hematologic malignancies. CAR-T cell treatments for GBM have several challenges. This paper reviewed the use of CAR-T cell therapy in hematologic tumors and the selection of targets, difficulties, and challenges in GBM.

CAR T-cells to treat brain tumors

Tremendous success using CAR T therapy in hematological malignancies has garnered significant interest in developing such treatments for solid tumors, including brain tumors. This success, however, has yet to be mirrored in solid organ neoplasms. CAR T function has shown limited efficacy against brain tumors due to several factors including the immunosuppressive tumor microenvironment, blood-brain barrier, and tumor-antigen heterogeneity. Despite these considerations, CAR T-cell therapy has the potential to be implemented as a treatment modality for brain tumors. Here, we review adult and pediatric brain tumors, including glioblastoma, diffuse midline gliomas, and medulloblastomas that continue to portend a grim prognosis. We describe insights gained from different preclinical models using CAR T therapy against various brain tumors and results gathered from ongoing clinical trials. Furthermore, we outline the challenges limiting CAR T therapy success against brain tumors and summarize advancements made to overcome these obstacles.

Preclinical and clinical studies of CAR-NK-cell therapies for malignancies

The development of chimeric antigen receptor T (CAR-T) cell therapy, a specific type of immunotherapy, in recent decades was a fantastic breakthrough for the treatment of hematological malignancies. However, difficulties in collecting normal T cells from patients and the time cost of manufacturing CAR-T cells have limited the application of CAR-T-cell therapy. In addition, the termination of related clinical trials on universal CAR-T cell therapy has made further research more difficult. Natural killer (NK) cells have drawn great attention in recent years. Chimeric antigen receptor-NK (CAR-NK) cell therapy is a promising strategy in the treatment of malignant tumors because of its lack of potential for causing graft-versus-host disease (GVHD). In this review, we will address the advances in and achievements of CAR-NK cell therapy.

GD2-targeting CAR-T cells enhanced by transgenic IL-15 expression are an effective and clinically feasible therapy for glioblastoma

Background

Aggressive primary brain tumors such as glioblastoma are uniquely challenging to treat. The intracranial location poses barriers to therapy, and the potential for severe toxicity. Effective treatments for primary brain tumors are limited, and 5-year survival rates remain poor. Immune checkpoint inhibitor therapy has transformed treatment of some other cancers but has yet to significantly benefit patients with glioblastoma. Early phase trials of chimeric antigen receptor (CAR) T-cell therapy in patients with glioblastoma have demonstrated that this approach is safe and feasible, but with limited evidence of its effectiveness. The choices of appropriate target antigens for CAR-T-cell therapy also remain limited.

Methods

We profiled an extensive biobank of patients’ biopsy tissues and patient-derived early passage glioma neural stem cell lines for GD2 expression using immunomicroscopy and flow cytometry. We then employed an approved clinical manufacturing process to make CAR- T cells from patients with peripheral blood of glioblastoma and diffuse midline glioma and characterized their phenotype and function in vitro. Finally, we tested intravenously administered CAR-T cells in an aggressive intracranial xenograft model of glioblastoma and used multicolor flow cytometry, multicolor whole-tissue immunofluorescence and next-generation RNA sequencing to uncover markers associated with effective tumor control.

Results

Here we show that the tumor-associated antigen GD2 is highly and consistently expressed in primary glioblastoma tissue removed at surgery. Moreover, despite patients with glioblastoma having perturbations in their immune system, highly functional GD2-specific CAR-T cells can be produced from their peripheral T cells using an approved clinical manufacturing process. Finally, after intravenous administration, GD2-CAR-T cells effectively infiltrated the brain and controlled tumor growth in an aggressive orthotopic xenograft model of glioblastoma. Tumor control was further improved using CAR-T cells manufactured with a clinical retroviral vector encoding an interleukin-15 transgene alongside the GD2-specific CAR. These CAR-T cells achieved a striking 50% complete response rate by bioluminescence imaging in established intracranial tumors.

Conclusions

Targeting GD2 using a clinically deployed CAR-T-cell therapy has a sound scientific and clinical rationale as a treatment for glioblastoma and other aggressive primary brain tumors.

B7-H3-targeted CAR-T cell therapy for solid tumors

Since B7-H3 is overexpressed or amplified in many types of solid tumors with a restricted expression in the normal tissues, it has been an emerging immunotherapeutic target for solid tumors. This review will focus on the structural designs of developing chimeric antigen receptors (CARs) targeting B7-H3. The expression, receptor, and function of the B7-H3, as well as a short overview of B7-H3-targeted monoclonal antibody therapy, are discussed. Finally, a detailed summary of B7-H3 redirected CAR-T and CAR-NK cell approaches utilized in preclinical models and currently ongoing or completed clinical trials are presented. It has been demonstrated that B7-H3-targeted CAR-based cell therapies were safe in initial trials, but their efficacy was limited. Employing the local delivery routes, the introduction of novel modifications promoting CAR-T persistence, and combined treatment with other standard therapies could improve the efficacy of B7-H3-targeted CAR-T cell therapy against solid tumors.