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BackgroundNatural killer (NK) cells are cytotoxic cells capable of recognizing heterogeneous cancer targets without prior sensitization, making them promising prospects for use in cellular immunotherapy. Companion dogs develop spontaneous cancers in the context of an intact immune system, representing a valid cancer immunotherapy model. Previously, CD5 depletion of peripheral blood mononuclear cells (PBMCs) was used in dogs to isolate a CD5dim-expressing NK subset prior to co-culture with an irradiated feeder line, but this can limit the yield of the final NK product. This study aimed to assess NK activation, expansion, and preliminary clinical activity in first-in-dog clinical trials using a novel system with unmanipulated PBMCs to generate our NK cell product.MethodsStarting populations of CD5-depleted cells and PBMCs from healthy beagle donors were co-cultured for 14 days, phenotype, cytotoxicity, and cytokine secretion were measured, and samples were sequenced using the 3'-Tag-RNA-Seq protocol. Co-cultured human PBMCs and NK-isolated cells were also sequenced for comparative analysis. In addition, two first-in-dog clinical trials were performed in dogs with melanoma and osteosarcoma using autologous and allogeneic NK cells, respectively, to establish safety and proof-of-concept of this manufacturing approach.ResultsCalculated cell counts, viability, killing, and cytokine secretion were equivalent or higher in expanded NK cells from canine PBMCs versus CD5-depleted cells, and immune phenotyping confirmed a CD3-NKp46+ product from PBMC-expanded cells at day 14. Transcriptomic analysis of expanded cell populations confirmed upregulation of NK activation genes and related pathways, and human NK cells using well-characterized NK markers closely mirrored canine gene expression patterns. Autologous and allogeneic PBMC-derived NK cells were successfully expanded for use in first-in-dog clinical trials, resulting in no serious adverse events and preliminary efficacy data. RNA sequencing of PBMCs from dogs receiving allogeneic NK transfer showed patient-unique gene signatures with NK gene expression trends in response to treatment.ConclusionsOverall, the use of unmanipulated PBMCs appears safe and potentially effective for canine NK immunotherapy with equivalent to superior results to CD5 depletion in NK expansion, activation, and cytotoxicity. Our preclinical and clinical data support further evaluation of this technique as a novel platform for optimizing NK immunotherapy in dogs.

The SWI/SNF complex is a chromatin remodeling complex comprised by several proteins such as SMARCA4 or SMARCB1. Mutations in its components can lead to the development of aggressive rhabdoid tumors such as epithelioid sarcoma, malignant rhabdoid tumor or small cell carcinoma of the ovary hypercalcemic type, among others. These malignancies tend to affect young patients and their prognosis is poor given the lack of effective treatments. Characteristically, these tumors are highly infiltrated by TILs, suggesting that some lymphocytes are recognizing tumor antigens. The use of those TILs as a therapeutic strategy is a promising approach worth exploring. Here, we report the clinical protocol of the TILTS study, a Phase II clinical trial assessing personalized adoptive cell therapy with TILs in patients affected by these tumor types. Clinical Trial Registration: 2023-504632-17-00 (www.clinicaltrialsregister.eu) (ClinicalTrials.gov). Article highlights Background & rationale There is a group of tumors associated with alterations in the SWI/SNF complex, such as epithelioid sarcoma, malignant rhabdoid tumor or small cell carcinoma of the ovary hypercalcemic type, among others. These tumors usually have rhabdoid features and tend to affect young patients. Patients affected by these malignancies have poor prognosis since there are no effective standard treatments. Tumors associated with alterations in the SWI/SNF complex are generally infiltrated by a high number of TILs that have been able to recognize a tumor antigen. The use of those TILs as a therapeutic strategy is a promising immunotherapy approach. The TILTS study The TILTS study is a clinical trial designed to assess the activity of adoptive cell therapy with TILs in these tumor types. The TILTS study is a prospective, single-arm, multicenter Phase II study that uses personalized TILs treatment in advanced tumors associated with alterations in the SWI/SNF complex. The primary end point is ORR per RECIST v1.1 as assessed by investigator. Secondary end points include toxicity evaluation, PFS and OS, among others. In addition, an associated translational study will be conducted in order to better understand the biology of these malignancies and their relationship with the immune system. [ABSTRACT FROM AUTHOR]

Tumor-infiltrating lymphocyte (TIL) therapy represents a groundbreaking advancement in the solid cancer treatment, offering new hope to patients and their families with high response rates and long overall survival. TIL therapy involves extracting immune cells from a patient's tumor tissue, expanding them ex vivo, and infusing them back into the patient to target and eliminate cancer cells. This revolutionary approach harnesses the power of the immune system to combat cancers, ushering in a new era of T cell-based therapies along with CAR-T and TCR-therapies. In this comprehensive review, we aim to elucidate the remarkable potential of TIL therapy by delving into recent advancements in basic and clinical researches. We highlight on the evolving landscape of TIL therapy as a prominent immunotherapeutic strategy, its multifaceted applications, and the promising outcomes. Additionally, we explore the future horizons of TIL therapy, next-generation TILs, and combination therapy, to overcome the limitations and improve clinical efficacy of TIL therapy. [ABSTRACT FROM AUTHOR]

Introduction: Adoptive cell therapy using TCR-engineered T-cells is one of the most effective strategies against tumor cells. The TCR T-cell approach has been well tested against a variety of blood neoplasms but is yet to be deeply tested against solid tumors. Among solid tumors, cancer-testis antigens are the most prominent targets for tumor-specific therapy, as they are usually found on cells that lie behind blood-tissue barriers. Methods: We have employed a novel efficient protocol for MAGE-A3-specific Tcell clonal expansion, performed single-cell multi-omic analysis of the expanded T-cells via BD Rhapsody, engineered a selected T-cell receptor into a lentiviral construct, and tested it in an in vitro LDH-cytotoxicity test. Results and discussion: We have observed a 191-fold increase in the MAGE-A3-specific T-cell abundance, obtained a dominant T-cell receptor via single-cell multi-omic BD Rhapsody data analysis in the TCRscape bioinformatics tool, and observed potent cytotoxicity of the dominant-clonotype transduced TCR T-cells against a MAGE-A3-positive tumor. We have demonstrated the efficiency of our Tcell enrichment protocol in obtaining potent anti-tumor T-cells and their T-cell receptors, especially when paired with the modern single-cell analysis methods. [ABSTRACT FROM AUTHOR]

Ovarian cancer, often referred to as the "silent killer," is notoriously difficult to detect in its early stages, leading to a poor prognosis for many patients. Diagnosis is often delayed until the cancer has advanced, primarily due to its ambiguous and frequently occurring clinical symptoms. Ovarian cancer leads to more deaths than any other cancer of the female reproductive system. The main reasons for the high mortality rates include delayed diagnosis and resistance to treatment. As a result, there is an urgent need for improved diagnostic and treatment options for ovarian cancer. The standard treatments typically involve debulking surgery along with platinum-based chemotherapies. Among patients with advanced-stage cancer who initially respond to current therapies, 50-75% experience a recurrence. Recently, immunotherapy-based approaches to enhance the body's immune response to combat tumor growth have shown promise. Immune checkpoint inhibitors have shown promising results in treating other types of tumors. However, in ovarian cancer, only a few of these inhibitors have been effective because the tumor's environment suppresses the immune system and creates barriers for treatment. This hampers the effectiveness of existing immunotherapies. Nonetheless, advanced immunotherapy techniques and delivery systems based on nanotechnology hold promise for overcoming these challenges. [ABSTRACT FROM AUTHOR]

Background: Pneumocystis jirovecii pneumonia (PcP) is an opportunistic infection associated with immunocompromised patients. The development of novel immunotherapies has promoted the incidence of PcP. This study describes the clinical course and outcome of PcP in chimeric antigen receptor (CAR) T cell recipients with hematological malignancies. Methods: This is a retrospective case series of CAR-T recipients diagnosed with PcP in our center. The cases were all confirmed by metagenomic next-generation sequencing of clinical samples. The demographic, clinical, and outcome data were retrieved from the patients' medical charts and electronic medical record system. Results: In total, 8 cases of PcP were identified. The underlying malignancies included T-acute lymphoblastic leukemia (ALL) (n = 1), diffuse large B cell lymphoma (DLBCL) (n = 4), and B-ALL (n = 3). One patient received short-term sulfamethoxazole-trimethoprim (SMZ-TMP) while the others had no prophylaxis. Four patients had neutropenia/lymphopenia at the diagnosis of PcP, and two patients had immunosuppressants within one month before PcP manifestation. The median time from CAR-T infusion to PcP diagnosis was 98.5 days (range 52–251). Seven patients recovered from PcP after proper management while one died of septic shock. Conclusion: PcP can occur after different CAR-T product, and the long-term depletion of immune cells seems to be related to PcP. SMZ-TMP is effective in this setting. More real-world experience of CAR-T therapy is required to assess the incidence and outcome of PcP in this population. [ABSTRACT FROM AUTHOR]

Post-transplant or hematological cancer patients have a higher risk of mortality after infection with ancestral and early variants of severe acute respiratory syndrome (SARS)-CoV-2. Adoptive cell therapy (ACT) with virus-specific T cells (VSTs) could augment endogenous T cell immunity to avoid disease deterioration before viral clearance. We established a third-party SARS-CoV-2-specific T cell (COVID-T) bank in 2020 (NCT04351659) using convalescent and/or vaccinated donors. In a phase I/II study (NCT04457726), 13 adult and pediatric patients, acutely positive for SARS-CoV-2 and predicted to have a high chance of mortality, were recruited from September 2021 to February 2022. Twelve patients received a single dose of COVID-T cells, matched on at least 1 HLA. A dose of either 75,000 or 150,000 IFN-γ+CD3+ cells/m2 SARS-COV-2-specific T cells did not cause cytokine release syndrome, acute respiratory distress syndrome, or graft-versus-host disease. In the 8 patients who had detectable donor SARS-COV-2-specific T cells after ACT, none progressed to severe disease or died with COVID-19. In contrast, among the other four patients without evidence of donor micro-chimerism, two died of COVID-19. Long-acting third-party VSTs from convalescent or vaccinated donors could be expediently produced and might be clinically useful in future pandemics, particularly before global vaccination is implemented. [ABSTRACT FROM AUTHOR]

Adoptive cell therapy (ACT) is an immunotherapy strategy for cancer that has seen widespread clinical success. During ACT, patient-derived lymphocytes are stimulated with the antigen of interest ex vivo, proliferated, then returned to the patient to initiate an antigen-specific antitumor response. While effective, this process is resource-intensive and logistically impossible for many patients. Particulate artificial antigen presenting cells (aAPCs) offer a potential "off-the-shelf" alternative to ex vivo ACT. While particulate aAPCs perform well in vitro, they have had limited success in vivo due to poor bioavailability after injection. Barriers to bioavailability include rapid clearance, unfavorable biodistribution, and inadequate interactions with CD8+ T cells at sites of interest. Biomaterial properties such as elasticity have been shown to vastly impact the bioavailability and particle-cell interactions, but this has yet to be investigated in the context of aAPCs for in vivo T-cell stimulation. Previous literature likewise indicates that biomaterial properties, especially elasticity, can modulate T-cell activation in vitro. With the goal of creating a more biomimetic, next-generation particulate aAPC, we developed a poly(ethylene) glycol hydrogel particle platform with tunable elasticity to investigate the impact of elasticity on antigen-specific T cell activation for in vivo adoptive transfer. Using this knowledge, we were able to gain more precise control over in vivo T cell activation and investigate possible mechanisms including the effects of aAPC elasticity on T cell binding, macrophage uptake, and the protein corona. [ABSTRACT FROM AUTHOR]

Background: Glioblastoma (GBM) is a poor prognosis grade 4 glioma. After surgical resection, the standard therapy consists of concurrent radiotherapy (RT) and temozolomide (TMZ) followed by TMZ alone. Our previous data on melanoma patients showed that Dendritic Cell vaccination (DCvax) could increase the amount of intratumoral-activated cytotoxic T lymphocytes. Methods: This is a single-arm, monocentric, phase II trial in two steps according to Simon's design. The trial aims to evaluate progression-free survival (PFS) at three months and the safety of a DCvax integrated with standard therapy in resected GBM patients. DCvax administration begins after completion of RTCTwith weekly administrations for 4 weeks, then is alternated monthly with TMZ cycles. The primary endpoints are PFS at three months and safety. One of the secondary objectives is to evaluate the immune response both in vitro and in vivo (DTH skin test). Results: By December 2022, the first pre-planned step of the study was concluded with the enrollment, treatment and follow up of 9 evaluable patients. Two patients had progressed within three months after leukapheresis, but none had experienced DCvax-related G3-4 toxicities Five patients experienced a positive DTH test towards KLH and one of these also towards Frontiers autologous tumor homogenate. The median PFS from leukapheresis was 11.3 months and 12.2 months from surgery. Conclusions: This combination therapy is well-tolerated, and the two endpoints required for the first step have been achieved. Therefore, the study will proceed to enroll the remaining 19 patients. [ABSTRACT FROM AUTHOR]

Gamma/delta T (γδ T)cells possess a unique mechanism for killing tumors, making them highly promising and distinguished among various cell therapies for tumor treatment. This review focuses on the major histocompatibility complex (MHC)-independent recognition of antigens and the interaction between γδ T cells and solid tumor cells. A comprehensive review is provided regarding the classification of human gamma-delta T cell subtypes, the characteristics and mechanisms underlying their functions, as well as their r545egulatory effects on tumor cells. The involvement of γδ T cells in tumorigenesis and migration was also investigated, encompassing potential therapeutic targets such as apoptosis-related molecules, the TNF receptor superfamily member 6(FAS)/FAS Ligand (FASL) pathways, butyrophilin 3A-butyrophilin 2A1 (BTN3A-BTN2A1) complexes, and interactions with CD4, CD8, and natural killer (NK) cells. Additionally, immune checkpoint inhibitors such as programmed cell death protein 1/Programmed cell death 1 ligand 1 (PD-1/PD-L1) have the potential to augment the cytotoxicity of γδ T cells. Moreover, a review on gamma-delta T cell therapy products and their corresponding clinical trials reveals that chimeric antigen receptor (CAR) gamma-delta T therapy holds promise as an approach with encouraging preclinical outcomes. However, practical issues pertaining to manufacturing and clinical aspects need resolution, and further research is required to investigate the long-term clinical side effects of CAR T cells. In conclusion, more comprehensive studies are necessary to establish standardized treatment protocols aimed at enhancing the quality of life and survival rates among tumor patients utilizing γδ T cell immunotherapy. [ABSTRACT FROM AUTHOR]

Chimeric antigen receptor (CAR)‐T cell therapy has demonstrated poor efficacy for solid tumors. The low number and poor functional persistence of CAR‐T cells in tumors are the main limiting factors. Here a Chemokine‐based Injectable platform for enhancing adoptive T cells' Efficacy (CITE) is presented. CITE consists of peritumorally‐injected immunogel co‐loading chemotactic CXCL9 particles with PD‐1 antibody (aPD1) and intravenously‐infused tumor‐penetrating peptide iRGD. Immunogel formed drug depots and allowed sustained release of cargo peritumorally while iRGD facilitated tumor infiltration of gel‐released drugs, thus remarkably increasing the amount of CXCL9 and aPD1 in the tumor. CITE induced an effective chemotactic gradient to promote the tumor‐specific migration of CAR‐T cells and boosted the function of infiltrated T cells by blocking immunosuppression via a two‐in‐one approach. Consequently, CITE yielded a 218‐fold increase in the intratumoral number of transferred T cells and substantially improved the efficacies of transferred T cell receptor (TCR)‐T cells and CAR‐T cells in multiple syngeneic tumor models, including immunologically "cold" tumors, in immunocompetent mice. More importantly, CITE enhanced systemic antitumor immunity and elicited immune memory, enabling CITE to treat multimodal, metastatic, and recurrent tumors. CITE is broadly applicable to adoptive cell therapies involving CAR‐T or TCR‐T cells. [ABSTRACT FROM AUTHOR]

Colorectal cancer is the third most common cancer and the second most lethal cancer in the world. The main cause of the disease is due to dietary and behavioral factors. The treatment of this complex disease is mainly based on traditional treatments, including surgery, radiotherapy, and chemotherapy. Due to its high prevalence and high morbidity, more effective treatments with fewer side effects are urgently needed. In recent years, immunotherapy has become a potential therapeutic alternative and one of the fastest-developing treatments. Immunotherapy inhibits tumor growth by activating or enhancing the immune system to recognize and attack cancer cells. This review presents the latest immunotherapies for immune checkpoint inhibitors, cell therapy, tumorinfiltrating lymphocytes, and oncolytic viruses. Some of these have shown promising results in clinical trials and are used in clinical treatment. [ABSTRACT FROM AUTHOR]

Adoptive cellular therapy (ACT) using memory-like (ML) natural killer (NK) cells, generated through overnight ex vivo activation with IL-12, IL-15, and IL-18, has shown promise for treating hematologic malignancies. We recently reported that a multifunctional fusion molecule, HCW9201, comprising IL-12, IL-15, and IL-18 domains could replace individual cytokines for priming human ML NK cell programming ("Prime" step). However, this approach does not include ex vivo expansion, thereby limiting the ability to test different doses and schedules. Here, we report the design and generation of a multifunctional fusion molecule, HCW9206, consisting of human IL-7, IL-15, and IL-21 cytokines. We observed > 300-fold expansion for HCW9201-primed human NK cells cultured for 14 days with HCW9206 and HCW9101, an IgG1 antibody, recognizing the scaffold domain of HCW9206 ("Expand" step). This expansion was dependent on both HCW9206 cytokines and interactions of the IgG1 mAb with CD16 receptors on NK cells. The resulting "Prime and Expand" ML NK cells exhibited elevated metabolic capacity, stable epigenetic IFNG promoter demethylation, enhanced antitumor activity in vitro and in vivo, and superior persistence in NSG mice. Thus, the "Prime and Expand" strategy represents a simple feeder cell-free approach to streamline manufacturing of clinical-grade ML NK cells to support multidose and off-the-shelf ACT. [ABSTRACT FROM AUTHOR]

Vγ9Vδ2 T cells are under investigation as alternative effector cells for adoptive cell therapy (ACT) in cancer. Despite promising in vitro results, anti-tumor efficacies in early clinical studies have been lower than expected, which could be ascribed to the complex interplay of tumor and immune cell metabolism competing for the same nutrients in the tumor microenvironment. To contribute to the scarce knowledge regarding gamma delta T-cell metabolism, we investigated the metabolic phenotype of 25-day-expanded Vγ9Vδ2 T cells and how it is intertwined with functionality. We found that Vγ9Vδ2 T cells displayed a quiescent metabolism, utilizing both glycolysis and oxidative phosphorylation (OXPHOS) for energy production, as measured in Seahorse assays. Upon T-cell receptor activation, both pathways were upregulated, and inhibition with metabolic inhibitors showed that Vγ9Vδ2 T cells were dependent on glycolysis and the pentose phosphate pathway for proliferation. The dependency on glucose for proliferation was confirmed in glucose-free conditions. Cytotoxicity against malignant melanoma was reduced by glycolysis inhibition but not OXPHOS inhibition. These findings lay the groundwork for further studies on manipulation of Vγ9Vδ2 T-cell metabolism for improved ACT outcome. [Display omitted] [ABSTRACT FROM AUTHOR]

Autologous cell therapy depends on T lymphocyte expansion efficiency and is hindered by suboptimal interactions between T cell receptors (TCR) and peptide-MHC molecules. Various artificial antigen presenting cell systems that enhance these interactions are often labor-intensive, fabrication costly, highly variable, and potentially unscalable toward clinical setting. Here, 3D centrifugation-enabled priming of T cell immune-synapse junctions is performed to generate tight T cell–Dynabead aggregates at a rate 200-fold faster than that of conventional 24-h bulk shaking. Furthermore, by forming T cell–Dynabead aggregates in the starting culture, two- to sixfold greater T cell expansion is achieved over conventional T cell expansion for cancer patient-derived primary T cells while limiting over-activation. Creating 3D T cell–Dynabead aggregates as the “booster” material enables highly efficient polyclonal T cell expansion without the need for complex surface modification of artificial antigen-presenting cells (APCs). This method can be modularly adapted to existing T cell expansion processes for various applications, including adoptive cell therapies (ACTs).

Abstract Background Pneumocystis jirovecii pneumonia (PcP) is an opportunistic infection associated with immunocompromised patients. The development of novel immunotherapies has promoted the incidence of PcP. This study describes the clinical course and outcome of PcP in chimeric antigen receptor (CAR) T cell recipients with hematological malignancies. Methods This is a retrospective case series of CAR-T recipients diagnosed with PcP in our center. The cases were all confirmed by metagenomic next-generation sequencing of clinical samples. The demographic, clinical, and outcome data were retrieved from the patients’ medical charts and electronic medical record system. Results In total, 8 cases of PcP were identified. The underlying malignancies included T-acute lymphoblastic leukemia (ALL) (n = 1), diffuse large B cell lymphoma (DLBCL) (n = 4), and B-ALL (n = 3). One patient received short-term sulfamethoxazole-trimethoprim (SMZ-TMP) while the others had no prophylaxis. Four patients had neutropenia/lymphopenia at the diagnosis of PcP, and two patients had immunosuppressants within one month before PcP manifestation. The median time from CAR-T infusion to PcP diagnosis was 98.5 days (range 52–251). Seven patients recovered from PcP after proper management while one died of septic shock. Conclusion PcP can occur after different CAR-T product, and the long-term depletion of immune cells seems to be related to PcP. SMZ-TMP is effective in this setting. More real-world experience of CAR-T therapy is required to assess the incidence and outcome of PcP in this population.

Abstract Ovarian cancer, often referred to as the “silent killer,” is notoriously difficult to detect in its early stages, leading to a poor prognosis for many patients. Diagnosis is often delayed until the cancer has advanced, primarily due to its ambiguous and frequently occurring clinical symptoms. Ovarian cancer leads to more deaths than any other cancer of the female reproductive system. The main reasons for the high mortality rates include delayed diagnosis and resistance to treatment. As a result, there is an urgent need for improved diagnostic and treatment options for ovarian cancer. The standard treatments typically involve debulking surgery along with platinum-based chemotherapies. Among patients with advanced-stage cancer who initially respond to current therapies, 50-75% experience a recurrence. Recently, immunotherapy-based approaches to enhance the body’s immune response to combat tumor growth have shown promise. Immune checkpoint inhibitors have shown promising results in treating other types of tumors. However, in ovarian cancer, only a few of these inhibitors have been effective because the tumor’s environment suppresses the immune system and creates barriers for treatment. This hampers the effectiveness of existing immunotherapies. Nonetheless, advanced immunotherapy techniques and delivery systems based on nanotechnology hold promise for overcoming these challenges.

T cells are closely associated with tumor development and the homeostasis of the tumor microenvironment (TME). The co-receptors of immune checkpoints on the surface of T cells collectively regulate immune responses and can inhibit or kill tumor cells by secreting various substances, correcting and restoring impaired anti-tumor immune responses. In recent years, there has been some progress in targeted T cell therapy, but some new immune test targets are still being studied. This article focuses on the role of T cells in the regulation of colorectal cancer (CRC) and TME, the mechanism of immune resistance to CRC and its targeted therapy, and discusses the relevant effects of T cells on the occurrence and development of CRC and the application prospect of targeted T cell therapy for CRC.

Background: Adoptive cell therapies (ACT) exhibit excellent efficacy in hematological malignancy. However, its application in solid tumors still has many challenges partly due to the tumor immune microenvironment. Cryo-thermal therapy (CTT) can induce an acute inflammatory response and remold the immune environment, providing an appropriate environment for the activation of adaptive immunity. However, it remains unclear whether CTT can enhance the efficacy of ACT. Methods: A bilateral B16F10 tumor-bearing mouse model was used to assess whether CTT could enhance the efficacy of ACT. The right large tumor was subjected to CTT, and the left small tumor was collected for flow cytometry, RNA-seq, immunohistochemistry and TCR Vβ sequencing. Finally, bilateral B16F10 tumor-bearing mice and 4T1 tumor-bearing mice were used to assess the efficacy after CTT combined with ACT. Results: CTT dramatically reshaped the immune microenvironment in distal tumors to an acute inflammatory state by promoting innate cell infiltration, increasing cytokine production by macrophages and DCs. The remodeling of the tumor immune microenvironment further enhanced the antitumor efficiency of ACT by increasing the proliferation of T cells, promoting activation of the effector functions of T cells and boosting the expansion of TCR clones. Conclusions: Our results suggest that CTT can significantly reshape the tumor immunosuppressive microenvironment and convert “cold tumors” into “hot tumors,” thereby enhancing ACT-induced immune responses and maximizing the therapeutic effect of ACT. [ABSTRACT FROM AUTHOR]

Abstract Background Lytic Epstein–Barr virus (EBV) infection plays a major role in the pathogenesis of nasopharyngeal carcinoma (NPC). For patients with recurrent or metastatic NPC and resistant to conventional therapies, adoptive cell therapy using EBV-specific cytotoxic T cells (EBV-CTLs) is a promising option. However, the long production period (around 3 to 4 weeks) and low EBV-CTL purity (approximately 40% of total CD8 T cells) in the cell product limits the application of EBV-CTLs in clinics. Thus, this study aimed to establish a protocol for the rapid production of EBV-CTLs. Methods By culturing peripheral blood mononuclear cells (PBMCs) from EBV-seropositive donors with EBV-specific peptides and interleukin (IL)-2, IL-15, and interferon α (IFN-α) for 9 days, we identified that IL-15 can enhance IL-2-mediated CTL activation and significantly increase the yield of CTLs. Results When IFN-α was used in IL-2/IL-15-mediated CTL production from days 0 to 6, the productivity of EBV-CTLs and EBV-specific cytotoxicity significantly were reinforced relative to EBV-CTLs from IL-2/IL-15 treatment. Additionally, IFN-α-induced production improvement of virus-specific CTLs was not only the case for EBV-CTLs but also for cytomegalovirus-specific CTLs. Conclusion We established a novel protocol to rapidly expand highly pure EBV-CTLs from PBMCs, which can produce EBV-CTLs in 9 days and does not require feeder cells during cultivation.

The oncolytic virus (OV) therapy utilizes natural or genetically modified viruses to specifically target and infect tumor cells, leading to the destruction of cancer cells by the replication of the virus itself. This process also alters the immune microenvironment of the tumor transforming “cold” into “hot”, and mobilizes the body's immune system. The effectiveness of oncolytic viruses in anti-tumor therapy depends on factors such as the type of virus, host immunity and route of administration. Immunotherapy aims to activate the immune system and exert anti-tumor effect by relying on autoimmune function. With the development of genetic engineering technology, oncolytic viruses can enhance the anti-tumor effect through gene editing reconstruction, and can be used to treat tumors alone or in combination with other therapies. In view of the limited efficacy of single application of oncolytic virus therapy in clinic, the combination of oncolytic virus therapy and immunotherapy provides a new strategy for tumor treatment. This review started from the types of oncolytic viruses approved in the clinic, characteristics and its anti-tumor mechanisms. At the same time, it combed through the treatment of oncolytic viruses in the clinical trial stage, summarized the combined treatment strategies of oncolytic viruses, especially the combination of tumor immunotherapy represented by immune checkpoint inhibitor (ICI) and adoptive cell therapy (ACT), and put forward some thoughts and prospects of oncolytic viruses in the anti-tumor treatment in combination with the experience accumulated by the project team in the research of oncolytic viruses.

Abstract Pancreatic cancer is a major cause of cancer-related death, but despondently, the outlook and prognosis for this resistant type of tumor have remained grim for a long time. Currently, it is extremely challenging to prevent or detect it early enough for effective treatment because patients rarely exhibit symptoms and there are no reliable indicators for detection. Most patients have advanced or spreading cancer that is difficult to treat, and treatments like chemotherapy and radiotherapy can only slightly prolong their life by a few months. Immunotherapy has revolutionized the treatment of pancreatic cancer, yet its effectiveness is limited by the tumor's immunosuppressive and hard-to-reach microenvironment. First, this article explains the immunosuppressive microenvironment of pancreatic cancer and highlights a wide range of immunotherapy options, including therapies involving oncolytic viruses, modified T cells (T-cell receptor [TCR]-engineered and chimeric antigen receptor [CAR] T-cell therapy), CAR natural killer cell therapy, cytokine-induced killer cells, immune checkpoint inhibitors, immunomodulators, cancer vaccines, and strategies targeting myeloid cells in the context of contemporary knowledge and future trends. Lastly, it discusses the main challenges ahead of pancreatic cancer immunotherapy.

Background: The clinical success of autologous adoptive cell therapy (ACT) is substantial but wide application is challenged by the quality and quantity of the patient’s immune cells and the need for personalized manufacturing processes. Induced pluripotent stem cells (iPSCs) can be differentiated into immune effectors and thus provide an alternative, allogeneic cell source for ACT. Here, we compare iPSC-derived immune effectors to their PBMC-derived counterparts and review iPSC-derived ACT products currently under preclinical and clinical development. Summary: iPSC-derived T cells, NK cells, macrophages, and neutrophils largely mimic their PBMC-derived counterparts in terms of cell-surface marker expression and cytotoxic effector functions. iPSC-derived immune effectors can be engineered with chimeric antigen receptors and other activating receptors to redirect their cytotoxic potential specifically to tumor-associated antigens (TAAs). However, several differences between iPSC- and PBMC-derived immune effectors remain and have inspired additional engineering strategies to enhance the antitumor capacity of iPSC-derived immune effectors. Key Messages: iPSCs can be engineered to facilitate the generation of immune effectors with homogenous specificity for TAAs and enhanced effector functions. TAA-specific and functionally enhanced iPSC-derived T and NK cells are currently undergoing clinical evaluation in phase 1 trials. Engineered iPSC-derived macrophages and neutrophils are in preclinical development. [ABSTRACT FROM AUTHOR]

Somatic cell therapy based on the infusion of donor-derived cytotoxic T lymphocytes (CTL) able to recognize patients' leukemia blasts (LB) is a promising approach to control leukemia relapse after allogeneic HSCT. The success of this approach strongly depends on the ex vivo generation of high-quality donor-derived anti-leukemia CTL in compliance with Good Manufacturing Practices (GMP). We previously described a procedure for generating large numbers of donor-derived anti-leukemia CTL through stimulation of CD8-enriched lymphocytes with dendritic cells (DCs) pulsed with apoptotic LB in the presence of interleukin (IL)-12, IL-7 and IL-15. Here we report that the use of IFN-DC and the addition of IFNα2b during the priming phase significantly improve the generation of an efficient anti-leukemia T cells response in vitro. Using this approach, 20 high-risk pediatric patients given haploidentical HSCT for high-risk acute leukemia were enrolled and 51 batches of advanced therapy medical products (ATMP), anti-leukemia CTL, were produced. Quality controls demonstrated that all batches were sterile, free of mycoplasma and conformed to acceptable endotoxin levels. Genotype analysis confirmed the molecular identity of the ATMP based on the starting biological material used for their production. The majority of ATMP were CD3+/CD8+ cells, with a memory/terminal activated phenotype, including T-central memory populations. ATMP were viable after thawing, and most ATMP batches displayed efficient capacity to lyse patients' LB and to secrete interferon-γ and tumor necrosis factor-α. These results demonstrated that our protocol is highly reproducible and allows the generation of large numbers of immunologically safe and functional anti-leukemia CTL with a high level of standardization. [ABSTRACT FROM AUTHOR]

Opinion Statement: Biliary tract cancer (BTC) is a heterogeneous group of aggressive malignancies that arise from the epithelium of the biliary tract. Most patients present with locally advanced or metastatic disease at the time of diagnosis. For patients with unresectable BTC, the survival advantage provided by systemic chemotherapy was limited. Over the last decade, immunotherapy has significantly improved the therapeutic landscape of solid tumors. There is an increasing number of studies evaluating the application of immunotherapy in BTC, including immune checkpoint inhibitors (ICIs), cancer vaccines and adoptive cell therapy. The limited response to ICIs monotherapy in unselected patients prompted investigators to explore different combination therapy strategies. Early clinical trials of therapeutic cancer vaccination and adoptive cell therapy have shown encouraging clinical results. However, there still has been a long way to go via validation of therapeutic efficacy and exploration of strategies to increase the efficacy. Identifying biomarkers that predict the response to immunotherapy will allow a more accurate selection of candidates. This review will provide an up-to-date overview of the current clinical data on the role of immunotherapy, summarize the promising biomarkers predictive of the response to ICIs and discuss the perspective for future research direction of immunotherapy in advanced BTC. [ABSTRACT FROM AUTHOR]

Purpose of Review: Squamous cell carcinoma of the anus (SCCA) is an HPV-associated malignancy that has limited treatment options. Immunotherapy has expanded these options and here we review current and emerging immunotherapeutic approaches. Recent Findings: Multiple studies of single-agent anti-PD1/PD-L1 immunotherapy have demonstrated a modest response rate of approximately 10% to 15%. While a minority of patients (~5%) with SCCA experience durable complete responses, most advanced SCCAs are resistant to anti-PD1/PD-L1 monotherapy. Given the need for more broadly effective immunotherapies, novel strategies, such as adaptive cell therapies and therapeutic vaccination, are being explored. To reduce the recurrence risk of localized high-risk SCCA, strategies combining immunotherapy with chemoradiation are also being investigated. Summary: While a small subset of patients with SCCA have prolonged responses to PD1-directed immunotherapy, the majority do not derive clinical benefit, and new immunotherapeutic strategies are needed. Better understanding of the immune microenvironment and predictive biomarkers could accelerate therapeutic advances. [ABSTRACT FROM AUTHOR]

Lipid nanoparticles encapsulating mRNA (LNP‐mRNA) revolutionized medicine over the past several years. While clinically approved indications currently focus on infectious disease vaccination, LNP‐mRNA based treatments also hold promise for cancer immunotherapy. However, the route of dosing may impact treatment efficacy, safety, and dose. To minimize adverse effects, it is hypothesized that LNP‐mRNA can be used to activate and engineer dendritic cells (DC) ex vivo before re‐administration of these cells. Here, it is shown that LNP‐mRNA engineered DCs can indeed vaccinate recipient mice. Vaccinated mice showed strong anti‐tumor T cell responses, rejected tumor challenge, and displayed no evidence of toxicity. Further, it is found that DC specific ablation of the immune activating kinase NFkB inducing kinase (NIK) abrogated vaccination efficacy, demonstrating that adoptively transferred DCs can be functionally modified in addition to their antigen presentation capacity. Collectively, these studies show that ex vivo LNP‐mRNA engineering of DCs is a feasible and robust therapeutic strategy for cancer. [ABSTRACT FROM AUTHOR]

Cell and gene therapies are an innovative solution to various severe diseases and unfulfilled needs. Adoptive cell therapy (ACT), a form of cellular immunotherapies, has been favored in recent years due to the approval of chimeric antigen receptor CAR-T products. Market research indicates that the industry’s value is predicted to reach USD 24.4 billion by 2030, with a compound annual growth rate (CAGR) of 21.5%. More importantly, ACT is recognized as the hope and future of effective, personalized cancer treatment for healthcare practitioners and patients worldwide. The significant global momentum of this therapeutic approach underscores the urgent need to establish it as a practical and standardized method. It is essential to understand how cell culture conditions affect the expansion and differentiation of T-cells. However, there are ongoing challenges in ensuring the robustness and reproducibility of the manufacturing process. The current study evaluated various adoptive T-cell culture platforms to achieve large-scale production of several billion cells and high-quality cellular output with minimal cell death. It examined factors such as bioreactor parameters, media, supplements and stimulation. This research addresses the fundamental challenges of scalability and reproducibility in manufacturing, which are essential for making adoptive T-cell therapy an accessible and powerful new class of cancer therapeutics. [ABSTRACT FROM AUTHOR]

Simple Summary: Chimeric antigen receptor (CAR)-T cells have revolutionized the treatment of blood cancers. However, their effectiveness meets challenges in solid tumors. Modifications to CAR-T cells altered stimulatory domains or added further functions with transgenic proteins (e.g., cytokines, chemokine receptors, degrading enzymes) to match specific barriers of the tumor microenvironment. But despite these enhancements, the inherent limitations of CAR-T cells such as dependency on human leukocyte antigen (HLA), toxicities and high costs for preparing autologous cell products remain. In response, alternative types of immune cells with different effects and advantages have become the focus of adoptive cell therapy research. For instance, natural killer cells have the benefit of HLA-independent killing and macrophages possess additional functions such as phagocytosis and antigen presentation. As these cells come with distinct properties, clinicians and researchers need a thorough understanding of their effects and peculiarities. This review summarizes the different modes of action of these CAR-immune cells. Chimeric antigen receptor-T cells have spearheaded the field of adoptive cell therapy and have shown remarkable results in treating hematological neoplasia. Because of the different biology of solid tumors compared to hematological tumors, response rates of CAR-T cells could not be transferred to solid entities yet. CAR engineering has added co-stimulatory domains, transgenic cytokines and switch receptors to improve performance and persistence in a hostile tumor microenvironment, but because of the inherent cell type limitations of CAR-T cells, including HLA incompatibility, toxicities (cytokine release syndrome, neurotoxicity) and high costs due to the logistically challenging preparation process for autologous cells, the use of alternative immune cells is gaining traction. NK cells and γδ T cells that do not need HLA compatibility or macrophages and dendritic cells with additional properties such as phagocytosis or antigen presentation are increasingly seen as cellular vehicles with potential for application. As these cells possess distinct properties, clinicians and researchers need a thorough understanding of their peculiarities and commonalities. This review will compare these different cell types and their specific modes of action seen upon CAR activation. [ABSTRACT FROM AUTHOR]

The oncolytic virus (OV) therapy utilizes natural or genetically modified viruses to specifically target and infect tumor cells, leading to the destruction of cancer cells by the replication of the virus itself. This process also alters the immune microenvironment of the tumor transforming “cold” into “hot”, and mobilizes the body's immune system. The effectiveness of oncolytic viruses in anti-tumor therapy depends on factors such as the type of virus, host immunity and route of administration. Immunotherapy aims to activate the immune system and exert anti-tumor effect by relying on autoimmune function. With the development of genetic engineering technology, oncolytic viruses can enhance the anti-tumor effect through gene editing reconstruction, and can be used to treat tumors alone or in combination with other therapies. In view of the limited efficacy of single application of oncolytic virus therapy in clinic, the combination of oncolytic virus therapy and immunotherapy provides a new strategy for tumor treatment. This review started from the types of oncolytic viruses approved in the clinic, characteristics and its anti-tumor mechanisms. At the same time, it combed through the treatment of oncolytic viruses in the clinical trial stage, summarized the combined treatment strategies of oncolytic viruses, especially the combination of tumor immunotherapy represented by immune checkpoint inhibitor (ICI) and adoptive cell therapy (ACT), and put forward some thoughts and prospects of oncolytic viruses in the anti-tumor treatment in combination with the experience accumulated by the project team in the research of oncolytic viruses. [ABSTRACT FROM AUTHOR]

Although ovarian cancer patients typically respond to standard of care therapies, including chemotherapy and DNA repair inhibitors, the majority of tumors recur highlighting the need for alternative therapies. Ovarian cancer is an immunogenic cancer in which the accumulation of tumor infiltrating lymphocytes (TILs), particularly T cells, is associated with better patient outcome. Thus, harnessing the immune system through passive administration of T cells, a process called adoptive cell therapy (ACT), is a promising therapeutic option for the treatment of ovarian cancer. There are multiple routes by which tumor-specific T cell products can be generated. Dendritic cell cancer vaccines can be administered to the patients to induce or bolster T cell responses against tumor antigens or be utilized ex vivo to prime T cells against tumor antigens; these T cells can then be prepared for infusion. ACT protocols can also utilize naturally-occurring tumor-reactive T cells isolated from a patient tumor, known as TILs, as these cells often are heterogeneous in composition and antigen specificity with patient-specific cancer recognition. Alternatively, T cells may be sourced from the peripheral blood, including those that are genetically modified to express a tumor antigen-specific T cell receptor (TCR) or chimeric antigen receptor (CAR) to redirect their specificity and promote their activity against tumor cells expressing the target tumor antigen. Here, we review current ACT strategies for ovarian cancer and provide insights into advancing ACT therapy strategies for the treatment of ovarian cancer. • Ovarian cancer is immunogenic and tumor infiltrating lymphocytes (TILs) are a prognostic biomarker for patient outcomes. • Adoptive cell therapies (ACTs) are promising therapeutic approaches for ovarian cancer. • Optimization of ACT strategies in ovarian cancer is needed for increased clinical efficacy and safety. [ABSTRACT FROM AUTHOR]

Purpose of review: This review provides a comprehensive update on recent advancements in melanoma treatment by highlighting promising therapeutics with an aim to increase awareness of novel interventions currently in development. Recent Findings: Over the last decade there has been considerable expansion of the previously available treatment options for patients with melanoma. In particular, novel immunotherapeutics have been developed to expand on the clinical advancements brought by BRAF targeting and immune checkpoint inhibitors. Summary: Despite the success of checkpoint inhibitors there remains an unmet need for patients that do not respond to treatment. This review delves into the latest advancements in novel checkpoint inhibitors, cytokines, oncolytic viruses, vaccines, bispecific antibodies, and adoptive cell therapy. Preclinical experiments and early-stage clinical trials studies have demonstrated promising results for these therapies, many of which have moved into pivotal, phase 3 studies. [ABSTRACT FROM AUTHOR]

Vitamin C (ascorbic acid) is a potent antioxidant and a cofactor for various enzymes including histone demethylases and methylcytosine dioxygenases. Vitamin C also exerts direct cytotoxicity toward selected tumor cells including colorectal carcinoma. Moreover, vitamin C has been shown to impact immune cell differentiation at various levels including maturation and/or functionality of T cells and their progenitors, dendritic cells, B cells, and NK cells. γδ T cells have recently attracted great interest as effector cells for cell‐based cancer immunotherapy, due to their HLA‐independent recognition of a large variety of tumor cells. While γδ T cells can thus be also applied as an allogeneic off‐the‐shelf product, it is obvious that the effector function of γδ T cells needs to be optimized to ensure the best possible clinical efficacy. Here we review the immunomodulatory mechanisms of vitamin C with a special focus on how vitamin C enhances the effector function of γδ T cells. We also discuss future directions of how vitamin C can be used in the clinical setting to boost the efficacy of adoptive cell therapies. [ABSTRACT FROM AUTHOR]

Through Smad3-dependent signalings, transforming growth factor-β (TGF-β) suppresses the development, maturation, cytokine productions and cytolytic functions of NK cells in cancer. Silencing Smad3 remarkably restores the cytotoxicity of NK-92 against cancer in TGF-β-rich microenvironment, but its effects on the immunoregulatory functions of NK cells remain obscure. In this study, we identified Smad3 functioned as a transcriptional repressor for CSF2 (GM-CSF) in NK cells. Therefore, disrupting Smad3 largely mitigated TGF-β-mediated suppression on GM-CSF production by NK cells. Furthermore, silencing GM-CSF in Smad3 knockout NK cells substantially impaired their anti-lung carcinoma effects. In-depth study demonstrated that NK-derived GM-CSF strengthened T cell immune responses by stimulating dendritic cell differentiation and M1 macrophage polarization. Meanwhile, NK-derived GM-CSF promoted the survival of neutrophils, which in turn facilitated the terminal maturation of NK cells, and subsequently boosted NK-cell mediated cytotoxicity against lung carcinoma. Thus, Smad3-silenced NK-92 (NK-92-S3KD) may serve as a promising immunoadjuvant therapy with clinical translational value given its robust cytotoxicity against malignant cells and immunostimulatory functions to reinforce the therapeutic effects of other immunotherapies. [ABSTRACT FROM AUTHOR]

Although preclinical investigations have shown notable efficacy in solid tumor models utilizing in vitro-differentiated Th17 cells for adoptive cell therapy (ACT), the potential benefits of this strategy in enhancing ACT efficacy in hematological malignancies, such as chronic lymphocytic leukemia (CLL), remain unexplored. CLL is a B-cell malignancy with a clinical challenge of increased resistance to targeted therapies. T-cell therapies, including chimeric antigen receptor (CAR) T cells, have demonstrated limited success in CLL, which is attributed to CLL-mediated T-cell dysfunction and skewing toward immunosuppressive phenotypes. Herein, we illustrate the feasibility of polarizing CD4+ T cells from the Eμ-TCL1 murine model, the most representative model for human CLL, into Th17 phenotype, employing a protocol of T-cell activation through the inducible co-stimulator (ICOS) alongside a polarizing cytokine mixture. We demonstrate augmented memory properties of in vitro-polarized IL-17-producing T cells, and preliminary in vivo persistence in leukemia-bearing mice. Our findings gain translational relevance through successful viral transduction of Eμ-TCL1 CD4+ T cells with a CD19-targeted CAR construct during in vitro Th17 polarization. Th17 CAR T cells exhibited remarkable persistence upon encountering antigen-expressing target cells. This study represents the first demonstration of the potential of in vitro-differentiated Th17 cells to enhance ACT efficacy in CLL. [ABSTRACT FROM AUTHOR]

Pancreatic cancer is a major cause of cancer-related death, but despondently, the outlook and prognosis for this resistant type of tumor have remained grim for a long time. Currently, it is extremely challenging to prevent or detect it early enough for effective treatment because patients rarely exhibit symptoms and there are no reliable indicators for detection. Most patients have advanced or spreading cancer that is difficult to treat, and treatments like chemotherapy and radiotherapy can only slightly prolong their life by a few months. Immunotherapy has revolutionized the treatment of pancreatic cancer, yet its effectiveness is limited by the tumor's immunosuppressive and hard-to-reach microenvironment. First, this article explains the immunosuppressive microenvironment of pancreatic cancer and highlights a wide range of immunotherapy options, including therapies involving oncolytic viruses, modified T cells (T-cell receptor [TCR]-engineered and chimeric antigen receptor [CAR] T-cell therapy), CAR natural killer cell therapy, cytokine-induced killer cells, immune checkpoint inhibitors, immunomodulators, cancer vaccines, and strategies targeting myeloid cells in the context of contemporary knowledge and future trends. Lastly, it discusses the main challenges ahead of pancreatic cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Simple Summary: Colorectal cancer (CRC) has become one of the leading causes of cancer-related morbidity and mortality worldwide. Immune checkpoint inhibitors (ICIs) and adoptive cell therapy (ACT) have been recently added to the clinical armamentarium of stage II/III diseases. Moreover, the improvement of a patient's telomere status may have a synergistic effect along with ICIs/ACT. This can be achieved either via lifestyle modifications with increased physical activity or with new promising treatments such as those acting on telomerase. Therefore, this review aims to comprehensively summarize the current data on immunotherapy in order to facilitate clinicians' familiarity with this relatively new therapeutic approach. Cancer of the colon and rectum (CRC) has been identified among the three most prevalent types of cancer and cancer-related deaths for both sexes. Even though significant progress in surgical and chemotherapeutic techniques has markedly improved disease-free and overall survival rates in contrast to those three decades ago, recent years have seen a stagnation in these improvements. This underscores the need for new therapies aiming to augment patient outcomes. A number of emerging strategies, such as immune checkpoint inhibitors (ICIs) and adoptive cell therapy (ACT), have exhibited promising outcomes not only in preclinical but also in clinical settings. Additionally, a thorough appreciation of the underlying biology has expanded the scope of research into potential therapeutic interventions. For instance, the pivotal role of altered telomere length in early CRC carcinogenesis, leading to chromosomal instability and telomere dysfunction, presents a promising avenue for future treatments. Thus, this review explores the advancements in CRC immunotherapy and telomere-targeted therapies, examining potential synergies and how these novel treatment modalities intersect to potentially enhance each other's efficacy, paving the way for promising future therapeutic advancements. [ABSTRACT FROM AUTHOR]

CAR-T-cell therapy has shown promise in treating hematological malignancies but faces challenges in treating solid tumors due to impaired T-cell function in the tumor microenvironment. To provide optimal T-cell activation, we developed a B7 homolog 3 protein (B7H3)-targeting CAR construct consisting of three activation signals: CD3ζ (signal 1), 41BB (signal 2), and the interleukin 7 receptor alpha (IL7Rα) cytoplasmic domain (signal 3). We generated B7H3 CAR-T cells with different lengths of the IL7Rα cytoplasmic domain, including the full length (IL7R-L), intermediate length (IL7R-M), and short length (IL7R-S) domains, and evaluated their functionality in vitro and in vivo. All the B7H3-IL7Rα CAR-T cells exhibited a less differentiated phenotype and effectively eliminated B7H3-positive glioblastoma in vitro. Superiority was found in B7H3 CAR-T cells contained the short length of the IL7Rα cytoplasmic domain. Integration of the IL7R-S cytoplasmic domain maintained pSTAT5 activation and increased T-cell proliferation while reducing activation-induced cell death. Moreover, RNA-sequencing analysis of B7H3-IL7R-S CAR-T cells after coculture with a glioblastoma cell line revealed downregulation of proapoptotic genes and upregulation of genes associated with T-cell proliferation compared with those in 2nd generation B7H3 CAR-T cells. In animal models, compared with conventional CAR-T cells, B7H3-IL7R-S CAR-T cells suppressed tumor growth and prolonged overall survival. Our study demonstrated the therapeutic potential of IL7Rα-incorporating CAR-T cells for glioblastoma treatment, suggesting a promising strategy for augmenting the effectiveness of CAR-T cell therapy. [ABSTRACT FROM AUTHOR]

CAR-T cell therapy is at the forefront of next-generation multiple myeloma (MM) management, with two B-cell maturation antigen (BCMA)-targeted products recently approved. However, these products are incapable of breaking the infamous pattern of patient relapse. Two contributing factors are the use of BCMA as a target molecule and the artificial scFv format that is responsible for antigen recognition. Tackling both points of improvement in the present study, we used previously characterized VHHs that specifically target the idiotype of murine 5T33 MM cells. This idiotype represents one of the most promising yet challenging MM target antigens, as it is highly cancer- but also patient-specific. These VHHs were incorporated into VHH-based CAR modules, the format of which has advantages compared to scFv-based CARs. This allowed a side-by-side comparison of the influence of the targeting domain on T cell activation. Surprisingly, VHHs previously selected as lead compounds for targeted MM radiotherapy are not the best (CAR-) T cell activators. Moreover, the majority of the evaluated VHHs are incapable of inducing any T cell activation. As such, we highlight the importance of specific VHH selection, depending on its intended use, and thereby raise an important shortcoming of current common CAR development approaches. [ABSTRACT FROM AUTHOR]

Summary: Hepatocellular carcinoma (HCC) is a major global healthcare challenge, with >1 million patients predicted to be affected annually by 2025. In contrast to other cancers, both incidence and mortality rates continue to rise, and HCC is now the third leading cause of cancer-related death worldwide. Immune checkpoint inhibitors (ICIs) have transformed the treatment landscape for advanced HCC, with trials demonstrating a superior overall survival benefit compared to sorafenib in the first-line setting. Combination therapy with either atezolizumab (anti-PD-L1) and bevacizumab (anti-VEGF) or durvalumab (anti-PD-L1) and tremelimumab (anti-CTLA-4) is now recognised as standard of care for advanced HCC. More recently, two phase III studies of ICI-based combination therapy in the early and intermediate disease settings have successfully met their primary end points of improved recurrence- and progression-free survival, respectively. Despite these advances, and in contrast to other tumour types, there remain no validated predictive biomarkers of response to ICIs in HCC. Ongoing research efforts are focused on further characterising the tumour microenvironment in order to select patients most likely to benefit from ICI and identify novel therapeutic targets. Herein, we review the current understanding of the immune landscape in which HCC develops and the evidence for ICI-based therapeutic strategies in HCC. Additionally, we describe the state of biomarker development and novel immunotherapy approaches in HCC which have progressed beyond the pre-clinical stage and into early-phase trials.

Chimeric antigen receptor (CAR) T-cell based immunotherapy has shown its potential in treating blood cancers, and its application to solid tumors is currently being extensively investigated. For glioma brain tumors, various CAR T-cell targets include IL13Rα2, EGFRvIII, HER2, EphA2, GD2, B7-H3, and chlorotoxin. In this work, we are interested in developing a mathematical model of IL13Rα2 targeting CAR T-cells for treating glioma. We focus on extending the work of Kuznetsov et al. (1994) by considering binding of multiple CAR T-cells to a single glioma cell, and the dynamics of these multi-cellular conjugates. Our model more accurately describes experimentally observed CAR T-cell killing assay data than the models which do not consider multi-cellular conjugates. Moreover, we derive conditions in the CAR T-cell expansion rate that determines treatment success or failure. Finally, we show that our model captures distinct CAR T-cell killing dynamics from low to high antigen receptor densities in patient-derived brain tumor cells.

Generation of chimeric antigen receptor (CAR) T cells from pluripotent stem cells (PSCs) will enable advances in cancer immunotherapy. Understanding how CARs affect T cell differentiation from PSCs is important for this effort. The recently described artificial thymic organoid (ATO) system supports in vitro differentiation of PSCs to T cells. Unexpectedly, PSCs transduced with a CD19-targeted CAR resulted in diversion of T cell differentiation to the innate lymphoid cell 2 (ILC2) lineage in ATOs. T cells and ILC2s are closely related lymphoid lineages with shared developmental and transcriptional programs. Mechanistically, we show that antigen-independent CAR signaling during lymphoid development enriched for ILC2-primed precursors at the expense of T cell precursors. We applied this understanding to modulate CAR signaling strength through expression level, structure, and presentation of cognate antigen to demonstrate that the T cell-versus-ILC lineage decision can be rationally controlled in either direction, providing a framework for achieving CAR-T cell development from PSCs.

Abstract Background CAR NK cells as vehicles for engineered “off-the-shelf” cellular cancer immunotherapy have attracted significant interest. Nonetheless, a comprehensive comparative assessment of the anticancer activity of CAR T cells and CAR NK cells carrying approved benchmark anti-CD19 CAR constructs is missing. Here, we report a direct head-to-head comparison of CD19-directed human T and NK cells. Methods We generated CAR T and CAR NK cells derived from healthy donor PBMC by retroviral transduction with the same benchmark second-generation anti-CD19 CAR construct, FMC63.28z. We investigated IFN-γ secretion and direct cytotoxicity in vitro against various CD19+ cancer cell lines as well as in autologous versus allogeneic settings. Furthermore, we have assessed anticancer activity of CAR T and CAR NK cells in vivo using a xenograft lymphoma model in an autologous versus allogeneic setting and a leukemia model. Results Our main findings are a drastically reduced capacity for CAR-mediated IFN-γ production and lower CAR-mediated cytotoxicity of CAR NK cells relative to CAR T cells in vitro. Consistent with these in vitro findings, we report superior anticancer activity of autologous CAR T cells compared with allogeneic CAR NK cells in vivo. Conclusions CAR T cells had significantly higher CAR-mediated effector functions than CAR NK cells in vitro against several cancer cell lines and autologous CAR T cells outperformed allogeneic CAR NK cells both in vitro and in vivo. CAR NK cells will likely benefit from further engineering to enhance anticancer activity to ultimately fulfill the promise of an effective off-the-shelf product.

Abstract Adoptive cell therapy has revolutionized cancer treatment, especially for hematologic malignancies. T cells are the most extensively utilized cells in adoptive cell therapy. Currently, tumor-infiltrating lymphocytes, T cell receptor-transgenic T cells and chimeric antigen receptor T cells are the three main adoptive T cell therapies. Tumor-infiltrating lymphocytes kill tumors by reinfusing enlarged lymphocytes that naturally target tumor-specific antigens into the patient. T cell receptor-transgenic T cells have the ability to specifically destroy tumor cells via the precise recognition of exogenous T cell receptors with major histocompatibility complex. Chimeric antigen receptor T cells transfer genes with specific antigen recognition structural domains and T cell activation signals into T cells, allowing T cells to attack tumors without the assistance of major histocompatibility complex. Many barriers have been demonstrated to affect the clinical efficacy of adoptive T cell therapy, such as tumor heterogeneity and antigen loss, hard trafficking and infiltration, immunosuppressive tumor microenvironment and T cell exhaustion. Several strategies to improve the efficacy of adoptive T cell therapy have been explored, including multispecific chimeric antigen receptor T cell therapy, combination with immune checkpoint blockade, targeting the immunosuppressive tumor microenvironment, etc. In this review, we will summarize the current status and clinical application, followed by major bottlenecks in adoptive T cell therapy. In addition, we will discuss the promising strategies to improve adoptive T cell therapy. Adoptive T cell therapy will result in even more incredible advancements in solid tumors if the aforementioned problems can be handled. Graphical abstract

The introduction of chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment of hematological diseases, particularly in combating blood cancer. The success of this cell therapy approach has led to the development of approximately seven commercial CAR-T based drugs. However, the application of CAR-T therapy for solid tumors has proven to be less effective due to challenges such as the varied antigens in solid tumors, an immunosuppressive tumor environment, limited immune cell infiltration, reduced CAR-T cell activity and toxicity issues. To solve these problems, scientists are making efforts to improve and improve the methods of treatment of solid tumors. Chemotherapy is the standard treatment for a large number of malignant neoplasms. It is also used before starting cell therapy for lymphodepletion and better engraftment of injected CAR-T cells. It has been shown that chemotherapy can reduce the immunosuppressive effect of the tumor microenvironment, destroy the stroma, and promote better infiltration of the tumor by CAR-T cells, improving their survival, persistence, cytotoxicity, and influencing the metabolism of immune cells inside the tumor. The effectiveness of combining chemotherapy and CAR-T cell therapy relies on various factors such as tumor type, dosage, treatment schedule, CAR-T cell composition, and individual biological traits. Similarly, radiation therapy can enhance tumor cell vulnerability to specific treatments while also supporting tumor cell survival.In this review, we discuss the use of CAR-T therapy to combat solid tumors, regarding the challenges of treating solid tumors, ways to overcome them, and also touch upon the possibility of using combination treatments to improve the effectiveness of cell therapy.