TCR Redirected T Cells for Cancer Treatment: Achievements, Hurdles, and Goals

Genetically Engineered T Cells and Recombinant Antibodies to Target Intracellular Neoantigens: Current Status and Future Directions

Recombinant antibodies and, more recently, T cell receptor (TCR)-engineered T cell therapies represent two immunological strategies that have come to the forefront of clinical interest for targeting intracellular neoantigens in benign and malignant diseases. T cell-based therapies targeting neoantigens use T cells expressing a recombinant complete TCR (TCR-T cell), a chimeric antigen receptor (CAR) with the variable domains of a neoepitope-reactive TCR as a binding domain (TCR-CAR-T cell) or a TCR-like antibody as a binding domain (TCR-like CAR-T cell). Furthermore, the synthetic T cell receptor and antigen receptor (STAR) and heterodimeric TCR-like CAR (T-CAR) are designed as a double-chain TCRαβ-based receptor with variable regions of immunoglobulin heavy and light chains (VH and VL) fused to TCR-Cα and TCR-Cβ, respectively, resulting in TCR signaling. In contrast to the use of recombinant T cells, anti-neopeptide MHC (pMHC) antibodies and intrabodies neutralizing intracellular neoantigens can be more easily applied to cancer patients. However, different limitations should be considered, such as the loss of neoantigens, the modification of antigen peptide presentation, tumor heterogenicity, and the immunosuppressive activity of the tumor environment. The simultaneous application of immune checkpoint blocking antibodies and of CRISPR/Cas9-based genome editing tools to engineer different recombinant T cells with enhanced therapeutic functions could make T cell therapies more efficient and could pave the way for its routine clinical application.

T-Switch: A specificity-based engineering platform for developing safe and effective T cell therapeutics

Many promising targets for adoptive T cell therapy (ACT) are self-antigens, but self-reactive T cells are generally eliminated during thymic selection or diverted to regulatory phenotypes. To bypass T cell tolerance and obtain potent and safe T cell therapeutics, we developed T-Switch, an in vitro T cell receptor (TCR) engineering platform for the creation, modification, and comprehensive profiling of TCRs that can target self-antigens. T-Switch first expands T cells that recognize a "foreign" peptide closely related to a self-antigen. The fine specificity of the TCR is then modified by directed evolution of the peptide binding region to switch its specificity to the self-antigen of interest. We applied T-Switch to engineer synthetic TCRs reactive to a tumor-associated self-antigen, validated the safety and efficacy of this approach, and detected no off-target recognition as measured against the human proteome. Thus, T-Switch represents a resource for the creation of collections of highly sensitive synthetic TCRs for T cell-based immunotherapies.

Exploring the therapeutic potential of precision T-Cell Receptors (TCRs) in targeting KRAS G12D cancer through in vitro development

Objectives

The Kirsten rat sarcoma virus (KRAS) G12D oncogenic mutation poses a significant challenge in treating solid tumors due to the lack of specific and effective therapeutic interventions. This study aims to explore innovative approaches in T cell receptor (TCR) engineering and characterization to target the KRAS G12D7-16 mutation, providing potential strategies for overcoming this therapeutic challenge.

Methods

In this innovative study, we engineered and characterized two T cell receptors (TCRs), KDA11-01 and KDA11-02 with high affinity for the KRAS G12D7-16 mutation. These TCRs were isolated from tumor-infiltrating lymphocytes (TILs) derived from tumor tissues of patients with the KRAS G12D mutation. We assessed their specificity and anti-tumor activity in vitro using various cancer cell lines.

Results

KDA11-01 and KDA11-02 demonstrated exceptional specificity for the HLA-A*11:01-restricted KRAS G12D7-16 epitope, significantly inducing IFN-γ release and eliminating tumor cells without cross-reactivity or alloreactivity.

Conclusions

The successful development of KDA11-01 and KDA11-02 introduces a novel and precise TCR-based therapeutic strategy against KRAS G12D mutation, showing potential for significant advancements in cancer immunotherapy.

The future of cellular therapy for the treatment of renal cell carcinoma

INTRODUCTION

Systemic treatment options for renal cell carcinoma (RCC) have expanded considerably in recent years, and both tyrosine kinase inhibitors and immune checkpoint inhibitors, alone or in combination, have entered the clinical arena. Adoptive cell immunotherapies have recently revolutionized the treatment of cancer and hold the promise to further advance the treatment of RCC.

AREAS COVERED

In this review, we summarize the latest preclinical and clinical development in the field of adoptive cell immunotherapy for the treatment of RCC, focusing on lymphokine-activated killer (LAK) cells, cytokine-induced killer (CIK) cells, tumor-infiltrating T cells (TILs), TCR-engineered T cells, chimeric antigen receptor (CAR) T cells, and dendritic cell vaccination strategies. Perspectives on emerging cellular products including CAR NK cells, CAR macrophages, as well as γδ T cells are also included.

EXPERT OPINION

So far, areas of greater therapeutic success of adoptive cell therapies include the adjuvant administration of CIK cells and the transfer of anti-CD70 CAR T cells in patients with metastatic RCC. Bench to bedside and back research will be needed to overcome current limitations of adoptive cell therapies in RCC, primarily aiming at improving the safety of immune cell products, optimizing their antitumor activity and generating off-the-shelf products ready for clinical use.

Regulatory T cell-based therapy in type 1 diabetes: Latest breakthroughs and evidence

Autoimmune diseases (ADs) are among the most significant health complications, with their incidence rising in recent years. Type 1 diabetes (T1D), an AD, targets the insulin-producing β cells in the pancreas, leading to chronic insulin deficiency in genetically susceptible individuals. Regulatory immune cells, particularly T-cells (Tregs), have been shown to play a crucial role in the pathogenesis of diabetes by modulating immune responses. In diabetic patients, Tregs often exhibit diminished effectiveness due to various factors, such as instability in forkhead box P3 (Foxp3) expression or abnormal production of the proinflammatory cytokine interferon-gamma (IFN-γ) by autoreactive T-cells. Consequently, Tregs represent a potential therapeutic target for diabetes treatment. Building on the successful clinical outcomes of chimeric antigen receptor (CAR) T-cell therapy in cancer treatment, particularly in leukemias, the concept of designing and utilizing CAR Tregs for ADs has emerged. This review summarizes the findings on Treg targeting in T1D and discusses the benefits and limitations of this treatment approach for patients suffering from T1D.

Finding potential targets in cell-based immunotherapy for handling the challenges of acute myeloid leukemia

Acute myeloid leukemia (AML) is a hostile hematological malignancy under great danger of relapse and poor long-term survival rates, despite recent therapeutic advancements. To deal with this unfulfilled clinical necessity, innovative cell-based immunotherapies have surfaced as promising approaches to improve anti-tumor immunity and enhance patient outcomes. In this comprehensive review, we provide a detailed examination of the latest developments in cell-based immunotherapies for AML, including chimeric antigen receptor (CAR) T-cell therapy, T-cell receptor (TCR)-engineered T-cell therapy, and natural killer (NK) cell-based therapies. We critically evaluate the unique mechanisms of action, current challenges, and evolving strategies to improve the efficacy and safety of these modalities. The review emphasizes how promising these cutting-edge immune-based strategies are in overcoming the inherent complexities and heterogeneity of AML. We discuss the identification of optimal target antigens, the importance of mitigating on-target/off-tumor toxicity, and the need to enhance the persistence and functionality of engineered immune effector cells. All things considered, this review offers a thorough overview of the rapidly evolving field of cell-based immunotherapy for AML, underscoring the significant progress made and the ongoing efforts to translate these innovative approaches into more effective and durable treatments for this devastating disease.

Engineered T cells for Colorectal Cancer

Colorectal cancer (CRC) is a major contributor to global cancer incidence and mortality. Conventional treatments have limitations; hence, innovative approaches are imperative. Recent advancements in cancer research have led to the development of personalized targeted therapies and immunotherapies. Immunotherapy, in particular, T cell-based therapies, exhibited to be promising in enhancing cancer treatment outcomes. This review focuses on the landscape of engineered T cells as a potential option for the treatment of CRC. It highlights the approaches, challenges and current advancements in this field. As the understanding of molecular mechanisms increases, engineered T cells hold great potential in revolutionizing cancer treatment. To fully explore their safety efficacy in improving patient outcomes, further research and clinical trials are necessary.

Expanding horizons in cancer therapy by immunoconjugates targeting tumor microenvironments

Immunoconjugates are promising molecules combining antibodies with different agents, such as toxins, drugs, radionuclides, or cytokines that primarily aim to target tumor cells. However, tumor microenvironment (TME), which comprises a complex network of various cells and molecular cues guiding tumor growth and progression, remains a major challenge for effective cancer therapy. Our review underscores the pivotal role of TME in cancer therapy with immunoconjugates, examining the intricate interactions with TME and recent advancements in TME-targeted immunoconjugates. We explore strategies for targeting TME components, utilizing diverse antibodies such as neutralizing, immunomodulatory, immune checkpoint inhibitors, immunostimulatory, and bispecific antibodies. Additionally, we discuss different immunoconjugates, elucidating their mechanisms of action, advantages, limitations, and applications in cancer immunotherapy. Furthermore, we highlight emerging technologies enhancing the safety and efficacy of immunoconjugates, such as antibody engineering, combination therapies, and nanotechnology. Finally, we summarize current advancements, perspectives, and future developments of TME-targeted immunoconjugates.

Assessing a single-cell multi-omic analytic platform to characterize ex vivo-engineered T-cell therapy products

Genetically engineered CD8+ T cells are being explored for the treatment of various cancers. Analytical characterization represents a major challenge in the development of genetically engineered cell therapies, especially assessing the potential off-target editing and product heterogeneity. As conventional sequencing techniques only provide information at the bulk level, they are unable to detect off-target CRISPR translocation or editing events occurring in minor cell subpopulations. In this study, we report the analytical development of a single-cell multi-omics DNA and protein assay to characterize genetically engineered cell products for safety and genotoxicity assessment. We were able to quantify on-target edits, off-target events, and potential translocations at the targeting loci with per-cell granularity, providing important characterization data of the final cell product. Conclusion: A single-cell multi-omics approach provides the resolution required to understand the composition of cellular products and identify critical quality attributes (CQAs).

Harnessing the tumor microenvironment to boost adoptive T cell therapy with engineered lymphocytes for solid tumors

Adoptive cell therapy (ACT) using Chimeric Antigen Receptor (CAR) and T Cell Receptor (TCR) engineered T cells represents an innovative therapeutic approach for the treatment of hematological malignancies, yet its application for solid tumors is still suboptimal. The tumor microenvironment (TME) places several challenges to overcome for a satisfactory therapeutic effect, such as physical barriers (fibrotic capsule and stroma), and inhibitory signals impeding T cell function. Some of these obstacles can be faced by combining ACT with other anti-tumor approaches, such as chemo/radiotherapy and checkpoint inhibitors. On the other hand, cutting edge technological tools offer the opportunity to overcome and, in some cases, take advantage of TME intrinsic characteristics to boost ACT efficacy. These include: the exploitation of chemokine gradients and integrin expression for preferential T-cell homing and extravasation; metabolic changes that have direct or indirect effects on TCR-T and CAR-T cells by increasing antigen presentation and reshaping T cell phenotype; introduction of additional synthetic receptors on TCR-T and CAR-T cells with the aim of increasing T cells survival and fitness.

Establishment of a humanized mouse model using steady-state peripheral blood-derived hematopoietic stem and progenitor cells facilitates screening of cancer-targeted T-cell repertoires

Background

Cancer-targeted T-cell receptor T (TCR-T) cells hold promise in treating cancers such as hematological malignancies and breast cancers. However, approaches to obtain cancer-reactive TCR-T cells have been unsuccessful.

Methods

Here, we developed a novel strategy to screen for cancer-targeted TCR-T cells using a special humanized mouse model with person-specific immune fingerprints. Rare steady-state circulating hematopoietic stem and progenitor cells were expanded via three-dimensional culture of steady-state peripheral blood mononuclear cells, and then the expanded cells were applied to establish humanized mice. The human immune system was evaluated according to the kinetics of dendritic cells, monocytes, T-cell subsets, and cytokines. To fully stimulate the immune response and to obtain B-cell precursor NAML-6- and triple-negative breast cancer MDA-MB-231-targeted TCR-T cells, we used the inactivated cells above to treat humanized mice twice a day every 7 days. Then, human T cells were processed for TCR β-chain (TRB) sequencing analysis. After the repertoires had been constructed, features such as the fraction, diversity, and immune signature were investigated.

Results

The results demonstrated an increase in diversity and clonality of T cells after treatment. The preferential usage and features of TRBV, TRBJ, and the V-J combination were also changed. The stress also induced highly clonal expansion. Tumor burden and survival analysis demonstrated that stress induction could significantly inhibit the growth of subsequently transfused live tumor cells and prolong the survival of the humanized mice.

Conclusions

We constructed a personalized humanized mouse model to screen cancer-targeted TCR-T pools. Our platform provides an effective source of cancer-targeted TCR-T cells and allows for the design of patient-specific engineered T cells. It therefore has the potential to greatly benefit cancer treatment.

The recent advancement of TCR-T cell therapies for cancer treatment

Adoptive cell therapies involve infusing engineered immune cells into cancer patients to recognize and eliminate tumor cells. Adoptive cell therapy, as a form of living drug, has undergone explosive growth over the past decade. The recognition of tumor antigens by the T-cell receptor (TCR) is one of the natural mechanisms that the immune system used to eliminate tumor cells. TCR-T cell therapy, which involves introducing exogenous TCRs into patients' T cells, is a novel cell therapy strategy. TCR-T cell therapy can target the entire proteome of cancer cells. Engineering T cells with exogenous TCRs to help patients combat cancer has achieved success in clinical trials, particularly in treating solid tumors. In this review, we examine the progress of TCR-T cell therapy over the past five years. This includes the discovery of new tumor antigens, protein engineering techniques for TCR, reprogramming strategies for TCR-T cell therapy, clinical studies on TCR-T cell therapy, and the advancement of TCR-T cell therapy in China. We also propose several potential directions for the future development of TCR-T cell therapy.

Nanoparticle-Mediated Synergistic Chemoimmunotherapy for Cancer Treatment

Until now, there has been a lack of effective strategies for cancer treatment. Immunotherapy has high potential in treating several cancers but its efficacy is limited as a monotherapy. Chemoimmunotherapy (CIT) holds promise to be widely used in cancer treatment. Therefore, identifying their involvement and potential synergy in CIT approaches is decisive. Nano-based drug delivery systems (NDDSs) are ideal delivery systems because they can simultaneously target immune cells and cancer cells, promoting drug accumulation, and reducing the toxicity of the drug. In this review, we first introduce five current immunotherapies, including immune checkpoint blocking (ICB), adoptive cell transfer therapy (ACT), cancer vaccines, oncolytic virus therapy (OVT) and cytokine therapy. Subsequently, the immunomodulatory effects of chemotherapy by inducing immunogenic cell death (ICD), promoting tumor killer cell infiltration, down-regulating immunosuppressive cells, and inhibiting immune checkpoints have been described. Finally, the NDDSs-mediated collaborative drug delivery systems have been introduced in detail, and the development of NDDSs-mediated CIT nanoparticles has been prospected.

Newer generations of multi-target CAR and STAb-T immunotherapeutics: NEXT CART Consortium as a cooperative effort to overcome current limitations

Adoptive T cellular immunotherapies have emerged as relevant approaches for treating cancer patients who have relapsed or become refractory (R/R) to traditional cancer treatments. Chimeric antigen receptor (CAR) T-cell therapy has improved survival in various hematological malignancies. However, significant limitations still impede the widespread adoption of these therapies in most cancers. To advance in this field, six research groups have created the "NEXT Generation CART MAD Consortium" (NEXT CART) in Madrid's Community, which aims to develop novel cell-based immunotherapies for R/R and poor prognosis cancers. At NEXT CART, various basic and translational research groups and hospitals in Madrid concur to share and synergize their basic expertise in immunotherapy, gene therapy, and immunological synapse, and clinical expertise in pediatric and adult oncology. NEXT CART goal is to develop new cell engineering approaches and treatments for R/R adult and pediatric neoplasms to evaluate in multicenter clinical trials. Here, we discuss the current limitations of T cell-based therapies and introduce our perspective on future developments. Advancement opportunities include developing allogeneic products, optimizing CAR signaling domains, combining cellular immunotherapies, multi-targeting strategies, and improving tumor-infiltrating lymphocytes (TILs)/T cell receptor (TCR) therapy. Furthermore, basic studies aim to identify novel tumor targets, tumor molecules in the tumor microenvironment that impact CAR efficacy, and strategies to enhance the efficiency of the immunological synapse between immune and tumor cells. Our perspective of current cellular immunotherapy underscores the potential of these treatments while acknowledging the existing hurdles that demand innovative solutions to develop their potential for cancer treatment fully.

Modulating extracellular matrix stiffness: a strategic approach to boost cancer immunotherapy

The interplay between extracellular matrix (ECM) stiffness and the tumor microenvironment is increasingly recognized as a critical factor in cancer progression and the efficacy of immunotherapy. This review comprehensively discusses the key factors regulating ECM remodeling, including the activation of cancer-associated fibroblasts and the accumulation and crosslinking of ECM proteins. Furthermore, it provides a detailed exploration of how ECM stiffness influences the behaviors of both tumor and immune cells. Significantly, the impact of ECM stiffness on the response to various immunotherapy strategies, such as immune checkpoint blockade, adoptive cell therapy, oncolytic virus therapy, and therapeutic cancer vaccines, is thoroughly examined. The review also addresses the challenges in translating research findings into clinical practice, highlighting the need for more precise biomaterials that accurately mimic the ECM and the development of novel therapeutic strategies. The insights offered aim to guide future research, with the potential to enhance the effectiveness of cancer immunotherapy modalities.

Novel insights into TCR-T cell therapy in solid neoplasms: optimizing adoptive immunotherapy

Adoptive immunotherapy in the T cell landscape exhibits efficacy in cancer treatment. Over the past few decades, genetically modified T cells, particularly chimeric antigen receptor T cells, have enabled remarkable strides in the treatment of hematological malignancies. Besides, extensive exploration of multiple antigens for the treatment of solid tumors has led to clinical interest in the potential of T cells expressing the engineered T cell receptor (TCR). TCR-T cells possess the capacity to recognize intracellular antigen families and maintain the intrinsic properties of TCRs in terms of affinity to target epitopes and signal transduction. Recent research has provided critical insight into their capability and therapeutic targets for multiple refractory solid tumors, but also exposes some challenges for durable efficacy. In this review, we describe the screening and identification of available tumor antigens, and the acquisition and optimization of TCRs for TCR-T cell therapy. Furthermore, we summarize the complete flow from  laboratory to clinical applications of TCR-T cells. Last, we emerge future prospects for improving therapeutic efficacy in cancer world with combination therapies or TCR-T derived products. In conclusion, this review depicts our current understanding of TCR-T cell therapy in solid neoplasms, and provides new perspectives for expanding its clinical applications and improving therapeutic efficacy.

Tumor immune evasion: insights from CRISPR screens and future directions

Despite the clinical success of cancer immunotherapies including immune checkpoint blockade and adoptive cellular therapies across a variety of cancer types, many patients do not respond or ultimately relapse; however, the molecular underpinnings of this are not fully understood. Thus, a system-level understating of the routes to tumor immune evasion is required to inform the design of the next generation of immunotherapy approaches. CRISPR screening approaches have proved extremely powerful in identifying genes that promote tumor immune evasion or sensitize tumor cells to destruction by the immune system. These large-scale efforts have brought to light decades worth of fundamental immunology and have uncovered the key immune-evasion pathways subverted in cancers in an acquired manner in patients receiving immune-modulatory therapies. The comprehensive discovery of the main pathways involved in immune evasion has spurred the development and application of novel immune therapies to target this process. Although successful, conventional CRISPR screening approaches are hampered by a number of limitations, which obfuscate a complete understanding of the precise molecular regulation of immune evasion in cancer. Here, we provide a perspective on screening approaches to interrogate tumor-lymphocyte interactions and their limitations, and discuss further development of technologies to improve such approaches and discovery capability.

Engineered Treg cells: The heir to the throne of immunotherapy

Recently, increased interest in the use of Tregs as adoptive cell therapy for the treatment of autoimmune diseases and transplant rejection had led to several advances in the field. However, Treg cell therapies, while constantly advancing, indiscriminately suppress the immune system without the permanent stabilization of certain diseases. Genetically modified Tregs hold great promise towards solving these problems, but, challenges in identifying the most potent Treg subtype, accompanied by the ambiguity involved in identifying the optimal Treg source, along with its expansion and engineering in a clinical-grade setting remain paramount. This review highlights the recent advances in methodologies for the development of genetically engineered Treg cell-based treatments for autoimmune, inflammatory diseases, and organ rejection. Additionally, it provides a systematized guide to all the recent progress in the field and informs the readers of the feasibility and safety of engineered adoptive Treg cell therapy, with the aim to provide a framework for researchers involved in the development of engineered Tregs.

Breakthroughs in Cancer Immunotherapy: An Overview of T Cell, NK Cell, Mφ, and DC-Based Treatments

Efforts to treat cancer using chimeric antigen receptor (CAR)-T therapy have made astonishing progress and clinical trials against hematopoietic malignancies have demonstrated their use. However, there are still disadvantages which need to be addressed: high costs, and side effects such as Graft-versus-Host Disease (GvHD) and Cytokine Release Syndrome (CRS). Therefore, recent efforts have been made to harness the properties of certain immune cells to treat cancer-not just T cells, but also natural killer (NK) cells, macrophages (Mφ), dendritic cells (DC), etc. In this paper, we will introduce immune cell-based cellular therapies that use various immune cells and describe their characteristics and their clinical situation. The development of immune cell-based cancer therapy fully utilizing the unique advantages of each and every immune cell is expected to enhance the survival of tumor patients owing to their high efficiency and fewer side effects.

Harnessing T cell exhaustion and trogocytosis to isolate patient-derived tumor-specific TCR

To study and then harness the tumor-specific T cell dynamics after allogeneic hematopoietic stem cell transplant, we typed the frequency, phenotype, and function of lymphocytes directed against tumor-associated antigens (TAAs) in 39 consecutive transplanted patients, for 1 year after transplant. We showed that TAA-specific T cells circulated in 90% of patients but display a limited effector function associated to an exhaustion phenotype, particularly in the subgroup of patients deemed to relapse, where exhausted stem cell memory T cells accumulated. Accordingly, cancer-specific cytolytic functions were relevant only when the TAA-specific T cell receptors (TCRs) were transferred into healthy, genome-edited T cells. We then exploited trogocytosis and ligandome-on-chip technology to unveil the specificities of tumor-specific TCRs retrieved from the exhausted T cell pool. Overall, we showed that harnessing circulating TAA-specific and exhausted T cells allow to isolate TCRs against TAAs and previously not described acute myeloid leukemia antigens, potentially relevant for T cell-based cancer immunotherapy.

Allo Beta Cell transplantation: specific features, unanswered questions, and immunological challenge

Type 1 diabetes (T1D) presents a persistent medical challenge, demanding innovative strategies for sustained glycemic control and enhanced patient well-being. Beta cells are specialized cells in the pancreas that produce insulin, a hormone that regulates blood sugar levels. When beta cells are damaged or destroyed, insulin production decreases, which leads to T1D. Allo Beta Cell Transplantation has emerged as a promising therapeutic avenue, with the goal of reinstating glucose regulation and insulin production in T1D patients. However, the path to success in this approach is fraught with complex immunological hurdles that demand rigorous exploration and resolution for enduring therapeutic efficacy. This exploration focuses on the distinct immunological characteristics inherent to Allo Beta Cell Transplantation. An understanding of these unique challenges is pivotal for the development of effective therapeutic interventions. The critical role of glucose regulation and insulin in immune activation is emphasized, with an emphasis on the intricate interplay between beta cells and immune cells. The transplantation site, particularly the liver, is examined in depth, highlighting its relevance in the context of complex immunological issues. Scrutiny extends to recipient and donor matching, including the utilization of multiple islet donors, while also considering the potential risk of autoimmune recurrence. Moreover, unanswered questions and persistent gaps in knowledge within the field are identified. These include the absence of robust evidence supporting immunosuppression treatments, the need for reliable methods to assess rejection and treatment protocols, the lack of validated biomarkers for monitoring beta cell loss, and the imperative need for improved beta cell imaging techniques. In addition, attention is drawn to emerging directions and transformative strategies in the field. This encompasses alternative immunosuppressive regimens and calcineurin-free immunoprotocols, as well as a reevaluation of induction therapy and recipient preconditioning methods. Innovative approaches targeting autoimmune recurrence, such as CAR Tregs and TCR Tregs, are explored, along with the potential of stem stealth cells, tissue engineering, and encapsulation to overcome the risk of graft rejection. In summary, this review provides a comprehensive overview of the inherent immunological obstacles associated with Allo Beta Cell Transplantation. It offers valuable insights into emerging strategies and directions that hold great promise for advancing the field and ultimately improving outcomes for individuals living with diabetes.

One-step shotgun approach for antigenic specific pMHCs capture stimulated CD8+ T cell activation and proliferation

Antigenic peptides play a central role in immune surveillance in cancer, infectious disease, autoimmunity, and allergy. The identification and isolation of antigenic peptides for T cell immune response are crucial for successful personalized adoptive immune cell therapy. The mainly methods includes gene sequencing and bioinformatic analysis. The antigenic peptides which identified by analysis and artificially synthesized still need antigen presenting cell (APC) to deliver to T cells. However, high costs and lengthy process times have limited its application in clinical practice. In order to overcome it, this study attempted to directly capture antigenic peptide-major histocompatibility complex (MHC) class I (pMHCs) from cell lysates using streptavidin Dynabeads and biotin-labeled antibodies, then the pMHCs was co-cultured with tumor infiltrating lymphocytes (TILs) of the same tissue origin. The results indicated that the captured pMHCs were able to enrich the tumor antigen-specific CD8+ T cells, and also effectively induce proliferation and cytotoxic responses of CD8+ T cells. This study provided a novel approach for obtaining tumor antigenic pMHCs, which could enrich antigen-specific CD8+ T cells, and could also function as artificial APCs (aAPCs) to stimulate proliferation and activation of T cells. Notably, these pMHCs can stimulate the proliferation of stem-like memory T cells. In conclusion, this study describes a time-saving and low-cost method to isolate tumour antigen peptide MHC complexs, helping tumor antigen-specific T cell enrichment, activation, and proliferation.

TCR-Engineered Lymphocytes Targeting NY-ESO-1: In Vitro Assessment of Cytotoxicity against Tumors

Adoptive T-cell therapies tailored for the treatment of solid tumors encounter intricate challenges, necessitating the meticulous selection of specific target antigens and the engineering of highly specific T-cell receptors (TCRs). This study delves into the cytotoxicity and functional characteristics of in vitro-cultured T-lymphocytes, equipped with a TCR designed to precisely target the cancer-testis antigen NY-ESO-1. Flow cytometry analysis unveiled a notable increase in the population of cells expressing activation markers upon encountering the NY-ESO-1-positive tumor cell line, SK-Mel-37. Employing the NanoString platform, immune transcriptome profiling revealed the upregulation of genes enriched in Gene Ontology Biological Processes associated with the IFN-γ signaling pathway, regulation of T-cell activation, and proliferation. Furthermore, the modified T cells exhibited robust cytotoxicity in an antigen-dependent manner, as confirmed by the LDH assay results. Multiplex immunoassays, including LEGENDplex™, additionally demonstrated the elevated production of cytotoxicity-associated cytokines driven by granzymes and soluble Fas ligand (sFasL). Our findings underscore the specific targeting potential of engineered TCR T cells against NY-ESO-1-positive tumors. Further comprehensive in vivo investigations are essential to thoroughly validate these results and effectively harness the intrinsic potential of genetically engineered T cells for combating cancer.

A lentiviral vector for the production of T cells with an inducible transgene and a constitutively expressed tumour-targeting receptor

Vectors that facilitate the engineering of T cells that can better harness endogenous immunity and overcome suppressive barriers in the tumour microenvironment would help improve the safety and efficacy of T-cell therapies for more patients. Here we report the design, production and applicability, in T-cell engineering, of a lentiviral vector leveraging an antisense configuration and comprising a promoter driving the constitutive expression of a tumour-directed receptor and a second promoter enabling the efficient activation-inducible expression of a genetic payload. The vector allows for the delivery of a variety of genes to human T cells, as we show for interleukin-2 and a microRNA-based short hairpin RNA for the knockdown of the gene coding for haematopoietic progenitor kinase 1, a negative regulator of T-cell-receptor signalling. We also show that a gene encoded under an activation-inducible promoter is specifically expressed by tumour-redirected T cells on encountering a target antigen in the tumour microenvironment. The single two-gene-encoding vector can be produced at high titres under an optimized protocol adaptable to good manufacturing practices.

Genome Editing in Engineered T Cells for Cancer Immunotherapy

Advanced gene transfer technologies and profound immunological insights have enabled substantial increases in the efficacy of anticancer adoptive cellular therapy (ACT). In recent years, the U.S. Food and Drug Administration and European Medicines Agency have approved six engineered T cell therapeutic products, all chimeric antigen receptor-engineered T cells directed against B cell malignancies. Despite encouraging clinical results, engineered T cell therapy is still constrained by challenges, which could be addressed by genome editing. As RNA-guided Clustered Regularly Interspaced Short Palindromic Repeats technology passes its 10-year anniversary, we review emerging applications of genome editing approaches designed to (1) overcome resistance to therapy, including cancer immune evasion mechanisms; (2) avoid unwanted immune reactions related to allogeneic T cell products; (3) increase fitness, expansion capacity, persistence, and potency of engineered T cells, while preserving their safety profile; and (4) improve the ability of therapeutic cells to resist immunosuppressive signals active in the tumor microenvironment. Overall, these innovative approaches should widen the safe and effective use of ACT to larger number of patients affected by cancer.

Messenger RNA electroporated hepatitis B virus (HBV) antigen-specific T cell receptor (TCR) redirected T cell therapy is well-tolerated in patients with recurrent HBV-related hepatocellular carcinoma post-liver transplantation: results from a phase I trial

BACKGROUND AND AIMS

Liver transplantation (LT) is the primary curative option for cirrhotic patients with early-stage hepatocellular carcinoma (HCC). However, tumor recurrence occurs in 15-20% of cases with unfavorable prognosis. We have developed a library of T cell receptors (TCRs) specific for different hepatitis B virus (HBV) antigens, restricted by different molecules of human leucocyte antigen (HLA)-class I, to redirect T cells against HBV antigens (Banu in Sci Rep 4:4166, 2014). We further demonstrated that these transiently functional T cells specific for HBV obtained through messenger RNA (mRNA) electroporation can eliminate HCC cells expressing HBV antigens in vitro and in vivo (Kah in J Clin Invest 127:3177-3188, 2017). A phase I clinical trial for patients with HCC recurrence post-liver transplant was conducted to assess the safety, tolerability, and anti-tumor efficacy of transiently functional HBV-TCR T cells. Here, we report the clinical findings with regard to the safety and anti-tumor efficacy of mRNA electroporated HBV-specific TCR-T cells. (ClinicalTrials.gov identifier: NCT02719782).

PATIENTS AND METHODS

A total of six patients with HBV-positive recurrent HCC post-liver transplant and HLA-matched to TCR targeting hepatitis B surface antigen (HBsAg) or hepatitis B core antigen (HBcAg) (HLA-A*02:01/HBsAg, HLA-A*11:01/HBcAg, HLA-B*58:01/HBsAg or HLA-C*08:01/HBsAg) were enrolled in this study. The primary objective was to assess the safety of short-lived mRNA electroporated HBV-TCR T cells based on the incidence and severity of the adverse event (AE) graded per National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE), Version 4.0. The secondary objective was to determine the effectiveness of HBV-TCR T cells as per RECIST 1.1 criteria. Patients were followed up for survival for 2 years post-end of treatment.

RESULTS

The median age of the six patients was 35.5 years (range: 28-47). The median number of HBV-TCR T cell infusions administered was 6.5 (range: 4-12). The treatment-related AE included grade 1 pyrexia. This study reported no cytokine release syndrome nor neurotoxicity. One patient remained alive and five were deceased at the time of the data cutoff (30 April 2020).

CONCLUSION

This study has demonstrated that multiple infusions of mRNA electroporated HBV-specific TCR T cells were well-tolerated in patients with HBV-positive recurrent HCC post-liver transplant.

Prospects of Cytomegalovirus-Specific T-Cell Receptors in Clinical Diagnosis and Therapy

Human cytomegalovirus (HCMV) is responsible for widespread infections worldwide. In immunocompetent individuals it is typically latent, while infection or reactivation in immunocompromised individuals can result in severe clinical symptoms or even death. Although there has been significant progress in the treatment and diagnosis of HCMV infection in recent years, numerous shortcomings and developmental limitations persist. There is an urgent need to develop innovative, safe, and effective treatments, as well as to explore early and timely diagnostic strategies for HCMV infection. Cell-mediated immune responses are the primary factor controlling HCMV infection and replication, but the protective role of humoral immune responses remains controversial. T-cells, key effector cells of the cellular immune system, are critical for clearing and preventing HCMV infection. The T-cell receptor (TCR) lies at the heart of T-cell immune responses, and its diversity enables the immune system to differentiate between self and non-self. Given the significant influence of cellular immunity on human health and the indispensable role of the TCR in T-cell immune responses, we posit that the impact of TCR on the development of novel diagnostic and prognostic methods, as well as on patient monitoring and management of clinical HCMV infection, will be far-reaching and profound. High-throughput and single-cell sequencing technologies have facilitated unprecedented quantitative detection of TCR diversity. With these current sequencing technologies, researchers have already obtained a vast number of TCR sequences. It is plausible that in the near future studies on TCR repertoires will be instrumental in assessing vaccine efficacy, immunotherapeutic strategies, and the early diagnosis of HCMV infection.

CAR-Based Therapy for Autoimmune Diseases: A Novel Powerful Option

The pervasive application of chimeric antigen receptor (CAR)-based cellular therapies in the treatment of oncological diseases has long been recognized. However, CAR T cells can target and eliminate autoreactive cells in autoimmune and immune-mediated diseases. By doing so, they can contribute to an effective and relatively long-lasting remission. In turn, CAR Treg interventions may have a highly effective and durable immunomodulatory effect via a direct or bystander effect, which may have a positive impact on the course and prognosis of autoimmune diseases. CAR-based cellular techniques have a complex theoretical foundation and are difficult to implement in practice, but they have a remarkable capacity to suppress the destructive functions of the immune system. This article provides an overview of the numerous CAR-based therapeutic options developed for the treatment of immune-mediated and autoimmune diseases. We believe that well-designed, rigorously tested cellular therapies could provide a promising new personalized treatment strategy for a significant number of patients with immune-mediated disorders.

Cell therapy biomanufacturing: integrating biomaterial and flow-based membrane technologies for production of engineered T-cells

Adoptive T-cell therapies (ATCTs) are increasingly important for the treatment of cancer, where patient immune cells are engineered to target and eradicate diseased cells. The biomanufacturing of ATCTs involves a series of time-intensive, lab-scale steps, including isolation, activation, genetic modification, and expansion of a patient's T-cells prior to achieving a final product. Innovative modular technologies are needed to produce cell therapies at improved scale and enhanced efficacy. In this work, well-defined, bioinspired soft materials were integrated within flow-based membrane devices for improving the activation and transduction of T cells. Hydrogel coated membranes (HCM) functionalized with cell-activating antibodies were produced as a tunable biomaterial for the activation of primary human T-cells. T-cell activation utilizing HCMs led to highly proliferative T-cells that expressed a memory phenotype. Further, transduction efficiency was improved by several fold over static conditions by using a tangential flow filtration (TFF) flow-cell, commonly used in the production of protein therapeutics, to transduce T-cells under flow. The combination of HCMs and TFF technology led to increased cell activation, proliferation, and transduction compared to current industrial biomanufacturing processes. The combined power of biomaterials with scalable flow-through transduction techniques provides future opportunities for improving the biomanufacturing of ATCTs.

TCR-engineered T cell therapy in solid tumors: State of the art and perspectives

T cell engineering has changed the landscape of cancer immunotherapy. Chimeric antigen receptor T cells have demonstrated a remarkable efficacy in the treatment of B cell malignancies in hematology. However, their clinical impact on solid tumors has been modest so far. T cells expressing an engineered T cell receptor (TCR-T cells) represent a promising therapeutic alternative. The target repertoire is not limited to membrane proteins, and intrinsic features of TCRs such as high antigen sensitivity and near-to-physiological signaling may improve tumor cell detection and killing while improving T cell persistence. In this review, we present the clinical results obtained with TCR-T cells targeting different tumor antigen families. We detail the different methods that have been developed to identify and optimize a TCR candidate. We also discuss the challenges of TCR-T cell therapies, including toxicity assessment and resistance mechanisms. Last, we share some perspectives and highlight future directions in the field.

Targeting tumor-associated macrophages in hepatocellular carcinoma: biology, strategy, and immunotherapy

Hepatocellular carcinoma (HCC), one of the most malignant tumors, is characterized by its stubborn immunosuppressive microenvironment. As one of the main members of the tumor microenvironment (TME) of HCC, tumor-associated macrophages (TAMs) play a critical role in its occurrence and development, including stimulating angiogenesis, enhancing immunosuppression, and promoting the drug resistance and cancer metastasis. This review describes the origin as well as phenotypic heterogeneity of TAMs and their potential effects on the occurrence and development of HCC and also discusses about various adjuvant therapy based strategies that can be used for targeting TAMs. In addition, we have highlighted different treatment modalities for TAMs based on immunotherapy, including small molecular inhibitors, immune checkpoint inhibitors, antibodies, tumor vaccines, adoptive cellular immunotherapy, and nanocarriers for drug delivery, to explore novel combination therapies and provide feasible therapeutic options for clinically improving the prognosis and quality of life of HCC patients.

Receptors of immune cells mediates recognition for tumors

Over the last few decades, the immune system has been steered toward eradication of cancer cells with the help of cancer immunotherapy. T cells, B cells, monocytes/macrophages, dendritic cells, T-reg cells, and natural killer (NK) cells are some of the numerous immune cell types that play a significant part in cancer cell detection and reduction of inflammation, and the antitumor response. Briefly stated, chimeric antigen receptors, adoptive transfer and immune checkpoint modulators are currently the subjects of research focus for successful immunotherapy-based treatments for a variety of cancers. This chapter discusses ongoing investigations on the mechanisms and recent developments by which receptors of immune cells especially that of lymphocytes and monocytes/macrophages regulate the detection of immune system leading to malignancies. We will also be looking into the treatment strategies based on these mechanisms.

Inferencing Bulk Tumor and Single-Cell Multi-Omics Regulatory Networks for Discovery of Biomarkers and Therapeutic Targets

There are insufficient accurate biomarkers and effective therapeutic targets in current cancer treatment. Multi-omics regulatory networks in patient bulk tumors and single cells can shed light on molecular disease mechanisms. Integration of multi-omics data with large-scale patient electronic medical records (EMRs) can lead to the discovery of biomarkers and therapeutic targets. In this review, multi-omics data harmonization methods were introduced, and common approaches to molecular network inference were summarized. Our Prediction Logic Boolean Implication Networks (PLBINs) have advantages over other methods in constructing genome-scale multi-omics networks in bulk tumors and single cells in terms of computational efficiency, scalability, and accuracy. Based on the constructed multi-modal regulatory networks, graph theory network centrality metrics can be used in the prioritization of candidates for discovering biomarkers and therapeutic targets. Our approach to integrating multi-omics profiles in a patient cohort with large-scale patient EMRs such as the SEER-Medicare cancer registry combined with extensive external validation can identify potential biomarkers applicable in large patient populations. These methodologies form a conceptually innovative framework to analyze various available information from research laboratories and healthcare systems, accelerating the discovery of biomarkers and therapeutic targets to ultimately improve cancer patient survival outcomes.

γδ T cells: The potential role in liver disease and implications for cancer immunotherapy

The γδ T cell subset was discovered over 30 years ago, yet continues to be an exciting and challenging component of the adaptive immune response. While γδ T cells represent a very small fraction of all T cells in humans, γδ T cells have a vital effect on human immunity, serving as a bridge between the innate and adaptive immune systems. The characteristics of γδ T cells include recognition of non-MHC restrictive antigens, as well as the ability to secrete an abundance of cytokines, suggesting that γδ T cells have high antitumor activity. As such, they have gained ample attention with respect to tumor immunotherapy in the last decade. The γδ T cell subset comprises up to ∼15-20% of the T-lymphocyte population in the liver, although the liver is recognized as an immune organ with primary immune functions, the role of γδ T cells in liver disease has not been established. Herein, we present a comprehensive overview of molecular mechanisms underlying immune γδ T cell activity in liver disease, including immune liver injury, viral hepatitis, cirrhosis, and hepatocellular carcinoma, and review γδ T cell-based clinical immunotherapeutic approaches.

T Cells Directed against the Metastatic Driver Chondromodulin-1 in Ewing Sarcoma: Comparative Engineering with CRISPR/Cas9 vs. Retroviral Gene Transfer for Adoptive Transfer

Ewing sarcoma (EwS) is a highly malignant sarcoma of bone and soft tissue with early metastatic spread and an age peak in early puberty. The prognosis in advanced stages is still dismal, and the long-term effects of established therapies are severe. Efficacious targeted therapies are urgently needed. Our previous work has provided preliminary safety and efficacy data utilizing T cell receptor (TCR) transgenic T cells, generated by retroviral gene transfer, targeting HLA-restricted peptides on the tumor cell derived from metastatic drivers. Here, we compared T cells engineered with either CRISPR/Cas9 or retroviral gene transfer. Firstly, we confirmed the feasibility of the orthotopic replacement of the endogenous TCR by CRISPR/Cas9 with a TCR targeting our canonical metastatic driver chondromodulin-1 (CHM1). CRISPR/Cas9-engineered T cell products specifically recognized and killed HLA-A*02:01+ EwS cell lines. The efficiency of retroviral transduction was higher compared to CRISPR/Cas9 gene editing. Both engineered T cell products specifically recognized tumor cells and elicited cytotoxicity, with CRISPR/Cas9 engineered T cells providing prolonged cytotoxic activity. In conclusion, T cells engineered with CRISPR/Cas9 could be feasible for immunotherapy of EwS and may have the advantage of more prolonged cytotoxic activity, as compared to T cells engineered with retroviral gene transfer.

Adoptive cell therapies in thoracic malignancies

Immunotherapy has gained great interest in thoracic malignancies in the last decade, first in non-small cell lung cancer (NSCLC), but also more recently in small-cell lung cancer (SCLC) and malignant pleural mesothelioma (MPM). However, while 15-20% of patients will greatly benefit from immune checkpoint blockers (ICBs), a vast majority will rapidly exhibit resistance. Reasons for this are multiple: non-immunogenic tumors, immunosuppressive tumor microenvironment or defects in immune cells trafficking to the tumor sites being some of the most frequent. Current progress in adoptive cell therapies could offer a way to overcome these hurdles and bring effective immune cells to the tumor site. In this review, we discuss advantages, limits and future perspectives of adoptive cell therapy (ACT) in thoracic malignancies from lymphokine-activated killer cells (LAK), cytokine-induced killer cells (CIK), natural killer cells (NK), dendritic cells (DC) vaccines and tumor-infiltrating lymphocytes (TILs) to TCR engineering and CARs. Trials are still in their early phases, and while there may still be many limitations to overcome, a combination of these different approaches with ICBs, chemotherapy and/or radiotherapy could vastly improve the way we treat thoracic cancers.

Immunotherapeutic Strategies for Head and Neck Squamous Cell Carcinoma (HNSCC): Current Perspectives and Future Prospects

Neoantigens are abnormal proteins produced by genetic mutations in somatic cells. Because tumour neoantigens are expressed only in tumour cells and have immunogenicity, they may represent specific targets for precision immunotherapy. With the reduction in sequencing cost, continuous advances in artificial intelligence technology and an increased understanding of tumour immunity, neoantigen vaccines and adoptive cell therapy (ACT) targeting neoantigens have become research hotspots. Approximately 900,000 patients worldwide are diagnosed with head and neck squamous cell carcinoma (HNSCC) each year. Due to its high mutagenicity and abundant lymphocyte infiltration, HNSCC naturally generates a variety of potential new antigen targets that may be used for HNSCC immunotherapies. Currently, the main immunotherapy for HNSCC is use of immune checkpoint inhibitors(ICIs). Neoantigen vaccines and adoptive cell therapy targeting neoantigens are extensions of immunotherapy for HNSCC, and a large number of early clinical trials are underway in combination with immune checkpoint inhibitors for the treatment of recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC). In this paper, we review recent neoantigen vaccine trials related to the treatment of HNSCC, introduce adoptive cell therapy targeting neoantigens, and propose a potential treatment for HNSCC. The clinical application of immune checkpoint inhibitor therapy and its combination with neoantigen vaccines in the treatment of HNSCC are summarized, and the prospect of using neoantigen to treat HNSCC is discussed and proposed.

Plasmacytoid Dendritic Cells, a Novel Target in Myeloid Neoplasms

Plasmacytoid dendritic cells (pDC) are the main type I interferon producing cells in humans and are able to modulate innate and adaptive immune responses. Tumor infiltration by plasmacytoid dendritic cells is already well described and is associated with poor outcomes in cancers due to the tolerogenic activity of pDC. In hematological diseases, Blastic Plasmacytoid Dendritic Cells Neoplasm (BPDCN), aggressive leukemia derived from pDCs, is well described, but little is known about tumor infiltration by mature pDC described in Myeloid Neoplasms (MN). Recently, mature pDC proliferation (MPDCP) has been described as a differential diagnosis of BPDCN associated with acute myeloid leukemia (pDC-AML), myelodysplastic syndrome (pDC-MDS) and chronic myelomonocytic leukemia (pDC-CMML). Tumor cells are myeloid blasts and/or mature myeloid cells from related myeloid disorders and pDC derived from a clonal proliferation. The poor prognosis associated with MPDCP requires a better understanding of pDC biology, MN oncogenesis and immune response. This review provides a comprehensive overview about the biological aspects of pDCs, the description of pDC proliferation in MN, and an insight into putative therapies in pDC-AML regarding personalized medicine.

Structural insights into engineering a T-cell receptor targeting MAGE-A10 with higher affinity and specificity for cancer immunotherapy

BACKGROUND

T-cell receptor (TCR) immunotherapy is becoming a viable modality in cancer treatment with efficacy in clinical trials. The safety of patients is paramount, so innovative cell engineering methods are being employed to exploit adaptive immunity while controlling the factors governing antigen receptor (ie, TCR) specificity and cross-reactivity. We recently reported a TCR engineering campaign and selectivity profiling assay (X-scan) targeting a melanoma antigen gene (MAGE)-A10 peptide. This helped to distinguish between two well-performing TCRs based on cross-reactivity potential during preclinical drug evaluation, allowing one to be advanced to T-cell immunotherapeutic clinical trials. Here, we present three-dimensional structural information on those TCRs, highlighting engineering improvements and molecular mechanisms likely underpinning differential selectivity.

METHODS

Parental and engineered TCRs were purified and crystallized either alone or complexed to human leucocyte antigen (HLA)-A*02:01 presenting the MAGE-A10 9-mer peptide, GLYDGMEHL (pHLA/MAGE-A10-9). Using X-ray diffraction, we solved four high-resolution crystal structures and evaluated them relative to previously reported functional results.

RESULTS

The unligated parental TCR displayed similar complementarity-determining region (CDR) loop conformations when bound to pHLA/MAGE-A10-9; a rigid-body movement of TCR beta chain variable domain (TRBV) relative to TCR alpha chain variable domain helped optimal pHLA engagement. This first view of an HLA-bound MAGE-A10 peptide revealed an intrachain non-covalent 'staple' between peptide Tyr3 and Glu7. A subtle Glu31-Asp mutation in βCDR1 of the parental TCR generated a high-affinity derivative. Its pHLA-complexed structure shows that the shorter Asp leans toward the pHLA with resulting rigid-body TRBV shift, creating localized changes around the peptide's C-terminus. Structural comparison with a less selective TCR indicated that differential cross-reactivity to MAGE-A10 peptide variants is most readily explained by alterations in surface electrostatics, and the size and geometry of TCR-peptide interfacial cavities.

CONCLUSIONS

Modest changes in engineered TCRs targeting MAGE-A10 produced significantly different properties. Conformational invariance of TCR and antigen peptide plus more space-filling CDR loop sequences may be desirable properties for clinically relevant TCR-pHLA systems to reduce the likelihood of structurally similar peptide mimics being tolerated by a TCR. Such properties may partially explain why the affinity-enhanced, in vitro-selected TCR has been generally well tolerated in patients.

Stem cell like memory T cells: A new paradigm in cancer immunotherapy

Stem cell like memory T (T_SCM) cells have emerged as the apex of memory T cell differentiation for their properties of self-renewal and replenishing progenies. With potent long-term persistence, proliferative capacity and antitumor activity, T_SCM cells were thought to be the ideal candidate for cancer immunotherapies. Several strategies have been proposed, such as manipulations of cytokines, metabolic factors, signal pathways, and T cell receptor signal intensity, to induce more T_SCM cells in vitro, in the hope that they could reach a clinical order of magnitude to provide more long-lasting and effective anti-tumor effects in vivo. In this review, we summarized the differentiation characteristics of T_SCM cells and strategies to generate more T_SCM cells. We focused on their roles and application in the cancer immunotherapy especially in adoptive cell transfer therapy and cancer therapeutic vaccines, and hopefully provided clues for future understanding and researches.

Exploration of the Immunotyping Landscape and Immune Infiltration-Related Prognostic Markers in Ovarian Cancer Patients

Background

Increasing evidence indicates that immune cell infiltration (ICI) affects the prognosis of multiple cancers. This study aims to explore the immunotypes and ICI-related biomarkers in ovarian cancer.

Methods

The ICI levels were quantified with the CIBERSORT and ESTIMATE algorithms. The unsupervised consensus clustering method determined immunotypes based on the ICI profiles. Characteristic genes were identified with the Boruta algorithm. Then, the ICI score, a novel prognostic marker, was generated with the principal component analysis of the characteristic genes. The relationships between the ICI scores and clinical features were revealed. Further, an ICI signature was integrated after the univariate Cox, lasso, and stepwise regression analyses. The accuracy and robustness of the model were tested by three independent cohorts. The roles of the model in the immunophenoscores (IPS), tumor immune dysfunction and exclusion (TIDE) scores, and immunotherapy responses were also explored. Finally, risk genes (GBP1P1, TGFBI, PLA2G2D) and immune cell marker genes (CD11B, NOS2, CD206, CD8A) were tested by qRT-PCR in clinical tissues.

Results

Three immunotypes were identified, and ICI scores were generated based on the 75 characteristic genes. CD8 TCR pathways, chemokine-related pathways, and lymphocyte activation were critical to immunophenotyping. Higher ICI scores contributed to better prognoses. An independent prognostic factor, a three-gene signature, was integrated to calculate patients’ risk scores. Higher TIDE scores, lower ICI scores, lower IPS, lower immunotherapy responses, and worse prognoses were revealed in high-risk patients. Macrophage polarization and CD8 T cell infiltration were indicated to play potentially important roles in the development of ovarian cancer in the clinical validation cohort.

Conclusions

Our study characterized the immunotyping landscape and provided novel immune infiltration-related prognostic markers in ovarian cancer.

Microbial short-chain fatty acids: a strategy to tune adoptive T cell therapy

The gut microbiota and its metabolites have been shown to play a pivotal role in the regulation of metabolic, endocrine and immune functions. Though the exact mechanism of action remains to be fully elucidated, available knowledge supports the ability of microbiota-fermented short-chain fatty acids (SCFAs), such as acetate, propionate, and butyrate, to influence epigenetic and metabolic cascades controlling gene expression, chemotaxis, differentiation, proliferation, and apoptosis in several non-immune and immune cell subsets. While used as preferred metabolic substrates and sources of energy by colonic gut epithelial cells, most recent evidence indicates that these metabolites regulate immune functions, and in particular fine-tune T cell effector, regulatory and memory phenotypes, with direct in vivo consequences on the efficacy of chemotherapy, radiotherapy and immunotherapy. Most recent data also support the use of these metabolites over the course of T cell manufacturing, paving the way for refined adoptive T cell therapy engineering. Here, we review the most recent advances in the field, highlighting in vitro and in vivo evidence for the ability of SCFAs to shape T cell phenotypes and functions.

Single B Cell Gene Co-Expression Networks Implicated in Prognosis, Proliferation, and Therapeutic Responses in Non-Small Cell Lung Cancer Bulk Tumors

Simple Summary

This study presents novel insights on dysregulated B cell proliferation networks in non-small cell lung cancer (NSCLC). Within this network, a nine-gene signature demonstrated prognostic and predictive indications in more than 1400 NSCLC patients using their gene and protein expression profiles in bulk tumors. Furthermore, novel therapeutic candidates are identified to improve NSCLC treatment outcomes.

Abstract

In NSCLC, there is a pressing need for immunotherapy predictive biomarkers. The processes underlying B-cell dysfunction, as well as their prognostic importance in NSCLC, are unknown. Tumor-specific B-cell gene co-expression networks were constructed by comparing the Boolean implication modeling of single-cell RNA sequencing of NSCLC tumor B cells and normal B cells. Proliferation genes were selected from the networks using in vitro CRISPR-Cas9/RNA interfering (RNAi) screening data in more than 92 human NSCLC epithelial cell lines. The prognostic and predictive evaluation was performed using public NSCLC transcriptome and proteome profiles. A B cell proliferation and prognostic gene co-expression network was present only in normal lung B cells and missing in NSCLC tumor B cells. A nine-gene signature was identified from this B cell network that provided accurate prognostic stratification using bulk NSCLC tumor transcriptome (n = 1313) and proteome profiles (n = 103). Multiple genes (HLA-DRA, HLA-DRB1, OAS1, and CD74) differentially expressed in NSCLC B cells, peripheral blood lymphocytes, and tumor T cells had concordant prognostic indications at the mRNA and protein expression levels. The selected genes were associated with drug sensitivity/resistance to 10 commonly used NSCLC therapeutic regimens. Lestaurtinib was discovered as a potential repositioning drug for treating NSCLC.

Progress and Prospect of Immunotherapy for Triple-Negative Breast Cancer

Breast cancer is the most commonly diagnosed cancer (estimated 2.3 million new cases in 2020) and the leading cause of cancer death (estimated 685,000 deaths in 2020) in women globally. Breast cancers have been categorized into four major molecular subtypes based on the immunohistochemistry (IHC) expression of classic hormone and growth factor receptors including the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), as well as a proliferation marker Ki-67 protein expression. Triple-negative breast cancer (TNBC), a breast cancer subtype lacking ER, PR, and HER2 expression, is associated with a high metastatic potential and poor prognosis. TNBC accounts for approximately only 15%-20% of new breast cancer diagnoses; it is responsible for most breast cancer-related deaths due to the lack of targeted treatment options for this patient population, and currently, systemic chemotherapy, radiation, and surgical excision remain the major treatment modalities for these patients with TNBC. Although breast cancer patients in general do not have a robust response to the immunotherapy, a subset of TNBC has been demonstrated to have high tumor mutation burden and high tumor-infiltrating lymphocytes, resembling the features observed on melanoma or lung cancers, which can benefit from the treatment of immune checkpoint inhibitors (ICIs). Therefore, the immunogenic nature of this aggressive disease has presented an opportunity for the development of TNBC-targeting immunotherapies. The recent US Food and Drug Administration approval of atezolizumab in combination with the chemotherapeutic agent nab-paclitaxel for the treatment of PD-L1-positive unresectable, locally advanced, or metastatic TNBC has led to a new era of immunotherapy in TNBC treatment. In addition, immunotherapy becomes an active research area, both in the cancer biology field and in the oncology field. In this review, we will extend our coverage on recent discoveries in preclinical research and early results in clinical trials from immune molecule-based therapy including cytokines, monoclonal antibodies, antibody-drug conjugates, bi-specific or tri-specific antibodies, ICIs, and neoantigen cancer vaccines; oncolytic virus-based therapies and adoptive immune cell transfer-based therapies including TIL, chimeric antigen receptor-T (CAR-T), CAR-NK, CAR-M, and T-cell receptor-T. In the end, we will list a series of the challenges and opportunities in immunotherapy prospectively and reveal novel technologies such as high-throughput single-cell sequencing and CRISPR gene editing-based screening to generate new knowledges of immunotherapy.

The Past, Present, and Future of Non-Viral CAR T Cells

Adoptive transfer of chimeric antigen receptor (CAR) T lymphocytes is a powerful technology that has revolutionized the way we conceive immunotherapy. The impressive clinical results of complete and prolonged response in refractory and relapsed diseases have shifted the landscape of treatment for hematological malignancies, particularly those of lymphoid origin, and opens up new possibilities for the treatment of solid neoplasms. However, the widening use of cell therapy is hampered by the accessibility to viral vectors that are commonly used for T cell transfection. In the era of messenger RNA (mRNA) vaccines and CRISPR/Cas (clustered regularly interspaced short palindromic repeat-CRISPR-associated) precise genome editing, novel and virus-free methods for T cell engineering are emerging as a more versatile, flexible, and sustainable alternative for next-generation CAR T cell manufacturing. Here, we discuss how the use of non-viral vectors can address some of the limitations of the viral methods of gene transfer and allow us to deliver genetic information in a stable, effective and straightforward manner. In particular, we address the main transposon systems such as Sleeping Beauty (SB) and piggyBac (PB), the utilization of mRNA, and innovative approaches of nanotechnology like Lipid-based and Polymer-based DNA nanocarriers and nanovectors. We also describe the most relevant preclinical data that have recently led to the use of non-viral gene therapy in emerging clinical trials, and the related safety and efficacy aspects. We will also provide practical considerations for future trials to enable successful and safe cell therapy with non-viral methods for CAR T cell generation.

Immunotherapy discovery on tumor organoid-on-a-chip platforms that recapitulate the tumor microenvironment

Cancer immunotherapy has achieved remarkable success over the past decade by modulating patients' own immune systems and unleashing pre-existing immunity. However, only a minority of cancer patients across different cancer types are able to benefit from immunotherapy treatment; moreover, among those small portions of patients with response, intrinsic and acquired resistance remains a persistent challenge. Because the tumor microenvironment (TME) is well recognized to play a critical role in tumor initiation, progression, metastasis, and the suppression of the immune system and responses to immunotherapy, understanding the interactions between the TME and the immune system is a pivotal step in developing novel and efficient cancer immunotherapies. With unique features such as low reagent consumption, dynamic and precise fluid control, versatile structures and function designs, and 3D cell co-culture, microfluidic tumor organoid-on-a-chip platforms that recapitulate key factors of the TME and the immune contexture have emerged as innovative reliable tools to investigate how tumors regulate their TME to counteract antitumor immunity and the mechanism of tumor resistance to immunotherapy. In this comprehensive review, we focus on recent advances in tumor organoid-on-a-chip platforms for studying the interaction between the TME and the immune system. We first review different factors of the TME that recent microfluidic in vitro systems reproduce to generate advanced tools to imitate the crosstalk between the TME and the immune system. Then, we discuss their applications in the assessment of different immunotherapies' efficacy using tumor organoid-on-a-chip platforms. Finally, we present an overview and the outlook of engineered microfluidic platforms in investigating the interactions between cancer and immune systems, and the adoption of patient-on-a-chip models in clinical applications toward personalized immunotherapy.

A review on targeting tumor microenvironment: The main paradigm shift in the mAb-based immunotherapy of solid tumors

Monoclonal antibodies (mAbs) as biological macromolecules have been remarked the large and growing pipline of the pharmaceutical market and also the most promising tool in modern medicine for cancer therapy. These therapeutic entities, which consist of whole mAbs, armed mAbs (i.e., antibody-toxin conjugates, antibody-drug conjugates, and antibody-radionuclide conjugates), and antibody fragments, mostly target tumor cells. However, due to intrinsic heterogeneity of cancer diseases, tumor cells targeting mAb have been encountered with difficulties in their unpredictable efficacy as well as variability in remission and durable clinical benefits among cancer patients. To address these pitfalls, the area has undergone two major evolutions with the intent of minimizing anti-drug responses and addressing limitations experienced with tumor cell-targeted therapies. As a novel hallmark of cancer, the tumor microenvironment (TME) is becoming the great importance of attention to develop innovative strategies based on therapeutic mAbs. Here, we underscore innovative strategies targeting TME by mAbs which destroy tumor cells indirectly through targeting vasculature system (e.g., anti-angiogenesis), immune system modulation (i.e., stimulation, suppression, and depletion), the targeting and blocking of stroma-based growth signals (e.g., cancer-associated fibroblasts), and targeting cancer stem cells, as well as, their effector mechanisms, clinical uses, and relevant mechanisms of resistance.

Adoptive Cell Therapy in Pediatric and Young Adult Solid Tumors: Current Status and Future Directions

Advances from novel adoptive cellular therapies have yet to be fully realized for the treatment of children and young adults with solid tumors. This review discusses the strategies and preliminary results, including T-cell, NK-cell and myeloid cell-based therapies. While each of these approaches have shown some early promise, there remain challenges. These include poor trafficking to the tumor as well as a hostile tumor microenvironment with numerous immunosuppressive mechanisms which result in exhaustion of cellular therapies. We then turn our attention to new strategies proposed to address these challenges including novel clinical trials that are ongoing and in development.