Tumor immunotherapy has revolutionized the treatment prospects for various malignant tumors. Immune checkpoint inhibitors (ICIs) and chimeric antigen receptor T-cell therapy (CAR-T) , as representative of tumor immunotherapy, have achieved tremendous success in clinical practice and have become the first-line clinical treatment options for certain tumors. This article summarizes the progress and challenges of immune checkpoint inhibitors and CAR-T therapy in tumor treatment, and discusses the future direction of tumor therapeutic vaccines development. Identifying novel therapeutic targets within the realm of tumor immunology, engineering innovative drug delivery systems, and employing combinatorial therapeutic strategies are poised to enhance therapeutic efficacy and patient outcomes in oncology, thereby extending benefits to a broader patient population.
Humans ; Neoplasms/immunology* ; Immune Checkpoint Inhibitors/therapeutic use* ; Receptors, Chimeric Antigen/genetics* ; Immunotherapy/methods* ; Immunotherapy, Adoptive/methods* ; Animals ; Cancer Vaccines/therapeutic use*

Chimeric antigen receptor T (CAR-T) lymphocytes are at the forefront of adoptive immunotherapy research, and this technology has significantly advanced the prospects of tumor immunotherapy. CAR-T therapy has demonstrated remarkable efficacy in haematological tumours of lymphoid origin and provided therapeutic possibility for solid tumours. Currently, CAR-T cell preparation predominantly involves transfection of T cells with viral vectors. However, the production of viral vectors is time-consuming, expensive, and the vectors have low loading capacity, along with insertion instability. Consequently, there is a pressing need to develop more convenient and precise non-viral gene delivery methods. This paper reviews the most promising non-viral gene delivery technologies, including CRISPR/Cas9 gene editing, transposon systems such as Sleeping Beauty (SB) and PiggyBac (PB), and mRNA, and anticipates the future development of non-viral vector-based CAR-T therapies.
Humans ; Immunotherapy, Adoptive/methods* ; Receptors, Chimeric Antigen/immunology* ; Animals ; Gene Transfer Techniques ; Genetic Vectors/genetics* ; Gene Editing ; CRISPR-Cas Systems/genetics* ; DNA Transposable Elements/genetics* ; T-Lymphocytes/immunology* ; Neoplasms/immunology*

Objective To investigate the effect of ATP synthase inhibitory factor 1 (ATPIF1) on the antitumor activity of chimeric antigen receptor (CAR)-NK92 cells. Methods HER2-targeted CAR-NK92 cells with ATPIF1 overexpression or knockdown were constructed. CAR-positive expression rate was detected by flow cytometry. Cell proliferation capacity was measured using CCK-8 assay. Glycolytic capacity was analyzed by Seahorse metabolic analyzer. Mitochondrial membrane potential levels were detected using JC-1 probe. Target cell lysis rate was evaluated by firefly luciferase reporter assay. Expression levels of CD107a, natural-killer group 2 member D (NKG2D), granzyme B (GzmB), perforin, and interleukin 2 (IL-2) were detected via flow cytometry. Quantitative real-time PCR was used to measure the expression of interferon-induced protein with tetratricopeptide repeats 1 (IFIT1), tumor necrosis factor α (TNF-α), ATPIF1, and hexokinase 1 (HK1). The impact of glycolytic inhibition by 2-Deoxy-D-glucose (2-DG) on CAR-NK92 antitumor capacity was examined. Results Successfully generated HER2-targeting control CAR-NK92 cells, as well as ATPIF1-overexpressing and ATPIF1 knockdown CAR-NK92 cells. The ATPIF1-overexpressing CAR-NK92 cells showed significantly enhanced target cell lysis rate, elevated expression levels of NKG2D and CD107a, increased secretion capacities of Granzyme B (GzmB) and IL-2, and upregulated mRNA expression levels of IFIT1 and TNF-α, while ATPIF1-knockdown cells exhibited opposite effects. ATPIF1 overexpression induced metabolic reprogramming in CAR-NK92 cells, manifested by significantly decreased mitochondrial membrane potential (δpsim), markedly upregulated HK1 mRNA expression, and enhanced basal glycolysis and glycolytic capacity. After glycolysis inhibition with 2-DG (5 μmol/L), both ATPIF1-overexpressing and knockdown CAR-NK92 cells showed no significant differences in NKG2D and CD107a expression levels compared to control cells. Conclusion ATPIF1 regulates the antitumor activity of CAR-NK92 cells through modulating glycolytic metabolism. Overexpression of ATPIF1 can enhance the antitumor efficacy of CAR-NK92 cells.
Humans ; Glycolysis ; Killer Cells, Natural/metabolism* ; Receptors, Chimeric Antigen/immunology* ; Granzymes/genetics* ; Hexokinase/metabolism* ; Cell Line, Tumor ; Interleukin-2/genetics* ; Cell Proliferation ; NK Cell Lectin-Like Receptor Subfamily K/genetics* ; Membrane Potential, Mitochondrial

This study is designed to address the development, synthesis, and screening of non-animal-derived nanoantibody libraries. Furthermore, it seeks to elucidate the impact of framework region selection and complementarity-determining region (CDR) design on the characteristics of synthesized nanoantibody libraries. These investigations aim to establish a robust theoretical and technical foundation for enhancing the efficacy, diversity, and practical applicability of synthetic nanoantibody libraries. In this study, a new framework (IGHV3S65*01-IGHJ4*01) was identified based on the high-throughput sequencing results of natural nanobodies, and degenerate primers were designed based on the frequency of amino acids at each position in the complementarity-determining region (CDR) region to synthesize the coding fragments of nanobodies by overlap PCR. After 40 times of electro-transformation, a single-frame synthesized nanobody library (SS-Library) containing 6×10⁹ clones was obtained, and the titer of the library was demonstrated to be 10¹³ PFU/mL after rescue by the helper phage M13K07. Random 48 single colonies were picked for PCR, which revealed an insertion rate of 95.8%. Sanger sequencing results showed that 38 clones had complete sequences, none of which showed cysteines or stop codons, and no identical sequences appeared, suggesting that the library had higher diversity. The library was screened and validated with three antigens, including bovine serum albumin (BSA), acetylcholinesterase (AchE), and immunoglobulin G (IgG). Finally, 2 nanobodies against BSA, 10 against AchE, and 15 against IgG were obtained. One positive clone of each antigen was singled out for recombinant expression, and the results showed that all the three nanobodies were expressed in a soluble form. The binding activity of recombinantly expressed nanobodies was evaluated using indirect enzyme-linked immunosorbent assay (ELISA) and bio-layer interferometry (BLI). The results demonstrated that the anti-AChE and anti-IgG nanobodies exhibited specific binding to their respective antigens, with affinity constants (KD) of 294 nmol/L and 250 nmol/L, respectively. The nanobody synthetic library preparation method proposed in this study is simple and easy to use with low preference, and it is expected to be a universal nanobody discovery platform for the preparation and development of lead specific nanobodies.
Single-Domain Antibodies/biosynthesis* ; Peptide Library ; Complementarity Determining Regions/immunology* ; Animals

Cancer ranks as the second leading cause of death globally and has surpassed cardiovascular diseases to become the primary cause of mortality in developed countries. Cancer stem cells (CSCs), which play crucial roles in cancer recurrence, metastasis, and drug resistance, have attracted significant attention in targeted therapeutic strategies. Aptamers, with unique three-dimensional structures capable of specifically recognizing the surface markers of CSCs, show promising potential in targeted drug delivery systems. Compared with conventional antibodies, aptamers are praised for small molecular weights, low production costs, and easy chemical modification. This review systematically summarizes recent advances in aptamer research targeting the surface markers of CSCs, with particular emphasis on aptamer-drug conjugate systems targeting the markers including EpCAM, CD133, CD44, and ABCG2. Both in vitro cellular studies and in vivo animal models have demonstrated the definite anti-cancer efficacy of aptamer-based drug delivery systems, which are of great significance to develop novel therapeutic strategies and improving the therapeutic effects of CSC-targeted treatment. Thus, aptamer-based drug delivery system has broad application prospects in the field of precise cancer treatment.
Humans ; Neoplastic Stem Cells/metabolism* ; Aptamers, Nucleotide/therapeutic use* ; Drug Delivery Systems/methods* ; Neoplasms/drug therapy* ; Biomarkers, Tumor/metabolism* ; Animals ; Epithelial Cell Adhesion Molecule ; AC133 Antigen ; Hyaluronan Receptors

OBJECTIVE: To investigate the predictive role of the modified Endothelial Activation and Stress Index (mEASIX) in the efficacy of chimeric antigen receptor T-cell (CAR-T) therapy and cytokine release syndrome (CRS). METHODS: The clinical data of 70 relapsed and refractory (R/R) B-cell tumor patients who were treated with CAR-T therapy from September 1, 2018 to February 28, 2023 in the Department of Hematology, Affiliated Hospital of Xuzhou Medical University, were retrospectively analyzed. The value of log-2 mEASIX before conditioning (-7 d) was calculated, and the patients were divided into a low-mEASIX group (42 patients) and a high-mEASIX group (28 patients) based on the cut-off value of 5.443 determined by the receiver operating characteristic (ROC) curve. Eventually, the predictive role of mEASIX before conditioning on the efficacy of CAR-T cell therapy and CRS was analyzed. RESULTS: The high-mEASIX group exhibited significantly worse median overall survival (OS) and median progression-free survival (PFS) in comparison to the low mEASIX group (OS: 3.2 months vs not reached, P < 0.01; PFS: 1.3 months vs 6.0 months, P =0.009). The incidence of grade ≥2 CRS in the high-mEASIX group was substantially higher than that in the low-mEASIX group (57.1% vs 19.0%, P =0.007). The degree of remission after CAR-T therapy (P =0.001), whether CRS occurs or not (P =0.041), the lactate dehydrogenase (LDH) level before conditioning (P =0.046), and the mEASIX score before conditioning (P =0.047) were independent influencing factors for the OS of patients receiving CAR-T cell therapy. CONCLUSION The mEASIX score before conditioning can predict OS and the incidence of grade ≥2 CRS in patients with relapsed and refractory B-cell tumors who receive CAR-T cell therapy.
Cytokine Release Syndrome/therapy* ; Immunotherapy, Adoptive/methods* ; Humans ; Lymphoma, B-Cell/therapy* ; Retrospective Studies ; Hematology ; China ; Receptors, Chimeric Antigen/blood* ; Predictive Value of Tests

OBJECTIVE: To screen anti-tumor drugs that improve antigen processing and presentation in acute myeloid leukemia (AML) cells. METHODS: A TCR-like or TCR mimic antibody that can specifically recognize HLA-A*0201:WT1_126-134 ( RMFPNAPYL) complex (hereafter referred to as HLA-A2:WT1) was synthesized to evaluate the function of antigen processing and presentation machinery (APM) in AML cells. AML cell line THP1 was incubated with increasing concentrations of IFN-γ, hypomethylating agents (HMA), immunomodulatory drugs (IMiD), proteasome inhibitors (PI) and γ-secretase inhibitors (GSI), followed by measuring of HLA-ABC, HLA-A2 and HLA-A2:WT1 levels by flow cytometry at consecutive time points. RESULTS: The TCR-like antibody we generated only binds to HLA-A*0201⁺WT1⁺ cells, indicating the specificity of the antibody. HLA-A2:WT1 level of THP-1 cells detected with the TCR-like antibody was increased significantly after co-incubation with IFN-γ, showing that the HLA-A2:WT1 TCR like antibody could evaluate the function of APM. Among the anti-tumor agents screened in this study, GSI (LY-411575) and HMA (decitabine and azacitidine) could significantly increase the HLA-A2:WT1 level. The IMiD lenalidomide and pomalidomide could aslo upregulate the expression of HLA-A2:WT1 complex under certain concentrations of the drugs and incubation time. As proteasome inhibitors, carfilzomib could significantly decreased the expression of HLA-A2:WT1, while bortezomib had no significant effect on HLA-A2:WT1 expression. CONCLUSION HLA-A2:WT1 TCR-like antibody can effectively reflect the APM function. Some of the anti-tumor drugs can affect the APM function and immunogenicity of tumor cells.
Humans ; Leukemia, Myeloid, Acute/immunology* ; Antineoplastic Agents/pharmacology* ; Antigen Presentation/drug effects* ; HLA-A2 Antigen/immunology* ; Receptors, Antigen, T-Cell/immunology* ; Cell Line, Tumor ; Interferon-gamma

Chimeric antigen receptor (CAR) T-cell therapy has shown remarkable efficacy in treating hematological malignancies and is expanding into other indications such as autoimmune diseases, fibrosis, aging and viral infection. However, clinical challenges persist in treating solid tumors, including physical barriers, tumor heterogeneity, poor in vivo persistence, and T-cell exhaustion, all of which hinder therapeutic efficacy. This review focuses on the critical role of tonic signaling in CAR-T therapy. Tonic signaling is a low-level constitutive signaling occurring in both natural and engineered antigen receptors without antigen stimulation. It plays a pivotal role in regulating immune cell homeostasis, exhaustion, persistence, and effector functions. The "Peak Theory" suggests an optimal level of tonic signaling for CAR-T function: while weak tonic signaling may result in poor proliferation and persistence, excessively strong signaling can cause T cell exhaustion. This review also summarizes the recent progress in mechanisms underlying the tonic signaling and strategies to fine-tune the CAR tonic signaling. By understanding and precisely modulating tonic signaling, the efficacy of CAR-T therapies can be further optimized, offering new avenues for treatment across a broader spectrum of diseases. These findings have implications beyond CAR-T cells, potentially impacting other engineered immune cell therapies such as CAR-NK and CAR-M.
Humans ; Immunotherapy, Adoptive/methods* ; Receptors, Chimeric Antigen/immunology* ; Signal Transduction/immunology* ; T-Lymphocytes/immunology* ; Neoplasms/immunology* ; Animals

Colorectal cancer (CRC), a major global health concern, necessitates innovative treatments. Chimeric antigen receptor (CAR) T cells have shown promises, yet they grapple with challenges. The spotlight pivots to the rising heroes: CAR natural killer (NK) cells, offering advantages such as higher safety profiles, cost-effectiveness, and efficacy against solid tumors. Nevertheless, the specific mechanisms underlying CAR NK cell trafficking and their interplay within the complex tumor microenvironment require further in-depth exploration. Herein, we provide insights into the design and engineering of CAR NK cells, antigen targets in CRC, and success in overcoming resistance mechanisms with an emphasis on the potential for clinical trials.
Colorectal Neoplasms/immunology* ; Humans ; Killer Cells, Natural/metabolism* ; Receptors, Chimeric Antigen/genetics* ; Immunotherapy, Adoptive/methods* ; Tumor Microenvironment/immunology* ; Animals

The remarkable efficacy of chimeric antigen receptor (CAR) T cell therapy in hematological malignancies has provided a solid basis for the therapeutic concept, wherein specific pathogenic cell populations can be eradicated by means of targeted recognition. During the past few years, CAR-based cell therapies have been extensively investigated in preclinical and clinical research across various non-tumor diseases, with particular emphasis in the treatment of autoimmune diseases (ADs), yielding significant advancements. The recent deployment of CD19-directed CAR T cells has induced long-lasting, drug-free remission in patients with systemic lupus erythematosus (SLE) and other systemic ADs, alongside a more profound immune reconstruction of B cell repertoire compared with conventional immunosuppressive agents and B cell-targeting biologics. Despite the initial success achieved by CAR T cell therapy, it is critical to acknowledge the divergences in its application between cancer and ADs. Through examining recent clinical studies and ongoing research, we highlight the transformative potential of this therapeutic approach in the treatment of SLE, while also addressing the challenges and future directions necessary to enhance the long-term efficacy and safety of CAR-based cell therapies in clinical practice.
Humans ; Lupus Erythematosus, Systemic/immunology* ; Receptors, Chimeric Antigen/metabolism* ; Immunotherapy, Adoptive/methods* ; Cell- and Tissue-Based Therapy/methods* ; Animals ; T-Lymphocytes/immunology*