Unlocking the potential of broadly reactive coronavirus monoclonal antibodies (mAbs) and their derivatives offers a transformative therapeutic avenue against severe COVID-19, especially crucial for safeguarding high-risk populations. Novel mAb-based immunotherapies may help address the reduced efficacy of current vaccines and neutralizing mAbs caused by the emergence of variants of concern (VOCs). Using phage display technology, we discovered a pan-SARS-CoV-2 mAb (C10) that targets a conserved region within the receptor-binding domain (RBD) of the virus. Noteworthy, C10 demonstrates exceptional efficacy in recognizing all assessed VOCs, including recent Omicron variants. While C10 lacks direct neutralization capacity, it efficiently binds to infected lung epithelial cells and induces their lysis via natural killer (NK) cell-mediated antibody-dependent cellular cytotoxicity (ADCC). Building upon this pan-SARS-CoV-2 mAb, we engineered C10-based, Chimeric Antigen Receptor (CAR)-T cells endowed with efficient killing capacity against SARS-CoV-2-infected lung epithelial cells. Notably, NK and CAR-T-cell mediated killing of lung infected cells effectively reduces viral titers. These findings highlight the potential of non-neutralizing mAbs in providing immune protection against emerging infectious diseases. Our work reveals a pan-SARS-CoV-2 mAb effective in targeting infected cells and demonstrates the proof-of-concept for the potential application of CAR-T cell therapy in combating SARS-CoV-2 infections. Furthermore, it holds promise for the development of innovative antibody-based and cell-based therapeutic strategies against severe COVID-19 by expanding the array of therapeutic options available for high-risk populations.Trial registration: ClinicalTrials.gov identifier: NCT04093596.

The persistence of chimeric antigen receptor (CAR) T cells in the tumor microenvironment limits their antitumor effects against solid tumors. Many studies have reported that the in vitro phenotype and metabolism of CAR-T cells correlates with their in vivo antitumor activity. Herein, we constructed PD-1 scFv-secreting and CD133-specific CAR-T (referred to as CAR-T) cells based on our previous work. We found that suitable concentration metformin-treated CAR-T (mCAR-T) cells exhibited an increased memory phenotype and demonstrated stronger and faster antitumor abilities with a reduced exhaustion phenotype. Using RNA sequencing, transmission electron microscope, and metabolic analysis, we discovered enhanced mitochondrial biogenesis and metabolism in CAR-T cells treated with 10 μM metformin, is associated with increased peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1α) expression, promotion of signal transducer and activator of transcription (STAT)3 and inhibition of STAT5 phosphorylation. This resulted in enhanced antitumor effects of mCAR-T cells in both subcutaneous and orthotopic xenograft models. Importantly, in some relapsed hepatocellular carcinoma (HCC) patients, high CD133 expression was observed in their paired primary or metastatic tumor sections. Our study revealed that enhancing metabolic fitness and central memory by in vitro metformin treatment is an effective strategy to improve the efficacy of CAR-T cell therapy, potentially benefiting some relapsed HCC patients.
© The author(s).

The challenges that remain in the treatment of solid tumors with chimeric antigen receptor (CAR)-T cells include limited solid tumor-specific targets and poor CAR-T cell expansion and function due to limited availability of solid tumor antigens outside the tumor microenvironment. Prostate cancer is the second most common cancer among men worldwide. Current CAR-T therapies for prostate cancer lack specific targets, posing safety risks. To overcome these problems, we identified prostatic acid phosphatase (PAP, also known as ACPP or ACP3) as a feasible CAR-T target for prostate cancer and developed CoupledCAR, a novel approach for expanding tumor-targeting CAR-T cells without tumor antigens.
We analyzed the expression of PAP from The Cancer Genome Atlas database and validated its expression in normal and cancer tissues through immunohistochemistry staining. To generate anti-PAP specific antibodies, we screened the human single-chain antibody library using transmembrane PAP-His antigen and selected antibodies based on their binding ability and specificity. We constructed PAP-targeted CAR and evaluated their antitumor efficacy both in vitro and in vivo. We validated the function of PAP CoupledCAR in both in vitro and in vivo experiments, and further analyzed its mechanism using single-cell RNA sequencing (scRNA-Seq).
PAP was specifically expressed in prostate epithelial and prostate cancer cells, with no expression in other tissues. Seven single-chain variable fragments were screened from the human single-chain antibody library, with S5D1 showing the highest binding ability for the PAP. PAP CAR-T cells demonstrated strong antitumor efficacy both in vitro and in vivo. Furthermore, the CoupledCAR system significantly expanded PAP CAR-T cells, promoting memory-like status, reducing exhaustion, and enhancing their antitumor efficacy. The scRNA-Seq demonstrated that the expansion of PAP CAR-T cells in the CoupledCAR system is mediated by costimulatory signals and cytokine signals, rather than T-cell receptor signals.
Our study is the first to demonstrate that PAP is a specific target for CAR-T therapy in prostate cancer, both in vitro and in vivo. We developed the CoupledCAR platform technology for solid tumor CAR-T cell therapy, enabling the expansion of tumor-targeting CAR-T cells without requiring tumor antigens and thereby enhancing their functionality against solid tumors.
© Author(s) (or their employer(s)) 2025. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ Group.

Rationale: Short-term starvation (STS) has been shown to enhance the sensitivity of tumors to chemotherapy while concurrently safeguarding normal cells from its detrimental side effects. Nonetheless, the extent to which STS relies on the anti-tumor immune response to impede the progression of hepatocellular carcinoma (HCC) remains uncertain. Methods: In this study, we employed mass cytometry, flow cytometry, immunoprecipitation, immunoblotting, CUT&Tag, RT-qPCR, and DNA pull-down assays to evaluate the relationship between STS and T-cell antitumor immunity in HCC. Results: We demonstrated that STS alleviated T cell exhaustion in HCC. This study elucidated the mechanism by which STS blocked CD36 N-glycosylation, leading to the upregulation of AMPK phosphorylation and the downregulation of USP7 UFMylation, thus enhancing ubiquitination and destabilized USP7. Consequently, diminished USP7 levels facilitated the ubiquitination and subsequent degradation of RBPJ, thereby inhibiting T cell exhaustion through the IRF4/TNFRSF1B axis. From a therapeutic standpoint, STS not only suppressed the growth of patient-derived orthotopic xenografts but also enhanced their sensitivity to immunotherapy. Conclusions: These findings uncovered a novel mechanism by which N-glycosylation participated in UFMylation/ubiquitination to regulate T cell exhaustion, and we underscored the potential of targeting USP7 and RBPJ in anti-tumor immunotherapy strategies.
© The author(s).

The efficacy of chimeric antigen receptor T cells (CART) in solid tumors is limited by immune inhibition. In our study, we observed that effector cytokines mediated the upregulation of the PD-L1 immune checkpoint in primary glioblastoma. To offset the PD-L1 inhibitory signal, we engineered PD-1 checkpoint reversal receptors (CPR) with a CD28 or 41BB costimulatory endodomain and coexpressed them with a first-generation or a CD28-containing second-generation HER2-specific CAR (CPR/CART) using bicistronic vectors. We found that bipartite T-cell activation, by CAR-generated signal 1 and CPR costimulation (signal 2), fine-tuned proinflammatory cytokine release and sustained antitumor activity. Whereas both CPR28 and CPR41BB effectively counteracted the PD-1 signal in vitro, CPR41BB, when coexpressed with a first-generation CAR (CARζ/CPR41BB), promoted central memory differentiation following repeat antigenic stimulation. CARζ/CPR41BB T cells formed a robust immune synapse with tumor targets, similar to a 41BB-containing second-generation CART, maintained the favorable metabolic parameters associated with 41BB costimulation, and demonstrated superior antitumor function after adoptive transfer in xenograft models of gioblastoma and metastatic osteosarcoma. Thus, a CPR molecule with 41BB costimulation that curtails PD-1 inhibition and complements CAR signaling to optimize T-cell activation could enhance CART efficacy against solid tumors.
Enhancing CART function and persistence while balancing immune effector-mediated inflammation is crucial. Using our clinically relevant HER2-CAR platform, we demonstrate that tumor-intrinsic signals like the PD-1/PD-L1 immune checkpoint can be leveraged in CART design to modulate immune synapse and metabolic parameters, improving antitumor function without increasing cytokine production.
©2025 The Authors; Published by the American Association for Cancer Research.