Summary CD19-directed chimeric antigen receptor (CAR)-engineered T cells have transformed cellular therapy for hematologic malignancies but have also raised concerns about secondary malignancies. A spatial profiling method was used to analyze the tumor microenvironment and define native and CAR T cell association with a pleomorphic sarcoma arising 12 months post-CAR T therapy for B cell lymphoma. Although CAR T sequences were absent in the secondary tumor, our approach enabled profiling of the stroma, tumor, and infiltrating T cells. Spatial analysis incorporated proteomics via serial antibody staining and transcriptomics using RNA hybridization on an automated MACSima imaging cyclic staining (MICS) system, which allows for in situ detection of CAR T cells. We report here the prevalence of CAR-positive T cells in patient-derived tissue sections, observed metabolic and proliferative shifts in the tumor and its microenvironment, and immune checkpoint analysis. These findings provide insights into post-CAR T secondary cancers and highlight tools that may guide future targeted therapies.
Jia-Jye Lee, Peirong Hu, Kun Luo et al.· iScience· 0 citations
A trispecific CAR targeting CD19, CD20, and CD22 with OX40 co-stimulatory domain with overall response rate was 50%, including complete responses in 83% of lymphoma patients, and one-year overall survival rate was 61%, with durable remissions observed in lymphoma.
S. Vasu, N. Denlinger, No-Joon Song et al.· Blood Cancer Discovery· 0 citations
Epigenetic scarring restricts the long-term function of exhausted CD8 T cells (TEX), impairing their ability to control chronic infections and tumors, or to respond effectively to immunotherapy. While our prior work established that de novo DNA methylation reinforces terminal exhaustion, how upstream histone modifications influence these methylation programs remains largely unknown. Defining these molecular mechanisms is essential for reversing exhaustion and enhancing the durability of T cell immunotherapies.
We employed a novel in vitro model of human CD8 T cell dysfunction alongside preclinical murine models of T cell exhaustion. Using integrative epigenomic approaches, we profiled H3K4 methylation states (H3K4me1/3) and DNA methylation signatures across distinct TEX subsets. To investigate functional relevance, we performed CRISPR/Cas9-gene editing, retroviral transduction, and pharmacological inhibition of histone demethylases to assess their impact on TEX functions, stemness, and response to immune checkpoint blockade (ICB).
While distinct histone and DNA methylation landscapes defined TEX subsets in both human and murine models, H3K4me1/3–histone marks that inhibit Dnmt3a-mediated DNA methylation–were enriched at effector/memory-associated genes in cytolytic/progenitor TEX but diminished in terminally exhausted cells. Genetic or therapeutic inhibition of specific H3K4 demethylases (KDM5A/B) improved effector function and cytotoxicity in dysfunctional human CD8 T cells. In vivo, KDM5A/B targeting enhanced TEX fitness and responsiveness to anti-PD-L1 therapy during chronic viral infection and cancer.
Our findings uncover a central histone—DNA methylation circuit, regulated by KDM5A/B and DNMT3A, that drives epigenetic scarring and terminal exhaustion in CD8 T cells. Therapeutic targeting of this circuit offers a novel approach to epigenetically reprogram TEX cells and enhance the efficacy of cancer immunotherapy.
R01AI170926 (NIH, NIAID)
Tumor Immunology: Checkpoints, Prevention, and Treatment (TIPT)
Hazem E. Ghoneim, Amira Yousif, Abbey A. Saadey et al.· Journal of Immunology· 0 citations