Biology subjects

Knudsen, N. H.

Publications and source records attributed to Knudsen, N. H..

2 recordsLinked to original sources

bioRxiv2026

CRISPR screens identify targets to rescue age-related T cell dysfunction in cancer

Immune aging is being increasingly recognized as a critical barrier to effective cancer immunotherapy, as the aged tumor microenvironment (TME) drives T cell dysfunction and impairs immune control of cancer1-4. However, the key molecular drivers of this process as well as potential targets to rescue T cell dysfunction in aged tumors remain incompletely understood. Therefore, we performed in vivo single-cell CRISPR screens in CD8 T cells within aged tumors and tumor-draining lymph nodes (tdLNs). We identified Dusp5 and Zfp219 as key regulators of T cell persistence and effector differentiation in aged hosts. Loss of Dusp5, a negative regulator of ERK signaling, increased ERK1/2 phosphorylation and enhanced T cell proliferation in both young and aged tumors. In contrast, loss of Zfp219, a transcriptional repressor, induced epigenetic reprogramming of cytotoxic gene programs, thereby increasing granzyme secretion and enhancing antitumor immunity. Moreover, expression of the human ortholog gene ZNF219 is increased within intratumoral CD8 T cells in older cancer patients. High ZNF219 expression correlates with poorer survival following immune checkpoint blockade (ICB) and reduces persistence of human intratumoral T cells. Notably, Zfp219 ablation synergized with anti-PD-1 blockade in mice to expand effector-like CD8 T cells, leading to significantly enhanced anti-tumor immunity and tumor clearance in aged hosts. Together, these findings highlight Dusp5 and Zfp219 as critical drivers of age-related T cell dysfunction and as potential therapeutic targets to rejuvenate T cell antitumor immunity in older cancer patients.

immunology↗

bioRxiv2024

In vivo CRISPR screens identify key modifiers of CAR T cell function in myeloma

Chimeric antigen receptor (CAR) T cells are highly effective in hematologic malignancies. However, loss of CAR T cells can contribute to relapse in a significant number of patients. These limitations could potentially be overcome by targeted gene editing to increase CAR T cell persistence. Here, we performed in vivo loss-of-function CRISPR screens in BCMA-targeting CAR T cells to investigate genes that influence CAR T cell persistence, function and efficacy in a human multiple myeloma model. We tracked the expansion and persistence of CRISPR-library edited T cells in vitro and then at early and late timepoints in vivo to track the performance of gene modified CAR T cells from manufacturing to survival in tumors. The screens revealed several context-specific regulators of CAR T cell expansion and persistence. Ablation of RASA2 and SOCS1 enhanced T cell expansion in vitro, while loss of PTPN2, ZC3H12A, and RC3H1 conferred early selective growth advantages to CAR T cells in vivo. Strikingly, we identified cyclin-dependent kinase inhibitor 1B (CDKN1B), a cell cycle regulator, as the most important factor limiting CAR T cell fitness at late timepoints in vivo. CDKN1B ablation increased BCMA CAR T cell proliferation and effector function in response to antigen, significantly enhancing tumor clearance and overall survival. Thus, our findings reveal differing effects of gene-perturbation on CAR T cells over time and in different selective environments, highlight CDKN1B as a promising target to generate highly effective CAR T cells for multiple myeloma, and underscore the importance of in vivo screening as a tool for identifying genes to enhance CAR T cell function and efficacy.

immunology↗