Biology subjects

van Kooten, C.

Publications and source records attributed to van Kooten, C..

3 recordsLinked to original sources

bioRxiv2026

CD19-CAR T-cell therapy resets the EBV+ autoreactive B cell repertoire in autoimmune disease

Epstein-Barr virus (EBV) reprograms autoreactive B cells into activated antigen-presenting cells that drive pathogenic T- and B-cell responses in autoimmune disease. Whether eliminating these cells contributes to durable remission after CD19 chimeric antigen receptor (CAR) T-cell therapy is unknown. Here, using EBV B-cell sequencing (EBV-seq), we profiled EBV+ B cells from patients treated with CD19-CAR T cells (systemic lupus erythematosus, n=6; inflammatory myopathy, n=3; systemic sclerosis, n=3) or rituximab (n=15) and recombinantly expressed their antibodies to define antigen specificity. At baseline, EBV+ B cells were enriched relative to healthy donors, class-switched and hypermutated, expressed the latency III program with heightened antigen-presentation signatures, and encoded autoantibodies. CAR T cells, but not rituximab, depleted EBV+ B cells and shifted the reconstituted repertoire towards IgM+, minimally mutated, largely non-autoreactive cells, consistent with infection of newly generated B cells. After rituximab, EBV+ B cells retained a class-switched, hypermutated and autoreactive with an activated antigen-presenting phenotype. Sustained drug-free remission occurred in 8/12 CAR T-cell-treated versus 0/15 rituximab-treated patients. In vitro, EBV+ B cells resisted anti-CD20 and anti-CD19 antibodies but were killed by CAR T cells and a CD19 T-cell engager. Our findings suggest resetting the EBV+ autoreactive B-cell repertoire contributes to sustained drug-free remission.

immunology↗

bioRxiv2025

Normothermic human kidney preservation drives iron accumulation and ferroptosis

Ex vivo normothermic machine perfusion has been proposed to protect deceased donor organs, promoting metabolic recovery and allowing quality assessment. However, its benefits for preserving deceased donor kidneys remain ambiguous. We postulate that the use of red blood cells (RBCs) as oxygen carriers and associated secondary hemolysis may in fact cause renal injury, offsetting potential advantages. During 48-hour normothermic perfusion of seven human deceased donor kidneys, we observed progressive hemolysis, leading to iron accumulation in perfusate, tissue, and urine. Untargeted lipidomic analysis revealed profound increases in oxidized phospholipid species in perfused kidneys, pointing towards iron-dependent cell death known as ferroptosis. Next, in twelve additional human kidney perfusions, we demonstrate that either dialysis-based free hemoglobin removal or cell-free perfusion attenuates hemolysis-driven iron accumulation, phospholipid peroxidation, and acute kidney injury. Our findings highlight the pathological role of hemolysis and iron on the kidney, urging restraint in the clinical application of RBC-based kidney perfusion.

physiology↗

bioRxiv2023

Advancing multi-day ex vivo kidney perfusion using spatially resolved metabolomics

The ability to preserve metabolically active kidneys ex vivo for multiple days may permit reconditioning, repair and regeneration of deceased donor kidneys. However, the kidneys high metabolic demand limits its functional preservation. Current approaches focus on normothermic machine perfusion (NMP) at 37{degrees}C or hypothermic machine perfusion (HMP) at 4-8{degrees}C. At normothermia, kidneys are metabolically active but ex vivo preservation is limited to hours. During hypothermia kidneys can be preserved up to 24 hours but are metabolically inactive and suffer cold-induced injury. Therefore, we revisited sub normothermic perfusion (at 25{degrees}C) as an alternative approach to preserve human kidneys in a metabolically active state for extended periods of time. In a custom-made platform that includes a cell-free perfusate enriched with TCA cycle fuels, urine recirculation, and continuous hemofiltration we perfused discarded human kidneys up to 8 days. Using spatially resolved single cell resolution isotope tracing we demonstrate active metabolism in all the different renal cell types over this period. However, beyond 4 days cell composition of nephron segments assessed with spatial lipidomics changed substantially and injury markers such as NGAL and LDH increased in the perfusate. Up to 4 days, perfused human discarded donor kidneys maintained metabolic fluxes, functional parameters and allow for reperfusion using a porcine auto transplantation model. These data underpin that extended multi-day metabolic preservation of human kidneys is achievable using a sub normothermic perfusion platform.

bioengineering↗