Targeting TGFβ-activated kinase-1 activation in microglia reduces CAR T immune effector cell-associated neurotoxicity syndrome

In this study, researchers explored the role of the TAK1 activation pathway in CAR T cell therapy-associated immune effector cell-associated neurotoxicity syndrome (ICANS). They established a mouse ICANS model and found that following the transfer of CAR19 T cells, cerebellar cells were activated, underwent morphological changes, and expressed more activation markers (such as CD80, CD11c, and major histocompatibility complex class II).

Microarray and single-nuclei RNA sequencing analyses showed upregulation of pro-inflammatory factors such as TNF, CCL2, GM-CSF, and their associated pathway genes in activated cerebellar cells. Behavioral tests revealed cognitive impairments such as increased anxiety and decreased memory in mice receiving CAR19 T cell therapy, accompanied by increased blood-brain barrier permeability. By using gene knockout and pharmacological inhibition (Takinib), the researchers found that inhibiting TAK1 activity in cerebellar cells ameliorated these cognitive deficits without affecting the tumor-killing ability of CAR T cells.

In human sample analysis, researchers used imaging mass spectrometry and immunohistochemistry techniques to confirm the activation of cerebellar cells in ICANS patients, which could be detected by TSPO-PET imaging. Overall, this study revealed the critical role of cerebellar cells in the pathogenesis of ICANS and proposed TAK1 as a potential therapeutic target to alleviate ICANS severity while preserving the anti-tumor activity of CAR T cells.

The introduction briefly introduced the application of CAR T cell therapy in lymphoma and leukemia, as well as the clinical manifestations and current understanding of the pathogenesis of ICANS. It then introduced the authors and the publishing journal of this study.

The methods section detailed the experimental procedures. First, in B-cell non-Hodgkin lymphoma (B-NHL) and B-cell acute lymphoblastic leukemia (B-ALL) mouse models, syngeneic CAR19 T cells were transferred, and the morphology and marker changes of cerebellar cells were observed. Single-nucleus RNA sequencing, microarray, and other techniques were used to analyze the transcriptome and activation pathways of cerebellar cells. Various behavioral tests were performed to evaluate cognitive function in mice, and blood-brain barrier permeability was assessed.

Gene knockout and pharmacological inhibition of TAK1 activity were used to observe changes in cerebellar activation and cognitive function. The tumor-killing activity of CAR T cells was further analyzed to determine if it was affected. Finally, in post-mortem samples from ICANS patients, cerebellar activation was detected using imaging mass spectrometry and immunohistochemistry, and TSPO-PET imaging was performed.

The results section reported the key findings: After CAR19 T cell therapy, mouse cerebellar cells underwent significant morphological changes, and the expression of activation markers CD80, CD11c, and MHC class II molecules increased. Transcriptomic analysis revealed a significant upregulation of pro-inflammatory factors such as TNF, CCL2, GM-CSF, and their associated pathway genes in these activated cerebellar cells.

Behavioral tests confirmed cognitive impairments such as anxiety and memory deficits in mice receiving CAR19 T cell therapy, accompanied by increased blood-brain barrier permeability. Gene knockout and pharmacological inhibition experiments showed that inhibiting the TAK1-NF-κB-p38 MAPK signaling pathway in cerebellar cells could reverse these cognitive deficits without affecting the tumor-killing ability of CAR T cells. In contrast, conventional corticosteroid treatment, although improving neurological symptoms, suppressed the anti-tumor activity of CAR T cells.

In the analysis of ICANS patient samples, researchers found a significant increase in the activated microglia/monocyte population in the cerebellar cells of ICANS patients compared to controls, expressing activation markers such as HLA-DR, CD74, CD204, and CD163, using imaging mass spectrometry. Immunohistochemistry also confirmed the presence of abundant activated cerebellar cell infiltration in the white matter of ICANS patients’ brains. Furthermore, TSPO-PET imaging revealed significant TSPO elevation in the cerebellum of ICANS patients, reflecting cerebellar cell activation.

The conclusion emphasized that this study elucidated the role of cerebellar cells in the pathogenesis of ICANS and, for the first time, identified TAK1 as a potential therapeutic target, helping to alleviate ICANS severity while preserving the anti-tumor activity of CAR T cells, providing new insights for the clinical treatment of ICANS.