Chemotherapy Dosing Regimens Differentially Affect Immune Responses and Neuropathic Pain in Mice
A new preprint study in mice shows that how paclitaxel chemotherapy is dosed — as a single high dose or multiple lower doses — differentially programs immune cells in the dorsal root ganglia and affects the severity of chemotherapy-induced peripheral neuropathy (CIPN). The multiple low-dose regimen, despite delivering a higher cumulative dose, produced earlier T cell responses, less mechanical hypersensitivity, and fewer injured neurons than the single high-dose regimen. The findings suggest that dosing schedule may be a modifiable factor in managing CIPN, a debilitating side effect that often forces clinicians to reduce or stop cancer treatment.
Researchers administered paclitaxel to female mice using either a single high dose (sHD) or multiple low doses (mLD) and examined CD4+ and CD8+ T cell responses in the dorsal root ganglia (DRG), the sensory nerve clusters implicated in neuropathic pain. Despite receiving a higher cumulative dose, mLD mice showed earlier T cell infiltration in the DRG, reduced mechanical hypersensitivity, and fewer ATF3-positive neurons — a marker of nerve injury — compared to sHD mice. The mLD regimen drove a focused CD4+ T cell response alongside broad CD8+ T cell expansion, while the sHD regimen produced a delayed but polyfunctional CD4+ response with limited CD8+ effector differentiation. To isolate the role of CD4+ T cells, the team used CD4-deficient mice and found they were significantly less hypersensitive than CD4-sufficient mice, with the effect most pronounced in the sHD group. These results challenge the prevailing assumption that cumulative dose is the primary driver of CIPN risk, pointing instead to dosing concentration and frequency as key determinants of peripheral immune programming and neuropathy severity. The study was posted as a preprint on bioRxiv and has not yet undergone peer review.
What's missing
The study was conducted exclusively in female mice, leaving open whether findings generalize to males or to humans. It does not address other commonly used chemotherapy agents associated with CIPN, nor does it test whether CD4+ T cell-targeted interventions could therapeutically reduce neuropathy without compromising anti-tumor immunity. Long-term outcomes beyond the observation window and the precise molecular mechanisms linking CD4+ T cell activity to pain signaling remain uncharacterized.
What different sources said
- bioRxivCenter
Paclitaxel Dosing Regimens Drive Differential CD4⁺ T Cell Responses in the Dorsal Root Ganglia and Modulate Neuropathic Pain Severity
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