Targeting PD-L1 for Ischemic Stroke Recovery: Age-Dependent Modulation of Immune and BBB Pathways.
Aging has a profound impact on the pathophysiology of ischemic stroke and the effectiveness of therapeutic interventions. This study aims to evaluate the therapeutic efficacy of programmed death-ligand 1 (PD-L1) monoclonal antibody (mAb) in modulating immune responses and neurovascular repair following ischemic stroke, with a focus on age-dependent differences.
Young and aged mice were subjected to middle cerebral artery occlusion (MCAO) followed by PD-L1 mAb treatment. RNA sequencing, immunofluorescence, and molecular analyses were employed to assess immune modulation, blood-brain barrier (BBB) integrity, and functional recovery.
RNA sequencing revealed significant differential gene expression in ischemic brain tissues, with CD274 (PD-L1) prominently upregulated among immune checkpoint-related genes in young mice. Immunofluorescence confirmed PD-L1 expression in microglia/macrophages, with significantly higher upregulation in young mice. PD-L1 mAb treatment showed superior efficacy in young mice, significantly reducing infarct volume, enhancing neurological recovery, and preserving BBB integrity through greater upregulation of tight junction proteins such as ZO-1, Claudin-5, and Occludin compared to aged mice. It also more effectively reduced neuroinflammation, apoptosis, and pro-inflammatory cytokines (TNF-α, IL-1β), eliciting stronger spleen responses in young mice. These findings underscore the age-dependent advantages of PD-L1-targeted therapies for ischemic stroke recovery.
PD-L1 plays a critical role in ischemic stroke recovery, with PD-L1 mAb treatment demonstrating age-dependent therapeutic efficacy by enhancing BBB integrity, reducing neuroinflammation and apoptosis, and modulating peripheral immune responses.
Young and aged mice were subjected to middle cerebral artery occlusion (MCAO) followed by PD-L1 mAb treatment. RNA sequencing, immunofluorescence, and molecular analyses were employed to assess immune modulation, blood-brain barrier (BBB) integrity, and functional recovery.
RNA sequencing revealed significant differential gene expression in ischemic brain tissues, with CD274 (PD-L1) prominently upregulated among immune checkpoint-related genes in young mice. Immunofluorescence confirmed PD-L1 expression in microglia/macrophages, with significantly higher upregulation in young mice. PD-L1 mAb treatment showed superior efficacy in young mice, significantly reducing infarct volume, enhancing neurological recovery, and preserving BBB integrity through greater upregulation of tight junction proteins such as ZO-1, Claudin-5, and Occludin compared to aged mice. It also more effectively reduced neuroinflammation, apoptosis, and pro-inflammatory cytokines (TNF-α, IL-1β), eliciting stronger spleen responses in young mice. These findings underscore the age-dependent advantages of PD-L1-targeted therapies for ischemic stroke recovery.
PD-L1 plays a critical role in ischemic stroke recovery, with PD-L1 mAb treatment demonstrating age-dependent therapeutic efficacy by enhancing BBB integrity, reducing neuroinflammation and apoptosis, and modulating peripheral immune responses.