Differential Effects of Regulatory T Cells in the Meninges and Spinal Cord of Male and Female Mice with Neuropathic Pain

This study investigates how regulatory T cells (Tregs) affect neuropathic pain in male and female mice after nerve injury. Tregs are a type of immune cell that can reduce inflammation and help maintain balance in the immune system. Researchers injected activated Tregs into the spinal canal of mice with nerve damage and observed how it affected their pain behavior, immune cell populations in different tissues (lymphoid, meningeal), and the activity of certain cells (microglia, astrocytes) in the spinal cord. The findings showed that Treg treatment reduced pain in both male and female mice. However, the way Tregs affected the immune system and spinal cord cells differed between the sexes, suggesting different mechanisms are at play.

• 1
  Intrathecal delivery of activated Tregs reduced mechanical pain hypersensitivity and improved exploratory behaviors in both male and female mice following chronic constriction injury (CCI) of the sciatic nerve.
• 2
  Adoptively transferred Tregs accumulated in the choroid plexus, pia mater, and peripheral lymph nodes, indicating drainage from the CNS borders to the peripheral lymphatic system.
• 3
  Treg treatment resulted in differential changes in meningeal and lymph node immune cell profiles in male and female mice, and modulated spinal glial reactivity in a sex-dependent manner, suppressing inflammatory microglia and neurotoxic astrocytes in males and promoting neuroprotective astrocytes in females.