Adoptive transfer of peripheral immune cells potentiates allodynia in a graded chronic constriction injury model of neuropathic pain

► Intraperitoneal adoptive transfer of peripheral immune cells potentiates chronic constriction injury-induced allodynia. ► Peripheral immune cells only capable of potentiating existing allodynia, rather than establishing allodynia. ► Intraperitoneal adoptive transfer of high pain splenocytes may induce the migration of host-derived immune cells from the spleen to the CNS. ► Intrathecal transfer of “pain-activated” CD45+ cells results in potentiated allodynia.