VPAC1 receptor (Vipr1)-deficient mice exhibit ameliorated experimental autoimmune encephalomyelitis, with specific deficits in the effector stage.

VPAC1 knockout mice exhibited significantly reduced experimental autoimmune encephalomyelitis (EAE) severity, associated with decreased CNS chemokine expression and immune cell infiltration. The immunization phase was unaffected, but the effector phase of disease was impaired, indicating VPAC1's critical role in mediating immune cell invasion into the CNS.

EAE was induced in VPAC1-deficient and wild-type mice using MOG35-55 peptide. Disease progression was monitored over 30 days with clinical scoring, histology, PCR, and immunofluorescence. Immune function was assessed via antigen recall assays, adoptive transfer, and bone marrow chimera experiments. VPAC1 antagonists were administered to test receptor involvement.

Understanding VPAC1's role in autoimmune neuroinflammation could guide development of targeted therapies for diseases like multiple sclerosis by modulating immune cell entry into the brain and spinal cord.

The study was conducted in mice, which may not fully replicate human disease. The exact molecular mechanisms by which VPAC1 influences immune cell trafficking remain to be elucidated.