Abstract: Objective To define the phenotype of Copolymer-1(Cop-1) antigen-specific lymphocytes to protect the dopaminergic neurons in 1-methy1-4-pheny1-1,2,3,6-tetrahydropyritine(MPTP)-intoxicated C57BL/6J mice. Methods The C57BL/6J mice were divided randomly into Cop-1/BSA antigen-specific lymphocyte adoptive transfer, Cop-1/BSA antigen-specific T lymphocyte adoptive transfer, Cop-1/BSA antigen-specific lymphocyte without T cells adoptive transfer, MPTP model control and normal control groups. All the mice except normal controls received four intraperitoneal injections at 2 hour intervals of MPTP(18 mg·kg^-1). After the last injection, the animals of transfer groups received adoptive transfers of different types of antigen-specific lymphocytes immediately. All mice were killed after 7 days of last MPTP injection. The dopaminergic neurons were analyzed quantitatively using immunohistochemistry of tyrosine hydroxylase(TH) and stereological counts. Results Stereological counts revealed that that MPTP caused a significant loss of TH-positive neurons in substantia nigra(SN) (37.78% of normal controls). Similar results were observed in MPTP-injected mice that received BSA-lymphocytes(38.15% of normal controls), BSA-T-lymphocytes(41.44% of normal controls), Cop-1/BSA lymphocytes without T cells transfer(Cop-1: 40.06% of normal controls; BSA: 34.81% of normal controls). In contrast, MPTP-injected mice that received Cop-1 lymphocytes or Cop-1-T-lymphocytes exhibited a much smaller reduction in the number of TH-positive neurons(74.38%, or 84.64% of normal controls). Conclusion Cop-1 antigen-specific T lymphocytes may protect dopaminergic neurons in SN of MPTP C57BL/6J mouse.

Key words: Parkinson’s disease, Copolymer-1, T lymphocyte