Figure 6

Blocking MCAM following N-4YSyn-specific splenocyte transfers elicits partial neuroprotection. Donor immune cells containing N-4YSyn-specific Teffs were obtained from spleens of mice immunized and boosted with N-4YSyn. To recipient mice that were treated with MPTP at dosages of 18 mg/kg every 2 hours for 4 doses, 30 × 10⁶ donor cells were adoptively transferred (AT) twelve hours after the last dose of MPTP, while one group of MPTP mice received no donor immune cells. Of the 4 groups that received donor immune cells, one group received no other treatment, one group was treated with 10 mg/kg rat isotype control antibody (MPTP/Isotype/AT), one group with 10 mg/kg anti-MCAM antibody (MPTP/anti-MCAM/AT), and one group with 1 mg/kg fingolimod (MPTP/fingolimod/AT). Antibody and fingolimod treatments began the day before adoptive transfer and continued until the end of study. One group was treated with only PBS (PBS), and served as total neuron control. Seven days after MPTP treatment, mice were terminally anesthetized, transcardially perfused with PBS for exsanguination, fixed with 4% paraformaldehyde in PBS, and brains removed and processed for immunohistochemistry. Brains were sectioned through the midbrain, immunostained with rabbit anti-tyrosine hydroxylase (TH) and HRP-conjugated goat anti rabbit IgG, and visualized with DAB. Total numbers of surviving dopaminergic neurons (TH+) in the SN were quantified by stereological analysis (Stereo Investigator, MBF Bioscience). Means ± SEMs of total numbers of surviving dopaminergic neurons were determined from 5–8 mice per treatment group and were compared by one way ANOVA and Fisher’s LSD post-hoc test.