Expression of MCAM (CD146) parallels MPTP treatment and adoptive T cell transfers. CD3+ T cells were obtained from donor mice expressing CD90.1 (Thy1.1) and were activated with anti-CD3. (A) Following activation, and prior to adoptive transfer (AT), donor cells were analyzed for co-expression of CD4 and CD146 (CD4+CD146+) (Pre AT). Activated donor T cells (Thy1.1) were adoptively transferred to recipient mice expressing CD90.2 (Thy1.2) after treatment with MPTP at dosages of 18 mg/kg every 2 hours for 4 doses or with PBS. Thus, detection of Thy1.1 or Thy1.2 by flow cytometric analysis differentiates donor (adoptively transferred) and recipient (endogenous) T cells, respectively. (A) Forty-eight hours after adoptive transfer (AT), spleens (SP) and lymph nodes (LN) were removed from recipient animals and cells were analyzed by flow cytometric analysis for percentages of CD4+CD146+ T cells among donor (Thy1.1) T cells. (B) Twenty-four or forty-eight hours after PBS- or MPTP-treatment, lymph nodes were removed from mice that did not receive adoptive transfer, and cells analyzed by flow cytometric analysis for percentages of CD4+CD146+ T cells among the endogenous Thy1.2+ T cells. Additionally, 48 hours after adoptive transfer, lymph nodes from recipient mice were removed and analyzed for percentages of CD4+CD146+ T cells among the endogenous recipient Thy1.2 T cells. Means ± SEMs were determined from data within the 95% confidence intervals of the means for n =4-5 mice per group and were compared by one-way ANOVA with Fisher’s LSD post-hoc test where p ≤0.05 was considered significant.