CD8 T cell-mediated vascular permeability is specific to the CNS. At 24 h postadministration of VP2121–130 or mock E7 peptide, vascular integrity was assessed in the whole animal using gadolinium-enhanced T1-weighted MRI. At 24 h, there is gadolinium leakage into the brain of (D) VP2121–130 peptide-administered but not (A) E7 peptide-administered animals. Body scans demonstrate a lack of i.v.-injected gadolinium leakage into the peripheral organs with either (B and C) E7 peptide or (E and F) VP2121–130 peptide-administration (n = 4 per treatment group). Examples of major organs include (a) kidney, (b) spleen, (c) intestine, and (d) liver. All are negative for gadolinium leakage.