Figure 4

HPPH-PDT enhances adhesion molecule expression and neutrophil adhesion in tumour microvessels. Animals were treated as in Figure 1 for the indicated time periods and tumour cryosections were either stained for vascular adhesion molecule expression using specific mAb (A) or evaluated for the ability to support adhesion of neutrophils under mechanical shear (B). In (A), arrows denote tumour vessels; note that fluorescence was not detected in tumour vessels stained with isotype-matched control Ab (left panels) or in tumours that were not treated with light (i.e. no PDT, right panels). In contrast, E-selectin and ICAM-1 were highly expressed on tumour vessels following HPPH-PDT treatment. Data in (B) are the mean +s.d. of triplicate samples and are representative of three independent experiments. The differences between adhesion in untreated contralateral tumours and PDT-treated tumours were significant, P<0.005 (^*), P<0.0005 (^**) by unpaired two-tailed Student's t-test.