Inhibition of Src kinase had no effect on A. castellanii adhesion to and cytotoxicity of HBMEC. (A) Various concentrations of PP2 or PP3 were added to A. castellanii (4 x 105 amoebae/well) for 30 min. After this incubation, A. castellanii were washed with PBS, and added to HBMEC monolayers for 1 h. The unbound amoebae were counted using a haemocytometer and the numbers of bound amoebae were deduced as follows: No. of unbound amoebae/Total number of amoebae x 100 = % unbound amoebae. The numbers of bound amoebae were deduced as follows: % unbound amoebae – 100 = % bound amoebae. (B) As for adhesion assays, amoebae were incubated with HBMEC for up to 24 h and the percent HBMEC cytotoxicity was determined by measuring LDH release. Results represent the mean of three independent experiments performed in duplicate. Bars represent standard error.