Fig. 6.

A sublytic dose of antibody and complement protects carcinoma cells from lytic doses of complement; involvement of PKC. T47D, SKOV3 and PC-3 cells were pretreated under light with calphostin C (1 µm) (▪) or with DMSO (0·03%) as control (□), for 30 min at 37°C. Next, the cells were incubated with rabbit anti-CA antibodies and with NHS or HI-NHS at a dilution producing a sublytic effect of complement (further details in Methods). Finally, the cells were washed and incubated with lytic doses of antibody and complement (NHS). Percentage cell lysis was determined by trypan blue exclusion and percentage protection was calculated as explained under Methods.