FIG. 3.

Specific cytotoxic activity of total T cells. Four weeks after immunization, splenocytes from mice immunized with pcDNA-SOD or the parental plasmid pcDNA3 were stimulated for 5 days with J774.A1 macrophages (Mφ) infected with B. abortus RB51-SOD at a ratio of 1:100 (cells to RB51-SOD). These effector cells were incubated with J774.A1 cells alone or J744.A1 cells infected with RB51-SOD. A neutral red uptake assay was used to measure target lysis. The data are means for triplicate estimations, and standard deviations did not exceed 20% of the means. E, effector; T, target.