Figure 3

Evaluation of proliferation of canine peripheral blood mononuclear cells (PBMC) stimulated with recombinant canine IL-2 produced by E. coli or COS-7 cells. PBMC of 6 adult mongrel dogs were cultured for 4 to 14 days with: (A) affinity purified rcaIL-2-F43L produced in E. coli at 50 ng/mL (squares) or excipient (circles); (B, C, and D) supernatant of COS-7 cells transfected with either pcDNA3.1 without insert (circles) or pcDNA3.1-caIL-2 (squares) at 0.5% (B), 5% (C) or 50% (D). The cells were pulsed with 3H-thymidine for 18 h. The data represent the median of the CPM obtained for the six animals and the bars the 25 and 75 percentiles. *p < 0.05, **p < 0.01; Dunn’s post-test (p < 0.001, Friedman’s test).