FIG. 2.

IFN-γ secretion from short-term T-lymphocyte effector cell lines stimulated with overlapping peptides of NcSRS2. T lymphocytes were obtained from PBMC of N. caninum-infected cows 495 (A), 612 (B), 63(C), and 562 (D) and cultured with antigen-presenting cells stimulated sequentially with live tachyzoites, rNcSRS2, and synthetic peptide as described in the text. Culture supernatants were tested for bovine IFN-γ using commercial Bovigam kit, and units were calculated from a standard curve. The far-right three bars show results for control cultures stimulated with ConA, NSo (whole N. caninum tachyzoite lysate) (positive control), or rNcSRS2 (positive control), respectively. A response was considered positive (*) as described in the text.Error bars indicate ± standard deviations.