FIG. 1.

Lymphocyte proliferation responses of T-cell subsets from control uninfected animals (a) and proliferation (b) and IFN-γ release (c) by T-cell subsets from M. bovis-infected animals in response to mycobacterial antigen preparations of MBSE and PKMBSE. WC1⁺ γδ and CD4⁺ T cells were magnetically (MACS) purified and cultured with antigen in the presence of autologous mitomycin C-treated PBMC as a source of APC. APC alone were included as controls. Lymphocyte proliferation data are presented as cpm. A proliferation response was considered positive if the test antigen cpm value was ≥2 × the PBS control cpm value. IFN-γ ELISA results are expressed as the OD₄₅₀; an OD value of 2 × the background (PBS) value was considered a positive response. The results presented show the mean group cpm or the mean group OD₄₅₀ plus the standard error of the mean for six repeated experiments. Statistically significant differences between control PBS-treated and antigen-stimulated cells are indicated as follows: ✽✽✽, P <0.001; ✽✽, P < 0.01.