FIG. 5.

(a) ELISA measurement of IgG anti-ML65 and anti-MTB70 antibody response elicited in mice after priming with heat-killed (HK) M. vaccae and boosting with ML65 and MTB70, respectively. Statistical analysis showed significant differences at P values of <0.005 compared with the respective control group by Student's t test (*). (b) ML65- and MTB70-specific IgG1 and IgG2a antibody responses were measured from individual sera, and titers are expressed as the log₁₀ of the reciprocal of the highest dilution giving an OD of 1.0. (c) In vitro IFN-γ production by the splenocytes stimulated with various HSPs from mice primed with heat-killed M. vaccae. Splenocytes of individual mice from each group were stimulated separately in triplicate with 10 μg/ml of each HSP and with 2 μg/ml of ConA (positive control) in 96-well cell culture plates and incubated for 72 h at 37°C in 5% CO₂. Cell supernatants were collected, pooled, and assayed for the presence of IFN-γ by ELISA. Data are expressed as the ratio between HSP and ConA stimulation multiplied by 100. Values represent means of triplicate samples (three spleens) with SD. *, P < 0.005; **, P = 0.07 with the respective controls.