Group | IFN-γ response^{a} to recall antigen: | ||
---|---|---|---|

PPDa | PPDb | rESAT-6:CFP-10 | |

M. bovis-infected (6 mo postinfection) | 17.3^{b} (3.0) | 55.2^{c} (9.7) | 29.1^{c} (6.1) |

M. avium-exposed (natural exposure) | 7.5 (3.0) | −2.4 (1.1) | −2.9 (0.7) |

↵

*a*Values are the mean IFN-γ responses (in nanograms per milliliter) (*n*= 8) of PBMC to antigen stimulation minus their response to medium alone after 48 h. Values in parentheses are the standard errors of the means.↵

*b*Significantly different from the response by*M. avium*-exposed cattle (*P*< 0.05).↵

*c*Significantly different from the response by*M. avium*-exposed cattle (*P*< 0.01).