Group | TNF-α response^{a} to recall antigen: | ||
---|---|---|---|

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

M. bovis-infected (6 mo postinfection) | 0.316 (0.084) | 1.370^{b} (0.524) | 0.790^{b} (0.285) |

M. avium-exposed (natural exposure) | 0.164 (0.048) | 0.056 (0.052) | 0.038 (0.095) |

↵

*a*Values are the mean TNF-α 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).