TABLE 1.

Comparison of IFN-γ responses by PBMC from M. bovis-infected cattle to responses by cattle naturally sensitized to M. avium

GroupIFN-γ responsea to recall antigen:
PPDaPPDbrESAT-6:CFP-10
M. bovis-infected (6 mo postinfection)17.3b (3.0)55.2c (9.7)29.1c (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).