Table 2.

NO production and cytokine mRNA expression in bovine alveolar macrophages infected with M. bovis strains

M. bovis strainUnstimulated macrophagesMacrophages stimulated with IFN-γ and LPS
NO (μM)aTNF-αbIL-1βcIL-6cNO (μM)TNF-αIL-1βIL-6
WAg2013.4 ± 1.36.4 ± 0.8++++++14.3 ± 4.63.7 ± 1.1+++++
WAg4053.2 ± 1.25.6 ± 0.8++++++15.0 ± 2.44.0 ± 0.8+++++
ATCC 357213.9 ± 2.04.8 ± 1.4++++++16.8 ± 2.73.1 ± 0.8+++++
BCG3.0 ± 1.41.1 ± 0.3++16.1 ± 2.44.0 ± 1.6+++++
  • a NO in macrophage culture supernatants was determined at 48 h after infection. Results are means of determinations with macrophages from three animals ± standard errors.

  • b TNF-α mRNA was determined at 24 h after infection by quantitative competitive RT-PCR and is shown as copies (106) of TNF-α mRNA per microgram of total cellular RNA. Results are means of determinations with macrophages from three animals ± standard errors. The TNF-α mRNA level in noninfected unstimulated macrophages was 7.8 (±1.0) × 104copies/μg of total RNA, and that in noninfected stimulated macrophages was 3.6 (±1.2) × 106 copies/μg of total RNA.

  • c Determined at 24 h after infection by qualitative RT-PCR. +, weak signal; ++, moderate signal; +++, strong signal.