FIG. 2.

TNF-α production by Mφ stimulated with B. bovis. Mφ were cultured for 24 h with URBCs, IRBCs, or LPS in the presence or absence of 50 U of IFN-γ per ml. Supernatants were tested by ELISA and compared with recombinant bovine TNF-α as a standard. Results are presented as the mean ± 1 SD of duplicate determinations and are representative of three independent experiments performed with Mφ from different cattle. ∗, P < 0.05, for Mφ cultured with LPS alone or plus IFN-γ compared to Mφ cultured with medium or IFN-γ alone, respectively. #, P < 0.05, for Mφ cultured with IRBCs alone or plus IFN-γ compared to Mφ cultured with URBCs alone or URBCs plus IFN-γ, respectively.