Figure 7
TNF-α induces MMP-9 secretion from B. abortus -infected astrocytes. Astrocytes were incubated in the presence of anti-TNF-α (a-TNF) antibody or its isotype (ISO) control before the infection of astrocytes at different multiplicities of infection (MOI) or stimulated with HKBA (108 bacteria/ml), L-Omp19 (1,000 ng/ml) or TNF-α (5 ng/ml). Culture supernatants were harvested at 48 hours post stimulation to assess the expression of MMP-9 by zymography (A, C) and ELISA (B). Bars express the mean ± SEM of duplicates. Data shown are from a representative experiment of four performed. NI: non-infected. NS: non-stimulated. ***P < 0.001 versus untreated (minus sign).