TNF and infection: When LVS propagated in Muller Hinton Broth (MHB, the prevailing medium at the time for cultivation of Ft) were used to infect MΦs, increased mRNA levels of pro-inflammatory cytokines (TNF, IL-6, IFN-γ, IL-1β) were observed beginning at 4 hours post-infection, followed by increased protein secretion at 12–20 hours post-infection.