FIG. 2.

The spore form of ΔgerH B. anthracis elicits a stronger cytokine protein response than the vegetative form in murine Mφ. Primary murine Mφ were exposed to the heat-killed vegetative or the exo⁺ form of the ΔgerH B. anthracis spores at an MOI of 0.2:1 in serum-free RPMI 1640. The Mφ were viable after 24 h, when the supernatants were harvested and analyzed by ELISA for amounts of IL-1β (A), TNF-α (B), IL-6 (C), and RANTES protein (D) made by the Mφ. **, P ≤ 0.01.