FIGURE 1.

B. anthracis PGN inhibits efferocytosis in the presence of human serum.

(A) Secreted TNF and IL-10 (24 h–treated MФ in various serum conditions) from four independent donors. (B) Gating strategy for flow cytometric evaluation of efferocytosis. Gating strategy: After gating on MΦ and excluding dead cells and debris using scatter properties (forward scatter [FSC], side scatter [SSC]), MΦ with CD66b⁺ surface-bound apoptotic PMNs are excluded. Next, live MΦ are gated as CD11b⁺ and Zombie Aqua viability dye negative. Finally, we gate on CD64⁺ MΦ and measure the percentage of intracellular apoptotic PMNs present (CD64⁺ eFluor 670⁺). (C) Percentage of CD64⁺ MФ containing apoptotic eFluor 670–labeled PMNs from the indicated serum conditions in the presence or absence of 10 μg/ml PGN from ≥5 independent donors analyzed by two-way ANOVA with Sidak’s multiple comparison test. *p < 0.05, ***p < 0.001, ****p < 0.0001.