TLR2 and infection: WT or TLR2−/− BMMs were infected with WT or ∆tolC Schu S4, and cell death was measured by LDH release at 24 h p.i. Infection of WT BMMs with the Schu S4 ∆tolC mutant led to an approximately sixfold increase in cell death compared to infection with WT bacteria (Fig. 4B).