Thus, the decreased secretion of the pro-inflammatory cytokines IL-6 and IL-12p40 by DEPe that we observed in a context of TLR4 activation in M1 MΦ and of TNFα in LPS-stimulated human alveolar MΦ [9] will probably reduce their capacities to activate B and T lymphocytes and NK cells and therefore support the notion that DEP can reduce host defence, especially resistance to infection. Here, TLR4 is linked to infection.