Figure 4

Effect of lactobacilli on the production of cytokines induced by the nasal administration of the viral pathogen-associated molecular pattern poly(I:C). Effect of viable (Lr05) or heat-killed (HkLr05) Lactobacillus rhamnosus CRL1505 and viable (Lr06) or heat-killed (HkLr06) L. rhamnosus CRL1506 nasal administration on the tumor necrosis factor (TNF)-α, interferon (IFN)-α, IFN-β, IFN-γ, interleukin (IL)-6 and IL-10 concentrations in broncho-alveolar lavages (BAL). Lr05, Lr06, HkLr05 or HkLr06 were nasally administered to different groups of mice for 2 consecutive days at a dose of 10⁸ cells/mouse/day. After lactobacilli treatment, mice received three doses of poly(I:C) with 24 hours rest period between each administration. BAL cytokines were studied 12 (TNF-α, IFN-α, IFN-β and IL-6) or 48 (IFN-γ and IL-10) hours after the third challenge with poly(I:C). The results represent data from three independent experiments. Different letters indicate significant differences (P < 0.05).