Protective effect of probiotic Lactobacillus rhmanosus against respiratory syncytial virus infection in young mice

SUSANA SALVA; ERIKO CHIBA; MARIA GUADALUPE VIZOSO-PINTO; HARUKI KITAZAWA; SUSANA ALVAREZ; JULIO VILLENA

Los Cocos, Córdoba

Congreso; LXI Reunión Científica Anual de la Sociedad Argentina de Inmunología (SAI); 2013

Sociedad Argentina de Inmunología

The oral administration of Lactobacillus rhamnosus CRL1505 (Lr1505) is capable of beneficially regulate the proinflammatory response in lungs of poly(I:C)-challenged mice, allowing an effective inflammatory response against the TLR3/RIG-I agonist but at the same time reducing tissue damage. In this work we investigated whether oral administration of Lr1505 was able to improve resistance against respiratory syncytial virus (RSV) infection in infant mice and to evaluate the immunological mechanisms involved in the protective effect. Lr1505 was orally administered to different groups of 3-week old BALB/c mice for 5 consecutive days at a dose of 108 cells/mouse/day. On day 6, this group and untreated control mice were infected nasally with 2.4 x 106 PFU of RSV. Levels of protein, albumin and LDH activity; and levels of IFN-β, TNF-α, IL-6, IFN-γ and IL-10 were studied in broncho-alveolar lavages (BAL). In addition, titers of RSV and expression of CD3, CD4, CD11b, CD11c, CD103, MHC II, IL-10 and INF-γ were studied in lung. Treatment with Lr1505 significantly reduced lung viral loads (p