Immunobiotic Lactobacillus rhamnosus improves resistance of infant mice against respiratory syncytial virus infection

CHIBA, E.; TOMOSADA, Y.; VIZOSO PINTO, M. G.; SALVA, S.; TAKAHASHI, T.; TSUKIDA, K.; HARUKI, K.; ALVAREZ, S.; VILLENA, J.

INTERNATIONAL IMMUNOPHARMACOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2013 p. 373 - 382

1567-5769

Previously we showed that orally administered Lactobacillus rhamnosus CRL1505 bene!cially regulated thebalance between pro- and anti-in"ammatory mediators in the lungs of poly(I:C)-challenged mice, allowingan effective in"ammatory response against the TLR3/RIG-I agonist but at the same time reducing tissue damage.The aim of the present study was to investigate whether oral administration of the CRL1505 strain wasable to improve resistance against respiratory syncytial virus (RSV) infection in infant mice and to evaluatethe immunological mechanisms involved in the immunobiotic effect. We demonstrated that treatment of3-week old BALB/c mice with L. rhamnosus CRL1505 signi!cantly reduce lung viral loads and tissue injuriesafter the challenge with RSV. Moreover, we showed that the protective effect achieved by the CRL1505 strainis related to its capacity to differentially modulate respiratory antiviral immune response. Our results showsthat IFN-! and IL-10 secreted in response to L. rhamnosus CRL1505 oral stimulation would modulate the pulmonaryinnate immune microenvironment conducting to the activation of CD103+ and CD11bhigh dendriticcells and the generation of CD3+CD4+IFN-!+ Th1 cells with the consequent attenuation of the strong anddamaging Th2 reactions associated with RSV challenge. Our results indicate that modulation of the commonmucosal immune system by immunobiotics could favor protective immunity against respiratory viral pathogenswith a high attack rate in early infancy, such as RSV.