Non-viable immunobiotic Lactobacillus rhamnosus CRL1505 improves respiratory immunity and reduces influenza virus-associated lung injury

ZELAYA, HORTENSIA; KANMANI, PAULRAJ; VIZOSO-PINTO, MARÍA GUADALUPE; SALVA, SUSANA; ALVAREZ, SUSANA; KITASAWA, HARUKI; VILLENA, JULIO

Maastricht

Congreso; 6th Congress of European Microbiologists FEMS 2011; 2015

Background: Symptoms of influenza infection are variable ranging from mild respiratory distress to massive organ failure resulting in death. Seasonal influenza is usually self-limiting but in susceptible patients it may progress to acute lung injury, which is characterized by augmented pulmonary microvascular permeability, hypoxemia and respiratory failure. The ongoing threat of influenza epidemics and pandemics has emphasized the importance of developing novel, safe and effective therapeutic or preventive strategies against infections from divergent influenza viruses. Objective: To examine the effect of nasal administration of heat-killed Lactobacillus rhamnosus 1505 (Lr1505) on immune response to influenza infection in mice.Methods: Six-week old BALB/c mice were treated with 108 cells of Lr1505 by the nasal route during two consecutive days. Lr1505-treated and untreated control mice were then nasally challenged with Influenza virus. Lung tissue damage and respiratory and systemic immune responses were studied at several time points after viral challenge. Results demonstrated that non-viable immunobiotic strain protected infected mice by reducing pulmonary injury and lung viral loads trough several mechanisms: a) inflammatory cytokines were down-regulated diminishing inflammation (p