Lactobacillus rhamnosus enhances adaptive immune response elicited by influenza vaccine and influenza virus infection in mice

RAYA-TONETTI, M.F.; TADA, A.; KOBAYASHI, H.; MARRANZINO, G.; SALVA, S.; ALVAREZ, S.; KITAZAWA, H.; VIZOSO PINTO, M. G.; VILLENA, J.

CABA

Congreso; Reunion Conjunta de Sociedades de Biociencias; 2017

SAB, SAIB, SAI, SAIC, SAA, SAFE, SAH, SAP, SAFIS

We demonstrated previously that nasal administration of viable (Lr05) or heat-killed (HK05) Lactobacillus rhamnosus CRL1505 protects mice against influenza virus (IFV) infection by stimulating respiratory innate immune response. In this study, we evaluated whether Lr05 and Hk05 treatments modulated respiratory and systemic anti-IFV adaptive immune response. We also studied the induction of humoral responses after intranasal immunization of mice with H1N1 split vaccine using Lr05 and HK05 as adjuvants. 6-week-old BALB/c mice were treated with Lr05 or HK05 nasally for 2 days (d). Treated and untreated control mice were nasally challenged with IFV. A 2nd group of mice were nasal immunized with H1N1 split vaccine added with Lr05 or HK05 as adjuvants. In the infection model, levels of respiratory and serum IFN-γ, IL-4, IL-17, IL-10, anti-IFV IgG and IgA were evaluated after IFV challenge. As expected, IFV increased the levels of several cytokines in serum and BAL (Bronchoalveolar lavage). Lr05 and HK05 increased IFN- and IL-10 when compared to controls, being Lr05 more effective than HK05 to induce those effects (p