Immunomodulatory Properties of Bacterium-Like Particles Obtained From Immunobiotic Lactobacilli: Prospects for Their Use as Mucosal Adjuvants

RAYA TONETTI, FERNANDA; ARCE, LORENA; SALVA, SUSANA; ALVAREZ, SUSANA; TAKAHASHI, HIDEKI; KITAZAWA, HARUKI; VIZOSO-PINTO, MARIA GUADALUPE; VILLENA, JULIO

Frontiers in Immunology

International Union of Immunological Societies (IUIS).

Año: 2020 vol. 11

Non-viable lactic acid bacteria (LAB) have been proposed as antigen deliveryplatforms called bacterium-like particles (BLPs). Most studies have been performedwith Lactococcus lactis-derived BLPs where multiple antigens were attached to thepeptidoglycan surface and used to successfully induce specific immune responses. Itis well-established that the immunomodulatory properties of LAB are strain dependentand therefore, the BLPs derived from each individual strain could have different adjuvantcapacities. In this work, we obtained BLPs from immunomodulatory (immunobiotics)and non-immunomodulatory Lactobacillus rhamnosus and Lactobacillus plantarumstrains and comparatively evaluated their ability to improve the intestinal and systemicimmune responses elicited by an attenuated rotavirus vaccine. Results demonstratedthat orally administered BLPs from non-immunomodulatory strains did not inducesignificant changes in the immune response triggered by rotavirus vaccine in mice. Onthe contrary, BLPs derived from immunobiotic lactobacilli were able to improve the levelsof anti-rotavirus intestinal IgA and serum IgG, the numbers of CD24+B220+ B and CD4+T cells in Peyer?s patches and spleen as well as the production of IFN-g by immune cells.Interestingly, among immunobiotics-derived BLPs, those obtained from L. rhamnosusCRL1505 and L. rhamnosus IBL027 enhancedmore efficiently the intestinal and systemichumoral immune responses when compared to BLPs from other immunobiotic bacteria.The findings of this work indicate that it is necessary to perform an appropriate selectionof BLPs in order to find those with the most efficient adjuvant properties. We propose theterm Immunobiotic-like particles (IBLPs) for the BLPs derived from CRL1505 and IBL027strains that are an excellent alternative for the development of mucosal vaccines.