BACTERIUM-LIKE PARTICLES DERIVED FROM THE RESPIRATORY COMMENSAL BACTERIA CORYNEBACTERIUM PSEUDODIPHTHERITICUM 090104 AS A PROMISING MUCOSAL ADJUVANT

ORTIZ MOYANO, RAMIRO; RAYA-TONETTI, FERNANDA; VIZOSO-PINTO, M. GUADALUPE; VILLENA, JULIO

Buenos Aires

Congreso; Reunión Conjunta SAIC. SAI. AAFE. NANOMED-AR; 2021

SAIC. SAI. AAFE. NANOMED-AR

BACTERIUM-LIKE PARTICLES DERIVED FROMTHE RESPIRATORY COMMENSAL BACTERIA CORYNEBACTERIUMPSEUDODIPHTHERITICUM 090104 AS APROMISING MUCOSAL ADJUVANTRamiro Ortiz Moyano 1, Fernanda Raya-Tonetti 1, JacintoSacur2, Mikado Tomokiyo 3; Vyacheslav Melnikov 4, SusanaAlvarez1, Haruki Kitazawa 4,5, María Guadalupe Vizoso-Pinto2, Julio Villena 1,31 Laboratory of Immunobiotechnology, Reference Centre forLactobacilli (CERELA-CONICET), Tucuman, Argentina.2 Infection Biology Laboratory, Instituto Superior de InvestigacionesBiológicas (INSIBIO), CONICET-UNT, Tucumán,Argentina.3 Food and Feed Immunology Group, Laboratory of AnimalProducts Chemistry, Graduate School of Agricultural Science,Tohoku University, Sendai, Japan.4 Gabrichevsky Research Institute of Epidemiology and Microbiology,Russia5 Livestock Immunology Unit, International Education and ResearchCenter for Food and Agricultural Immunology (CFAI),Graduate School of Agricultural Science, Tohoku University,Sendai, Japan.Corynebacterium pseudodiphtheriticum is a Gram-positive bacteriumthat is part of the nasopharyngeal microbiota. This bacteriumwas shown to prevent the colonization of the respiratory mucosaby pathogenic bacteria including Streptococcus pneumoniae (Sp).We recently demonstrated that C. pseudodiphtheriticum 090104(Cp), when nasally administered to mice; differentially modulatedthe respiratory immune responses triggered by TLR2 and improvedthe resistance to pneumococcal pneumonia. We also reported thatbacterium-like particles derived from Cp (BPCp) had the ability tomodulate the innate respiratory immunity. These results allowed usto hypothesize that Cp or BPCp could be used as mucosal adjuvantsto enhance the respiratory adaptive immunity. In this work,infant Swiss-albino mice were nasally immunized with 6.25 pg ofPneumovax23® vaccine (PV), PV plus Cp (108 CFU) or PV plusBPCp at days 0, 14 and 28. Seven days after the last immunizationsamples of bronco-alveolar lavages (BAL) and serum were collectedfor specific antibodies determinations. In addition, immunized micewere challenged with Sp serotypes 6B or 19F (106 CFU) and theresistance to the infection was evaluated 2 days after the challenge.Mice in the PV+Cp and PV+BPCp groups had significantly higherlevels of BAL anti-Sp IgG and IgA (p