CENTRO DE REFERENCIA PARA LACTOBACILOS
Unidad Ejecutora - UE
Respiratory Commensal Bacteria Corynebacterium pseudodiphtheriticum Improves Resistance of Infant Mice to Respiratory Syncytial Virus and Streptococcus pneumoniae Superinfection
KANMANI, PAULRAJ; RODRIGUEZ, CECILIA; TAKAHASHI, HIDEKI; CLUA, PATRICIA; ALVAREZ, SUSANA; KITAZAWA, HARUKI; VIZOSO-PINTO, MARIA G.; MELNIKOV, VYACHESLAV; VILLENA, JULIO
Frontiers in Microbiology
Frontiers in Microbiology
Año: 2017 vol. 8
Corynebacterium pseudodiphtheriticum is a Gram-positive bacterium found as amember of the normal microbiota of the upper respiratory tract. It was suggested thatC. pseudodiphtheriticum may be potentially used as a next-generation probiotic for nasalapplication, although no deep studies were performed in this regard. We hypothesizedthat human isolate C. pseudodiphtheriticum strain 090104 is able to modulate therespiratory innate immune response and beneficially influence the resistance to viral andbacterial infections. Therefore, in the present study we investigated how the exposure ofinfant mice to nasal priming with viable or non-viable C. pseudodiphtheriticum 090104influences the respiratory innate immune response triggered by Toll-like receptor (TLR)-3activation, the susceptibility to primary Respiratory Synsytial Virus (RSV) infection, and theresistance to secondary Streptococcus pneumoniae pneumonia. We demonstrated thatthe nasal priming with viable C. pseudodiphtheriticum 090104 differentially modulatedTLR3-mediated innate antiviral immune response in the respiratory tract of infant mice,improving their resistance to primary RSV infection, and secondary pneumococcalpneumonia. In association with the protection against RSV-pneumococcalsuperinfection, we found that viable C. pseudodiphtheriticum improved lungCD3+CD4+IFN-g+, and CD3+CD4+IL-10+ T cells as well as CD11c+SiglecF+IFN-b+alveolar macrophages. Of interest, non-viable bacteria did not have the sameprotective effect, suggesting that C. pseudodiphtheriticum colonization is needed forachieving its protective effect. In conclusion, we present evidence that nasal applicationof viable C. pseudodiphtheriticum could be thought as an alternative to boost defensesagainst RSV and secondary pneumococcal pneumonia, which should be further studiedand validated in clinical trials. Due to the absence of a long-lasting immunity, re-infectionwith RSV throughout life is common. Thus, a possible perspective use could be aseasonal application of a nasal probiotic spray to boost respiratory innate immunity inimmunocompetent subjects.