Evaluación de las propiedades adyuvantes de fracciones celulares de bacterias inmunobióticas para el diseño de nuevas formulaciones vacunales contra Streptococcus pneumoniae

YANINA KOLLING; MARIA GRACIELA AGÜERO; JONATHAN E. LAIÑO; JULIO VILLENA

Anales de la Fundación Alberto J. Roemmers ? Vol XXX

Ediciones Médicas del Sur S.R.L.

Lugar: Buenos Aires; Año: 2019; p. 207 - 218

Streptococcus pneumoniae is a major global health problem in high-riskgroups. Even when vaccines are available, they show reduced immunogenicityand low immunological memory in these populations. Other disadvantageis the high cost as a public health strategy in communities with low incomes. Inthis context, immunobiotic bacteria such as Lactobacillus rhamnosus CRL1505or its cellular fractions could represent candidates as mucosal adjuvant. Theaim of this work was to study the potential use of cell wall (PC) or peptidoglycan(PG) from the immunomodulatory strain L. rhamnosus CRL1505, aseffective mucosal adjuvant in infant and adult mice when are co-administeredwith the commercially available conjugated-polysaccharide 13-valent pneumococcalvaccine (Vc). Results showed that administration of the Vc inducedproduction of pneumococcal-specific antibodies in serum and broncho-alveolarlavage (BAL) in adult and infant mice. Infant mice showed higher levelsof specific IgM and IgA in serum, and specific IgA and IgG in BAL, respectto adults after nasal immunization. In addition, subcutaneous immunizationinduced higher antibody levels in adults than infant mice. Co-administrationof Vc+PC or Vc+PG induced higher pneumococcal-specific antibodies (IgM,IgA, IgG) compared to Vc alone in infant mice. To evaluate the capability of Vcand cell fractions to protect from infection, four S. pneumoniae serotypes (3,6B, 14, and 19F) were used. Only the nasal immunization with Vc+PC significantlyreduced the pneumococcal lung colonization by the 4 serotypes, whilethe combination Vc+PG reduced lung colonization by serotype 3 and 6B, withno effect on serotypes 14 and 19F. All treatments (Vc, Vc+PC, and Vc+PG)avoided pathogen dissemination into blood. The results suggest that cell wallfrom L. rhamnosus CRL1505 is an interesting and potential mucosal adjuvantto improve effectiveness of commercial vaccines and increasing protection inchildren.