Non-viable immunobiotic Lactobacillus rhamnosus CRL1505 and its peptidoglycan improve systemic and respiratory innate immune response during recovery of immunocompromised-malnourished mice

YANINA KOLLING; SUSANA SALVA; JULIO VILLENA; GABRIELA MARRANZINO; SUSANA ALVAREZ

INTERNATIONAL IMMUNOPHARMACOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 25 p. 474 - 484

1567-5769

The effect of non-viable Lactobacillus rhamnosus CRL1505 and its cell wall and peptidoglycan on respiratory immunity inmalnourished mice was studied.Weaned mice were malnourishedwith a protein-free diet for 21d and received BCD during 7d (BCD) or BCD with nasal non-viable L. rhamnosus CRL1505 (BCD + UV) or its cell wall (BCD + CW) or peptidoglycan (BCD + PG) supplementation during last 2d of the treatment. Malnourished mice without treatment (MNC) and well-nourished mice (WNC) were used as controls. Mice were infected nasally with Streptococcus pneumoniae after treatments. Resistance against pneumococci was reduced inMNC mice. Repletion with BCD reduced lung and blood bacterial cell countswhen compared toMNC mice but the counts did not reach the levels of the WNC group. However, when malnourished mice received BCD + UV, BCD + CW or BCD+PG, pneumococciwas not detected in lung or blood samples. Pneumococcal infection increased the levels of TNF-α, IL-1β, IL-6, and IL-10 in the respiratory tract, however the valueswere lower inMNC than inWNC mice. BCD + UV and BCD + PG groups showed values of phagocytes, IL-1β and IL-6 that were similar to WNC mice, while TNF-α was significantly higher in those groups when compared to WNC mice. Moreover, BCD + UV and BCD+PG treatments improved levels of respiratory IL-10, reaching values thatwere superior to those observed in WNC mice. The work demonstrates for the first time that non-viable probiotic bacteria or their cellular fractions could be an interesting alternative as mucosal immunomodulators, especially in immunocompromised hosts in which the use of live bacteria might be dangerous.