IMPORTANCE OF Lactobacillus rhamnosus ADMINISTRATION ROUTE IN THE ACTIVATION OF THE HUMORAL IMMUNE RESPONSE IN MALNOURISHED MICE

BARBIERI NATALIA; HERRERA MATÍAS; SALVA SUSANA; VILLENA JULIO; ALVAREZ SUSANA

Tafí del Valle, Tucumán

Jornada; XXVII Jornadas Científicas de la Asociación de Biología de Tucumán; 2010

Asociación Argentina de Biología

We evaluated the effect of oral and nasal treatment with L. rhamnosus CRL1505 (Lr) on the humoral immune response against Streptococcus pneumoniae (Sp) in malnourished mice. Malnourished mice were fed a balanced diet (B) for 7d, or B for 7d with Lr oral or nasal treatment (LrO and LrN). At the end of each treatment, these animals, together with well-nourished (W) and malnourished (M) controls were challenged with Sp. We evaluated the resistance to infection and humoral immunity through B lymphocytes (BL) study in spleen by flow cytometry (B220+CD24+) and levels of IgA and IgG anti-Sp in serum and bronchoalveolar fluid (BAF). Both treatments with Lr prevented the dissemination of Sp into blood. LrO treatment decreased the Sp count in lung, whereas nasal treatment was able to remove it on day 5. Malnutrition significantly decreased the BL number in the spleen. LrO and LrN groups were able to improve this parameter with values of BL similar to W mice. Levels of specific IgG in the serum and BAF of mice treated with Lr were higher than in the M mice. Only the LrN mice reached the values of the W mice. In addition, mice treated with Lr showed higher levels of specific respiratory IgA, and the values of the LrN were greater than the LrO. Hence, the nasal route of administration of Lr proved to be the more effective one against respiratory challenge.