Lactobacillus casei modulates tissue factor expression, PARs and platelet activation in an experimental infection in malnourished mice

H. ZELAYA; J. LAIÑO; G. AGÜERO

San Miguel de Tucumán

Simposio; IV Simposio Internacional de Bacterias Lácticas: Alimento, Salud y Aplicaciones; 2013

CERELA-CONICET

Previously, it was demonstrated that Lactobacillus casei CRL431 (Lc), a well-known immunomodulatory bacterium, regulates coagulation activation, fibrin formation in lung,endothelial activation, and pro-inflammatory state induced by malnourishment and infection. The objective was to evaluate the effect of Lc on tissue factor expression, Proteases Activated Receptors (PARs) and platelet activation in an experimental respiratory infection model in malnourished mice. Malnourished Swiss Albino mice received during 7 days (d) balanced conventional diet (BCD) or BCD supplemented with Lc in the drink water (109 cells/d/mouse) during the last 2 d of the renutrition (BCD+Lc). Once the feeding procedures were completed, BCD+Lc, BCD, malnourished control (MNC) and well-nourished control (WNC) were intranasally challenged with Streptococcus pneumoniae. At different hours post-infection (hpi) were determined in peripheral blood: a) platelet counts, b) PARs and P-selectin expression in platelets and c) tissue factor (TF) in monocytes by flow cytometry; and in lung: a) P-selectin in platelet by immunofluorescence, b) TF by flow cytometry, and c) PAR1 and PAR4 by immunohistochemistry. Before the infection, malnourishment altered the most of the evaluated parameters and only renutrition diet supplemented with Lc normalized them. In blood, the infection induced an increase in platelet counts, PARs activation and P-selectin expression in platelets, and TF in monocytes. In addition, an increase in TF expression, and PARs and platelet activation in lung were observed. The MNC group evidenced the highest alterations. The supplementation with Lc was effective to normalize platelet counts in blood (WNC12 hpi= 1492 SD 5.7x109/L; MNC= 1026 SD 32.2; BCD= 1088 SD 11.3; BCD+Lc= 1400 SD 56.6; p