Inflammation–hemostasis relationship in infected malnourished mice: modulatory effect of Lactobacillus casei CRL 431

Lactobacillus casei CRL431 modulates hemostatic activation induced by protein malnourishment and pneumococcal respiratory infection

Previously, we demonstrated that Lactobacillus casei CRL431, a well-known immunomodulatory bacterium, beneficially regulates coagulation activation, fibrin formation in lung, and the pro-inflammatory state induced by protein malnourishment and pneumococcal infection. In this study, we deepen in the understanding of the mechanisms involved in the immunoregulatory activity of L. casei CRL431 during a nutritional repletion process by evaluating (a) platelet and endothelial activation, (b) tissue factor (TF) expression, and (c) protease-activated receptor (PAR) activation in an experimental bacterial respiratory infection model in malnourished mice. Our findings demonstrate for the first time that the repletion diet supplemented with L. casei CRL431 was effective to normalize platelet counts in blood, modulate platelet activation and their recruitment into the lung, and regulate local and systemic TF expression and endothelial activation, which were affected by malnourishment. Streptococcus pneumoniae challenge induced local and systemic increase of platelet counts, PARs activation, P-selectin and TF expression, as well as endothelial activation in both well-nourished and malnourished mice. Malnourished animals evidenced the highest alterations of the parameters evaluated while the mice fed with the probiotic bacterium had similar behavior to normal controls but with lower PAR activation in lung. These results demonstrate that supplementation of repletion diet with L. casei CRL431 is effective to modulate alterations induced by malnourishment and pneumococcal infection, restraining coagulation activation, the inflammatory process, and lung damage. These observations contribute to set the basis for the application of probiotic functional foods to modulate the inflammation-hemostasis interactions altered by malnourishment or bacterial respiratory infections. KEY POINTS: • Pneumococcal infection increases pro-coagulant state induced by protein malnourishment. • Repletion with L. casei CRL431 modulates platelet, TF, and endothelial activation. • L. casei CRL431 improves immune-coagulative response in protein malnourishment.

Lactobacillus casei beneficially modulates immuno-coagulative response in an endotoxemia model

: The current study aims at evaluating the effect of the oral administration of Lactobacillus casei CERELA (CRL) 431 on parameters implicated in inflammation-coagulation interaction using a model of acute inflammation induced by lipopolysaccharide (LPS) in mice. Six-week-old Balb/c mice were treated with L. casei for 5 consecutive days. Then treated and untreated mice received an LPS injection (L. casei + LPS and LPS groups, respectively). Liver and kidney were removed, blood samples were obtained, and hemostatic and inflammatory parameters were evaluated at different times post LPS injection. Preventive L. casei administration induced a significant decrease in proinflammatory TNF-α and IL-6 cytokines by decreasing tissue factor expression in liver and kidney. Moreover, the lower expression of tissue factor in the L. casei + LPS group led to a lower activation of the coagulation system, which was observed by the fast systemic restoration of factors VII and V coagulation factors and antithrombin levels. This study highlights the capacity of L. casei to modulate the hemostatic unbalance in an acute endotoxemia model. Our findings showed the ability of L. casei CRL 431 to regulate the immuno-coagulative response. This fact could be helpful to propose new adjunctive strategies addressed to the restoration of physiological anticoagulant mechanisms in sepsis patients.

Chitosan–PVA monodisperse millimeter-sized spheres prepared by electrospraying reduce the thromboembolic risk in hemorrhage control

Chitosan–PVA monodisperse millimeter-sized spheres are efficient in hemorrhage control and also reduce the risk of thromboembolic complication.

Immunobiotic lactobacilli reduce viral-associated pulmonary damage through the modulation of inflammation-coagulation interactions

The exacerbated disease due to immune- and coagulative-mediated pulmonary injury during acute respiratory viruses infection results in severe morbidity and mortality. Identifying novel approaches to modulate virus-induced inflammation-coagulation interactions could be important alternatives for treating acute respiratory viruses infections. In this study we investigated the effect of the probiotic strain Lactobacillus rhamnosus CRL1505 on lung TLR3-mediated inflammation, and its ability to modulate inflammation-coagulation interaction during respiratory viral infection. Our findings reveal for the first time that a probiotic bacterium is able to influence lung immune-coagulative reaction triggered by TLR3 activation, by modulating the production of proinflammatory and anti-inflammatory cytokines as well as expression of tissue factor and thrombomodulin in the lung. We also demonstrated that the preventive treatment with the probiotic bacteria beneficially modulates the fine tune balance between clearing respiratory viruses (respiratory syncytial virus and influenza virus) and controlling immune-coagulative responses in the lung, allowing normal lung function to be maintained in the face of a viral attack. Our data also pinpoint a crucial role for IL-10 in the immune protection induced by L. rhamnosus CRL1505 during respiratory viral infections. These observations might be helpful to propose new preventive or therapeutic approaches to better control virus-inflammatory lung damage using probiotic functional foods.

Lactobacillus rhamnosus CRL1505 beneficially modulates the immuno-coagulative response after pneumococcal infection in immunocompromised malnourished mice

This work evaluated the effect of orally or nasally administered Lactobacillus rhamnosus CRL1505 on the resistance of immunocompromised protein-malnourished mice to pneumococcal infection. In particular, we aimed to gain knowledge of the mechanism involved in the immunomodulatory effect of L. rhamnosus CRL1505 in malnourished hosts by evaluating its impact on the immuno-coagulative response. Malnutrition significantly increased lung tissue damage caused by Streptococcus pneumoniae infection. Lung damage was associated with a deregulated activation of coagulation and an altered inflammatory response. Pneumococcal colonization of lung and bacteremia were significantly reduced (p < 0.05) in malnourished mice receiving the CRL1505 strain. Moreover, mice repleted with supplemental L. rhamnosus CRL1505 showed the least alteration of the alveolar–capillary barrier and cell damage in lungs after the infectious challenge, especially when the CRL1505 strain was administered by nasal route. Besides, mice treated with L. rhamnosus CRL1505 showed an improved respiratory innate immune response and a lower activation of coagulation. The results of this work indicate that L. rhamnosus CRL1505 is able to beneficially modulate the inflammation–coagulation interaction after respiratory infections in malnourished hosts.