Lacticaseibacillus rhamnosus CRL1505 Peptidoglycan Modulates the Inflammation-Coagulation Response Triggered by Poly(I:C) in the Respiratory Tract.

Lacticaseibacillus rhamnosus CRL1505 beneficially modulates the inflammation-coagulation response during respiratory viral infections. This study evaluated the capacity of the peptidoglycan obtained from the CRL1505 strain (PG-Lr1505) to modulate the immuno-coagulative response triggered by the viral pathogen-associated molecular pattern poly(I:C) in the respiratory tract. Adult BALB/c mice were nasally treated with PG-Lr1505 for two days. Treated and untreated control mice were then nasally challenged with poly(I:C). Mice received three doses of poly(I:C) with a 24 h rest period between each administration. The immuno-coagulative response was studied after the last administration of poly(I:C). The challenge with poly(I:C) significantly increased blood and respiratory pro-inflammatory mediators, decreased prothrombin activity (PT), and increased von Willebrand factor (vWF) levels in plasma. Furthermore, tissue factor (TF), tissue factor pathway inhibitor (TFPI), and thrombomodulin (TM) expressions were increased in the lungs. PG-Lr1505-treated mice showed significant modulation of hemostatic parameters in plasma (PT in %, Control = 71.3 ± 3.8, PG-Lr1505 = 94.0 ± 4.0, p < 0.01) and lungs. Moreover, PG-Lr1505-treated mice demonstrated reduced TF in F4/80 cells from lungs, higher pro-inflammatory mediators, and increased IL-10 compared to poly(I:C) control mice (IL-10 in pg/mL, Control = 379.1 ± 12.1, PG-Lr1505 = 483.9 ± 11.3, p < 0.0001). These changes induced by PG-Lr1505 correlated with a significant reduction in lung tissue damage. Complementary in vitro studies using Raw 264.7 cells confirmed the beneficial effect of PG-Lr1505 on poly(I:C)-induced inflammation, since increased IL-10 expression, as well as reduced damage, production of inflammatory mediators, and hemostatic parameter expressions were observed. In addition, protease-activated receptor-1 (PAR1) activation in lungs and Raw 264.7 cells was observed after TLR3 stimulation, which was differentially modulated by PG-Lr1505. The peptidoglycan from L. rhamnosus CRL1505 is able to regulate inflammation, the procoagulant state, and PAR1 activation in mice and macrophages in the context of the activation of TLR3 signaling pathways, contributing to a beneficial modulation of inflammation-hemostasis crosstalk.

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.

Nasal priming with immunobiotic Lactobacillus rhamnosus modulates inflammation-coagulation interactions and reduces influenza virus-associated pulmonary damage.

OBJECTIVE: To evaluate the effect of the nasal administration of live and heat-killed Lactobacillus rhamnosus CRL1505 (Lr1505) on immune-coagulative response during influenza virus (IFV) infection to improve survival and reduce lung injury. METHODS: Six-week-old BALB/c mice were treated with live or heat-killed Lr1505 by the nasal route during two consecutive days. Treated and untreated control mice were then nasally challenged with IFV. RESULTS: Both viable and non-viable Lr1505 protected infected mice by reducing pulmonary injury and lung viral loads trough several mechanisms: (a) Inflammatory cytokines were efficiently regulated allowing higher clearance of virus and reduction of inflammatory lung tissue damage, associated to higher levels of the regulatory cytokine IL-10. (b) The antiviral immune response was enhanced with improved levels of type I interferons, CD4(+)IFN-γ(+) lymphocytes, and lung CD11c(+)CD11b(low)CD103(+) and CD11c(+)CD11b(high)CD103(-) dendritic cells. (c) The procoagulant state was reversed mainly by down-regulating tissue factor expression and restoring thrombomodulin levels in lung. The capacity of Lr1505 to improve the outcome of IFV infection would be related to its ability to beneficially modulate lung TLR3-triggered immune response. CONCLUSIONS: Our work is the first to demonstrate the ability of an immunobiotic strain to beneficially modulate inflammation-coagulation interactions during IFV infection. Interestingly, non-viable L. rhamnosus CRL1505 was as effective as the viable strain to beneficially modulate respiratory antiviral immune response.

Probiotic Lactobacillus strains protect against myelosuppression and immunosuppression in cyclophosphamide-treated mice.

This work evaluated the capacity of two probiotic strains, Lactobacillus casei CRL431 and Lactobacillus rhamnosus CRL1506, to protect against myelosuppression and immunosuppression in cyclophosphamide (Cy)-treated mice. Changes in mature granulocytes and progenitor cells in bone marrow (BM) and blood were studied. In addition, the ability of probiotics to accelerate the recovery of the immune response against the opportunistic pathogen Candida albicans was evaluated. We demonstrated for the first time that the preventive treatment with immunomodulatory lactobacilli such as L. casei CRL431 or L. rhamnosus CRL1506 was able to increase immature myeloid progenitors in the BM, allowing an early recovery of myeloid cells after Cy administration. Probiotic lactobacilli were also capable to induce an early recovery of neutrophils in blood, improve phagocytic cells recruitment to infectious sites and increase the resistance against the opportunistic pathogen C. albicans. Although deeper studies regarding the cellular and molecular mechanisms of probiotic actions are needed, these findings support the idea that strains like CRL431 and CRL1506 may accelerate the recovery of Cy-caused immunosuppression by immunopotentiating myeloid cells. Then, probiotic lactobacilli have the potential to be used as alternatives for lessening chemotherapy-induced immunosuppression in cancer patients.

Modulation of the inflammation-coagulation interaction during pneumococcal pneumonia by immunobiotic Lactobacillus rhamnosus CRL1505: role of Toll-like receptor 2.

The present study evaluated the effect of nasally given Lactobacillus rhamnosus CRL1505 on the immunocoagulative response during pneumococcal infection in immunocompetent mice. In addition, we aimed to gain insight into the mechanism involved in the immunomodulatory effect of the L. rhamnosus CRL1505 strain by evaluating the role of TLR2. Results showed that nasally given L. rhamnosus CRL1505 effectively regulates inflammation and hemostatic alterations during the pneumococcal infection. Immunobiotic treatment significantly reduced permeability of the bronchoalveolar-capillary barrier, and general cytotoxicity, decreasing lung tissue damage. The CRL1505 strain improved the production of TNF-α, IFN-γ, and IL-10 after pneumococcal challenge. In addition, increased TM and TF expressions were found in lungs of L. rhamnosus CRL1505-treated mice. Moreover, we demonstrated, for the first time, that the TLR2 signaling pathway has a role in the induction of IFN-γ and IL-10 and in the reduction of TF. The results also allow us to speculate that a PRR, other than TLR2, may mediate the immunobiotic activity of L. rhamnosus CRL1505 and could explain changes in TNF-α and TM.

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.

Effects of human milk on blood and bone marrow cells in a malnourishedmice model; comparative study with cow milk / Efecto de la leche humana sobre células de sangre y de médula ósea en un modelo de ratos desnutridos; estudio comparativo con leche de vaca

Introduction: It has been demonstrated that the alterations caused by nutrient deficiency can be reverted by adequate nutritional repletion. Objective: To perform comparative studies between human and cow milks in order to evaluate the impact of both milks on the recovery of blood and bone marrow cells affected in malnourished mice. Method: Weaned mice were malnourished after consuming a protein free diet for 21 days. Malnourished mice received cow or human milk (CM or HM) for 7 or 14 consecutive days. During the period of administration of milk, the mice consumed the protein free diet ad libitum. The malnourished control (MNC) group received only protein free diet whereas the well-nourished control (WNC) mice consumed the balanced conventional diet. Results and Discussion: Both milks normalized serum albumin levels and improved thymus weight. Human milk was less effective than cow milk to increase body weight and serum transferrin levels. In contrast, human milk was more effective than cow milk to increase the number of leukocytes (WNC: 6.90 ± 1.60a; MNC: 2.80 ± 0.90b; CM 7d: 3.74 ± 1.10b; HM 7d: 7.16 ± 1.90a; CM 14d: 4.35 ± 1.20b; HM 14d: 6.75 ± 1.20a (109/L);p < 0.05) and lymphocytes (WNC: 5.80 ± 0.36a; MNC: 1.80 ± 0.40b; CM 7d: 2.50 ± 0.30b; HM 7d: 4.20 ± 0.50c; CM 14d: 3.30 ± 0.31d; HM 14d: 4.70 ± 0.28c (109/L);p < 0.05) in peripheral blood. Both milks induced an increment in mitotic pool cells in bone marrow and α-naphthyl butyrate esterase positive cells in peripheral blood. They also normalized phagocytic function in blood neutrophils and oxidative burst in peritoneal cells. Conclusion: Both milks were equally effective to exert favorable effects on the number of the bone marrow cells and the functions of the blood and peritoneal cells involved in immune response. However, only human milk normalized the number of leukocytes and increased the number of neutrophils in peripheral blood (AU)

Introducción: Las alteraciones causadas por la deficiencia de nutrientes pueden ser revertidas por un aporte nutricional adecuado. Objetivos: Realizar estudios comparativos entre leche humana y leche de vaca para evaluar su impacto en la recuperación de las células de sangre y de médula ósea afectadas en ratones desnutridos. Métodos: Los ratones fueron desnutridos al recibir una dieta libre de proteínas durante 21 días a partir del destete. Posteriormente, estos ratones desnutridos recibieron leche de vaca (LV) o leche humana (LH) durante 7 o 14 días consecutivos, mientras continuaban consumiendo la dieta libre de proteínas ad libitum. El grupo control de desnutrición (CD) sólo recibió la dieta libre de proteínas mientras que los ratones controles bien nutridos (CBN) consumieron la dieta balanceada convencional. Resultados y Discusión: Ambas leches normalizaron los niveles de albumina sérica e incrementaron el peso del timo. La leche humana fue menos efectiva que la leche de vaca para incrementar el peso corporal y los niveles de transferrina en suero. Sin embargo, la leche humana fue más efectiva para incrementar el número de leucocitos (CBN: 6,90 ± 1,60a; CD: 2,80 ± 0,90b; LV 7d: 3,74 ± 1,10b; LH 7d: 7,16 ± 1,90a; LV 14d: 4,35 ± 1,20b; LH 14d: 6,75 ± 1,20a (109/L);p < 0,05) y linfocitos (CBN: 5,80 ± 0,36a; CD: 1,80 ± 0,40b; LV 7d: 2,50 ± 0,30b; LH 7d: 4,20 ± 0,50c; LV 14d: 3,30 ± 0,31d; LH 14d: 4,70 ± 0,28c (109/L); p < 0,05) en sangre periférica. Ambas leches indujeron un incremento de las células del compartimiento mitótico de médula ósea y de las células ±-naftil butirato esterasa positivas en sangre periférica. Además, normalizaron la función fagocítica en neutrófilos de sangre periférica y el estallido oxidativo en las células peritoneales. Conclusiones: Ambas leches fueron igualmente efectivas para ejercer efectos favorables en el número de las células de la médula ósea y en las funciones de las células peritoneales y de la sangre involucradas en la respuesta inmune. Sin embargo, sólo la leche humana normalizó el número de leucocitos e incrementó el número de neutrófilos en sangre periférica (AU)

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.

Modulation of the immuno-coagulative response in a pneumococcal infection in malnourished mice nasally treated with Lactobacillus casei.

We studied the systemic effects of the intranasal administration of Lactobacillus casei on the immuno-coagulative response in pneumoccocal infection in immunocompromised mice. Weaned mice consumed a protein-free diet (PFD) for 21 days and were therefore malnourished. Malnourished mice were fed a balanced conventional diet (BCD) for 7 days (BCD group) or a BCD for 7 days with nasal administration of viable L. casei on days 6 and 7 (BCD+LcN group). The malnourished control mice (MNC) received a PFD, whereas the well-nourished control mice (WNC) continually consumed a BCD. At the end of the treatment period, the mice were infected with Streptococcus pneumoniae. At different times after infection, we analysed the following parameters: global coagulation system, activation of coagulation, coagulation inhibitors, platelet count, leukocyte count and myeloperoxidase (MPO) activity, total proteins, albumin and acute phase proteins (APPs). The MNC group showed greater impairment in the coagulation tests and an increase in the positive APPs. These parameters were normalized by the L. casei treatment. However, the number of leukocytes, decreased by malnutrition, was improved only by the administration of L. casei. After infection, the BCD+LcN group showed similar results to those of the WNC group for most of the haemostatic parameters. The BCD+LcN group did not show significant variations in the prothrombin time or in the level of anticoagulant protein C, but showed higher levels of fibrinogen, platelets, albumin, leukocytes and MPO activity compared with the different experimental groups. The intranasal administration of L. casei was effective in modulating the pro-inflammatory aspects of coagulation without affecting coagulation itself.

Effect of human milk on blood and bone marrow cells in a malnourished mice model; comparative study with cow milk.

INTRODUCTION: It has been demonstrated that the alterations caused by nutrient deficiency can be reverted by adequate nutritional repletion. OBJECTIVE: To perform comparative studies between human and cow milks in order to evaluate the impact of both milks on the recovery of blood and bone marrow cells affected in malnourished mice. METHOD: Weaned mice were malnourished after consuming a protein free diet for 21 days. Malnourished mice received cow or human milk (CM or HM) for 7 or 14 consecutive days. During the period of administration of milk, the mice consumed the protein free diet ad libitum. The malnourished control (MNC) group received only protein free diet whereas the wellnourished control (WNC) mice consumed the balanced conventional diet. RESULTS AND DISCUSSION: Both milks normalized serum albumin levels and improved thymus weight. Human milk was less effective than cow milk to increase body weight and serum transferrin levels. In contrast, human milk was more effective than cow milk to increase the number of leukocytes (WNC: 6.90 ± 1.60a; MNC: 2.80 ± 0.90b; CM 7d: 3.74 ± 1.10b; HM 7d: 7.16 ± 1.90a; CM 14d: 4.35 ± 1.20b; HM 14d: 6.75 ± 1.20a (109/L); p < 0.05) and lymphocytes (WNC: 5.80 ± 0.36a; MNC: 1.80 ± 0.40b; CM 7d: 2.50 ± 0.30b; HM 7d: 4.20 ± 0.50c; CM 14d: 3.30 ± 0.31d; HM 14d: 4.70 ± 0.28c (109/L); p < 0.05) in peripheral blood. Both milks induced an increment in mitotic pool cells in bone marrow and α-naphthyl butyrate esterase positive cells in peripheral blood. They also normalized phagocytic function in blood neutrophils and oxidative burst in peritoneal cells. CONCLUSION: Both milks were equally effective to exert favorable effects on the number of the bone marrow cells and the functions of the blood and peritoneal cells involved in immune response. However, only human milk normalized the number of leukocytes and increased the number of neutrophils in peripheral blood.

We studied the impact of human (HM) and cow (CM) milk on the recovery of blood and bone marrow cells in malnourished mice. Results: both milks normalized serum albumin levels and improved thymus weight. HM was less effective than CM to increase body weight and serum transferrin levels. In contrast, HM was more effective than CM to increase the number of leukocytes and lymphocytes in peripheral blood. Both milks induced an increment in mitotic pool cells in bone marrow and α-naphthyl butyrate esterase positive cells in peripheral blood. They also normalized phagocytic function in blood neutrophils and oxidative burst in peritoneal cells. Conclusion: both milks were equally effective to exert favorable effects on the number of the bone marrow cells and the functions of the blood and peritoneal cells involved in immune response. However, only HM normalized the number of leukocytes and increased the number of neutrophils in peripheral blood.

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

OBJECTIVE AND DESIGN: The coagulation system is considered part of the defense machinery, but its excessive activation can lead to additional damage. We studied the effects of oral administration of Lactobacillus casei CRL 431--a probiotic bacterium--on the activation of coagulation and the relationship with inflammatory parameters during a respiratory infection in malnourished mice. MATERIALS AND METHODS: Malnourished Swiss albino mice were nourished with a balanced commercial diet (BCD) for 7 days or BCD with L. casei for the last 2 days (BCD + Lc). BCD, BCD + Lc, malnourished (MNC) and well-nourished controls (WNC) were infected with Streptococcus pneumoniae. Blood and bronchoalveolar lavage samples were obtained at different times post-infection. RESULTS AND CONCLUSIONS: Malnutrition altered most of the evaluated parameters before and after infection. The repletion diet with supplemental L. casei was the most effective in limiting coagulation activation and normalizing coagulation inhibition mechanisms. These findings will help develop further strategies to reduce the damaging effects of clotting and enhance its beneficial contribution to immune reactions.

Dietary supplementation with probiotics improves hematopoiesis in malnourished mice.

BACKGROUND: Lactobacillus rhamnosus CRL1505 (Lr) administered during the repletion of immunocompromised-malnourished mice improves the resistance against intestinal and respiratory infections. This effect is associated with an increase in the number and functionality of immune cells, indicating that Lr could have some influence on myeloid and lymphoid cell production and maturation. OBJECTIVE: This study analyzed the extent of the damage caused by malnutrition on myeloid and lymphoid cell development in the spleen and bone marrow (BM). We also evaluated the impact of immunobiotics on the recovery of hematopoiesis affected in malnourished mice. METHODS: Protein malnourished mice were fed on a balanced conventional diet for 7 or 14 consecutive d with or without supplemental Lr or fermented goat's milk (FGM). Malnourished mice and well-nourished mice were used as controls. Histological and flow cytometry studies were carried out in BM and spleen to study myeloid and lymphoid cells. RESULTS: Malnutrition induced quantitative alterations in spleen B and T cells; however, no alteration was observed in the ability of splenic B cells to produce immunoglobulins after challenge with LPS or CpG. The analysis of BM B cell subsets based on B220, CD24, IgM and IgD expression showed that malnutrition affected B cell development. In addition, BM myeloid cells decreased in malnourished mice. On the contrary, protein deprivation increased BM T cell number. These alterations were reverted with Lr or FGM repletion treatments since normal numbers of BM myeloid, T and B cells were observed in these groups. CONCLUSIONS: Protein malnutrition significantly alters B cell development in BM. The treatment of malnourished mice with L. rhamnosus CRL1505 was able to induce a recovery of B cells that would explain its ability to increase immunity against infections. This work highlights the possibility of using immunobiotics to accelerate the recovery of lymphopoyesis in immunocompromised-malnourished hosts.

Immunomodulatory and protective effect of probiotic Lactobacillus casei against Candida albicans infection in malnourished mice.

The effect of Lactobacillus casei CRL 431 (Lc), when administered as a supplement to a repletion diet, on the resistance of malnourished mice to Candida albicans infection was studied. Weaned mice were malnourished by being given a protein-free diet (PFD) for 21 days. The malnourished mice were then fed a balanced conventional diet (BCD) for 7 days or BCD for 7 days with supplemental Lc on days 6 and 7 (BCD+Lc). Malnourished (MNC) and well-nourished (WNC) mice were used as controls. At the end of the treatments the mice were infected intraperitoneally with C. albicans. Animals that had received probiotics had improved survival and resistance against this infection compared to those in the BCD and MNC groups. The number and fungicidal activity of phagocytes, and the concentrations of tumor necrosis factor-α, interferon-γ and interleukin-6 (IL-6), increased in blood and infected tissues in all experimental groups, but MNC mice showed lower concentrations than those in the WNC group. BCD and BCD+Lc mice showed higher concentrations of these variables than those in the MNC group, but only the BCD+Lc group presented values similar to the WNC mice. Malnutrition also impaired the production of IL-17 and IL-10 in response to infection. Both repletion treatments normalized IL-17 concentrations, but IL-10 in the BCD+Lc group was significantly higher than in WNC mice. The addition of L. casei to the repletion diet normalized the immune response against C. albicans, allowing efficient recruitment and activation of phagocytes, as well as effective release of pro-inflammatory cytokines. In addition, probiotic treatment induced an increase in IL-10 concentrations, which would have helped to prevent damage caused by the inflammatory response.

Coagulation activation in an experimental pneumonia model in malnourished mice.

Malnutrition induces a decrease in immunity that affects the ability of the organism to deal with an infectious challenge. The clotting system is considered a branch of immunity and its activation is important in the pathogenesis of an infectious disease. This work was conducted to determine coagulation modifications in malnourished hosts before and during infection. Weaned mice were malnourished via a protein-free diet. Well-nourished control mice (WNC) consumed a balanced conventional diet. Malnourished mice (MN) and WNC were challenged intranasally with Streptococcus pneumoniae. Blood, bronchoalveolar lavages (BAL), and lung samples were taken at different times post infection. The results were that MN showed altered hemostatic tests and fibrin(ogen) deposits in the lung. Thus, an increase in thrombin-antithrombin complexes (TATc) in plasma and BAL was observed. In the MN group, infection induced a rise in TATc in plasma and BAL and increased plasma fibrinogen and fibrin(ogen) deposits in the lung. A decrease in activated protein C and antithrombin in BAL and an early decrease followed by an increase in plasma Factor VIII were also observed. Thus, malnourishment induced a procoagulant state increased by infection. This is the first work that presents results of an exhaustive study of coagulation in malnourished hosts before and during an infection.

Lactobacillus casei modulates the inflammation-coagulation interaction in a pneumococcal pneumonia experimental model.

BACKGROUND: We have previously demonstrated that Lactobacillus casei CRL 431 administration improved the resistance to pneumococcal infection in a mouse model. METHODS: This study examined the effects of the oral administration of Lactobacillus casei CRL 431 (L. casei) on the activation of coagulation and fibrinolytic systems as well as their inhibitors during a Streptococcus pneumoniae infection in mice. RESULTS: The alveolo-capillary membrane was damaged and the coagulation system was also activated by the infection. As a consequence, we could see fibrin(ogen) deposits in lung histological slices, increased levels of thrombin-antithrombin complex (TATc) in bronchoalveolar lavage (BAL) and plasma, decrease in prothrombin activity (PT) and prolonged activated partial thromboplastin time test (APTT) values. Factor VII (FVII) and factor X (FX) were decreased in plasma, whereas fibrinogen (F) and factor VIII (FVIII) were increased. The low levels of protein C (PC) in BAL and plasma proved damage on inhibitory activity. The infected animals showed reduced fibrinolytic activity, evidenced by an increase in plasminogen activation inhibitor-1 (PAI-1) in BAL and plasma. The pathogen induced an increase of TNF-alpha, IL-1beta and IL-6 in BAL and serum a few hours after challenge followed by a significant decrease until the end of the assayed period. IL-4 and IL-10 in BAL and serum were also augmented, especially at the end of the experiment. The animals treated with L. casei showed an improvement of alveolo-capillary membrane, lower fibrin(ogen) deposits in lung and decrease in TATc. APTT test and PT, FVII and FX activity were normalized. L. casei group showed lower F levels than control during whole experiment. In the present study no effect of L. casei on the recovery of the inhibitory activity was detected. However, L. casei was effective in reducing PAI-1 levels in BAL and in increasing anti-inflammatory ILs concentration. CONCLUSION: L. casei proved effective to regulate coagulation activation and fibrinolysis inhibition during infection, leading to a decrease in fibrin deposits in lung. This protective effect of L. casei would be mediated by the induction of higher levels of IL-4 and IL-10 which could regulate the anti-inflammatory, procoagulant and antifibrinolytic effects of TNF-alpha, IL-1beta and IL-6.

Lactobacillus casei: influence on the innate immune response and haemostatic alterations in a liver-injury model.

UNLABELLED: Lactobacilllus casei CRL 431 has the ability to modulate the local and systemic immune responses, which are significantly involved in liver injury caused by hepatotoxins. This work was conducted to determine whether L. casei has a preventive effect on the hepatic damage undergone during an acute liver injury (ALI). METHODS: ALI was induced by an intraperitoneal injection of d-galactosamine (D-Gal). Different groups of mice received 1x 109 L. casei cells/day/mouse for 2 days before D-Gal injection. Blood and liver samples were obtained 0, 6, 12, and 24 h after D-Gal administration. RESULTS: D-Gal induced increases in serum aminotransferases, reduced the number of blood leukocytes, enhanced neutrophil myeloperoxidase activity, increased dead cells, and altered prothrombin time and plasma fibrinogen levels. The preventive treatment with L. casei for 2 days modulated the innate immune response. This effect was shown by the earlier normalization of white blood cell counts, myeloperoxidase activity and aminotransferases levels. However, the haemostatic parameters were only partially recovered. The favourable effects obtained could be due to the capacity of L. casei to moderate the inflammatory response at the site of the injury with less damage to liver tissue.

Yogurt: effect on leukocytes and blood coagulation in an acute liver injury model.

This study determined whether cow or goat yogurt administration has a preventive effect on the hepatic damage undergone during an acute liver injury. Acute liver injury was induced by an intraperitoneal injection of d-galactosamine. Groups of mice were fed with cow or goat yogurt for 2 days or 7 days before the d-galactosamine injection. Blood and liver samples were obtained 12 hours after d-galactosamine inoculation. d-Galactosamine induced an increase in serum amino-transaminases, a reduction in the number of blood leukocytes, an enhancement in neutrophil myeloperoxidase activity, a recruitment of leukocytes toward the liver, an increase in cell death, and an alteration in prothrombin time, activated partial thromboplastin time, and fibrinogen levels. Treatment with cow or goat yogurt was effective at increasing leukocyte number and decrease myeloperoxidase activity. We also observed a decrease in leukocyte accumulation in the liver and a reduction in cell death. Activated partial thromboplastin time and fibrinogen were normalized, but prothrombin time only showed an improvement without reaching normal values. Cow or goat yogurts were effective at protecting against an experimental acute liver injury, especially when administered for 7 days.

Lactobacillus casei administration reduces lung injuries in a Streptococcus pneumoniae infection in mice.

The effect of the oral administration of Lactobacillus casei on the prevention of a Streptococcus pneumoniae lung infection in a mouse experimental model was studied, analyzing the innate and specific immune response. Adult Swiss albino mice were treated with L. casei (10(9)CFU/day) for 2, 5 and 7 d. Mice were infected intranasally with S. pneumoniae (10(6)CFU/mouse) after each treatment and the microbiological, histopathological and host responses were determined for 15 d after infection. Feeding L. casei for 2 d induced a faster clearance of S. pneumoniae, with a lower number of pneumococci in lung and a shorter period of septicemia than in the control group. L. casei administration induced activation of phagocytes as evidenced by the strong myeloperoxidase activity and the nitro blue tetrazolium assay in lung. Mice given L. casei for 2 d showed higher levels of anti-pneumococcal serum IgG and bronchoalveolar lavage IgA than the control mice. The group fed L. casei for 2 d could beneficially regulate the balance between tumor necrosis factor alpha and interleukin 10, allowing a more effective immune response against infection and modulating the inflammatory response, with less damage to the lung.

Beneficial immunomodulatory activity of Lactobacillus casei in malnourished mice pneumonia: effect on inflammation and coagulation.

OBJECTIVE: The effect of Lactobacillus casei CRL 431 immunomodulatory activity on inflammation and coagulation during pneumococcal pneumonia was investigated in malnourished mice. METHODS: Weaned mice were malnourished after they consumed a protein-free diet for 21 d. Malnourished mice were treated for 7 d with a balanced conventional diet (BCD) with L. casei supplementation (BCD+Lc) or without it. The malnourished control group received only a protein-free diet whereas well-nourished control (WNC) mice consumed BCD ad libitum. Mice were challenged by the intranasal route with pneumococci at the end of each dietary treatment. Lung injury, leukocyte recruitment, cytokine production, coagulation tests, and fibrin(ogen) deposition in lungs were evaluated. RESULTS: Malnourished control mice showed impaired leukocyte recruitment and cytokine production, and more severe lung injuries when compared with WNC mice. Coagulation tests were significantly impaired in malnourished control group versus WNC group. Repletion with BCD or BCD+Lc improved these parameters, but only BCD+Lc mice achieved the values of WNC mice. In addition, the interleukin-10 level was higher in the BCD+Lc group than in the WNC group. CONCLUSION: Repletion with supplemental L. casei accelerated recovery of the defense mechanisms against pneumococci by inducing different cytokine profiles. These cytokines would be involved in the improvement of the immune response and in the induction of a more efficient regulation of the inflammatory process, limiting the injury caused by infection.

Yoghurt accelerates the recovery of defence mechanisms against Streptococcus pneumoniae in protein-malnourished mice.

Experiments studied the effect of yoghurt on the recovery of defence mechanisms against Streptococcus pneumoniae respiratory infection in malnourished mice. Weaned mice were malnourished with a protein-free diet (PFD) for 21 d. Malnourished mice were made replete with a balanced diet (BD), yoghurt, or the BD with supplemental yoghurt (BD + Y) for 7, 14 or 21 d. The normal control (NC) group was fed the BD whereas malnourished control (MC) mice consumed only the PFD. Mice were challenged with pneumococci at the end of each dietary treatment. MC mice showed increased susceptibility to pneumococcal infection. Blood leucocytes, phagocyte activity and serum and bronco-alveolar anti-pneumococcal IgG and IgA were significantly lower in the MC than in the NC group. Repletion of malnourished mice with the BD for 21 d was necessary to obtain a response to infection similar to that of NC mice; however, administration of the BD + Y for 14 d was enough to normalise the immune defence mechanisms. Histological examination of MC lungs showed progressive loss of alveolar architecture. Lung injuries were significantly less pronounced in NC mice. Mice treated with the BD + Y for 14 d showed histological signs similar to the NC group. The present study showed that administration of yoghurt to malnourished mice induced an early recovery of the immunological parameters studied. Despite the uncertainties about the mechanisms involved and about the human relevance of the effects observed in animal models, the present study provides a strong rationale for the hypothesis that yoghurt consumption by malnourished hosts will accelerate the recovery of the immune mechanisms involved in the protection against respiratory infections.