Immunomodulatory effects of different strains of Lactococcus lactis in DSS-induced colitis.

Inflammatory bowel diseases (IBD) are gastrointestinal disorders characterized by a breakdown in intestinal homeostasis by inflammatory immune responses to luminal antigens. Novel strategies for ameliorating IBD have been proposed in many studies using animal models. Our group has demonstrated that administration of Lactococcus lactis NCDO 2118 can improve clinical parameters of colitis induced by oral administration of dextran sulphate sodium (DSS).

Neuroimmune circuits involved in β-lactoglobulin-induced food allergy.

Several antigens can act as allergens eliciting IgE-mediated food allergy reactions when fed to sensitized animals. One of them is ovalbumin (OVA) which is the main allergen in egg white. Allergic mice develop aversion to OVA consumption.

Consumption of conjugated linoleic acid (CLA)-supplemented diet during colitis development ameliorates gut inflammation without causing steatosis in mice.

Dietary supplementation with conjugated linoleic acid (CLA) has been proposed for weight management and to prevent gut inflammation. However, some animal studies suggest that supplementation with CLA leads to the development of nonalcoholic fatty liver disease. The aims of this study were to test the efficiency of CLA in preventing dextran sulfate sodium (DSS)-induced colitis, to analyze the effects of CLA in the liver function, and to access putative liver alterations upon CLA supplementation during colitis.

Consumption of Diet Containing Free Amino Acids Exacerbates Colitis in Mice.

Dietary proteins can influence the maturation of the immune system, particularly the gut-associated lymphoid tissue, when consumed from weaning to adulthood. Moreover, replacement of dietary proteins by amino acids at weaning has been shown to impair the generation of regulatory T cells in the gut as well as immune activities such as protective response to infection, induction of oral and nasal tolerance as well as allergic responses. Polymeric and elemental diets are used in the clinical practice, but the specific role of intact proteins and free amino acids during the intestinal inflammation are not known.

Hsp65-Producing Prevents Inflammatory Intestinal Disease in Mice by IL-10- and TLR2-Dependent Pathways.

Heat shock proteins (Hsps) are highly expressed at all sites of inflammation. As they are ubiquitous and immunodominant antigens, these molecules represent good candidates for the therapeutic use of oral tolerance in autoimmune and chronic inflammatory diseases. Evidences from human and animal studies indicate that inflammatory bowel disease (IBD) results from uncontrolled inflammatory responses to intestinal microbiota.

Lactococcus lactis carrying the pValac eukaryotic expression vector coding for IL-4 reduces chemically-induced intestinal inflammation by increasing the levels of IL-10-producing regulatory cells.

Background: Inflammatory bowel diseases are characterized by chronic intestinal inflammation that leads to severe destruction of the intestinal mucosa. Therefore, the understanding of their aetiology as well as the development of new medicines is an important step for the treatment of such diseases. Consequently, the development of Lactococcus lactis strains capable of delivering a eukaryotic expression vector encoding the interleukin 4 (IL-4) of Mus musculus would represent a new strategy for the elaboration of a more effective alternative therapy against Crohn's disease.

Preventive rather than therapeutic treatment with high fiber diet attenuates clinical and inflammatory markers of acute and chronic DSS-induced colitis in mice.

Purpose: Inflammatory bowel diseases (IBDs) are chronic inflammatory disorders with important impact on global health. Prebiotic and probiotic strategies are thought to be useful in the context of experimental IBD. Here, we compared the effects of preventive versus therapeutic treatment with a high fiber diet (prebiotic) in combination or not with Bifidobacterium longum (probiotic) in a murine model of chronic colitis.

Hydrolyzed whey protein prevents the development of food allergy to β-lactoglobulin in sensitized mice.

Food allergy is an adverse immune response to dietary proteins. Hydrolysates are frequently used for children with milk allergy. However, hydrolysates effects afterwards are poorly studied.

Previous Ingestion of Lactococcus lactis by Ethanol-Treated Mice Preserves Antigen Presentation Hierarchy in the Gut and Oral Tolerance Susceptibility.

Background: Ethanol (EtOH) consumption is able to disturb the ovalbumin (OVA)-oral tolerance induction by interfering on the function of antigen presenting cells (APC), down-regulating dendritic cells (DCs) and macrophages and up-regulating B-lymphocytes and their function, which results in an overall allergic-type immune status. In this study, the potential of a priori administration of Lactococcus lactis (LL) in avoiding loss of oral tolerance in EtOH-treated mice was investigated.

Methods: Female C57BL/6 mice received, by oral route, ad libitum wild-type (WT) LL or heat-shock protein producer (Hsp65) LL for 4 consecutive days.

Antigen administration by continuous feeding enhances oral tolerance and leads to long-lasting effects.

The ability to avoid inflammatory responses to dietary components and microbiota antigens in the gut mucosa is achieved by a mechanism termed oral tolerance. This phenomenon is crucial to maintain the physiological immune activity in the gut and to prevent inflammatory disorders such as food allergy and inflammatory bowel diseases. Moreover, orally administered antigens induce regulatory cells that control systemic inflammatory responses as well.

Milk fermented with a 15-lipoxygenase-1-producing Lactococcus lactis alleviates symptoms of colitis in a murine model.

Inflammatory bowel diseases (IBD), such as Crohn's disease and ulcerative colitis, is characterized by extensive inflammation due to dysregulation of the innate and adaptive immune system whose exact etiology is not yet completely understood. Currently there is no cure for IBD, thus the search for new molecules capable of controlling IBD and their delivery to the site of inflammation are the goal of many researchers. The aim of this work was to evaluate the anti-inflammatory effect of the administration of milks fermented by a Lactococcus (L.

Anti-inflammatory effects of Lactococcus lactis NCDO 2118 during the remission period of chemically induced colitis.

Background: Many probiotic bacteria have been described as promising tools for the treatment and prevention of inflammatory bowel diseases (IBDs). Most of these bacteria are lactic acid bacteria, which are part of the healthy human microbiota. However, little is known about the effects of transient bacteria present in normal diets, including Lactococcus lactis.

Local and systemic immune mechanisms underlying the anti-colitis effects of the dairy bacterium Lactobacillus delbrueckii.

Several probiotic bacteria have been proposed for treatment or prevention of inflammatory bowel diseases (IBD), showing a protective effect in animal models of experimental colitis and for some of them also in human clinical trials. While most of these probiotic bacteria are isolated from the digestive tract, we recently reported that a Lactobacillus strain isolated from cheese, L. delbrueckii subsp.

Oral combined therapy with probiotics and alloantigen induces B cell-dependent long-lasting specific tolerance.

Allogeneic hematopietic stem cell transplantation (aHSCT) is widely used for the treatment of hematologic malignancies. Although aHSCT provides a good response against the malignant cells (graft-versus-leukemia [GVL]), it also leads to the development of graft-versus-host disease (GVHD), a severe disease with high mortality and morbidity rates. Therapy for GVHD is commonly based on nonspecific immunosupression of the transplanted recipient, resulting in the concomitant inhibition of the GVL effect.

Food components and the immune system: from tonic agents to allergens.

The intestinal mucosa is the major site of contact with antigens, and it houses the largest lymphoid tissue in the body. In physiological conditions, microbiota and dietary antigens are the natural sources of stimulation for the gut-associated lymphoid tissues (GALT) and for the immune system as a whole. Germ-free models have provided some insights on the immunological role of gut antigens.

Oral tolerance correlates with high levels of lymphocyte activity.

Oral tolerance is defined as an inhibition of specific immune responsiveness to a previously ingested antigen. Paradoxically, we found an increased lymphocyte activity in tolerant mice alongside the specific inhibition. Orally-tolerant mice presented higher number of immunoglobulin secreting cells (ISC) in spleen and bone marrow; showed a greater variety of Ig classes being produced: IgM and IgA in the spleen and IgG and IgM in the bone marrow.

Hsp65-producing Lactococcus lactis prevents experimental autoimmune encephalomyelitis in mice by inducing CD4+LAP+ regulatory T cells.

Heat shock proteins (Hsps) participate in the cellular response to stress and they are hiperexpressed in inflammatory conditions. They are also known to play a major role in immune modulation, controlling, for instance, autoimmune responses. In this study, we showed that oral administration of a recombinant Lactococcus lactis strain that produces and releases LPS-free Hsp65 prevented the development of experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice.

New insights into the immunological changes in IL-10-deficient mice during the course of spontaneous inflammation in the gut mucosa.

IL-10 is a regulatory cytokine that plays a major role in the homeostasis of the gut and this is illustrated by the fact that IL-10(-/-) mice develop spontaneous colitis. In this study, IL-10(-/-) mice were analyzed for immunological changes during colitis development. We found a reduced frequency of regulatory T cells CD4(+)CD25(+)Foxp3(+) and higher frequency of activated T cells in the colon that precedes the macroscopic signs of the disease.

Pro-inflammatory effects of the mushroom Agaricus blazei and its consequences on atherosclerosis development.

Purpose: Extracts of the mushroom Agaricus blazei (A. blazei) have been described as possessing immunomodulatory and potentially cancer-protective activities. However, these effects of A.

Oral administration of sodium butyrate attenuates inflammation and mucosal lesion in experimental acute ulcerative colitis.

Butyrate is a four-carbon short-chain fatty acid that improves colonic trophism. Although several studies have shown the benefits of butyrate enemas in ulcerative colitis (UC), studies using the oral route are rare in the literature. In the present study, we evaluated the effect of butyrate intake in the immune response associated to UC.

Antigenic dietary protein guides maturation of the host immune system promoting resistance to Leishmania major infection in C57BL/6 mice.

The immature immune system requires constant stimulation by foreign antigens during the early stages of life to develop properly and to create efficient immune responses against later infections. We have previously shown that intake of antigenic dietary protein is critical for inducing maturation of the immune system as well as for the development of T helper type 1 (Th1) immunity. In this study, we show that administration of an amino acid (aa)-based diet during the development of the immune system subsequently resulted in inefficient control of Leishmania major infection in adult C57BL/6 mice.