Lipopolysaccharide and lipotheicoic acid differentially modulate epididymal cytokine and chemokine profiles and sperm parameters in experimental acute epididymitis.

Bacterial infections are the most prevalent etiological factors of epididymitis, a commonly diagnosed inflammatory disease in the investigation of male infertility factors. The influence of early pathogenic mechanisms at play during bacterial epididymitis on reproductive outcomes is little understood. We report here that experimental epididymitis induced in rats by Gram-negative (LPS) and Gram-positive (LTA) bacterial products resulted in differential patterns of acute inflammation in the cauda epididymis. LPS elicited a strong inflammatory reaction, as reflected by upregulation of levels of mRNA for seven inflammatory mediators (Il1b, Tnf, Il6, Ifng, Il10, Nos2 and Nfkbia), and tissue concentration of six cytokines/chemokines (IL1A, IL1B, IL6, IL10, CXCL2 and CCL2) within the first 24 h post-treatment. Conversely, LTA induced downregulation of one (Nfkbia) and upregulation of six (Il1b, Il6, Nos2, Il4 Il10 and Ptgs1) inflammatory gene transcripts, whereas increased the tissue concentration of three cytokines/chemokines (IL10, CXCL2 and CCL2). The stronger acute inflammatory response induced by LPS correlated with a reduction of epididymal sperm count and transit time that occurred at 1, 7, and 15 days post-treatment. Our study provides evidence that early epididymal inflammatory signaling events to bacterial activators of innate immunity may contribute to the detrimental effects of epididymitis upon male fertility.

Apigenin reduce lipoteichoic acid-induced inflammatory response in rat cardiomyoblast cells.

Infective endocarditis is caused by Streptococcus sanguinis present in dental plaque, which can induce inflammatory responses in the endocardium. The present study depicts research on the properties of apigenin in embryonic mouse heart cells (H9c2) treated with lipoteichoic acid (LTA) obtained from S. sanguinis. Interleukin-1ß and cyclooxygenase (COX)-2 expression were detected by reverse transcriptase polymerase chain reaction. In addition, western blot assays and immuno-fluorescence staining were used to assess translocation of nuclear factor kappa beta (NF-κB), degradation of IκB, as well as activity of the mitogen activated protein kinases: extracellular signal-regulated kinase (ERK)1/2, p38, and c-Jun N-terminal kinase (JNK). Effect of apigenin on cell viability was equally assessed in other experimental series. Our results showed that apigenin blocked activation of ERK, JNK, and p38 in cardiomyocytes treated with LTA in a dose-dependent fashion. Moreover, apigenin showed no cytotoxic effects; it blocked NF-κB translocation and IκB degradation. Our findings suggested that apigenin possessed potential value in the treatment of infectious endocarditis.

Myricetin suppresses lipoteichoic acid-induced interleukin-1ß and cyclooxygenase-2 expression in human gingival fibroblasts.

Periodontitis is an inflammatory disease affecting the connective tissue and supporting bone surrounding the teeth. In periodontitis, human gingival fibroblasts (HGFs) synthesize IL-1ß, causing a progressive inflammatory response. Flavones demonstrate a variety of biological activity: among others, they possess anti-inflammatory properties. Myricetin is a flavone with a strong anti-inflammatory activity. The objective of this study was to evaluate the effect of the flavonoid myricetin on HGFs under inflammatory conditions induced by lipoteichoic acid (LTA). the effect of myricetin on HGFs was assessed by measuring cell viability, signaling pathways and IL-1ß expression and synthesis. It was found that, over time, myricetin did not affect cell viability. However, it inhibited activation of p38 and extracellular-signal-regulated kinase-1/2 in LTA-treated HGFs and also blocked IκB degradation and cyclooxygenase-2 and prostaglandin E2 synthesis and expression. These findings suggest that myricetin has therapeutic effects in the form of controlling LTA-induced inflammatory responses.

Immune response of non-pathogenic gram(+) and gram(-) bacteria in inductive sites of the intestinal mucosa study of the pathway of signaling involved.

The gut associated lymphoid tissue (GALT) is anatomical and functionally divided in inductive and effectors sites. In previous works we demonstrated that non-pathogenic bacteria with probiotic characteristics can improve the gut mucosal immune system, with an increase in the number of IgA and cytokines producing cells in the effector site of the intestine. In the present work we studied the effect of non-pathogenic Gram(+), Gram(-) bacteria and a Gram(+) probiotic strain on the inductor site (PP) after the oral administration to BALB/c mice. We also studied some signals induced by the assayed strain in the effectors site, such as the enzyme calcineurin and TLR-9 as a way to understand the mechanisms induced in such bacterial stimulation. The implicance of the lipoteichoic acid (LTA) in the immunostimulation was analyzed. All strains increased the number of IFN-gamma and TNF-alpha(+) cells, but not of IL-10(+) cells in the total population of PP. The release of IFN-gamma and TNF-alpha was only induced by LPS stimulation. All assayed strains increased the number of calcineurin(+) cells, while only Gram(+) strains increased the number of TLR-9(+) cells. The immunostimulatory properties of the purified LTA from Gram(+) strains was evaluated on a monocyte-macrophage U937 cell line. These cells showed capacity to release TNF-alpha and IL-10 in response to all LTA assayed in a dose-dependent way. Gram(+) strains induced signals through the calcineurin enzyme able to activate the transcriptional factor NFAT and through TLR-9. The LTA molecule from Gram(+) strains would not be the only structure involved in the immunostimulatory properties observed, specially for the probiotic strain.

Lipoteichoic acid from Staphylococcus aureus increases matrix metalloproteinase 9 expression in RAW 264.7 macrophages: modulation by A2A and A2B adenosine receptors.

Peptidoglycan (PEG) and lipoteichoic acid (LTA) are the main constituents of Gram-positive bacteria cell wall and are described to modulate immune functions. Increased levels of matrix metalloproteinases (MMPs) were described in endotoxemia, suggesting that they participate to tecidual damage, multiple organs failure and vascular disfunction. Staphylococcus aureus PEG is described to increase MMPs 2 and 9 levels in plasma from rat and MMP 9 secretion by human neutrophils, however, the effect of LTA on MMPs is unknown. In this work, was evaluated the modulation of MMPs 2 and 9 expression and secretion in RAW 264.7 macrophages by LTA from S. aureus. The role of A2A and A2B adenosine receptors was also investigated. LTA increased MMP 9 expression and secretion at 12h of treatment. The modulation of MMP 9 secretion was dose dependent, with maximal effect above 1microg/ml. The inhibitor of mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway (U0126, 10microM) prevented LTA stimulation of MMP 9 secretion; however, the inhibitors of p38 (SB203580, 10microM) and Jun N-terminal kinase (JNK; SP600125, 10microM) presented any effect. A2A and A2B adenosine receptors pharmacological blockade or gene knockdown resulted in exacerbated MMP 9 secretion, while an adenosine receptors agonist inhibited LTA-stimulated MMP 9 secretion. These results suggest that LTA increased MMP 9 secretion in macrophages could be involved in complications associated to S. aureus infections. Moreover, LTA modulation of MMP 9 is dependent on MEK/ERK pathway and is regulated by A2A and A2B adenosine receptors.

Behçet's disease patients present high levels of deglycosylated anti-lipoteichoic acid IgG and high IL-8 production after lipoteichoic acid stimulation.

OBJECTIVES: Lipoteichoic acid (LTA), induces some of the clinical symptoms of Behçet's disease (BD) in a rat animal model. These results led to the hypothesis that LTA may also trigger BD in humans. We investigated the humoral and cellular immune response against LTA and lipopolysaccharide (LPS) in patients with BD, and compared these responses with those of patients with active chronic oral ulcers (OU) and normal controls. METHODS: Samples were obtained from 12 active BD, 12 inactive BD, 12 active OU and 12 normal controls. Anti-LTA, anti-LPS antibodies levels and the capacity of immune complexes anti-LTA IgG-LTA to activate complement were studied. Exposed mannose residues in anti-LTA IgG were analyzed in the four groups. The interleukin-8 (IL-8) production by peripheral blood mononuclear cells cultures after LTA and LPS stimulation was also studied in all groups. RESULTS: The capacity to bind mannan binding protein (MBP) of anti-LTA IgGs was significantly higher in BD and active OU patients relative to normal controls (p < 0.001). However, only active BD patients generated significantly higher levels of C5a than controls (p < 0.0001). The IgGs purified from the sera of BD patients showed a high specificity for LTA from Streptococcus sanguis or Streptococcus faecalis. LTA also stimulates the secretion of IL-8 in peripheral blood mononuclear cells isolated from active BD patients. Anti-LPS IgA and IgG titers were significantly higher only in active OU patients relative to normal controls (p < 0.0018). CONCLUSION: These results suggest a mechanism involving LTA from streptococci in the pathogenesis of BD.

Teichoic acid serology in staphylococcal infections of infants and children.

Counterimmunoelectrophoresis and gel diffusion were utilized for the detection and titration of antibodies to staphylococcal teichoic acids in various disease states caused by coagulase-positive staphylococcus in infants and children. Serum samples were obtained on admission and serially for 2 to 12 weeks during illness. Teichoic acid antibodies were found by CIE in 12 of 21 patients (57%) with invasive CPS disease with bacteremia (Group A), in two of 17 patients (12%) with CPS infection without bacteremia (Group B), in none of 27 patients with bacteremia and/or invasive infections caused by organisms other than CPS (Group C), and in none of 24 noninfected, hospitalized patients or healthy children (Group D). Gel diffusion was useful for titrating antibodies in seropositive sera. Teichoic acid serology is a useful adjunct in the diagnosis of invasive CPS infections. The presence of these antibodies by CIE and gel diffusion may help to identify patients with endothelial or metastatic infections associated with staphylococcal bacteremia.