Intestinal microbiota-derived short-chain fatty acids regulation of immune cell IL-22 production and gut immunity.

Innate lymphoid cells (ILCs) and CD4+ T cells produce IL-22, which is critical for intestinal immunity. The microbiota is central to IL-22 production in the intestines; however, the factors that regulate IL-22 production by CD4+ T cells and ILCs are not clear. Here, we show that microbiota-derived short-chain fatty acids (SCFAs) promote IL-22 production by CD4+ T cells and ILCs through G-protein receptor 41 (GPR41) and inhibiting histone deacetylase (HDAC). SCFAs upregulate IL-22 production by promoting aryl hydrocarbon receptor (AhR) and hypoxia-inducible factor 1α (HIF1α) expression, which are differentially regulated by mTOR and Stat3. HIF1α binds directly to the Il22 promoter, and SCFAs increase HIF1α binding to the Il22 promoter through histone modification. SCFA supplementation enhances IL-22 production, which protects intestines from inflammation. SCFAs promote human CD4+ T cell IL-22 production. These findings establish the roles of SCFAs in inducing IL-22 production in CD4+ T cells and ILCs to maintain intestinal homeostasis.

Livestock abundance predicts vampire bat demography, immune profiles and bacterial infection risk.

Human activities create novel food resources that can alter wildlife-pathogen interactions. If resources amplify or dampen, pathogen transmission probably depends on both host ecology and pathogen biology, but studies that measure responses to provisioning across both scales are rare. We tested these relationships with a 4-year study of 369 common vampire bats across 10 sites in Peru and Belize that differ in the abundance of livestock, an important anthropogenic food source. We quantified innate and adaptive immunity from bats and assessed infection with two common bacteria. We predicted that abundant livestock could reduce starvation and foraging effort, allowing for greater investments in immunity. Bats from high-livestock sites had higher microbicidal activity and proportions of neutrophils but lower immunoglobulin G and proportions of lymphocytes, suggesting more investment in innate relative to adaptive immunity and either greater chronic stress or pathogen exposure. This relationship was most pronounced in reproductive bats, which were also more common in high-livestock sites, suggesting feedbacks between demographic correlates of provisioning and immunity. Infection with both Bartonella and haemoplasmas were correlated with similar immune profiles, and both pathogens tended to be less prevalent in high-livestock sites, although effects were weaker for haemoplasmas. These differing responses to provisioning might therefore reflect distinct transmission processes. Predicting how provisioning alters host-pathogen interactions requires considering how both within-host processes and transmission modes respond to resource shifts.This article is part of the theme issue 'Anthropogenic resource subsidies and host-parasite dynamics in wildlife'.

Downregulation of inflammatory cytokines by berberine attenuates Riemerella anatipestifer infection in ducks.

Riemerella anatipestifer, an important infectious bacterium affecting the duck industry, has 5-75% mortality, depending on strain virulence. We previously demonstrated that proinflammatory cytokines are involved in inflammation during, and regulating susceptibility to, R. anatipestifer infection. We investigated the effects of the anti-inflammatory compound berberine in duck splenic lymphocytes stimulated with killed R. anatipestifer, and in R. anatipestifer-infected ducks. IL-17A, IL-17F, and IL-1ß transcripts were downregulated, and IFN-γ and IL-10 transcripts enhanced, in berberine-treated stimulated splenic lymphocytes, compared to stimulated untreated splenic lymphocytes. Similarly, IL-17A, IL-17F, IL-6, and IL-1ß expressions were significantly reduced, and IFN-γ and IL-10 expressions significantly upregulated, in spleens and livers of R. anatipestifer-infected berberine-treated ducks, compared to infected untreated birds. Moreover, infected and treated birds showed increased survival rates and significantly decreased bacterial burdens compared to infected untreated birds, confirming that inflammatory cytokines are strongly associated with R. anatipestifer infection in ducks.

Efecto in vitro de la Matricaria recutita L. sobre la respuesta de linfocitos y neutrófilos / In vitro effect of Matricaria recutita L. on Lymphocytes and Neutrophils response

La manzanilla de Castilla, dulce o cimarrona (Matricaria recutita o Matricaria chamomilla), es una planta herbácea anual de la familia de las asteráceas, nativa de Europa y de regiones templadas de Asia, que se ha naturalizado en algunas regiones de América, África y Australia. Ha sido utilizada por el hombre desde hace miles de años con diferentes fines medicinales. Se estudió el efecto in vitro de un extracto fluido de esta planta sobre los linfocitos de 20 donantes voluntarios de sangre y de 20 enfermos con diagnóstico de inmunodeficiencia celular, mediante la cuantificación de los linfocitos T por las técnicas de formación de roseta espontánea y activa y el ultramicrométodo inmunocitoquímico (UMICIQ), así como la función fagocítica (índice opsonofagocítico) de los neutrófilos. No se hallaron diferencias estadísticamente significativas en los parámetros estudiados entre las condiciones experimentales con Matricaria y sin esta

Castilla Chamomile, sweet, or maroon (Matricaria recutita or Matricaria chamomilla) is an annual herbaceous plant of the Asteraceae family, native to Europe and temperate zones of Asia, which has become naturalized in parts of America, Africa, and Australia. It has been used by man for thousands of years with different medicinal purposes. We studied the in vitro effect of an extract fluid of this plant on lymphocytes from 20 blood donors and 20 patients with a diagnosis of cellular immunodeficiency. We quantified T lymphocytes by the techniques of spontaneous and active rosette formation, and the immunocytochemical ultramicromethod (UMICIQ) as well as the phagocytic function (opsonophagocytic index) of neutrophils. There were no statistically significant differences in the studied parameters between experimental conditions with Matricaria and without it

Folic acid increases global DNA methylation and reduces inflammation to prevent Helicobacter-associated gastric cancer in mice.

BACKGROUND & AIMS: Previous studies have suggested that dietary folic acid (FA) can protect against certain types of cancers. However, the findings have varied, and the mechanisms by which FA exerts chemopreventive effects remain to be clarified. We examined the effects of FA supplementation on DNA methylation, gene expression, and gastric dysplasia in a transgenic mouse model that is etiologically and histologically well matched with human gastric cancers. METHODS: Hypergastrinemic mice infected with Helicobacter felis were studied at multiple stages of gastric dysplasia and early cancer with FA supplementation initiated both at weaning and later in life. Global DNA methylation was assessed by a methylation sensitive cytosine incorporation assay, bisulfite pyrosequencing of B1 repetitive elements, and immunohistochemistry with anti-5-methylcytosine. We also profiled gene expression in the same tissues. RESULTS: We found a decrease in global DNA methylation and tissue folate and an increase in serum homocysteine with progression of gastric dysplasia. FA supplementation prevented this loss of global DNA methylation and markedly reduced gastric dysplasia and mucosal inflammation. FA protected against the loss of global DNA methylation both in the dysplastic gastric epithelial cells and in gastric stromal myofibroblasts. In addition, FA supplementation had an anti-inflammatory effect, as indicated by expression profiling and immunohistochemistry for lymphocyte markers. CONCLUSIONS: We conclude that FA supplementation is chemopreventive in this model of Helicobacter-associated gastric cancer. The beneficial effect of FA is likely due to its ability to prevent global loss of methylation and suppress inflammation.

[Effects of oil-refining microbes (genus Acinetobacter) on cytogenetical structures of human lymphocytes in cell cultures].

The objective of this study was to assess ability of oil-refining bacteria Acinetobacter calcoaceticus and A. valentis to induce karyopathological abnormalities and chromosomal aberrations in human lymphocyte cultures. It was found that the cultures infected with A. calcoaceticus showed significantly high frequencies of cytogenetical effects and chromosomal aberrant cells as compared to the intact cultures and cultures infected with A. valentis. The most of chromosomal aberrations, mainly chromatid aberrations, were located in 1 and 2 chromosomes. Moreover, the aberrations were detected in some specific chromosome areas. Abnormalities of mitotic cell division and nucleus morphology were determined in lymphocyte cultures infected with A. calcoaceticus. There were found significantly high frequencies of cells with micronuclei, nucleus protrusions, anaphase or metaphase chromosome and chromosomal fragments lagging as well as multipolar and C-mitoses. Thus, the oil-refining bacteria A. calcoaceticus in contrast to A. valentis demonstrated strong genotoxic effects in human lymphocyte cultures in vitro.

Metabolic activity of the enteric microbiota influences the fatty acid composition of murine and porcine liver and adipose tissues.

BACKGROUND: Recent reports suggest that the metabolic activity of the gut microbiota may contribute to the pathogenesis of obesity and hepatic steatosis. OBJECTIVE: The objective was to determine whether the fat composition of host tissues might be influenced by oral administration of commensal bifidobacteria previously shown by us to produce bioactive isomers of conjugated linoleic acid (CLA). DESIGN: Murine trials were conducted in which linoleic acid-supplemented diets were fed with or without Bifidobacterium breve NCIMB 702258 (daily dose of 10(9) microorganisms) to healthy BALB/c mice and to severe combined immunodeficient mice for 8-10 wk. To ensure that the observations were not peculiar to mice, a similar trial was conducted in weanling pigs over 21 d. Tissue fatty acid composition was assessed by gas-liquid chromatography. RESULTS: In comparison with controls, there was an increase in cis-9, trans-11 CLA in the livers of the mice and pigs after feeding with linoleic acid in combination with B. breve NCIMB 702258 (P < 0.05). In addition, an altered profile of polyunsaturated fatty acid composition was observed, including higher concentrations of the omega-3 (n-3) fatty acids eicosapentaenoic acid and docosahexaenoic acid in adipose tissue (P < 0.05). These changes were associated with reductions in the proinflammatory cytokines tumor necrosis factor-alpha and interferon-gamma (P < 0.05). CONCLUSIONS: These results are consistent with the concept that the metabolome is a composite of host and microbe metabolic activity and that the influence of the microbiota on host fatty acid composition can be manipulated by oral administration of CLA-producing microorganisms.

Effects of the probiotic agent Saccharomyces Boulardii on the DNA damage in acute necrotizing pancreatitis induced rats.

Pancreatitis is a mild and self-limiting disease. Although severe forms such as acute necrotizing pancreatitis (ANP) are rare it is associated with significant mortality rate reported to be 30-70%. Probiotics are viable microbial dietary supplements when introduced in sufficient quantities can have beneficial effects. The physiological effects of probiotics include suppression of bacterial infections, production of some digestive enzymes and vitamins and reconstruction of normal intestinal microflora. In the present study, the aim was to investigate the role of probiotics on the DNA damage in the peripheral lymphocytes, in the exfoliated epithelial cells and lymphocytes of the peritoneal fluids and in the pancreatic acinar cells of ANP induced rats. DNA damage was determined by COMET assay. ANP was induced by intravenous infusion of cerulein and superimposed infusion glycodeoxycholic acid into biliopancreatic duct. Saccharomyces Boulardii was used as the probiotic agent. DNA damage in pancreatic acinar cells and exfoliated epithelial cells and the lymphocytes of the peritoneal fluids was significantly higher in pancreatitis group compared to the controls and probiotic treated groups (P<0.001). No significant difference was observed in the DNA damage between the groups in the peripheral lymphocytes. In conclusion; our results support that probiotic agent Saccharomyces Boulardii can diminish bacterial infections and offer health benefits in the therapy of pancreatitis.

Relevance of dietary lipids as modulators of immune functions in cells infected with Listeria monocytogenes.

Nutritional status may have significant importance for the immune system, and particularly, unsaturated fatty acids may serve as modulators of immune functions. Clinical and epidemiological studies have demonstrated that fatty acids are involved in the reduction of the inflammatory processes that occur in diseases characterized by an overactivation of the immune system. At the same time, an increase in susceptibility to infection has also been reported. The importance of immune system modulation by dietary lipids in the presence of an intracellular bacterial pathogen, such as Listeria monocytogenes, was evaluated in the present study. BALB/c mice were divided into four groups which were each fed a low-fat (2.5% by weight) diet, an olive oil (OO; 20% by weight) diet, a fish oil (FO; 20% by weight) diet, or a hydrogenated coconut oil (HCO; 20% by weight) diet for 4 weeks. In each group, lymphocye proliferation was measured, and a reduction in the stimulation index was observed in the FO and HCO groups. Cytotoxicity exerted by L. monocytogenes was increased in the groups fed diets containing OO and FO after 6 h of incubation with the bacterium. An important increase in the production of reactive oxygen species was found in the groups fed the HCO diet after 12 h of incubation with L. monocytogenes. Finally, invasion and adhesion factors were not modified substantially by the action of dietary lipids, although these factors were reduced in cells from mice fed an FO diet. These results underline the importance of several dietary lipids as biological modulators of immune functions and their crucial role in the alteration of host natural resistance.

Screening for biological activity and chemical composition of Euodia borbonica var. borbonica (Rutaceae), a medicinal plant in Reunion Island.

Three simple coumarins; scoparone, limettin and psoralen have been isolated as major components from the leaves of Euodia borbonica var. borbonica (Rutaceae) together with xanthoxylin, a common phenolic compound in Rutaceae family. Their structures were elucidated through GC/MS and NMR studies. A minor furocoumarin, bergapten, was also detected in the extracts. Preliminary biological tests on ethanolic leaf extracts did not show any activity.

Inhibition of tumour promotion by various palm-oil tocotrienols.

Inhibition of tumour promotion by various vitamin E compounds (tocopherols and tocotrienols) and some of their dimers was examined by an in vitro assay utilizing the activation of Epstein-Barr virus (EBV) early antigen (EA) expression in EBV-genome-carrying human lymphoblastoid cells. The results reveal that gamma- and delta-tocotrienols derived from palm oil exhibit a strong activity against tumour promotion by inhibiting EBV EA expression in Raji cells induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). However, alpha- and gamma-tocopherols and dimers of gamma-tocotrienol or gamma-tocopherol lack this activity.

Anti-AIDS agents, 11. Betulinic acid and platanic acid as anti-HIV principles from Syzigium claviflorum, and the anti-HIV activity of structurally related triterpenoids.

Betulinic acid [1] and platanic acid [2], isolated from the leaves of Syzigium claviforum, were found to be inhibitors of HIV replication in H9 lymphocyte cells. Evaluation of anti-HIV activity with eight derivatives of 1 revealed that dihydrobetulinic acid [3] was also a potent inhibitor of HIV replication. The C-3 hydroxy group and C-17 carboxylic acid group, as well as the C-19 substituents, contribute to enhanced anti-HIV activity. The inhibitory activity of these compounds against protein kinase C (PKC) was also examined, since a correlation between anti-HIV and anti-PKC activities has been suggested. However, there was no apparent correlation between anti-HIV activity and the inhibition of PKC among these compounds.

Phenylselenenyl- and phenylthio-substituted pyrimidines as inhibitors of dihydrouracil dehydrogenase and uridine phosphorylase.

Lithiation of 5-bromo-2,4-bis(benzyloxy)pyrimidine (3) with n-BuLi at -80 degrees C followed by the addition of diphenyl diselenide or diphenyl disulfide as an electrophile furnished the corresponding 5-(phenylhetera)-2,4-bis(benzyloxy)pyrimidine, which on exposure to trimethylsilyl iodide in CH2-Cl2 at room temperature yielded the 5-(phenylhetera)uracils in 70-75% yield. Similarly, the 6-(phenylhetera)uracils were prepared from 6-bromo-2,4-bis(benzyloxy)pyrimidine (10). 1-[(2-Hydroxyethoxy)methyl]-5-(phenylselenenyl)uracil (PSAU, 18) and 1-(ethoxymethyl)-5-(phenylselenenyl)uracil (17) were synthesized by the electrophilic addition of benzeneselenenyl chloride to the acyclic uracils under basic conditions. These compounds were evaluated for their ability to inhibit dihydrouracil dehydrogenase (DHUDase, E.C. 1.3.1.2), orotate phosphoribosyltransferase (OPRTase, E.C. 2.4.2.10), uridine phosphorylase (UrdPase, E.C. 2.4.2.3), and thymidine phosphorylase (dThdPase, E.C. 2.4.2.4). 5-(Phenylselenenyl)uracil (PSU, 6) and 5-(phenylthio)uracil (PTU, 7) inhibited DHUDase with apparent K(i) values of 4.8 and 5.4 microM, respectively. The corresponding 6-analogues, compounds 13 and 14, demonstrated inhibitory activity against OPRTase. PTU as well as PSU and its riboside, 2'-deoxyriboside, and acyclonucleosides were inhibitors of UrdPase, with PSAU (18) being the most potent with an apparent K(i) value of 3.8 microM. None of the compounds evaluated had any effect on dThdPase. Interestingly, most of the compounds showed modest selective anti-human-immunodeficiency-virus activity in acutely infected primary human lymphocytes.

Anti-AIDS agents, 9. Suberosol, a new C31 lanostane-type triterpene and anti-HIV principle from Polyalthia suberosa.

A new C31 lanostane-type triterpene, assigned the trivial name suberosol [1], has been isolated from Polyalthia suberosa as an anti-HIV principle. The structure has been characterized as 24-methylenelanost-7,9(11)-diene-3 beta, 15 alpha-diol (suberosol) [1], based on spectroscopic evidence. Compound 1 was found to show anti-HIV replication activity in H9 lymphocyte cells with an EC50 of 3 micrograms/ml.

Inhibition of type 1 human immunodeficiency virus replication by a tat antagonist to which the virus remains sensitive after prolonged exposure in vitro.

The transactivator of transcription, Tat, of human immunodeficiency virus type 1 (HIV-1) is required for viral replication. Inhibition of Tat function could have the potential to keep integrated provirus in dormancy. In the presence of Tat, Ro 24-7429, an analog of Ro 5-3335, inhibited expression of indicator genes controlled by the HIV-1 long terminal repeat promoter in transient transfection assays and in a constitutive cell line at noncytotoxic concentrations. Reduction of steady-state mRNA of the indicator gene by the compound correlated with reduction of the gene product in the constitutive cell line. Ro 24-7429 has broad activity against several strains of HIV-1 in different cell lines, peripheral blood lymphocytes, and macrophages (IC90 = 1-3 microM). Importantly, Ro 24-7429 inhibited viral replication in both acute and chronic infection in vitro, a characteristic expected of a Tat antagonist and not shared by viral reverse transcriptase inhibitors. Consistent with this, the compound reduced cell-associated viral RNA and proteins and partially restored cell-surface CD4 in chronically infected cells. After 2 years of continued weekly passage of the virus in fresh CEM cells grown in the presence of the compound at 1 or 10 microM, the virus did not develop resistance to the drug. These results indicate that the compound's action might involve a cellular factor.

Anti-aids agents, 6. Salaspermic acid, an anti-HIV principle from Tripterygium wilfordii, and the structure-activity correlation with its related compounds.

Salaspermic acid [1], an inhibitor of HIV reverse transcriptase and HIV replication in H9 lymphocyte cells, was isolated from the roots of Tripterygium wilfordii for the first time. The structure of 1 derived from spectral data was established unequivocally by an X-ray analysis of crystals of the monohydrate. A structure-activity correlation of 1 with ten related compounds indicated that the acetal linkage in ring A and the carboxyl group in ring E of 1 may be required for the anti-HIV activity.

Inhibition of HIV replication in lymphocyte cultures of virus-positive subjects in the presence of sho-saiko-to, an oriental plant extract.

An oriental remedy, Sho-saiko-to (SST) consisting of a mixture of aqueous extracts from seven different plants and whose most active component is the chemically defined compound baicalein was tested for its ability to inhibit the production of the human immunodeficiency virus (HIV). The testing was done with cultures of human lymphocytes obtained from HIV-positive asymptomatic subjects and patients with ARC or AIDS. The replication of the virus was monitored by quantitative assay of the reverse transcriptase (RT) activity and of the synthesis of antigen p24. The lymphocyte cultures (LC) were maintained in the absence and in the presence of 25, 50 or 100 micrograms/ml of SST, and monitored for up to 5 weeks. The results showed that in LC from asymptomatic subjects RT activity and synthesis of p24 was completely inhibited by low concentrations of SST. High concentrations of SST inhibited virus replication in 80% of LC from ARC patients, but were completely ineffective in LC from AIDS patients. It was observed that the RT activity was more sensitive to inhibition by SST than the synthesis of p24, and that the antiviral effect was dependent on the virus load of the LC.

Modification of human immunodeficiency viral replication by pine cone extracts.

We have shown previously that two fractions (PC6 and PC7) extracted from cones of the Japanese white pine Pinus parvifloria Sieb. et Zucc have potent immunopotentiating effects. Here, we show that PC6 and PC7 inhibited HIV-1 replication (greater than 95%), in a dose-dependent manner, in chronically infected CR10/HIV-1 cells and in acute cytolytic HIV-1 infection of CEM cells. Treatment of CEM cells, prior to or after acute infection with HIV-1, reduced subsequent viral production, but the best inhibitory effect was obtained with treatment before and after infection: an 80% inhibition was achieved with as little as 3 micrograms/ml of PC6. Comparable results were also obtained when PC6 was used to inhibit HIV-1 replication in the U937 human histiocytic lymphoma cell line. Both PC6 and PC7 were relatively nontoxic to cells. The anti-HIV-1 effect of PC6 and PC7 we observed in this report, coupled with earlier reports of their immunopotentiating properties suggest their potential as ideal therapeutic agents for the treatment of AIDS.

Epstein-Barr virus-enhancing plant promoters in east Africa.

The extracts of a certain African plant species, Euphorbia tirucalli, were found to have markedly enhancing effects on the activation of latent Epstein-Barr virus (EBV) genomes in the EBV carrying lymphoblastoid cells and also on EBV-induced transformation of human lymphocytes. The Euphorbia tirucalli was especially noticeable in highly endemic areas of Burkitt's lymphoma (BL), an EBV-associated malignancy, in Kenya and Tanzania. The activation of the latent EBV genome and the EBV-induced transformation enhancement were also observed with the soil and drinking water taken around the plants, strongly indicating that the people living in BL endemic areas are frequently exposed to such an EBV-enhancing plant promoter substance.