Analysis of bacterial communities of infected primary teeth in a Mexican population

The objective of this study was to describe the bacterial communities associated with pediatric patients with endodontic infections of temporal teeth by targeting the 16S rRNA gene using pyrosequencing. Microbiological samples were obtained from the lower primary molars of thirteen 13 pediatric patients with dental infections. An aspiration method for microbiological sampling was used. The identification of microbiota employing the pyrosequencing method by targeting the 16S gene was performed. Ribosomal 16S RNA gene sequences were amplified, obtaining a total of 16,182 sequences from 13 primary infected molars (13 different individuals) by pyrosequencing. Bacteroidetes phyla (35.15%) were the most abundant followed by Firmicutes (33.3%) and Fusobacteria (10.05%); the presence of specific pathogenic bacteria was determined as well. The infected root canal of primary teeth contains a high diversity of anaerobic bacteria, and Bacteroidetes, Firmicutes, and Fusobacteria phyla were the most abundant; Prevotella and Streptococcus genera were the most prevalent

Comparative and Prospective Study of Different Immune Parameters in Healthy Subjects at Risk for Tuberculosis and in Tuberculosis Patients

It has not been fully elucidated which of the components of the immune response against Mycobacterium tuberculosis is indicative of resistance or susceptibility. The aim of this study was to identify an immune parameter that could be indicative of either resistance or susceptibility to M. tuberculosis infection. We prospectively studied (three determinations, at months 0, 8, and 12) 15 patients with chronic pulmonary tuberculosis and 42 healthy individuals with a recent and frequent contact with tuberculosis patients. Peripheral blood mononuclear cells were stimulated with a whole-protein extract or the 30-kDa antigen of M. tuberculosis for 6 days, and several immune parameters were determined. No consistent differences between tuberculosis patients and healthy controls were detected in most immune parameters studied, including the expression of different activation antigens, cytokine secretion, lymphocyte proliferation, and nitric oxide production. However, the synthesis of tumor necrosis factor alpha, the intracellular detection of gamma interferon, and the apoptosis of monocytes under certain culture conditions tended to show clear-cut differences in cells from patients and controls (P < 0.05 in all cases for most determinations). Nevertheless, when results were analyzed on an individual basis, it was evident that a significant degree of overlapping of values from patients and controls occurred for all parameters studied. We conclude that although the immune parameters tested do not allow the identification of individuals susceptible to M. tuberculosis, the specificity and sensitivity of some of them could be improved through future studies

Induction of Th17 Lymphocytes and Treg Cells by Monocyte-Derived Dendritic Cells in Patients with Rheumatoid Arthritis and Systemic Lupus Erythematosus

Dendritic cells (DCs) have a key role in the regulation of immune response. We herein explored, in patients with inflammatory diseases, the role of monocyte derived DC’s (mo-DCs) on the generation of Th17 and T regulatory (Treg) lymphocytes. Peripheral blood was obtained from thirty-five patients with rheumatoid arthritis (RA), twelve with systemic lupus erythematosus (SLE), and twenty healthy subjects. Mo-DCs were generated under standard (IL-4/GM-CSF) or tolerogenic (IL-4/GM-CSF plus recombinant P-selectin or PD-1 or IL-10) conditions, and their ability to induce Th17 and Treg lymphocytes was tested. We detected that mo-DCs from patients with RA showed an enhanced release of IL-6 and IL-23 as well as an increased capability to induce Th17 cells. Although mo-DCs from SLE patients also released high levels of IL-6/IL-23, it did not show an increased ability to induce Th17 lymphocytes. In addition, mo-DCs, from patients with RA and SLE generated under the engagement of PSGL-1, showed a defective capability to induce Foxp3+ Treg cells. A similar phenomenon was observed in SLE, when DC’s cells were generated under PDL-1 engagement. Our data indicate that DCs from patients with rheumatic inflammatory disease show an aberrant function that may have an important role in the pathogenesis of these conditions

Evaluation of the expression and function of the P2X7 receptor and ART1 in human regulatory T-cell subsets

"Regulatory T cells that express CD39 (CD39+ Treg) exhibit specific immunomodulatory properties. Ectonucleotidase CD39 hydrolyses ATP and ADP. ATP is a ligand of the P2X7 receptor and induces the shedding of CD62L and apoptosis. However, the role of ATP in CD39+ Treg cells has not been defined. Furthermore, NAD can activate the P2X7 receptor via ADP-ribosyltransferase (ART) enzymes and cause cell depletion in murine models. We evaluated the expression and function of P2X7 and ART1 in CD39+ Treg and CD39- Treg cells in the presence or absence of ATP and NAD. We isolated peripheral blood mononuclear cells from healthy subjects and purified CD4+ T cells, CD4+ CD25+ T cells and CD4+ CD25+ CD39+ T cells. P2X7 and ART1 expression was assessed by flow cytometry and real-time PCR. Our results showed low P2X7 expression on CD39+ Treg cells and higher levels of ART1 expression in CD4+ CD39+ T cells than the other subtypes studied. Neither shedding of CD62L nor cell death of CD39+ Treg or CD39- Treg cells was observed by 1mM ATP or 60 mu M NAD. In contrast, P2Xs receptor-dependent proliferation with 300 p,M ATP, was inhibited by NAD in the different cell types analysed. The NAD proliferation-inhibition was increased with P2X5 and A2a agonist and was reversed with P2X5 and A2a antagonist, therefore NAD inhibits P2Xs-dependent proliferation and A2a activation. In conclusion, our results suggest that the altered function and expression of P2X7 and ART1 in the human CD39+ Treg or CD39 Treg cells could participate in the resistance against cell death induced by ATP or NAD. (C) 2015 Elsevier GmbH. All rights reserved.