α-IRAK-4 Suppresses the Activation of RANK/RANKL Pathway on Macrophages Exposed to Endodontic Microorganisms.

Periapical lesions are common pathologies affecting the alveolar bone, often initiated by intraradicular lesions resulting from microbial exposure to dental pulp. These microorganisms trigger inflammatory and immune responses. When endodontic treatment fails to eliminate the infection, periapical lesions persist, leading to bone loss. The RANK/RANKL/OPG pathway plays a crucial role in both the formation and the destruction of the bone. In this study, the objective was to inhibit the RANK/RANKL pathway in vitro within exposed Thp-1 macrophages to endodontic microorganisms, specifically Enterococcus faecalis, which was isolated from root canals of 20 patients with endodontic secondary/persistent infection, symptomatic and asymptomatic, and utilizing an α-IRAK-4 inhibitor, we introduced endodontic microorganisms and/or lipoteichoic acid from Streptococcus spp. to cellular cultures in a culture plate, containing thp-1 cells and/or PBMC from patients with apical periodontitis. Subsequently, we assessed the percentages of RANK+, RANKL+, and OPG+ cells through flow cytometry and measured the levels of several inflammatory cytokines (IL-1ß, TNF-α, IL-6, IL-8, IL-10, and IL-12p70) in the cellular culture supernatant through a CBA kit and performed analysis by flow cytometry. A significant difference was observed in the percentages of RANK+RANKL+, OPG+ RANKL+ cells in thp-1 cells and PBMCs from patients with apical periodontitis. The findings revealed significant differences in the percentages of the evaluated cells, highlighting the novel role of the IRAK-4 inhibitor in addressing this oral pathology, apical periodontitis, where bone destruction is observed.

Increased levels of pathogenic Th17 cells and diminished function of CD69+ Treg lymphocytes in patients with overweight.

A low-grade inflammatory phenomenon is a feature of overweight and metabolic syndrome. The involvement of a pro-inflammatory Th17 lymphocyte subset and the CD69+ T regulatory (Treg) cell subtype in patients with metabolic dysfunction associated with or without overweight has not been fully elucidated. The aim of this study was to perform a quantitative and functional analysis of pathogenic Th17 lymphocytes and CD69+ Treg cells in patients with metabolic dysfunction (insulin resistance and dyslipidemia). The number of pathogenic Th17 cells and the levels and function of CD69+ Treg cells were analyzed in blood samples from individuals with metabolic dysfunction, associated with or without overweight. Pathogenic and non-pathogenic Th17 lymphocytes as well as Th22 cells were determined by eight-color flow cytometry analysis, whereas the levels and suppressive function of CD69+ Treg cells were also analyzed by multiparametric flow cytometry. We detected increased levels of pro-inflammatory Th17 pathogenic cells and Th22 lymphocytes in overweight unhealthy individuals (P < 0.001, compared to normal weight healthy). Conversely, diminished numbers of CD69+ Treg lymphocytes were observed in metabolically unhealthy individuals, with or without overweight. Likewise, the immunosuppressive function of CD69+ Treg cells was also defective in these patients. The increased levels of pathogenic Th17 cells along with a diminished number and function of CD69+ Treg lymphocytes may significantly contribute to the low-grade inflammatory phenomenon of metabolically unhealthy patients.

Filifactor alocis and Dialister pneumosintes in a Mexican population affected by periodontitis and rheumatoid arthritis: An exploratory study.

Filifactor alocis and Dialister pneumosintes have been associated with the initiation and progression of periodontitis (PE). We determined and compared the frequency of both bacteria in patients with PE, rheumatoid arthritis (RA), and PE/RA simultaneously. Detection was performed by polymerase chain reaction in the subgingival biofilm. Bacteria were more frequent in patients with PE, and clinical periodontal parameters such as pocket depth (PD) and clinical attachment loss (CAL) were significantly higher in patients with PE/RA. F. alocis and D. pneumosintes could influence PD and CAL, hence participating in the initiation and progression of PE in patients with RA.

[Células T reguladoras en lupus eritematoso generalizado].

El lupus eritematoso generalizado (LEG) es una enfermedad autoinmune crónica caracterizada por la pérdida de la tolerancia a los antígenos propios y la síntesis de diferentes autoanticuerpos con la formación y depósito de complejos inmunes y el daño de múltiples órganos. Las células T reguladoras (Treg) desempeñan un papel esencial en el mantenimiento de la tolerancia periférica, controlan el estado de activación del sistema inmune y limitan las respuestas autoinmunes. El estudio del número y la función de las diferentes subpoblaciones de células Treg en LEG ha sido objeto de una intensa investigación. Dependiendo del fenotipo de las células Treg analizado se ha reportado que la frecuencia de estas células en pacientes con LEG se encuentra disminuida, aumentada o sin alteraciones. Además, diferentes grupos han descrito que la función supresora de las células Treg de los pacientes con LEG se encuentra reducida o no se ve afectada. En conjunto, lo datos reportados sugieren que las células Treg desempeñan un papel relevante en la patogénesis del LEG y que estos linfocitos pueden ser considerados blancos potenciales para el diseño de nuevas estrategias terapéuticas para esta enfermedad.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by a loss of tolerance to self-antigens and synthesis of different autoantibodies, with the formation and deposition of immune complexes and damage to multiple organs. T regulatory cells (Tregs) play a crucial role in maintaining peripheral tolerance, controlling the state of activation of the immune system and limiting autoimmune responses. The study of the number and function of the different Treg cell subpopulations in SLE has been the subject of intense research. Depending on the analyzed Treg cell phenotype, the frequency of these cells has been reported to be reduced, increased or unaltered in patients with SLE. In addition, different groups have described that Treg cells suppressive function is reduced or unaffected in patients with SLE. Taken together, the reported data suggest that Treg cells play a relevant role in the pathogenesis of SLE and that these lymphocytes can be considered potential targets for the design of new therapeutic strategies for this condition.

Concentrations of persistent organic pollutants (POPs) and heavy metals in soil from San Luis Potosí, México.

The aim of this study was to assess the levels of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), p,p'-dichlorodiphenyltrichloroethane (DDT), p,p'-dichlorodiphenyldichloroethylene (DDE), and four heavy metals (arsenic, cadmium, lead, and mercury) in soil from the city of San Luis Potosí in Mexico. In order to confirm the presence of the previously mentioned compounds, outdoor surface soil samples were collected and analyzed by gas chromatography/mass spectrometer for PBDEs, PCBs, DDT, and DDE. Meanwhile, heavy metals were quantified using the atomic absorption spectrophotometry technique. The total PBDEs levels ranged from 5.0 to 134 µg/kg dry weight (dw), with a total mean PBDEs level of 22.0 ± 32.5 µg/kg dw (geometric mean ± standard deviation). For PCBs, the total mean level in the studied soil was 21.6 ± 24.7 µg/kg dw (range,

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.

Levels of Pathogenic Th17 and Th22 Cells in Patients with Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune condition characterized, among others, by tissue damage and activation/differentiation of proinflammatory lymphocytes. Accordingly, several studies have concluded that type 17 T helper (Th17) cells seem to have an important role in the pathogenesis of this condition. However, the strategy for the identification and analysis of proinflammatory Th17 cells in those studies has not been consistent and has usually been different from what was originally described. Therefore, we decided to evaluate the levels of Th17 cells in patients with RA employing an extended immune phenotype by using an eight-color multiparametric flow cytometry analysis. For this purpose, blood samples were obtained from 30 patients with RA and 16 healthy subjects, and the levels of Th17 and type 22 helper (Th22) lymphocytes were analyzed as well as the in vitro differentiation of peripheral blood mononuclear cells into Th17 lymphocytes induced by interleukin-23 (IL-23) and IL-1ß. We found significant enhanced levels of total Th17 lymphocytes (defined as CD4+IL-17+) as well as enhanced numbers of their pathogenic (defined as CD4+CXCR3+IL-17+IL-22+CD243+CD161+IFN-γ +IL-10-) and nonpathogenic (CD4+CXCR3+IL-17+IL-22-CD243-CD161-IFN-γ -IL-10+) cell subsets in patients with RA. Likewise, the number of Th22 (CD4+CXCR3+/-IL-17-IL-22+) was also increased in these patients compared to healthy controls. However, the in vitro induction/differentiation of pathogenic Th17 cells showed similar results in controls and patients with RA. Likewise, no significant associations were detected in patients with RA between the levels of Th17 or Th22 cells and clinical or laboratory parameters. Our data indicate that patients with RA show enhanced blood levels of the different subsets of Th17 cells and Th22 lymphocytes tested in this study and suggest that these levels are not apparently associated with clinical or laboratory parameters.

Effect of fluoride exposure on different immune parameters in humans.

CONTEXT: T regulatory (Treg) cells play an important role in the modulation of the immune response, and are implicated in the pathogenesis of autoimmune diseases. Many people is exposed to fluoride (F), mainly through drinking water. OBJECTIVE: The aim of this work was to assess the possible effect of F exposure on different immune parameters, mainly Treg cells. MATERIALS AND METHODS: We studied 61 subjects from a community of the state of Durango, Mexico, where the population is exposed to F levels over 2.0 ppm in drinking water. Peripheral blood mononuclear cells (PBMC) were isolated and the level and function of Treg cells was analyzed by flow cytometry and cell proliferation assays. In addition, we detected the presence of apoptotic cells, the expression of TLR/CD14, and the in vitro synthesis of TNF-α by monocytes. RESULTS: We found a negative correlation between urinary F and percentage of CD4(+)CD25(+) Treg cells (r = -0.55, P < 0.001). Accordingly, a defective function of these cells was detected in 30% of individuals exposed to F. In contrast, a positive association between levels of CD4(+)TGF-ß(+) or CD4(+)IL-10(+) Treg lymphocytes and F urine concentrations was detected. In addition, a negative correlation was detected between the F urinary levels and the proportion of apoptotic cells, in PBMC or T cells or monocytes (P < 0.05 in all cases). Finally, no apparent association between F exposure and TLR4/CD14 expression or the synthesis of TNF-α was detected. CONCLUSION: Our data suggest that F exposure exerts a complex and relevant effect on Treg cells in humans.

Altered NK cell receptor repertoire and function of natural killer cells in patients with acute myocardial infarction: A three-month follow-up study.

NK cells are important in the onset of acute myocardial infarction (AMI) by their ability to secrete IFN-γ and other inflammatory cytokines. They also participate in regulating pathological cardiac remodeling after myocardial infarction. Mechanisms of regulation, however, are incompletely understood. Herein, the aim of this study is to explore the possible association between the expression pattern of different NK cell receptors (phenotype), as well as the cytotoxic function of NK cells from AMI patients with their myocardial function after three months follow-up. We analyzed the phenotype and function of both CD56dimCD16+ and CD56brightCD16- NK cells from twenty-one patients within the first 72 h after ST-elevation AMI and three-month follow-up, as well as fifteen healthy controls. Clinical characteristics and ventricular function determined by echocardiography were also evaluated. NK cells from AMI patients showed an activated phenotype, characterized by high TNF-α production and low percentages of the activating receptor NKG2D. Interestingly, AMI patients display higher levels of circulating IL-10+ NK cells. Three-month follow-up showed that NK cells exhibit a diminished cytotoxic function. These data show that NK cells may have a role mediating myocardial remodeling by regulating the inflammatory response, mainly by the production of IL-10. We also propose that NKG2D may have a role in the onset of the inflammatory response immediately after AMI. The precise regulation of NK cells function may represent an important step in recovery of myocardial function.

DDE and PCB 153 independently induce aryl hydrocarbon receptor (AhR) expression in peripheral blood mononuclear cells.

Recent studies have demonstrated that compounds inducing pro-inflammatory cytokines enhance AhR expression. The aim of this study was 2-fold: (1) to determine if two pro-inflammatory compounds, dichlorodiphenyldichloroethylene (DDE) and 2,2',4,4',5,5'-hexa-chlorobiphenyl (PCB 153), independently affect AhR gene expression in peripheral blood mononuclear cells (PBMC); and (2) if affected, to determine whether the mechanism involved was due to AhR activation or to a pro-inflammatory effect of the chemicals. PBMC isolated from healthy individuals were incubated in the presence of DDE (10 µg/ml) and PCB 153 (20 ng/ml) over time and AhR and CYP1A1 expression was assessed with a real-time PCR technique. The results indicated there was over-expression of the AhR mRNA in PBMC when the cells were treated with DDE and PCB 153. No changes in expression levels of CYP1A1 mRNA were found. Importantly, when the cells were exposed to DDE and PCB 153 in the presence of an antagonist of tumor necrosis factor (TNF)-α, the over-expression of AhR was abolished; as expected, the expression of CYP1A1 was unaffected. In conclusion, these studies demonstrated for the first time an increment of AhR expression "in vitro" in PBMC treated with two pro-inflammatory environmental pollutants, DDE and PCB153. Moreover, the over-expression of AhR was dependent of TNFα induced by DDE and PCB 153 and was independent of AhR activation.

Células T reguladoras en lupus eritematoso generalizado / Regulatory T cells in systemic lupus erythematosus

Resumen El lupus eritematoso generalizado (LEG) es una enfermedad autoinmune crónica caracterizada por la pérdida de la tolerancia a los antígenos propios y la síntesis de diferentes autoanticuerpos con la formación y depósito de complejos inmunes y el daño de múltiples órganos. Las células T reguladoras (Treg) desempeñan un papel esencial en el mantenimiento de la tolerancia periférica, controlan el estado de activación del sistema inmune y limitan las respuestas autoinmunes. El estudio del número y la función de las diferentes subpoblaciones de células Treg en LEG ha sido objeto de una intensa investigación. Dependiendo del fenotipo de las células Treg analizado se ha reportado que la frecuencia de estas células en pacientes con LEG se encuentra disminuida, aumentada o sin alteraciones. Además, diferentes grupos han descrito que la función supresora de las células Treg de los pacientes con LEG se encuentra reducida o no se ve afectada. En conjunto, lo datos reportados sugieren que las células Treg desempeñan un papel relevante en la patogénesis del LEG y que estos linfocitos pueden ser considerados blancos potenciales para el diseño de nuevas estrategias terapéuticas para esta enfermedad.

Abstract Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by a loss of tolerance to self-antigens and synthesis of different autoantibodies, with the formation and deposition of immune complexes and damage to multiple organs. T regulatory cells (Tregs) play a crucial role in maintaining peripheral tolerance, controlling the state of activation of the immune system and limiting autoimmune responses. The study of the number and function of the different Treg cell subpopulations in SLE has been the subject of intense research. Depending on the analyzed Treg cell phenotype, the frequency of these cells has been reported to be reduced, increased or unaltered in patients with SLE. In addition, different groups have described that Treg cells suppressive function is reduced or unaffected in patients with SLE. Taken together, the reported data suggest that Treg cells play a relevant role in the pathogenesis of SLE and that these lymphocytes can be considered potential targets for the design of new therapeutic strategies for this condition.

Clinical and immunological effects of Rituximab in patients with lupus nephritis refractory to conventional therapy: a pilot study.

We studied the clinical and immunological effects of Rituximab (anti-CD20) therapy in patients with lupus nephritis. In an open clinical trial, 22 patients with active systemic lupus erythematosis and renal involvement (mainly class III and IV according to the WHO classification) that was refractory to conventional therapy were studied. In all these patients, Rituximab (0.5 to 1.0 g at days 1 and 15) was added to the immunosuppressive therapy and its therapeutic effect was evaluated. In addition, the levels and function of regulatory T lymphocytes and the apoptosis of immune cells were assessed. We found a significant reduction in disease activity (p < 0.05, MEX-SLEDAI index), and proteinuria (p < 0.05) at days 60 and 90 of Rituximab therapy. Although most patients showed improvement in creatinine clearance and erythrocyturia, no significant changes in these parameters were detected. In most patients (20/22), B cell depletion was observed, but no clear-cut effect of Rituximab on complement levels or auto-antibody titers was detected (p > 0.05 in all cases). One patient died at day 70 with invasive histoplasmosis. No important adverse effects of Rituximab therapy were registered in other patients. A significant enhancement in the levels of different CD4+ regulatory cells (TREG, Th3, Tr1), but not CD8+ Ts lymphocytes, was observed at day 30. This increase was sustained for TREG cells at day 90, and accompanied by an improvement in their regulatory function. In addition, we observed an unexpected increase in the apoptosis of T cells at day 30. Interestingly, the enhancement in the suppressive function of TREG cells was not observed in the two patients that showed the poorest clinical response to Rituximab. We conclude that the data obtained in this open clinical trial suggest that Rituximab is a promising candidate for randomized controlled trials in patients with lupus nephritis refractory to the conventional immunosuppressive therapy. The effects of Rituximab on regulatory cells and apoptosis of T lymphocytes are interesting and its possible role in the putative effect of this biological agent in systemic lupus erythematosis deserves additional studies.

Regulatory T cells in patients with systemic lupus erythematosus.

Regulatory T cells have an important role in the control of self-reactivity, and in the pathogenesis of autoimmune inflammatory conditions. The aim of this work was to perform a quantitative and functional analysis of regulatory T cells in patients with systemic lupus erythematosus (SLE). We studied twenty-three patients with SLE (19 active, 4 inactive), and twenty-seven healthy subjects as well as fifteen patients with rheumatoid arthritis (RA). The following cell subsets were analyzed in peripheral blood mononuclear cells by flow cytometry: CD4+CD25+, CD4+CD25(bright), CD4+Foxp3+ (Treg cells), CD8+CD28- (Ts cells), CD4+IL-10+ (Tr1 cells), and CD4+TGF-beta+ (Th3 cells). In addition, the in vitro suppressive activity of CD4+CD25+ lymphocytes was tested. We found no significant differences in the levels of all regulatory cell subsets studied in SLE patients compared to controls and RA patients. However, a defective regulatory function of CD4+CD25+T cells was observed in a significant fraction (31%) of patients with SLE. Our data indicate that although approximately one third of patients with SLE show an abnormal immunosuppressive function of Treg lymphocytes, their levels of the different regulatory T cell subsets in peripheral blood are not significantly different from those found in controls.