Free exopolysaccharide from Mycoplasma mycoides subsp. mycoides possesses anti-inflammatory properties

In this study we explored the immunomodulatory properties of highly purified free galactan, the soluble exopolysaccharide secreted by Mycoplasma mycoides subsp. mycoides (Mmm). Galactan was shown to bind to TLR2 but not TLR4 using HEK293 reporter cells and to induce the production of the anti-inflammatory cytokine IL-10 in bovine macrophages, whereas low IL-12p40 and no TNF-α, both pro-inflammatory cytokines, were induced in these cells. In addition, pre-treatment of macrophages with galactan substantially reduced lipopolysaccharide (LPS)-induced production of pro-inflammatory cytokines TNF- and IL-12p40 while increasing LPS-induced secretion of immunosuppressive IL-10. Also, galactan did not activate naïve lymphocytes and induced only low production of the Th1 cytokine IFN-γ in Mmm-experienced lymphocytes. Finally, galactan triggered weak recall proliferation of CD4+ T lymphocytes from contagious bovine pleuropneumonia-infected animals despite having a positive effect on the expression of co-stimulatory molecules on macrophages. All together, these results suggest that galactan possesses anti-inflammatory properties and potentially provides Mmm with a mechanism to evade host innate and adaptive cell-mediated immune responses. (Résumé d'auteur

Adjustable Intragastric Balloons: A 12-Month Pilot Trial in Endoscopic Weight Loss Management

Intragastric balloons are associated with (1) early period intolerance, (2) diminished effect within 3–4 months, and (3) bowel obstruction risk mandating removal at 6 months. The introduction of an adjustable balloon could improve comfort and offer greater efficacy. A migration prevention function, safely enabling prolonged implantation, could improve efficacy and weight maintenance post-extraction. The first implantations of an adjustable balloon with an attached migration prevention anchor are reported. The primary endpoint was the absence of bowel perforation, obstruction, or hemorrhage. Eighteen patients with mean BMI of 37.3 were implanted with the Spatz Adjustable Balloon system (ABS) for 12 months. Balloon volumes were adjusted for intolerance or weight loss plateau. Mean weight loss at 24 weeks was 15.6 kg with 26.4% EWL (percent of excess weight loss) and 24.4 kg with 48.8% EWL at 52 weeks. Sixteen adjustments were successfully performed. Six downward adjustments alleviated intolerance, yielding additional mean weight loss of 4.6 kg. Ten upward adjustments for weight loss plateau yielded a mean additional weight loss of 7 kg. Seven balloons were removed prematurely. Complications necessitating early removal included valve malfunction (1), gastritis (1), Mallory–Weiss tear (1), NSAID (2× dose/2 weeks) perforating ulcer (1), and balloon deflation (1). Two incidents of catheter shear from the chain: one passed uneventfully and one caused an esophageal laceration without perforation during extraction. The Spatz ABS has been successfully implanted in 18 patients. (1) Upward adjustments yielded additional weight loss. (2) Downward adjustments alleviated intolerance, with continued weight loss. (3) Preliminary 1-year implantation results are encouraging

Mycoplasma Contamination Revisited: Mesenchymal Stromal Cells Harboring Mycoplasma hyorhinis Potently Inhibit Lymphocyte Proliferation In Vitro

Mesenchymal stromal cells (MSC) have important immunomodulatory effects that can be exploited in the clinical setting, e.g. in patients suffering from graft-versus-host disease after allogeneic stem cell transplantation. In an experimental animal model, cultures of rat T lymphocytes were stimulated in vitro either with the mitogen Concanavalin A or with irradiated allogeneic cells in mixed lymphocyte reactions, the latter to simulate allo-immunogenic activation of transplanted T cells in vivo. This study investigated the inhibitory effects of rat bone marrow-derived MSC subsequently found to be infected with a common mycoplasma species (Mycoplasma hyorhinis) on T cell activation in vitro and experimental graft-versus-host disease in vivo.We found that M. hyorhinis infection increased the anti-proliferative effect of MSC dramatically, as measured by both radiometric and fluorimetric methods. Inhibition could not be explained solely by the well-known ability of mycoplasmas to degrade tritiated thymidine, but likely was the result of rapid dissemination of M. hyorhinis in the lymphocyte culture.This study demonstrates the potent inhibitory effect exerted by M. hyorhinis in standard lymphocyte proliferation assays in vitro. MSC are efficient vectors of mycoplasma infection, emphasizing the importance of monitoring cell cultures for contamination

High cellular monocyte activation in people living with human immunodeficiency virus on combination antiretroviral therapy and lifestyle-matched controls is associated with greater inflammation in cerebrospinal fluid

Background. Increased monocyte activation and intestinal damage have been shown to be predictive for the increased morbidity and mortality observed in treated people living with human immunodeficiency virus (PLHIV). Methods. A cross-sectional analysis of cellular and soluble markers of monocyte activation, coagulation, intestinal damage, and inflammation in plasma and cerebrospinal fluid (CSF) of PLHIV with suppressed plasma viremia on combination antiretroviral therapy and age and demographically comparable HIV-negative individuals participating in the Comorbidity in Relation to AIDS (COBRA) cohort and, where appropriate, age-matched blood bank donors (BBD). Results. People living with HIV, HIV-negative individuals, and BBD had comparable percentages of classical, intermediate, and nonclassical monocytes. Expression of CD163, CD32, CD64, HLA-DR, CD38, CD40, CD86, CD91, CD11c, and CX3CR1 on monocytes did not differ between PLHIV and HIV-negative individuals, but it differed significantly from BBD. Principal component analysis revealed that 57.5% of PLHIV and 62.5% of HIV-negative individuals had a high monocyte activation profile compared with 2.9% of BBD. Cellular monocyte activation in the COBRA cohort was strongly associated with soluble markers of monocyte activation and inflammation in the CSF. Conclusions. People living with HIV and HIV-negative COBRA participants had high levels of cellular monocyte activation compared with age-matched BBD. High monocyte activation was predictive for inflammation in the CSF

Inhibition of Cowdria ruminantium infectious yield by interferons alpha and gamma in endothelial cells.

We have shown before that there is a positive correlation between resistance of cattle against Cowdria infection and early IFN production. Our in vitro studies demonstrated an activity of rBoIFN alpha 2C and rBoIFN gamma against Cowdria in bovine endothelial cells of brain microvasculature (BMEC). rBoIFN gamma is much more active in this respect than rBoIFN alpha 2C. These results suggest a role of IFNs in the resistance against the disease. Strikingly, in the same conditions rBoIFN alpha 2C has no effect on the yield of Cowdria from infected bovine endothelial cells of umbilical artery origin (BUEC). Similarly we showed that HuIFNa had no effect on the multiplication of Cowdria in human vein umbilical endothelial cells (HUVEC). We found no differences in the capacity of BUE and BME cells to bind rBoIFN alpha 2C. This may reflect a true difference between capillary and large blood vessels.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Inhibition of Cowdria ruminantium infectious yield by interferons alpha and gamma in endothelial cells.

We have shown before that there is a positive correlation between resistance of cattle against Cowdria infection and early IFN production. Our in vitro studies demonstrated an activity of rBoIFN alpha 2C and rBoIFN gamma against Cowdria in bovine endothelial cells of brain microvasculature (BMEC). rBoIFN gamma is much more active in this respect than rBoIFN alpha 2C. These results suggest a role of IFNs in the resistance against the disease. Strikingly, in the same conditions rBoIFN alpha 2C has no effect on the yield of Cowdria from infected bovine endothelial cells of umbilical artery origin (BUEC). Similarly we showed that HuIFNa had no effect on the multiplication of Cowdria in human vein umbilical endothelial cells (HUVEC). We found no differences in the capacity of BUE and BME cells to bind rBoIFN alpha 2C. This may reflect a true difference between capillary and large blood vessels.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Bovine CD4<sup(+)> T-cell lines reactive with soluble and membrane antigens of Cowdria ruminantium

Cowdria-specific CD4 T-cell lines generated from immunized cattle responded to both soluble and membrane proteins of the agent. The lines produced the Cowdria-inhibitory cytokine IFN- in response to soluble antigens fractionated by gel filtration and fast performance liquid chromatography. Activity eluted as a single peak around fraction 15 for all T-cell lines tested. This fraction induced the highest production of IFN- by the lines and was shown by SDS-PAGE and silver staining analysis to contain less than 10 different bands ranging from 22 to 32 kDa. It is suggested that given their high sensitivity and specificity, these short-term CD4 T-cell lines will be valuable tools for the identification of Cowdria antigens for incorporation in a subunit vaccine