IntroductionThe ability to self-renew, be easily expanded in vitro and differentiate into different mesenchymal tissues, render mesenchymal stem cells (MSCs) an attractive therapeutic method for degenerative diseases. The subsequent discovery of their immunosuppressive ability encouraged clinical trials in graft-versus-host disease and auto-immune diseases. Despite sharing several immunophenotypic characteristics and functional capabilities, the differences between MSCs arising from different tissues are still unclear and the published data are conflicting.MethodsHere, we evaluate the influence of human MSCs derived from umbilical cord matrix (UCM), bone marrow (BM) and adipose tissue (AT), co-cultured with phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (MNC), on T, B and natural killer (NK) cell activation; T and B cells’ ability to acquire lymphoblast characteristics; mRNA expression of interleukin-2 (IL-2), forkhead box P3 (FoxP3), T-bet and GATA binding protein 3 (GATA3), on purified T cells, and tumor necrosis factor-alpha (TNF-α), perforin and granzyme B on purified NK cells.ResultsMSCs derived from all three tissues were able to prevent CD4+ and CD8+ T cell activation and acquisition of lymphoblast characteristics and CD56dim NK cell activation, wherein AT-MSCs showed a stronger inhibitory effect. Moreover, AT-MSCs blocked the T cell activation process in an earlier phase than BM- or UCM-MSCs, yielding a greater proportion of T cells in the non-activated state. Concerning B cells and CD56bright NK cells, UCM-MSCs did not influence either their activation kinetics or PHA-induced lymphoblast characteristics, conversely to BM- and AT-MSCs which displayed an inhibitory effect. Besides, when co-cultured with PHA-stimulated MNC, MSCs seem to promote Treg and Th1 polarization, estimated by the increased expression of FoxP3 and T-bet mRNA within purified activated T cells, and to reduce TNF-α and perforin production by activated NK cells.ConclusionsOverall, UCM-, BM- and AT-derived MSCs hamper T cell, B cell and NK cell-mediated immune response by preventing their acquisition of lymphoblast characteristics, activation and changing the expression profile of proteins with an important role in immune function, except UCM-MSCs showed no inhibitory effect on B cells under these experimental conditions. Despite the similarities between the three types of MSCs evaluated, we detect important differences that should be taken into account when choosing the MSC source for research or therapeutic purposes.

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ESBL-producing E. coli isolates have been isolated from eight of seventy seven faecal samples (10.4%) of wild boars in Portugal. The ESBL types identified by PCR and sequencing were bla(CTX-M-1) (6 isolates) and bla(CTX-M-1) + bla(TEM1-b) (2 isolates). Further resistance genes detected included tet (A) or tet (B) (in three tetracycline-resistant isolates), aad A (in three streptomycin-resistant isolates), cml A (in one chloramphenicol-resistant isolate), sul 1 and/or sul 2 and/or sul 3 (in all sulfonamide-resistant isolates). The intI 1 gene encoding class 1 integrase was detected in all ESBL-producing E. coli isolates. One isolate also carried the intI 2 gene, encoding class 2 integrase. The ESBL-producing E. coli isolates could be assigned to phylogenetic groups B1 (3 isolates), B2 (3 isolates) or A (2 isolates). Amino acid change in GyrA protein (Ser83Leu or Asp87Tyr) was detected in three nalidixic acid-resistant and ciprofloxacin-susceptible isolates. Two amino acid changes in GyrA (Ser83Leu + Asp87Asn) and one in ParC (Ser80Ile) were identified in two nalidixic acid- and ciprofloxacin-resistant isolates. As evidenced by this study wild boars could be a reservoir of antimicrobial resistance genes.

Through their cytotoxic capacities and cytokine production, natural killer (NK) cells modulate autoimmune diseases. However, their role in the pathogenesis of systemic lupus erythematosus (SLE) has not been extensively studied. The aim of this study was to analyse the immunophenotypic and functional characteristics of the two major NK cell subsets in SLE and relate them with disease activity. Peripheral blood samples from 44 patients with active (n = 18) and inactive SLE (n = 26) and 30 controls were analysed by flow cytometry to evaluate NK cell subsets, according to: the differential expression of CXCR3 and CD57; expression of granzyme B and perforin; and production of interferon gamma (IFN-γ) and tumor necrosis alpha (TNF-α), after PMA/ionomycin activation. A clear decrease in absolute and relative numbers of circulating NK cells was found in SLE, particularly in active disease, while the proportions of the major NK cell subsets were unaffected. Active SLE was associated with a reduced CXCR3 expression on both NK cell subsets and a lower frequency of CD56(dim) NK cells expressing CXCR3. Furthermore, granzyme B expression was decreased in both SLE groups, but the percentage of NK cells expressing granzyme B and perforin was higher, particularly in active disease. We found a significant decrease in the percentage of CD56(bright) and CD56(dim) NK cells producing TNF-α and of its expression on CD56(dim) NK cells in active disease, while IFN-γ expression on CD56(bright) NK cells was increased in both SLE groups. Our findings suggest that NK cell subsets exhibit unique phenotypic and functional changes that are particularly evident in active SLE, and they may have the potential to affect the disease outcome.

2 AbstractPurpose: The purpose of this study was to quantify and characterize peripheral blood regulatory T cells (Tregs), as well as the IL-10 plasma concentration, in Masters athletes at rest and after an acute exhaustive exercise test. Methods: Eighteen Masters athletes (self-reported training: 24.6±1.83 years; 10.27±0.24 months and 5.45±0.42 hours/week per each month trained) and an age-matched control group of 10 subjects (that never took part in regular physical training) volunteered for this study. All subjects performed an incremental test to exhaustion on a cycle ergometer. Blood samples were obtained before (Pre), 10min into recovery (Post) and 1h after the test (1h). Results: Absolute numbers of Tregs were similar in both groups at rest. Acute exercise induced a significant increase in absolute numbers of Tregs at Post (0.0490.021 to 0.0560.024 x10 9 /L, P=0.029 for Masters; 0.0480.017 to 0.0580.020 x10 9 /L, P=0.037 for control) in both groups. Treg mRNA expression for Foxp3, IL-10 and TGF-β in sorted Tregs was similar throughout the trials in both groups. Masters athletes showed a higher percentage of subjects expressing the FoxP3 (100% for Masters vs. 78% for Controls, P=0.038) and TGF- (89% for Masters vs. 56% for Controls, P=0.002) after exercise and a higher plasma IL-10 concentration (15.3907.032 for Masters vs. 2.4111.117 for control P=0.001, ES =2.57) at all time-points. KLRG1 expression in Tregs was unchanged. Conclusion: Our findings showed that Masters athletes have elevated anti-inflammatory markers and maintain the number of Tregs, may be an adaptive response to lifelong training.