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Menstrual blood-derived stromal cells (MenSCs) are emerging as a strong candidate for cell-based therapies due to their immunomodulatory properties. However, their direct impact on innate immune populations remains elusive. Since macrophages play a key role in the onset and development of inflammation, understanding MenSCs implication in the functional properties of these cells is required to refine their clinical effects during the treatment of inflammatory disorders. In this study, we assessed the effects that MenSCs had on the recruitment of macrophages and other innate immune cells in two mouse models of acute inflammation, a thioglycollate (TGC)-elicited peritonitis model and a monobacterial sepsis model. We found that, in the TGC model, MenSCs injection reduced the percentage of macrophages recruited to the peritoneum and promoted the generation of peritoneal immune cell aggregates. In the sepsis model, MenSCs exacerbated infection by diminishing the recruitment of macrophages and neutrophils to the site of infection and inducing defective bacterial clearance. Additional in vitro studies confirmed that co-culture with MenSCs impaired macrophage bactericidal properties, affecting bacterial killing and the production of reactive oxygen intermediates. Our findings suggest that MenSCs modulate the macrophage population and that this modulation must be taken into consideration when it comes to future clinical applications. [ABSTRACT FROM AUTHOR]

Metallothioneins (MTs) constitute a heterogeneous family of ubiquitous metal ion-binding proteins. In plants, MTs participate in the regulation of cell growth and proliferation, protection against heavy metal stress, oxidative stress responses, and responses to pathogen attack. Despite their wide variety of functions, the role of MTs in symbiotic associations, specifically nodule-fabacean symbiosis, is poorly understood. Here, we analyzed the role of the PvMT1A gene in Phaseolus vulgaris-Rhizobium tropici symbiosis using bioinformatics and reverse genetics approaches. Using in silico analysis, we identified six genes encoding MTs in P. vulgaris, which were clustered into three of the four classes described in plants. PvMT1A transcript levels were significantly higher in roots inoculated with R. tropici at 7 and 30 days post inoculation (dpi) than in non-inoculated roots. Functional analysis showed that downregulating PvMT1A by RNA interference (RNAi) reduced the number of infection events at 7 and 10 dpi and the number of nodules at 14 and 21 dpi. In addition, nodule development was negatively affected in PvMT1A:RNAi transgenic roots, and these nodules displayed a reduced nitrogen fixation rate at 21 dpi. These results strongly suggest that PvMT1A plays an important role in the infection process and nodule development in P. vulgaris during rhizobial symbiosis. [ABSTRACT FROM AUTHOR]