Examinando por Autor "Suazo, Isidora D."
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Ítem Characterization of the Anti-Inflammatory Capacity of IL-10-Producing Neutrophils in Response to Streptococcus pneumoniae Infection(Frontiers Media S.A., 2021-04) González, Liliana A.; Melo González, Felipe; Sebastián, Valentina P.; Vallejos, Omar P.; Noguera, Loreani P.; Suazo, Isidora D.; Schultz, Bárbara M.; Manosalva, Andrés H.; Peñaloza, Hernán F.; Soto, Jorge A.; Parker, Dane; Riedel, Claudia A.; González, Pablo A.; Kalergis, Alexis M.; Bueno, Susan M.Neutrophils are immune cells classically defined as pro-inflammatory effector cells. However, current accumulated evidence indicates that neutrophils have more versatile immune-modulating properties. During acute lung infection with Streptococcus pneumoniae in mice, interleukin-10 (IL-10) production is required to temper an excessive lung injury and to improve survival, yet the cellular source of IL-10 and the immunomodulatory role of neutrophils during S. pneumoniae infection remain unknown. Here we show that neutrophils are the main myeloid cells that produce IL-10 in the lungs during the first 48 h of infection. Importantly, in vitro assays with bone-marrow derived neutrophils confirmed that IL-10 can be induced by these cells by the direct recognition of pneumococcal antigens. In vivo, we identified the recruitment of two neutrophil subpopulations in the lungs following infection, which exhibited clear morphological differences and a distinctive profile of IL-10 production at 48 h post-infection. Furthermore, adoptive transfer of neutrophils from WT mice into IL-10 knockout mice (Il10-/-) fully restored IL-10 production in the lungs and reduced lung histopathology. These results suggest that IL-10 production by neutrophils induced by S. pneumoniae limits lung injury and is important to mediate an effective immune response required for host survival. © Copyright © 2021 González, Melo-González, Sebastián, Vallejos, Noguera, Suazo, Schultz, Manosalva, Peñaloza, Soto, Parker, Riedel, González, Kalergis and Bueno.Ítem Human metapneumovirus respiratory infection affects both innate and adaptive intestinal immunity(Frontiers Media SA, 2024) Sepúlveda-Alfaro, Javiera; Catalán, Eduardo A.; Vallejos, Omar P.; Ramos-Tapia, Ignacio; Madrid-Muñoz, Cristóbal; Mendoza-León, María J.; Suazo, Isidora D.; Rivera-Asin, Elizabeth; Silva, Pedro H.; Alvarez-Mardones, Oscar; Castillo-Godoy, Daniela P.; Riedel, Claudia A.; Schinnerling, Katina; Ugalde, Juan A.; Soto, Jorge A.; Bueno, Susan M.; Kalergis, Alexis M.; Melo-Gonzalez, FelipeIntroduction: Respiratory infections are one of the leading causes of morbidity and mortality worldwide, mainly in children, immunocompromised people, and the elderly. Several respiratory viruses can induce intestinal inflammation and alterations in intestinal microbiota composition. Human metapneumovirus (HMPV) is one of the major respiratory viruses contributing to infant mortality in children under 5 years of age worldwide, and the effect of this infection at the gut level has not been studied. Methods: Here, we evaluated the distal effects of HMPV infection on intestinal microbiota and inflammation in a murine model, analyzing several post-infection times (days 1, 3, and 5). Six to eight-week-old C57BL/6 mice were infected intranasally with HMPV, and mice inoculated with a non-infectious supernatant (Mock) were used as a control group. Results: We did not detect HMPV viral load in the intestine, but we observed significant changes in the transcription of IFN-γ in the colon, analyzed by qPCR, at day 1 post-infection as compared to the control group. Furthermore, we analyzed the frequencies of different innate and adaptive immune cells in the colonic lamina propria, using flow cytometry. The frequency of monocyte populations was altered in the colon of HMPV -infected mice at days 1 and 3, with no significant difference from control mice at day 5 post-infection. Moreover, colonic CD8+ T cells and memory precursor effector CD8+ T cells were significantly increased in HMPV-infected mice at day 5, suggesting that HMPV may also alter intestinal adaptive immunity. Additionally, we did not find alterations in antimicrobial peptide expression, the frequency of colonic IgA+ plasma cells, and levels of fecal IgA. Some minor alterations in the fecal microbiota composition of HMPV -infected mice were detected using 16s rRNA sequencing. However, no significant differences were found in β-diversity and relative abundance at the genus level. Discussion: To our knowledge, this is the first report describing the alterations in intestinal immunity following respiratory infection with HMPV infection. These effects do not seem to be mediated by direct viral infection in the intestinal tract. Our results indicate that HMPV can affect colonic innate and adaptive immunity but does not significantly alter the microbiota composition, and further research is required to understand the mechanisms inducing these distal effects in the intestine.