Search

Introduction: Probiotics provide therapeutic benefits not only in the gut but also other mucosal organs, including the lungs., Objective and Design: To evaluate the effects of the probiotic strain L. delbrueckii UFV-H2b20 oral administration in an experimental murine model of A. fumigatus pulmonary infection. BALB/c mice were associated with L. delbrueckii and infected with Aspergillus fumigatus and compared with non-associated group., Methods: We investigated survival, respiratory mechanics, histopathology, colony forming units, cytokines in bronchoalveolar lavage, IgA in feces, efferocytosis, production of reactive oxygen species and the cell population in the mesenteric lymph nodes., Results: L. delbrueckii induces tolerogenic dendritic cells, IL-10 + macrophages and FoxP3 + regulatory T cells in mesenteric lymph nodes and increased IgA levels in feces; after infection with A. fumigatus, increased survival and decreased fungal burden. There was decreased lung vascular permeability without changes in the leukocyte profile. There was enhanced neutrophilic response and increased macrophage efferocytosis. L. delbrueckii-treated mice displayed more of FoxP3 + Treg cells, TGF-β and IL-10 levels in lungs, and concomitant decreased IL-1β, IL-17 A, and CXCL1 production., Conclusion: Uur results indicate that L. delbrueckii UFV H2b20 ingestion improves immune responses, controlling pulmonary A. fumigatus infection. L. delbrueckii seems to play a role in pathogenesis control by promoting immune regulation., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Higher MS relapse frequency is observed during warmer months in different regions, but evidence for an underlying immunological variation is lacking. Therefore, we investigated seasonal variations of cytokine production in relapsing-remitting MS patients. Twenty-one patients and eight controls had blood samples drawn in each season, evaluating for IL-10, IL-6, TNF-α and IFN-γ. The lowest levels of cytokine production were observed in spring samples, with a significant increase from spring to summer for most cytokines, and especially IFN-γ and TNF-α. This phenomenon may underlie the higher prevalence of clinical and subclinical MS activity observed in warmer months., (Copyright © 2015 Elsevier B.V. All rights reserved.)

To date, there is no vaccine available against human leishmaniasis. Although some vaccination protocols can induce immunity in murine models, they fail to induce protection in humans. The reasons for that remain unclear. The aim of the present study was to characterize the changes in the pattern of the immune response during subcutaneous vaccination with Leishvacin® in mice. We also investigated whether IFN-γ and nitric oxide synthase are indispensable for the protection elicited by the vaccine. C57BL/6 WT vaccinated mice showed smaller lesions and fewer numbers of parasites in footpads until 8 weeks post-infection. Up to this time, they produced higher levels of IFN-γ, IL-2, IL-4, IL-17A and IL-10 and higher specific antibody response than control non-vaccinated mice. Moreover, we showed that IFN-γ, most likely by induction of iNOS expression, is essential for immunity. However, after 12 weeks of infection, we observed loss of difference in lesion size and parasite burden between the groups. Loss of resistance was associated with the disappearance of differences in cytokine patterns between vaccinated and control mice, but not of antibody response, which remained different until a later time of infection. The reversal of resistance to L. amazonensis could not be explained by upregulation of regulatory cytokines. Our data point to a subversion of the host immune response by L. amazonensis even when a protective response was previously induced., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Objectives: Our group has concerned itself with the study of the effect of probiotics on the resistance to infections using experimental models. Here, we will focus on evidence that the UFV-H2b20 strain of Lactobacillus delbrueckii var. bulgaricus may be considered a probiotic and has protective effects on mice against a variety of bacterial infections., Methods: Germ-free, monoassociated, and conventional mice were used. Mice were treated with probiotics and challenged with Escherichia coli, Salmonella enterica serovar Typhimurium, or Listeria monocytogenes, and the outcome of infection was measured as mortality, quantification of bacteria in target organs, and systemic of local cytokine production., Results: L. delbrueckii increased clearance of E. coli and production of systemic inflammatory cytokines. This strain also protected monoassociated and conventional mice against infection with S. enterica serovar Typhimurium. Finally, monoassociated mice were more resistant to L. monocytogenes as measured by mortality and the number of bacteria in spleen and liver. In addition, monoassociated mice challenged with L. monocytogenes showed increased production of inflammatory cytokines (interferon-gamma and tumor necrosis factor-alpha) and nitric oxide. Interestingly, interleukin-10 levels were not altered by monoassociation or infection., Conclusions: L. delbrueckii UFV-H2b20 protects mice against infection, apparently by eliciting the up-regulation of production of inflammatory cytokines.