1,721,020 research outputs found
LACTOBACILLUS PLANTARUM RIDUCE LA VIRULENZA DI STREPTOCOCCUS PYOGENES MODULANDO LA PRODUZIONE DI IL-17, IL-23 E L’ESPRESSIONE DI TOLL-LIKE 2/4 IN CELLULE EPITELIALI UMANE
No full textEffetti dell’alcool sulla secrezione di citochine e defensine in cellule infettate sperimentalmente con Chlamydia pneumoniae
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Chlamydia pneumoniae stimulates the proliferation of HUVEC through the induction of VEGF by THP-1
No full textChlamydia pneumoniae, a gram-negative bacterium, is an important human intracellular pathogen; studies of C. pneumoniae pathogenesis have shown that the organism can infect many cell types associated with both respiratory and vascular sites, including arterial smooth muscle cells, macrophages and vascular endothelium. Recently, the recognition of atherosclerosis as an inflammatory disease in its genesis, progression and ultimate clinical manifestations has created an interesting area of vascular research. We assessed the hypothesis that growth factors from THP-1 macrophages infected with C. pneumoniae are involved in the regulation of cell proliferation in HUVEC.
The induction of these factors were dependent on time of infection, as medium harvested 48 h after infection had a greater activity than media harvested at 12 or 24 h after infection. Heat-killed C. pneumoniae produced similar results to those of live bacteria. In addition, conditioned medium filtered sterile from infected macrophages induced the proliferation of HUVEC, thus demonstrating its angiogenic potential. Moreover, pretreatment of macrophages with cytochalasin D, a phagocytosis inhibitor, yielded almost comparable results, suggesting that bacterium cell-attachment is sufficient for VEGF, IL-1β and IL-8 induction.
Further studies are necessary to elucidate the biological role of chlamydial involvement in the complex and mutifactored processes of angiogenesis and possibly contribute to the development of therapeutic strategies
Lactobacillus crispatus modulates epithelial cell defense against Candida albicans through Toll-like receptors 2 and 4, interleukin 8 and human β-defensin 2 and 3
No full textLactobacilli are members of the normal mucosal microflora of most animals. Probiotic bacteria, such as Lactobacilli, play a major role in the maintenance of a healthy urogenital tract by preventing the colonization of pathogenic bacteria. The potentially probiotic strain Lactobacillus crispatus (ATCC 33820) was investigated for its capacity to influence the innate immune response of HeLa epithelial cells to Candida albicans. In addition, its capacity to modulate the toll-like receptor (TLR) expression of HeLa cells was investigated by Western blot. When HeLa cells were pre-treated with the Lactobacillus crispatus and infected with C. albicans, the interleukin-8 levels were significantly lower than without pre-treatment. Also, the effect of L. crispatus on innate immunity was enhanced by its capacity to increase the effect of human β-defensin 3 against C. albicans growth. Pre-treating HeLa cells with L. crispatus attenuated the yeast’s virulence, as demonstrated by its reduced adhesion and growth on human epithelial cells. Our findings indicated, also, that after contact with C. albicans, epithelial cells expressed more TLR2/4 than non-infected cells, whereas pre-treatment with L. crispatus downregulated the TLR2/4 expression by epithelial cells stimulated with C. albicans. In conclusion, our results show that L. crispatus promotes epithelial cell defense against C. albicans infection through the involvement of TLR2/4, IL-8 and human β-defensin 2 and 3, thus suggesting a probiotic potential of this Lactobacillus as an anti-infective agent against C. albicans
Effect of resveratrol and quercetin in experimental infection by Salmonella enterica serovar Typhimurium
No full textFlavonoids are phenolic compounds widely distributed in almost every plant and act as pharmacologically
active constituents in many herbal medicines. They have multiple biological, pharmacological, and medicinal
properties including anti-inflammatory and cytoprotective effects. In the present study, the experiments were
performed to evaluate the effect of resveratrol and quercetin on proliferation, viability, nitric oxide (NO)
production, and apoptosis in Salmonella enterica serovar Typhimurium-infected U937cells and monocytes
(MN). The results showed in a time- and dose-dependent manner that both resveratrol and quercetin reduced
S. enterica serovar Typhimurium-induced NO production. In addition, the vegetable extracts resveratrol and
quercetin inhibited cell viability and proliferation in S. enterica serovar Typhimurium-infected cells. S. enterica
serovar Typhimurium-induced apoptosis was also blocked by resveratrol and quercetin. The results obtained
indicate that flavonoids modulate the host response during salmonellosis by protecting the host cells from the
toxic effects of bacterial infection and also by decreasing programmed cell death.
Hence, these polyphenols can be considered potential candidates against S. enterica serovar Typhimuriumrelated
gastric pathogenic processes, and further attention should be given to their application as a treatment
for infectious diseases
Espressione e regolazione di β-defensina-2 in cellule Caco-2 esposte al Lactobacillus plantarum
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Detection of Chlamydophila pneumoniae in children with upper respiratory tract infection from the Campania region of southern Italy
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