IADR Abstract Archives
Role of microRNAs in immune cells stimulated with Aggregatibacter actinomycetemcomitans
Objectives: Background: Periodontitis are inflammatory pathologies caused by a subgingival disbiotic biofilm. Aggregatibacter actinomycetemcomitans has been recognized as a pathobiont associated with these dysbioses. In particular, A. actinomycetemcomitans expresses several virulence factors, such as lipopolysaccharide (LPS), which determines its immunogenicity. Although, the presence of different serotypes of A. actinomycetemcomitans are associated with different clinical conditions in periodontitis lesions, it is not clear whether there is any mechanism of post-transcriptional regulation that could determine the differential immune response associated to the different serotypes.
Objectives: To determine the expression levels of miRNA-146a, miRNA-146b and miRNA-155 in human dendritic cells stimulated with the serotypes a, b o c of A. actinomycetemcomitans and to associate these expression levels with the expression levels of Toll-like receptors (TLRs) and the production of pro-inflammatory cytokines.
Methods: Methodology: Monocytes were separated through a Ficoll gradient from peripheral blood samples. These monocytes were differentiated to immature dendritic cells and, subsequently, stimulated with the different serotypes of A. actinomycetemcomitans. Then, the expression levels of miRNA-146a, -146b, -155, TLR2, TLR3, TLR4, TLR5 and TLR7, and the production of the cytokines interleukin (IL)-1β, IL-5, IL-6, IL-10, IL-12, IL-23, interferon (IFN)-γ and tumor necrosis factor (TNF)-α were quantified.
Results: Results: Dendritic cells stimulated with serotype b of A. actinomycetemcomitans expressed higher levels of miRNA-146a, -146b and -155 and reported a significant increase in TLR3 expression levels, compared to cells stimulated with the serotypes a, c or not stimulated. However, no significant correlation was found between secreted levels of cytokines and miRNAs expression levels.
Conclusions: Conclusion: Taken together, these data could allow us to speculate about the possible existence of alternative regulatory signaling pathways mediated by miRNAs after the stimulation of microbial recognition receptors, capable of determining the variability of the immune response to A. actinomycetemcomitans in dendritic cells.
Objectives: To determine the expression levels of miRNA-146a, miRNA-146b and miRNA-155 in human dendritic cells stimulated with the serotypes a, b o c of A. actinomycetemcomitans and to associate these expression levels with the expression levels of Toll-like receptors (TLRs) and the production of pro-inflammatory cytokines.
Methods: Methodology: Monocytes were separated through a Ficoll gradient from peripheral blood samples. These monocytes were differentiated to immature dendritic cells and, subsequently, stimulated with the different serotypes of A. actinomycetemcomitans. Then, the expression levels of miRNA-146a, -146b, -155, TLR2, TLR3, TLR4, TLR5 and TLR7, and the production of the cytokines interleukin (IL)-1β, IL-5, IL-6, IL-10, IL-12, IL-23, interferon (IFN)-γ and tumor necrosis factor (TNF)-α were quantified.
Results: Results: Dendritic cells stimulated with serotype b of A. actinomycetemcomitans expressed higher levels of miRNA-146a, -146b and -155 and reported a significant increase in TLR3 expression levels, compared to cells stimulated with the serotypes a, c or not stimulated. However, no significant correlation was found between secreted levels of cytokines and miRNAs expression levels.
Conclusions: Conclusion: Taken together, these data could allow us to speculate about the possible existence of alternative regulatory signaling pathways mediated by miRNAs after the stimulation of microbial recognition receptors, capable of determining the variability of the immune response to A. actinomycetemcomitans in dendritic cells.