| Congresso Brasileiro de Microbiologia 2023 | Resumo: 257-1 | ||||
Resumo:Streptococcus pneumoniae (Spn) is part of the normal human nasopharyngeal microbiota, but can also cause diseases such as sinusitis, otitis, pneumonia, bacteremia and meningitis. We aimed to establish an in vitro model using co-culture of epithelial cells, macrophages and dendritic cells to evaluate interaction with different pneumococcal strains. Human epithelial cell line A549 was co-cultured with macrophages (dMΦ) only or with dMΦ plus dendritic cells (dDC), both differentiated from the human monocytic cell line THP-1. After incubation with pneumococcal strains, the cytokine content in the supernatant was evaluated by ELISA. Firstly, the non-encapsulated Rx1 strain and the serotype 6B strain BHN418 were incubated with A549 only, dMΦ only or A549+dMΦ. Incubation with the co-culture of A549+dMΦ amplified the induction of IL-6 and IL-8 after incubation with Rx1 and at a lower extent with BHN418. Increase in IL-1β and TNF-α was observed for both dMΦ and A549+dMΦ with both strains. IL-10 was not detected. Co-culture of A549+dMΦ+dDC with Rx1 and BHN418 led to the induction of IL-6, IL-8, IL-1 β and TNF-α in a pattern similar to the one observed with A549+dMΦ, albeit at higher levels. Furthermore, BHN418 knockouts for the virulence factors PspA (Pneumococcal surface protein A - BHN418-pspAKO), PspC (Pneumococcal surface protein C - BHN418-pspCKO) and Ply (Pneumolysin - BHN418-plyKO) were evaluated using A549+dMΦ. Similar levels of IL-6, IL-8, IL-1β and TNF-α were observed for BHN418-pspAKO and BHN-418-pspCKO compared to the wild type strain. On the other hand, BHN418-plyKO induced lower levels of the four cytokines tested. Using A549+dMΦ+dDC, similar levels of the four cytokines were observed for BHN418pspA-KO and BHN418-pspCKO compared to the wild type strain. Lower levels of IL-6 and TNF-α were observed for BHN418-plyKO. Overall, the co-culture of A549+dMΦ+dDC seems to elicit higher levels of cytokines after incubation with pneumococci. Furthermore, Ply seems to play an important role in the induction of IL-6 and TNF-α. Palavras-chave: Streptococcus pneumoniae, epithelial cells, macrophages, dendritic cells, cytokines Agência de fomento:FAPESP, CNPq, Fundação Butantan | |||||