PROKARIOTIC RNA EFFECTS ON PULMONARY EPITHELIAL AND ENDOTHELIAL CELLS MODULATE THE INMUNE RESPONSE

BIRNBERG WEISS, FEDERICO;; LANDONI, VERÓNICA; LUIS CASTILLO; FERNÁNDEZ GC; PITTALUGA,JOSÉ R; MARTIRE-GRECO, D;

reunion anual de sociedades de biociencias

Congreso; Reunion anual de sociedades de biociencia SAIC SAI SAFIS; 2020

Escherichia coli (ECO), Klebsiella pneumoniae (KPN) and Pseudomonas aeruginosa (PAE) can cause severe pneumonia. Lung epithelial (EpCs) and endothelial cells (ECs) modulate local immune responses. In fact, the reciprocal relation between EpCs and ECs as well as their influence on cells from the innate immunity is determinant in the course of infection.At the site of infection, cells are exposed to prokaryotic RNA (pRNA). pRNA?s immunomodulatory role is relevant, but its effect on lung immune response has not been determined. The aim of this work was to determine the effect of pRNA on EpCs and ECs, and the influence of their response on neutrophil (PMN). For this, human pulmonary epithelial (Calu-6), and microvascular endothelial cell line (HMEC-1) were treated with pRNAs from ECO, KPN and PAE, and the result of this stimulation was evaluated on PMN response.Activation of Calu-6 and HMEC-1 was induced by ECO and KPN-RNA but not by PAE-RNA, as determined by the increased ICAM-1 expression by flow cytometry (FACS) (p≤0.01). Also, CALU-6 and HMEC-1 released IL-8 after stimulation with ECO and KPN-RNA (p≤0.001). Consistently, conditioned medium (CM) from both cell lines showed chemoattractant activity for PMN after stimulation with ECO and KPN-RNA (p≤0.001). Finally, CM from cells treated with ECO and KPN-RNA induced PMN activation as determined by the increment in CD11b expression by FACS (p≤0.01). Moreover, when PMN were treated directly with pRNA, CD11b upregulation was induced only by ECO and KPN-RNA (p≤0.05). Also, all pRNA were able to induce ROS generation (p≤ 0.05). Finally, PMN migration assay revealed that ECO and KPN-RNA resulted chemoattractant (p≤0.01). In conclusion, ECO and KPN-RNA are capable of activating EpCs, ECs and PMN. Also, they induce a response on EpCs and ECs capable of activating and attracting PMN to the site of infection. In addition, this study reveals that PAE-RNA constitute a poor stimulus in the context of a pulmonary immune response.