Inhibitory effect of Actinomyces on mucosal epithelial cells

SMALDINI P; STANFORD J; FOSSATI, CA; DOCENA GH,

Viñas del Mar, Chile

Congreso; IX Latin American Congres of Immunology. ALAI; 2009

<!-- /* Font Definitions */ @font-face {font-family:Calibri; mso-font-alt:"Century Gothic"; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin-top:0cm; margin-right:0cm; margin-bottom:10.0pt; margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri; mso-fareast-font-family:Calibri; mso-bidi-font-family:"Times New Roman"; mso-ansi-language:ES-AR; mso-fareast-language:EN-US;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} -->Inhibitory effect of Actinomyces on mucosal epithelial cells. Paola Smaldini1, John Stanford2, Carlos Fossati1 and Guillermo Docena1. 1 Research Laboratory of Immune System, University of La Plata. 2Centre for Infectious Diseases and International Health Windeyer Institute of Medical Sciences, University College London   Actinomyces are soil non-pathogenic bacteria with immunomodulatory properties. The intestinal mucosa is lined by epithelial cells, which are key cells in gut homeostasis. We hypothesize that Actinomyces may control activated epithelial cells in a wide range of inflammatory conditions. Our goal is to study the inhibitory effect of dead Gordonia bronchialis-Gb and Rhodococcus coprophilus-Rc on activated epithelial cells under different pro-inflammatory stimuli. Different cells lines (Caco-2, Caco-luc, A549 and ICcl2) and enterocytes from mouse gut were cultured with flagellin, LPS, Pam3C, IL-1b, TNFa and cholera toxin, and induction of cytokines (IL-1b, IL-6, TNFa) and chemokines (CCL20, IL-8 y MCP-1) were studied by RT-PCR and qPCR. We found that despite the response of Caco-2-luc to live and dead Salmonella tiphymurium, they were unresponsive to Gb and Rc. However, when cells were previously activated, TLR2/4/5/9 were up-regulated and Gb/Rc inhibited the induction of cytokines and chemokines in a dose-response manner. This inhibitory effect was also observed in mouse orally exposed to cholera toxin. Gb down modulated the expression of CCL20 in gut. In conclusion, these bacteria modulate the NF-KB pathway and the induction of several pro-inflammatory cytokines and chemokines. We propose to use these bacteria in different inflammatory mouse models.