SMALDINI Paola Lorena
congresos y reuniones científicas
Immunomodulatory properties of heat-killed Rhodococcus coprophilus control the allergic reaction in a mouse model of food allergy
Congreso; Reunión Conjunta de la Sociedad Argentina de Investigación Clínica (SAIC), la Sociedad Argentina de Inmunología (SAI) y la Sociedad Argentina de Fisiología (SAFIS); 2018
Actinomyces are non-pathogenic bacteria with immunomodulatoryproperties. The intestinal mucosa is lined by epithelial cells, which are keycells in gut homeostasis. We hypothesize that Actinomyces may control epithelialcells under inflammatory conditions. Our goal is to study the inhibitory effectof dead Rhodococcus coprophilus-Rc onactivated cells under different pro-inflammatory stimuli and then study theimmunomodulatory effect in an experimental food allergy model.Colon cell lines (Caco-2 and Caco-luc) were cultured with flagellin(FliC) and induction of cytokines (IL-1b, IL-6, TNFa) and chemokines (CCL20,IL-8 and MCP-1) were studied by qPCR. To study the immunododulatory effect in vivo, Balb/c mice were sensitizedwith cow´s milk proteins (CMP) plus cholera toxin by gavage, and orallychallenged with CMP to evidence hypersensitivity. Previosly, Rc was orallyadministered during one week to modulate the immune response. Mice were challengedand treatment efficacy was in vivo(clinical score and cutaneous test) and invitro (serum specific antibodies and cytokines by ELISA, and cell analysisby flow cytometry) evaluated.We found that despite the response of Caco-2-luc to live and dead Salmonella typhimurium, they wereunresponsive to Rc. However, when cells were previously activated, Rc inhibitedthe induction of cytokines and chemokines. By western blot we defined that thiseffect could be due a reduction of p65 translocation to the nucleus. Thisinhibitory effect was also observed in mouse orally exposed to cholera toxin. Intragastricadministration of Rc down modulated the expression of CCL20 in gut.In the CMP allergy mouse model, clinical signsand serum specific IgE levels were lower in Rc-treated mice compared withsensitized mice (p<0.05), with a concomitant reduction of IL-5. In conclusion, these bacteria modulate the NF-KBpathway and the induction of several pro-inflammatory cytokines and chemokines.And it is able to modulate the Th2-mediated allergic response<!-- /* Font Definitions */ @font-face{font-family:"Cambria Math";panose-1:2 4 5 3 5 4 6 3 2 4;mso-font-charset:0;mso-generic-font-family:roman;mso-font-pitch:variable;mso-font-signature:3 0 0 0 1 0;}@font-face{font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;mso-font-charset:0;mso-generic-font-family:swiss;mso-font-pitch:variable;mso-font-signature:-536859905 -1073732485 9 0 511 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal{mso-style-unhide:no;mso-style-qformat:yes;mso-style-parent:"";margin-top:0in;margin-right:0in;margin-bottom:10.0pt;margin-left:0in;line-height:115%;mso-pagination:widow-orphan;font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-font-family:Calibri;mso-bidi-font-family:"Times New Roman";mso-ansi-language:ES-AR;}.MsoChpDefault{mso-style-type:export-only;mso-default-props:yes;font-family:"Calibri",sans-serif;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;}@page WordSection1{size:8.5in 11.0in;margin:1.0in 1.0in 1.0in 1.0in;mso-header-margin:.5in;mso-footer-margin:.5in;mso-paper-source:0;}div.WordSection1{page:WordSection1;}-->