ÿþ<HTML><HEAD><TITLE>XI International Meeting on Paracoccidioidomycosis</TITLE><link rel=STYLESHEET type=text/css href=css.css></HEAD><BODY aLink=#ff0000 bgColor=#FFFFFF leftMargin=0 link=#000000 text=#000000 topMargin=0 vLink=#000000 marginheight=0 marginwidth=0><table align=center width=700 cellpadding=0 cellspacing=0><tr><td align=left bgcolor=#cccccc valign=top width=550><font face=arial size=2><strong><font face=Verdana, Arial, Helvetica, sans-serif size=3><font size=1>XI International Meeting on Paracoccidioidomycosis</font></font></strong><font face=Verdana size=1><b><br></b></font><font face=Verdana, Arial,Helvetica, sans-serif size=1><strong> </strong></font></font></td><td align=right bgcolor=#cccccc valign=top width=150><font face=arial size=2><strong><font face=Verdana, Arial, Helvetica, sans-serif size=1><font size=1>Resume:170-3</font></em></font></strong></font></td></tr><tr><td colspan=2><br><br><table align=center width=700><tr><td><b>Poster (Painel)</b><br><table width="100%"><tr><td width="60">170-3</td><td><b>INFLUENCE OF FUNGAL VIRULENCE ON CYTOKINES EXPRESSION IN GRANULOMATOUS LESIONS OF P. BRASILIENSIS-INOCULATED INBRED MICE</b></td></tr><tr><td valign=top>Authors:</td><td>Liana Verinaud (UNICAMP - Universidade Estadual de Campinas) ; Angela Satie Nishikaku (USP - Universidade de Sao PauloUNIFESP - Universidade Federal de Sao Paulo) ; Jose Vicente Alves (USP - Universidade de Sao Paulo) ; Raphael Fagnani Sanchez Molina (USP - Universidade de Sao Paulo) ; Jacy Gameiro (UNICAMP - Universidade Estadual de Campinas) ; Cf Andrade (UNICAMP - Universidade Estadual de Campinas) ; Dagmar Stach-machado (UNICAMP - Universidade Estadual de Campinas) ; Zoilo Pires de Camargo (UNIFESP - Universidade Federal de Sao Paulo) ; <u>Eva Burger </u> (USP - Universidade de Sao Paulo) </td></tr></table><p align=justify><b><font size=2>Abstract</font></b><p align=justify class=tres><font size=2>Paracoccidioidomycosis is the most prevalent systemic mycosis in Latin America. Of the many clinical manifestations of the disease, severe and mild forms may be determined by the genetic background of the patients; however the importance of variations in fungal virulence cannot be excluded. Indeed, in previous works we showed that 120 days after infection with a highly virulent Paracocidioides brasiliensis isolate susceptible (S) mice develop loose disseminated granulomas and resistant (R) mice show compact circumscribed granulomas. On the other hand, infection with an isolate of low virulence, initially elicits formation of active granulomas, which at later stages become residual. Here we analyse the participation of cytokines in the development of granulomas of S and R mice ip infected with the slightly virulent Pb265, in comparison with the granulomas architecture, the areas of lesions comprising Pb with preserved or altered morphology and the presence and distribution of different cell populations. Infection with Pb265 initially developed loose lesions that tended to resolution, as indicated by the reduction of the lesion area and the percentage of the area occupied by Pb, confirming the regressive nature of this infection even in S mice and confirming the role of fungal virulence in the development of different outcomes of Pb infection. In both mouse strains, secretion of the studied cytokines was found locally at 15 days after infection, but at 120 days, very few cells positive to TNF-&#61537; and IFN-&#61543; remained, whereas some still produced TGF-&#61538;. This phenomenon may eventually be explained by the irrelevance of stimulatory cytokines at the site of a residual infection, but the necessity of regulatory cytokines to eradicate the inflammatory response. We studied the expression of mRaNAs and the in situ presence of IFN-&#947;, TNF-&#945;, TGF-&#946; and IL-10 in granulomas in the omentum of these mice at 120 days, when the infection was under control in both mouse strains. RT-PCR revealed much higher expression of all studied cytokines in R than in S animals (8, 35, 30 and 20 folds respectively for IFN-&#947;, TNF-&#945;, TGF-&#946; and IL-10). This finding suggests that although both, R and S animals are able to efficiently control low virulence Pb infection, the mRNAs synthesis of these cytokines is maintained for a longer time-span in the R strain. However, the mRNAs expression was not in parallel with the protein synthesis of these cytokines: immunohistochemistry revealed an extremely low percentage of low intensity positive cells in the granulomas of either S or R animals. This fact suggests that although the mRNAs is still being secreted as the infection is restrained (at a higher level in R mice), there is a further control on the protein synthesis in both mouse strains. SUPPORT: FAPESP # 06/60091-6 & # 08/58604-0; CNPq 304630/2009-8 </font></p><br><b>Keyword: </b>&nbsp;Fungal strains, virulence, Granulomatous lesions, cytokines</td></tr></table></tr></td></table></body></html>