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:121-1</font></em></font></strong></font></td></tr><tr><td colspan=2><br><br><table align=center width=700><tr><td><b>Oral / Poster</b><br><table width="100%"><tr><td width="60">121-1</td><td><b>Synthetic peptides mimic gp75 from Paracoccidioides brasiliensis in the diagnosis of paracoccidioidomycosis
</b></td></tr><tr><td valign=top>Authors:</td><td>Camila Pisteli Caldini   (UNIFESP - Universidade Federal de São Paulo) ; <u>Patricia Xander Batista </u>  (UNIFESP/DIADEMA - Universidade Federal de São Paulo campus Diade) ; Érika Sekli Kioshima   (UNIFESP - Universidade Federal de São Paulo) ; Zoilo Pires de Camargo   (UNIFESP - Universidade Federal de São Paulo) ; Mario Mariano   (UNIFESP - Universidade Federal de São Paulo) ; José Daniel Lopes   (UNIFESP - Universidade Federal de São Paulo) </td></tr></table><p align=justify><b><font size=2>Abstract</font></b><p align=justify class=tres><font size=2>Paracoccidioidomycosis (PCM) is a systemic granulomatous disease caused by the dimorphic fungus <i>Paracoccidioides brasiliensis</i>. The fungus presents a complex structure of which many antigens remain to be fully characterized. Previous studies characterized two monoclonal antibodies (mAbs), 5E7C (IgG2a) and 1G6 (IgM), against a 75 kDa (gp75) protein of <i>P. brasiliensis</i>. Both mAbs were protective when administrated by passive immunization in PCM experimental model. Experiments in vitro showed that these mAbs also inhibited fungal growth. Considering such importance of anti-gp75 mAbs it became essential to identify and characterize the epitopes recognized by them. Phage display methodology was used to identify peptides that specifically bound to 5E7C mAb. The selected phages were sequenced and the sequences analyzed with databases. One peptide was prepared based in two parameters: (I) sequences obtained from phage-binding mAb 5E7C and (II) analysis of their homology to phosphatases expressed by the fungus, since gp75 has shown phosphatase activity. Using that approach, a synthetic peptide, named P2, was synthesized. P2 was recognized by anti-gp75 mabs by ELISA. In addition, polyclonal sera anti-P2 recognized by immunoblotting a band of approximately 75 kDa in <i>P. brasiliensis</i> exoantigen. This data are a strong evidence that P2 synthetic peptide may represent a mimotope of gp 75. Also, P2 was tested against PCM patients  sera. We observed a significant recognition of P2 by sera of PCM patients  sera from both forms (chronic and acute) when compared with normal human sera (p<0.0001). This results suggest a potential use of the  P2 synthetic peptide as diagnostic tool in PCM. The approach applied in this paper can be used to obtain different peptides applicable not only to diagnosis, but also for immunization and/or treatment of PCM. <b>Financial support:</b> CNPq, FAPESP.
</font></p><br><b>Keyword: </b>&nbsp;gp75, Phage display, synthetic peptides</td></tr></table></tr></td></table></body></html>