Development of monoclonal antibodies against the E7 oncoprotein

CERUTTI, M.L; FASSOLARI, M; DANTUR, K; CAMPOREALE, G; DE PRAT GAY, G

Viña del Mar, Chile.

Congreso; 9th Latin American Congress of Immunology.; 2009

Latin American Association of Immunology

<!-- /* Font Definitions */ @font-face {font-family:"Times New Roman"; panose-1:0 2 2 6 3 5 4 5 2 3; mso-font-charset:0; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:50331648 0 0 0 1 0;} @font-face {font-family:Arial; panose-1:0 2 11 6 4 2 2 2 2 2; mso-font-charset:0; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:50331648 0 0 0 1 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-ansi-language:EN-GB; mso-fareast-language:ES;} em {font-weight:bold; font-style:normal;} table.MsoNormalTable {mso-style-parent:""; font-size:10.0pt; font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Persistent infections by high-risk human papillomaviruses are the main etiologic factors for cervical cancer, the leading cause of cancer death among women in low-income countries.  Besides, increasing evidence links this virus to ano-genital and oropharyngeal carcinomas.  High-risk E7 oncoproteins play a key role in cellular transformation, constituting one presumed diagnostic marker.  Thus, here we aimed to develop a set of high affinity monoclonal antibodies against the poorly immunogenic E7 protein from the high-risk papillomavirus 16 subtype. Analysis of the polyclonal immune response and further hybridoma screenings show that E7 can turn into a good antigen after fusion to a carrier protein.  ELISA experiments demonstrate that one anti-E7 antibody, M1, is highly specific for the E7 strain 16 antigen, displaying low cross-reactivity against the homologous strain 18 E7.  Epitope mapping analysis shows that M1 recognizes a lineal epitope within a region of low homology between the two viral proteins.  Moreover, immunofluorescence staining shows that M1 can recognize E7 in various human papillomavirus positive cancer cell lines.  Taken together, our results suggest that this monoclonal antibody may be a useful tool to detect papillomavirus-related malignancies and identify different high-risk groups.