Biological charaterization of original and mutant human recombinant antibodies (scFv) anti-crotoxin generated by site-directed mutagenesis

• Grant number: 08/06647-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2008
• End date: September 30, 2010
• Field of knowledge: Biological Sciences - Immunology - Immunochemistry
• Principal Investigator: Irene Fernandes
• Grantee: Tamires Souza de Oliveira
• Host Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

Administration of heterologous antibodies, generally produced in horses, has been the treatment of choice to persons who suffered accidents by snake venoms. However, this kind of therapy can induce adverse reactions. Small fragments of antibodies containing only the VH and VL domains, known as Fv (Fragment variable) or single chain Fv (scFv) were constructed by genetic engineer aiming to avoid adverse reactions. Human scFv clones were isolated from a naive library of 1010 phages by CARDOSO et al., 2000. Original ScFv were redesigned by Antibody Evolution (AbEvo) technology and will be obtained in our lab by site-directed mutagenesis. AbEvo system aims the optimization of antibody affinity and specificity basing in the tridimensional structure of antigen and antibody, dictated by an evolutional algorithm. The objective of this project is to characterize recombinant human antibodies scFv anti-crotoxin original and mutants regarding their biological activities in vivo and in vitro: enzymatic activity of crotoxin (CTX), myotoxicity induced by CTX and ability to neutralize lethality induced by CTX and Crotalus durissus terrificus (Cdt) venom.