New strategies for recombinant antibodies generation against Stx1 and Stx2 toxins produced by Shiga toxin-producing E. coli

Abstract

Shiga toxin-producing Escherichia coli is responsible for hemorrhagic colitis and hemolytic-uremic syndrome, which aggravates the condition of the infected patients. The diagnosis of this pathogen is not included in routine laboratories in developing countries. The development of tools for detecting these toxins becomes very relevant to their diagnosis. Antibodies have proven to be an excellent paradigm for the design of high-affinity, protein-based binding reagents. In our laboratory, IgG antibodies can be obtained by two ways; polyclonal antibodies (pAbs), which have different affinities and specificities, being produced in, limited quantities. In contrast, monoclonal antibodies (mAbs) have homogeneity, high specificity, and are unlimitedly produced by specialty cell culture. In order to maintain homogeneity and specificity of the monoclonal antibodies, associated to a large-scale production with lower cost, the genetic engineering has been used to obtain recombinant antibodies such as scFv and Fab fragments which have the complementarity-determining regions (CDR). This project aimed apply different strategies for obtain the single-chain variable fragments against Stx1 and Stx2 toxins to be used as tools in the Shiga toxin-producing E. coli immunodiagnosis. (AU)