ANTIBODIES AND FV FRAGMENT RECOGNIZING ANTIGEN IOR C2

The invention relates to recombinant antibodies from monoclonal antibody IOR C5 that recognizes antigen IOR C2 of colorectal cells. Said recombinant antibodies have a reduced immunogenicity due to punctual mutations in the FRs. Said antibodies are useful for the diagnosis and therapy of colorectal tumors, their metastasis and relapses. The invention relates to the obtention of novel recombinant antibodies of novel recombinant antibodies from murine antibody ior C5 produced by the hybridome deposited under number ECCC 97061101 in accordance with the Budapest Treaty. Said recombinant antibodies were obtained using recombinant DNA technology and are characterized in that they recognize antigen ior C2. The recombinant antibodies are specifically chimeric antibody, humanized antibody and the single-chain Fv fragment. The chimeric antibody contains variable domains of murine immunoglobuline and the constant regions of human immunoglobuline. The humanized antibody contains the constant regions of human immunoglobuline and has been specifically modified in the murine framework regions (FRs) and within the latter, in those areas that may result in an antigenic site for cells T. The Fv fragment contains the variable domains of murine immunoglobuline. The invention also relates to the utilization of recombinant antibodies derived from murine antibody ior C5 in the diagnosis and therapy of colorectal tumors, the metastasis thereof and recurrences. La presente invención se relaciona con la obtención de nuevos anticuerpos recombinantes a partir del anticuerpo murino ior C5 producido por el hibridoma depositado según el tratado de Budapest bajo el número ECCC 97061101. Dichos anticuerpos recombinantes se obtuvieron mediante el empleo de la tecnología del ADN recombinante, y están caracterizados por su reconocimiento al antígeno denominado ior C2. Los anticuerpos recombinantes son específicamente, el anticuerpo quimérico, el anticuerpo humanizado y el fragmento tipo Fv de cadena sencilla. El anticuerpo quimérico contiene los dominios variables de la inmunoglobulina murina y las regiones constante de la inmunoglobulina humana. El anticuerpo humanizado contiene las regiones constante de la inmunoglobulina humana y ha sido modificado específicamente en la región de los marcos (FRs) murinos y dentro de estos en aquellas zonas que pudieran resultar en un sitio antigénico par las células T. El fragmento Fv contiene los dominios variables de la inmunoglobulina murina. La present