RECOGNITION OF Mycobacterium tuberculosis ANTIGENS MPT63 AND MPT83 WITH MURINE POLYCLONAL AND scFv ANTIBODIES

The goal of this study was to characterize serum immunoglobulin G (IgG) antibody responses during experimental immunization of laboratory mice by purified recombinant proteins MPT63, MPT83 of M. tuberculosis and artificial fusion protein MPT83-MPT63 and obtain the recombinant single chain variable fragments of antibodies (scFv) against these antigens. This study demonstrates that the humoral immune response to MPT63, MPT83, MPT83-MPT63 fusion protein and equimolar set of MPT63 and MPT83 was highly different. For each antigen, serum antibody levels were evaluated by a cutoff value based on optical density index. A crucial role of MPT83 for immunogenicity of chimeric protein and/or cocktail of individual antigens under conditions of immunization of laboratory animals. We obtained also specific scFv antibodies against MPT63 and MPT83. These antibodies can be used for the development of the system for quantitative determination of antigens as well as for their biological properties investigation. Thereby, based on the results of the immune response and mycobacterial proteins antigenicity we showed highly immunogenicity properties of N-terminal part of MPT83 antigen for enhencement of ELISA sensitivity. We suggest MPT83-MPT63 fusion protein as a potential candidate on the role of antigenic substance for the serological diagnosis of tuberculosis.