Aim: To obtain and study of immunochemical characteristics of monoclonal antibodies (MAbs) to CagA cytotoxin of Helicobacter pylori employing recombinant fragments of CagA protein.
Materials and methods: Standard methods of construction and selection of hybridomas, different variants of immunoenzyme analysis and immunoblotting were used. Molecular genotyping of H. pylori cultures by amplification of cagA gene fragments was performed.
Results: Panel of MAbs recognizing 4 different linear epitopes on the CagA molecule, three of which are localized in conservative parts of cytotoxin and one--in variable region of CagA, was developed. On the basis of two obtained antibodies, system of two-center immunoenzyme assay for quantitative detection of CagA protein which is characterized by high sensitivity and specificity, was developed. Obtained MAbs allow to differentiate CagA-positive and CagA-negative strains of H. pylori by immunochemical methods.
Conclusion: Employing pure recombinant fragments of CagA protein, first panel of MAbs to CagA cytotoxin of H. pylori was developed and characterized. Obtained MAbs open perspectives for study of the H. pylori cytotoxin molecule and construction of immunodiagnostic assays aimed on detection of CagA antigen.