Transient expression of Helicobacter pylori cagA oncoprotein in brinjal

Abstract Helicobacter pylori is closely connected to upper gastrointestinal tract diseases including gastric cancer. Transgenic plants are found to be successful in expressing the bacterial antigens, which could elicit an immune response when consumed. The Cytotoxicity- associated immunodominant antigen protein (cagA) of H. pylori is kindred with pathogenicity and cancer risk. We expressed the cagA transgenically in the brinjal. We amplified the cagA gene from H. pylori strain 26695 chromosomal DNA and transformed it into brinjal callus derived from leaf explants using the pBI121 expression vector. The stable expression and accumulation of the recombinant cagA gene were confirmed by using quantitative real-time PCR, western blot analysis and ELISA. The RT-PCR, western blot and ELISA showed stable expression of cagA gene in the transgenic lines B3, B5, B11, B17 and B21. Among them, B11 and B17 samples showed higher expression of the cagA compared to the other samples. Besides, the immunohistochemistry assay showed the abundant expression of cagA protein in the parenchymal regions of the transgenic plants. Out of the 52 plants, a set five plants were found to be positive for cagA expression. Our experimental outcomes can be used further to design the vaccines against H. pylori from the transgenic brinjal plants.