Browsing by Subject "AB5-toxin"

Bartonella species are facultative intracellular bacteria causing variety of diseases in humans and also infects endothelial cells and erythrocytes. Some Bartonella species utilize VirB/VirD4-type IV secretion system (T4SS) in order to secret Bartonella effector protein A (BepA) which infects endothelial host cells by inhibiting the apoptosis. But the enterotoxin homolog in Bartonella gene A (EhbA) and the enterotoxin homolog in Bartonella gene B (EhbB) are found in the non-BepA Bartonella strains. In my Master’s thesis, I study the host cell binding activity and identify host cell surface receptor of EhbB in Bartonella. In my thesis, the cell adhesion of multimeric B proteins of enterotoxin homologue in Bartonella (Ehb) have been analyzed with cell adhesion assay using HEK293T, HeLa 229, Ea.hy926, and CHO-K1 cells. The assay was conducted with EhbB1 and EhbB 1-1C proteins from Bartonella Bovis strain Bermond and Bartonella strain spp 1-1C and the experiment indicated the cell adhesion activity of both EhbB proteins compared to the controls used in the experiment. Moreover, the binding activity of EhbB1 with Ea.hy926 was studied at several incubation time points, such as; 30 min, 2 hours, 4 hours, 6 hours, and 8 hours. Several incubation period of EhbB1 and EhbB 1-1C with Ea.hy926 cells did not enhance cell surface adhesion because the same absorbance compared to controls. The interaction of EhbB1 with cell membrane HEK293T was studied by using western blot on cell membrane preparation from Ea.hy926 cells which was used to identify possible protein receptor of EhbB1. The experiment suggests that EbB1 is binding to receptors present on the cell membrane of HEK293T which could be protein. The cell adhesion activity of HEK293T cell membrane with EhbB1 was analyzed by inhibition assay. This experiment indicated that EhbB1 protein attached to cell surface receptors present on the HEK29T cell membrane, which inhibited EhbB1 protein to attach to Ea.hy926 cells. This also indicate that the cell surface receptor for EhbB1 could be protein but requires further study.