The Attachment of detergent-extracted outer membrane proteins of Orientia tsutsugamushi to the host cell surface

초록

Orientia tsutsugamushi, a causative agent of scrub typhus, is an obligate intracellular parasite. The mechanisms by which O. tsutsugamushi invades host cells are unknown. Given the importance of surface-exposed proteins in the pathogenesis of many organisms, outer membrane proteins(OMP) of O. tsutsugamushi were extracted with detergents and their cellular binding was studied. Outer membrane fraction of O. tsutsugamushi were inriched by sodiumlauryl sarcosinate (Sarkosyl) tretment of total membranes. Outer membrane proteins were solubilized with the treatment of outer membrane fraction with sodium dodecyl sulfate(SDS), Sarkosyl and the resulting soluble fractions were examined for their cellular binding by immunofluorescent test. 56-kDa protein was found to be bound to fixed ECV304 cells only whin the outer membrane preparation was not treated by DTT of heat. These results suggest that the protein conformation is important for the attachment of OMP to the host cell surface.