Tuyển tập các báo cáo nghiên cứu khoa học quốc tế về bệnh thú y đề tài: The C-terminal variable domain of LigB from Leptospira mediates binding to fibronectin | J. Vet. Sci. 2008 9 2 133-144 JOURNAL OF Veterinary Science The C-terminal variable domain of LigB from Leptospira mediates binding to fibronectin Yi-Pin Lin Yung-Fu Chang Department of Population Medicine and Diagnostic Sciences College of Veterinary Medicine Cornell University Ithaca NY 14853 USA Adhesion through microbial surface components that recognize adhesive matrix molecules is an essential step in infection for most pathogenic bacteria. In this study we report that LigB interacts with fibronectin Fn through its variable region. A possible role for LigB in bacterial attachment to host cells during the course of infection is supported by the following observations i binding of the variable region of LigB to Madin-Darby canine kidney MDCK cells in a dose-dependent manner reduces the adhesion of Leptospira ii inhibition of leptospiral attachment to Fn by the variable region of LigB and iii decrease in binding of the variable region of LigB to the MDCK cells in the presence of Fn. Furthermore we found a significant reduction in binding of the variable region of LigB to Fn using small interfering RNA siRNA . Finally the isothermal titration calorimetric results confirmed the interaction between the variable region of LigB and Fn. This is the first report to demonstrate that LigB binds to MDCK cells. In addition the reduction of Fn expression in the MDCK cells by siRNA reduced the binding of LigB. Taken together the data from the present study showed that LigB is a Fn-binding protein of pathogenic Leptospira spp. and may play a pivotal role in Leptospira-host interaction during the initial stage of infection. Keywords adhesion Fn Leptospira LigB MDCK cell siRNA Introduction Leptospirosis is a zoonotic disease caused by pathogenic spirochetes in the genus Leptospira 22 . The disease occurs widely in developing countries and is reemerging in the United States 29 . The clinical features are variable and include subclinical infection a self-limited anicteric febrile
