Decorin-binding protein A (DbpA) of Borrelia burgdorferi is not protectivewhen immunized mice are challenged via tick infestation and correlates with the lack of DbpA expression by B-burgdorferi in ticks

Previous studies showed that decorin-binding protein A (DbpA) of Borrelia b urgdorferi was a protective immunogen in the murine model of Lyme borrelios is when mice were challenged (needle inoculated) intradermally with in vitr o-cultivated spirochetes. In the present study, DbpA-immunized C3H/HeJ mice were not protected from infection when infested with Ixodes scapularis nym phs harboring virulent B. burgdorferi 297. This lack of protection correlat ed with the failure to detect DbpA on B. burgdorferi in ticks, suggesting t hat DbpA is not available as a target for bactericidal antibodies in serum when B. burgdorferi-infected ticks take their blood meal from an immunized host. The failure of DbpA immunization to protect tick-challenged mice cont radicts the results of earlier needle inoculation vaccination experiments a nd suggests that DbpA may not be suitable as a Lyme disease vaccine.