Evaluation of RevA, a Fibronectin-Binding Protein of Borrelia burgdorferi, as a Potential Vaccine Candidate for Lyme Disease

Abstract

Previous studies indicated that the Lyme disease spirochete Borrelia burgdorferi expresses the RevA outer surface protein during mammalian infection. As an adhesin that promotes bacterial interaction with fibronectin, RevA appears to be a good target for preventive therapies. RevA proteins are highly conserved across all Lyme borreliae, and antibodies against RevA protein are cross-reactive among RevA proteins from diverse strains. Mice infected with B. burgdorferi mounted a rapid IgM response to RevA, followed by a strong IgG response that generally remained elevated for more than 12 months, suggesting continued exposure of RevA protein to the immune system. RevA antibodies were bactericidal in vitro. To evaluate the RevA antigen as a potential vaccine, mice were vaccinated with recombinant RevA and challenged with B. burgdorferi by inoculation with a needle or by a tick bite. Cultured tissues from all treatment groups were positive for B. burgdorferi. Vaccinated animals also appeared to have similar levels of B. burgdorferi DNA compared to nonvaccinated controls. Despite its antigenicity, surface expression, and the production of bactericidal antibodies against it, RevA does not protect against Borrelia burgdorferi infection in a mouse model. However, passive immunization with anti-RevA antibodies did prevent infection, suggesting the possible utility of RevA-based immunotherapeutics or vaccine.

The Western Progression of Lyme Disease: Infectious and Nonclonal Borrelia burgdorferi Sensu Lato Populations in Grand Forks County, North Dakota

“…Two weeks postinjection, infection was preliminarily determined by assaying pre-and postinfection sera by enzyme-linked immunosorbent assay (ELISA). Larval I. scapularis ticks were allowed to feed on infected mice as previously described (39). Briefly, approximately 200 to 300 uninfected larval I. scapularis ticks (Oklahoma State University-Stillwater) were placed on infected BALB/c mice and allowed to attach and feed.…”

“…Anti-B. burgdorferi IgG in sera from inoculated mice was detected as previously described (39). Briefly, 96-well plates were coated with 10 g/ml B. burgdorferi lysate in a carbonate coating buffer and incubated overnight at 4°C.…”

Borrelia burgdorferi RevA Significantly Affects Pathogenicity and Host Response in the Mouse Model of Lyme Disease

“…Cultures were harvested at 1 ϫ 10 7 bacteria/ml. Infection of mice was confirmed by analysis of serum samples by enzyme-linked immunosorbent assays (ELISAs) for antibodies directed against B. burgdorferi whole-cell lysates as described previously (30,38). Two weeks after infection, ear pinnae, hearts, bladders, skin from the inoculation site, and tibiotarsal joints were collected and were either frozen for DNA extraction and quantitative PCR (qPCR) or cultured in BSK-II medium plus 6% rabbit serum and 50 g/ml rifampin.…”

“…RevA is antigenic, as evidenced by the fact that both mice and human Lyme disease patients produce antibodies against RevA (36,37). Antibodies against RevA are bactericidal in vitro, and passive immunization with anti-RevA antibodies prevents infection (38). However, mice vaccinated with recombinant RevA protein were not protected when challenged with B. burgdorferi by needle or tick bite (38).…”

“…Antibodies against RevA are bactericidal in vitro, and passive immunization with anti-RevA antibodies prevents infection (38). However, mice vaccinated with recombinant RevA protein were not protected when challenged with B. burgdorferi by needle or tick bite (38).…”