Related Experiment Videos
Murine Lyme borreliosis: route of inoculation determines immune response and infectivity
A R Pachner1, E Delaney, N S Ricalton
1Georgetown University School of Medicine, Department of Neurology, Washington, DC 20007.
Abstract:
Outer surface protein A OspA is the major outer surface protein of B. burgdorferi, the causative agent of Lyme disease, and has been advocated as a vaccine candidate. It is recognized late or not at all in the course of human Lyme disease, but has been identified as a major antigenic epitope for the anti-spirochetal immune response in a number of experimental models of B. burgdorferi infection. We injected B.burgdorferi into mice and tested the appearance of immunoreactivity to OspA by Western blotting. Three routes of infection were studied; other variables investigated were inoculum size and isolate of spirochete and strain of mouse. OspA immunoreactivity, as determined by Western blotting, was readily elicited by injection of sonicates under almost any condition. Intraperitoneal or intravenous injection of infectious spirochetes, especially at infective inoculum sizes, or injection of the noninfectious B31 isolate by any route, resulted in OspA immunoreactivity. However, mice from the three strains tested infected intradermally did not develop significant OspA immunoreactivity, but instead developed strong responses to B.burgdorferi proteins of different molecular weights. These data suggest that during infection within the skin after intradermal inoculation, the OspA protein may be altered in some way to make it less immunogenic than when it is presented to the immune system under other circumstances.(ABSTRACT TRUNCATED AT 250 WORDS)
Insights
Outer surface protein A (OspA) from Borrelia burgdorferi, the Lyme disease agent, is a vaccine candidate. OspA immunoreactivity was induced in mice by various infection routes, except intradermal inoculation, suggesting skin infection alters OspA immunogenicity.
Area of Science:
- Immunology
- Microbiology
- Vaccine Development
Background:
- Outer surface protein A (OspA) is a key Borrelia burgdorferi antigen and a potential Lyme disease vaccine candidate.
- OspA is recognized late in human Lyme disease but is immunogenic in experimental models.
Purpose of the Study:
- To investigate the immunogenicity of OspA in mice following different infection routes and conditions.
- To determine if the route of Borrelia burgdorferi infection influences the immune response to OspA.
Main Methods:
- Mice were infected with Borrelia burgdorferi via intraperitoneal, intravenous, or intradermal routes.
- OspA immunoreactivity was assessed using Western blotting.
- Variables included inoculum size, spirochete isolate, and mouse strain.
Main Results:
- OspA immunoreactivity was readily elicited by injecting spirochete sonicates.
- Intraperitoneal or intravenous infection with infectious spirochetes induced OspA immunoreactivity.
- Intradermal infection did not elicit significant OspA immunoreactivity, with responses directed against other B. burgdorferi proteins.
Conclusions:
- The route of Borrelia burgdorferi infection significantly impacts OspA immunogenicity in mice.
- Intradermal infection may lead to alterations in OspA, reducing its immunogenic potential.
- These findings have implications for the efficacy of OspA-based Lyme disease vaccines.