Inhibition of the production of anti-OspA borreliacidal antibody with T cells from hamsters vaccinated against Borrelia burgdorferi

Abstract

The serious morbidity associated with Lyme borreliosis has focused considerable effort on the development of a comprehensive vaccine for protection against infection with Borrelia burgdorferi. Induction of borreliacidal antibody by vaccination or infection has been shown to correlate with protection of humans and animals against infection with the Lyme spirochete. In this report, we showed that high levels of borreliacidal antibody (titer of 1,280) were produced in vitro when T and B cells from hamsters 14 days after vaccination were incubated with macrophages and B. burgdorferi. By contrast, T and B cells from hamsters 7 or 21 days after vaccination failed to initiate production of borreliacidal activity. Furthermore, the T cells from hamsters 7 or 21 days after vaccination inhibited the in vitro production of borreliacidal antibody when cocultured with T and B cells obtained from hamsters 14 days after vaccination. When cell-free supernatants from the suspensions of T and B cells from hamsters 14 days after vaccination were absorbed with recombinant OspA, they lost nearly all borreliacidal activity. The removal of anti-OspA antibody resulted in a decrease in borreliacidal titer from 1,280 to less than 4. These results demonstrate that T cells from vaccinated animals can prevent a sustained production of protective borreliacidal antibody.

FIG. 1

Outline of the procedure for production of borreliacidal antibody in vitro by incubating macrophages with B. burgdorferi and T and B cells.

FIG. 2

Production of borreliacidal antibody in suspensions of macrophages and B. burgdorferi incubated for 4, 8, or 10 days with T and B cells obtained from hamsters 7 (), 14 (░⃞), or 21 (▩) days after vaccination. The titers of borreliacidal antibody were determined by inoculating dilutions of the cell-free suspensions with B. burgdorferi and complement, incubating for 20 h at 32°C, adding acridine orange, and determining the number of fluorescence-stained B. burgdorferi by flow cytometric analysis. Controls included suspensions containing macrophages and B. burgdorferi, macrophages, B. burgdorferi, and immune cells. When the borreliacidal assays were repeated, results were identical or varied by only a dilution.