Specificity of infection-induced immunity among Borrelia burgdorferi sensulate species

The specificity of infection-induced immunity in mice infected with culture d or host-adapted Borrelia burgdorferi sensu rate, the agent of Lyme diseas e, was examined. Sera obtained from mice following infection with high and low doses of cultured B. burgdorferi sensu stricto, transplantation of infe cted tissue (host-adapted spirochetes), or tick-borne inoculation all showe d protective activity in passive immunization assays. Infection and disease were similar in mice infected with cultured spirochetes or by transplantat ion. Thus, the adaptive form of inoculated spirochetes did not influence th e immune response during active infection. Mice infected with B. burgdorfer i sensu stricto and then cured of infection with an antibiotic during early or late stages of infection were resistant to challenge with high doses of homologous cultured spirochetes for up to 1 gear. In contrast, actively im mune mice infected with different Borrelia species (B. burgdorferi sensu la te, B. burgdorferi sensu stricto cN40, Borrelia afzelii PKo, and Borrelia g arinii PBI) and then treated with an antibiotic were resistant to challenge with cultured homologous but not heterologous spirochetes, Similar results were achieved for actively immune mice challenged by transplantation and b y passive immunization with sera from mice infected with each of the Borrel ia species and then challenged with cultured spirochetes, Arthritis and car ditis in mice that had immunizing infections with B. afzelii and B. garinii and then challenged by transplantation with B, burgdorferi sensu stricto w ere equivalent in prevalence and severity to those in nonimmune recipient m ice. These results indicate that protective immunity and disease-modulating immunity that develop during active infection are universal among species related to B. burgdorferi sensu late but are species specific.