Involvement of CD4+ T lymphocytes in induction of severe destructive Lyme arthritis in inbred LSH hamsters.

We determined that Borrelia burgdorferi-specific CD4+ T lymphocytes are responsible for the development of severe destructive Lyme arthritis and affect the production of borreliacidal antibody. Severe destructive Lyme arthritis was readily evoked in immunocompetent inbred LSH hamsters vaccinated with a whole-cell preparation of Formalin-inactivated B. burgdorferi sensu stricto isolate C-1-11 in adjuvant when challenged with B. burgdorferi sensu stricto isolate 297. When vaccinated hamsters were depleted of CD4+ T lymphocytes by the administration of monoclonal antibody GK1.5 and challenged, they failed to develop severe destructive arthritis. Similarly, nonvaccinated hamsters with or without the depletion of CD4+ T lymphocytes failed to develop severe destructive arthritis. In addition, depleting CD4+ T lymphocytes impaired the development of borreliacidal antibody in vaccinated and nonvaccinated hamsters challenged with the Lyme borreliosis spirochete. These findings show that CD4+ T lymphocytes are important for the recognition of arthritogenic and protective antigens of B. burgdorferi sensu lato isolates. Additional studies are needed to define the mechanisms responsible for the development of severe destructive Lyme arthritis and the production of borreliacidal antibody.