INVOLVEMENT OF CD4(-LYMPHOCYTES IN INDUCTION OF SEVERE DESTRUCTIVE LYME ARTHRITIS IN INBRED LSH HAMSTERS() T)

We determined that Borrelia burgdorferi-specific CD4(+) T lymphocytes are responsible for the development of severe destructive Lyme arthrit is and affect the production of borreliacidal antibody. Severe destruc tive Lyme arthritis was readily evoked in immunocompetent inbred LSH h amsters vaccinated with a whole-cell preparation of Formalin-inactivat ed B. burgdorferi sensu stricto isolate C-1-11 in adjuvant when challe nged with B. burgdorferi sensu stricto isolate 297. When vaccinated ha msters were depleted of CD4(+) T lymphocytes by the administration of monoclonal antibody GK1.5 and challenged, they failed to develop sever e destructive arthritis, Similarly, nonvaccinated hamsters with or wit hout the depletion of CD4(+) T lymphocytes failed to develop severe de structive arthritis. In addition, depleting CD4(+) T lymphocytes impai red the development of borreliacidal antibody in vaccinated and nonvac cinated hamsters challenged with the Lyme borreliosis spirochete. Thes e findings show that CD4(+) T lymphocytes are important for the recogn ition of arthritogenic and protective antigens of B. burgdorferi sensu late isolates, Additional studies are needed to define the mechanisms responsible for the development of severe destructive Lyme arthritis and the production of borreliacidal antibody.