PROTECTIVE AND ARTHRITIS-RESOLVING ACTIVITY IN SERA OF MICE INFECTED WITH BORRELIA-BURGDORFERI

Transfer of immune serum from immunocompetent mice infected with B. bu rgdorferi protects mice against syringe challenge, and transfer of imm une serum after infection is established induces arthritis resolution but does not clear infection or spirochetemia or resolve carditis. Imm une serum had very-high-titer passive protective activity against syri nge challenge but failed to protect mice against host-adapted spiroche tes when they were challenged with infected tissue transplants. Mice w ere passively immunized at selected intervals relative to challenge in oculation with antisera to recombinant forms of an immunodominant regi on of flagellin, P39, and OspC (which are recognized by immune serum), but none provided protection or modified existing infection or diseas e, Results suggest that spirochetes within joints, but not in other ti ssues, are selectively vulnerable to immune serum and that immune seru m appears to contain antibody against yet-to-be-identified antigens th at may be selectively expressed in the context of joint tissue.