Fractionation of Borrelia burgdorferi was made by extraction of infectious spirochetes using the
detergent Triton X-114. Gel electrophoresis analysis of hydrophilic and hydrophobic
proteins demonstrated that
detergent extraction resulted in two populations of
proteins with nonoverlapping electrophoretic profiles. Immunoblot analysis with
monoclonal antibodies reactive with two abundant
membrane proteins demonstrated that hydrophilic
proteins were uncontaminated with hydrophobic
proteins. In addition, assay of
thymidine incorporation into and secretion of
tumor necrosis factor-alpha from splenocytes cocultured in vitro with either
detergent or aqueous phase
proteins showed that lymphocyte mitogenic and macrophage activation activities of B. burgdorferi were completely absent from the hydrophilic phase
proteins. The
Triton X-114 aqueous and
detergent phase
proteins were used to immunize BALB/c and separately microMT/microMT (B cell knockout) mice that were subsequently challenged with infectious B. burgdorferi. The hydrophilic phase
proteins were able to induce protective resistance to
infection in either strain of mice demonstrating that potential candidate
vaccine antigens are contained in the biochemical class of
antigens which is devoid of both lymphocyte
mitogen activity and major outer
surface proteins. Furthermore, the ability to vaccinate B cell knockout mice suggests that the humoral antispirochete immune response is not the exclusive basis for protective immunity.