Variations in the ospB gene of Borrelia burgdorferi result in differences in monoclonal antibody reactivity and in production of escape variants.

An escape variant of Borrelia burgdorferi, selected with a monoclonal antibody to OspB, expressed a truncated form of OspB, the result of point mutations in the ospB gene leading to a premature termination codon. A single amino acid position in the C terminus of OspB was critical for monoclonal antibody recognition. The variations in the ospB gene suggest a mechanism for the evasion of the immune response by these organisms and may also have implications for current diagnostic and vaccine efforts.