Borrelia burgdorferi BmpA, BmpB, and BmpD proteins are expressed in human infection and contribute to P39 immunoblot reactivity in patients with Lyme disease

The Bmp proteins are a paralogous family of chromosomally encoded Borrelia burgdorferi lipoproteins. They have similar predicted immunogenicities and similar electrophoretic mobilities by sodium dodecyl sulfate lysate in immunoblots of Lyme polyacrylamide gel electrophoresis. P39 reactivity against Borrelia burgdorferi disease patients has long been identified with reactivity to BmpA, but responses to other Bmp proteins have not been examined. To determine if patients with Lyme disease developed such responses, immunoglobulin G (IgG) anti-Bmp reactivity in patient and control sera was studied by using soluble recombinant Bmp (rBmp) proteins expressed in Escherichia coli. Although some patient sera contained IgG immunoblot and immunodot reactivities against all four Bmp proteins, analysis of IgG anti-Bmp fine specificity by a competitive enzymelinked inummosorbent assay with graded doses of soluble homologous and heterologous rBmp proteins showed that only the responses to BmpA, BmpB, and BmpD were specific. This suggests that at least three of the four fieri in infected patients and that specific antibodies to them are likely Bmp proteins are expressed by B. burgdorferi to be present in the P39 band in some patients.