Epitope Mapping of the Outer Surface Protein A (OspA) of the Spirochete Borrelia burgdorferi Using a Panel of Monoclonal Antibodies and Lanthanide Competition Fluoroimmunoassay

I. G. Kharitonenkov^1*, V. G. Pomelova², D. J. Bucher³, A. Cozzolino³, T. A. Bichenkova², R. K. Sadykbekova¹, and N. S. Osin²

¹School of Basic Medicine, Lomonosov Moscow State University, Moscow, 119899 Russia; fax: (095) 938-2291; E-mail: khariton@genebee.msu.su

²Institute of Biological Engineering, Moscow, 123424 Russia

³New York Medical College, Valhalla, New York, 10595 USA

^* To whom correspondence should be addressed.

Received April 4, 2001; Revision received April 27, 2001

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A panel of fourteen different monoclonal antibodies was used for detection and analysis of antigenic determinants located on the outer surface protein A (OspA) of the spirochete Borrelia burgdorferi, which is a causative agent of tick-borne borreliosis (Lyme disease). Two main and several minor partially overlapping antigenic determinants have been found on the surface of the OspA protein of Borrelia burgdorferi sensu stricto (strain 297) by lanthanide competition fluoroimmunoassay. One of the main antigenic determinants is located in the N- and the other in the C-half of the OspA molecule. The involvement of the OspA protein in intact Borrelia burgdorferi sensu stricto (four bacterial strains have been analyzed: 297, B31, FR90-594, and CA90-742) is associated with retention of the above-mentioned two major antigenic determinants, but unlike the case of the isolated OspA they are partially overlapping with each other and with other antigenic determinants. The protein of the spirochete Borrelia afzelii (two bacterial strains have been analyzed: Ip-21 and Pko) contains only one antigenic determinant, which is the same as the main determinant of the OspA protein of Borrelia burgdorferi sensu stricto located in the N-half of the OspA molecule.

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KEY WORDS: Lyme disease, tick-borne borreliosis, spirochete Borrelia burgdorferi, outer surface protein A (OspA), monoclonal antibodies, competition analysis, lanthanide fluoroimmunoassay

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