MOLECULAR AND IMMUNOLOGICAL CHARACTERIZATION OF THE P83 100 PROTEIN OF VARIOUS BORRELIA-BURGDORFERI SENSU-LATO STRAINS/

The complete coding regions of the chromosomally encoded p83/100 prote in of four Borrelia garinii strains and one Borrelia burgdorferi sensu stricto strain have been amplified by the polymerase chain reaction ( PCR), cloned and sequenced. From alignment studies with the deduced am ino acid sequences presented here, and five other published p83/100 se quences, the most heterologous region of the p83/100 molecule was iden tified to be located between amino acid position 390-540. To study the structure of this heterogeneous region, and internal fragment of the p83/100 genes from 11 additional B. burgdorferi sensu late strains was amplified by PCR. The PCR products were analyzed by DNA sequencing an d restriction enzyme analysis. These internal p83/100 fragments varied in size and sequence. Cluster analysis of internal p83/100 fragments, as well as restriction enzyme analysis, revealed three major groups i n accordance with grouping into the three species causing Lyme disease . Strains within the same species (six B. burgdorferi sensu stricto an d six B. afzelii strains) showed similar p83/100 partial structures. N evertheless, nine B. garinii strains showed more sequence variations a nd could be further divided into two major subgroups. One group is rep resented by OspA serotype 4 strains, the other more heterogeneous grou p is represented by OspA serotypes 3, 5, 6 and 7 strains. Phenotypic a nalysis with four p83/100-specific monoclonal antibodies revealed four distinct reactivity patterns. Antibody L100 1B4 recognized a common e pitope of B. burgdorferi sensu stricto and B. afzelii. Antibodies L100 17D3 and L100 18B4 were reactive with an epitope shared by strains of all three species. The broadest reactivity was shown by L100 18B4 whi ch, in constrast to L100 17D3, additionally recognized the relapsing f ever borreliae B. turicatae and B. hermsii. L100 8B8 detected a subgro up of the B. burgdorferi sensu stricto strains. Since comparison of th e p83/100 molecule with sequences from protein databases showed simila rities with characteristics of eukaryotic cell structures, the p83/100 might mimic these structures and may, therefore, be involved in the i mmune escape mechanism of the pathogenic agent of Lyme disease.