Genetic and immunological analyses of Vls (VMP-like sequences) of Borrelia burgdorferi

DNA fragments containing the VMP-like sequence (VIs) were cloned from Borrelia burgdorferi strain 297. Analyses by PCR, PFGE, and Southern hybridization revealed that the Vis sequences existed in multi-copies on the 20-kb borrelial plasmid, but not on chromosomes or other plasmids. One Vis unit of the strain 297 was about 669 bases, and predicted peptides length was 223 amino acids. Homologues of the Vis fragment were detected in three B. burgdorferi strains, a B. garinii strain 20047, and a B. afzelii strain P/Gau. A recombinant Vlslil protein prepared in Escherichia coli strain JM109 reacted with antibodies that existed in three of five patients, by immunoblotting. These results suggested that the Vis of B. burgdorferi is expressed in Lyme disease patients. (C) 1998 Academic Press Limited.