A bactericidal antibody to Borrelia burgdorferi is directed against a variable region of the OspB protein

Abstract

Borrelia burgdorferi, an agent of Lyme disease, is killed by some monoclonal antibodies in the absence of complement or phagocytes. In the present study, the bactericidal action of monoclonal antibodies against B. burgdorfieri and B. hermsii, a cause of relapsing fever, was further characterized. H6831, an antibody recognizing the OspB proteins of some B. burgdorferi strains, and H4825, an antibody specific for one serotype of B. hermsii, were purified, and Fab fragments of the antibodies were prepared. In time-kill studies, more than 99.9% of strain B31 B. burgdorferi cells were killed after 30 min of exposure to H6831 Fab fragments. The MBC of the Fab fragments was 10 ,ug/ml. Electron microscopy revealed that the bactericidal Fab fragments produced numerous blebs and cell lysis of the borrelias for which they were specific. To identify the epitope for H6831, the OspB sequences of H6831-susceptible and-resistant strains and mutants were determined. The deduced OspB proteins of all H6831-resistant strains and mutants differed from the strain B31 OspB at residue 253. Murine antisera raised against a 21-mer synthetic peptide representing the region around residue 253 were specific for strain B31 by Western blot (immunoblot) and growth inhibition assays. Furthermore, the antipeptide serum inhibited the binding of H6831 to whole borrelias. These findings indicated that the linear component of the bactericidal antibody's epitope was located at or near residue 253.

Non‐heritable change of a spirochaete's phenotype by decoration of the cell surface with exogenous lipoproteins

“…The final concentrations of ethylenediaminetetraacetate (EDTA) and Triton X-100 were 0.1 mM and 0.015% (v/v), respectively, for both lipidated and non-lipidated Osp proteins; at these concentrations these compounds were not inhibitory to the growth of B. burgdorferi. After incubation of cells with lipidated or non-lipidated OspA in BSK medium for 4 h, phase-contrast microscopy revealed motile cells without blebbing or other signs of damage (Barbour and Hayes, 1986;Sadziene et al, 1994). The spirochaetes were washed twice in PBS containing 5 mM Mg (PBS-Mg), lysed, and subjected to polyacrylamide gel electrophoresis (PAGE) and Western blot analysis with OspA-specific monoclonal antibody (Fig.…”

Delineating Surface Epitopes of Lyme Disease Pathogen Targeted by Highly Protective Antibodies of New Zealand White Rabbits

“…Hence, BBA36 176 VQKPV 180 may constitute or at least form part of an epitope that could be targeted by antibodies for effecting protective immunity, considering that BBA36 is upregulated by cultivation in mammalian hosts, while specific antibodies against BBA36 are bactericidal (69). (65)(66)(67). Peptide identifiers (on the lines of their respective sequences) are prefixed with either "p" for protection-associated peptides in mice from previous work (59) or "q" for peptides uniquely recognized by day 28 rabbit sera.…”

“…As before (59), aligned peptides were also analyzed in relation to three protective sequences ( Fig. 3), from OspA, OspB, and OspC, which had previously been shown to elicit antipeptide antibodies with complement-dependent (anti-OspA and anti-OspC) or complement-independent (anti-OspB) bactericidal activity (65)(66)(67). Unlike the mouse PA peptides, only one rabbit-recognized peptide (q204) overlapped a protective sequence (OspB 238 KWEDSTSTLTISADSKKTKD 257 ).…”

Identification of Surface Epitopes Associated with Protection against Highly Immune-Evasive VlsE-Expressing Lyme Disease Spirochetes

“…Three protective sequences (Fig. 5), one each from B. burgdorferi B31 OspA, OspB, and OspC, were previously shown to elicit antipeptide antibodies with complementdependent (anti-OspA and anti-OspC) or -independent (anti-OspB) bactericidal activity (42)(43)(44). Peptide p394 (NATSTLL) aligned with the OspA ( 221 STLTITVNSKKTKDLVFTKE 240 ) and OspB ( 238 KWEDSTSTLTISADSKKTKD 257 ) protective sequences.…”

“…Protective sequences of B. burgdorferi B31 outer surface proteins A (OspA), B (OspB), and C (OspC) with aligned protection-associated peptides. Underlined sequences (with the N-and C-terminal residue positions being numbered) of OspA, OspB, and OspC elicit antipeptide antibodies with complementdependent (anti-OspA and anti-OspC) and -independent (anti-OspB) bactericidal activity(42)(43)(44). Peptide identifiers are on the lines of their respective sequences, whose residues are rendered in uppercase if they are part of a BLASTP hit alignment or lowercase otherwise.…”