Peptides in Diagnosing Lyme
By Linda on Jan 12, 2011 in Infections
Excerpt:
Lyme disease (LD) is a tick-borne infection caused by the bacterial pathogen
Borrelia burgdorferi. Current diagnostic tests mostly use borrelial lysates
or select antigens to detect serum antibodies against B. burgdorferi. These
immunoassays are not entirely effective, especially to detect early
infection.
We have recently characterized a in vivo-induced antigen, BBK07, as a
serodiagnostic marker for LD. We now report that in a line blot assay,
recombinant BBK07 protein-based detection is 90% sensitive and nearly 100%
specific against B. burgdorferi infection in humans. Using an overlapping
peptide library of 23 peptides encompassing full-length BBK07, we identified
the immunodominant epitopes of BBK07 during human infection. We show that a
select combination of amino-terminal peptides significantly enhanced
BBK07-based diagnostic accuracy when compared to the full-length protein.
Although in ELISA studies BBK07 peptides had overall lower sensitivity than
established serodiagnostic peptides, such as the VlsE peptide C6 and OspC
peptide pepC10 for the detection of early human LD, a subset of serum
samples that failed to recognize either VlsE or OspC peptides were
preferentially reactive to BBK07 peptides. These results highlight the fact
that BBK07 peptides could be useful to complement the efficacy of VlsE and
OspC peptide-based serodiagnostic assays.
Finally, using a panel of canine sera, we show that BBK07 peptide is also
effective for LD diagnosis in infected dogs.
Together, our data show that
peptides from the B. burgdorferi surface protein BBK07 are highly specific
and sensitive serodiagnostic markers, and suggest their future use in LD
diagnostic assays.
