Inadequate binding of immune regulator Factor H

Full article: http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=20823202&retmode=ref&cmd=prlinks

Excerpt:

Spirochetes belonging to the Borrelia (B.) burgdorferi sensu lato
complex differ in their resistance to complement-mediated killing
by human serum. Here, we characterize complement sensitivity of a
panel of B. lusitaniae isolates derived from ticks collected in
Germany and Portugal as well as one patient-derived isolate,
PoHL. All isolates are highly susceptible to complement-mediated
lysis in human serum and activate complement predominantly by the
alternative pathway, leading to an increased deposition of
complement components C3, C6, and the terminal complement
complex. Interestingly, serum-sensitive B. lusitaniae isolates
were able to bind immune regulator Factor H (CFH), and some
strains also bind Factor H-related protein 1 (CFHR-1) and CFHR-2.
Moreover, CFH bound to the surface of B. lusitaniae was
inefficient in mediating C3b conversion.
Furthermore, the identification and characterization of a
potential CFH-binding protein, OspE revealed that this molecule
possesses a significantly reduced binding capacity for CFH
compared to CFH-binding OspE paralogs expressed by various
serum-resistant Borrelia species. This finding suggests that a
reduced binding capability of CFH is associated with an increased
serum sensitivity of B. lusitaniae to human complement.