Epitope of Bordetella pertussis protein characterized.

2004 SEP 1 - (NewsRx.com & NewsRx.net) -- Scientists have determined the epitope structure of the Bordetella pertussis protein P.69 pertactin, which is a major vaccine component and protective antigen.

According to a study from the Netherlands, "Bordetella pertussis is reemerging in several countries with a traditionally high vaccine uptake. An analysis of clinical isolates revealed antigenic divergence between vaccine strains and circulating strains with respect to P.69 pertactin. Polymorphisms in P.69 pertactin are mainly limited to regions comprised of amino acid repeats, designated region 1 and region 2. Region 1 flanks the RGD motif, which is involved in adherence. Although antibodies against P.69 pertactin are implicated in protective immunity, little is known about the structure and location of its epitopes."

"Here we describe the identification by pepscan analysis of the locations of mainly linear epitopes recognized by human sera and mouse monoclonal antibodies (MAbs)," said Marcel Hijnen at the National Institute of Public Health in Bilthoven and collaborators in the Netherlands. "A total of 24 epitopes were identified, and of these only two were recognized by both MAbs and human antibodies in serum. A number of immunodominant epitopes were identified which were recognized by 78 to 93% of the human sera tested. Blocking experiments indicated the presence of high-avidity human antibodies against conformational epitopes. Human antibodies against linear epitopes had much lower avidities, as ...