Neutralizing monoclonal antibodies against listeriolysin: Mapping of epitopes involved in pore formation

Six different mouse monoclonal antibodies (MAbs) and a specific rabbit polyclonal antibody were raised against listeriolysin, Four of the MAbs also recognized seeligeriolysin, and five cross-reacted with ivanolysin. The hemolytic activity could be neutralized by the polyclonal antibody as well as by five of the MAbs. None of the neutralizing antibodies interfered with the binding of listeriolysin to the cellular membrane. The epitopes recognized by the MAbs were localized by using overlapping synthetic peptides between positions 59 and 279, a region hitherto not implicated in mediating hemolytic activity.