Studies on the Hemagglutinin of Hemophilus Pertussis

Abstract

Hemagglutinin activity can be demonstrated in the early phases of cultivation of Hemophilus pertussis but disappears as the cultures approach maximal density. Previous work has shown that cells from cultures that have reached maximal density have high immunizing potency. Absorption of supernatants from sonically disrupted H. pertussis cell concentrates with chicken red blood cells removes all of the hemagglutinating activity without diminution of toxicity or agglutinogen titer. Supernatants, after complete removal of hemagglutinating activity by absorption on chicken cells, still retain a considerable portion of their protective antigenicity. A spontaneous precipitate that develops in supernatants contains hemagglutinating activity but does not actively immunize mice. Certain properties of the hemagglutinating principle have been described, and the suggestion is made that there may be at least two hemagglutinins. It is concluded that the hemagglutinating substance of H. pertussis cultures is not identical with the toxin, the agglutinogen, or the immunizing antigen.