Adhesin

Adherence is often an essential step in bacterial pathogenesis or infection, required for colonizing a new host. To effectively adhere to host surfaces, many bacteria produce multiple adherence factors called adhesins. For example, nontypeable Haemophilus influenzae expresses the adhesins Hia, Hap, Oap and a hemagglutinating pili.

Adhesins are attractive vaccine candidates because they are often essential to infection and are surface-located, making them readily accessible to antibodies.

The effectiveness of anti-adhesin antibodies is illustrated by studies with FimH, the adhesin of uropathogenic Escherichia coli (UPEC). In animal models, passive immunization with anti FimH-antibodies and vaccination with the protein significantly reduced colonization by UPEC. Moreover, the Bordetella pertussis adhesins FHA and pertactin are components of 3 of the 4 acellular pertussis vaccines currently licensed for use in the U.S.