| Back to article Figure 1. Four mechanisms of
bacterial adherence where anti-adhesin vaccines could potentially block colonization and
infection. A shows pili or fibrillae protruding from the bacterial surface. These
proteinaceous appendages bind to host cell surface molecules, usually carbohydrates, by
adhesin proteins located at the distal tip of the pilus/fibrillar organelle. Antibodies
targeting the adhesin protein block the bacterial/host interaction. B demonstrates a
similar process of bacterial/epithelial cell interactions mediated by afimbrial adhesin
proteins. In this case, antibodies directed against the bacterial surface proteins should
also block attachment and colonization by impeding the ability of the bacteria to
associate with mucosal tissues. C illustrates that some bacteria establish intimate
associations with eukaryotic cells by intimin proteins, resulting in cytoskeletal
rearrangements, host cell signaling, possible internalization of the bacteria, and in many
cases systemic disease. Blocking the intimate association/adherence may also be another
strategy to prevent bacterial infections. D shows a novel mechanism whereby bacteria
secrete their own receptor protein, which is internalized by the target host cell,
phosphorylated, and embedded in the eukaryotic cell as a new receptor for tight binding by
the bacterium. Theoretically, blocking the secreted receptor (Hp90) before it is
internalized by the host cell could provide another mechanism to block bacterial adherence
and infection. |
