Haemophilus influenzae adhesin (null)

Haemophilus influenzae adhesins are a family of bacterial outer membrane proteins that mediate specific adherence of H. influenzae to human epithelial cells, a key step in colonization and pathogenesis. Major adhesins include Protein E (PE), Hia, Hsf, and Hap. - **Protein E (PE):** Multifunctional; binds plasminogen, laminin, and vitronectin through defined surface-exposed regions; dimeric structure resembling a flattened β-barrel with immunogenic surface loops[1][5]. - **Hia:** Trimeric autotransporter present in nontypeable strains; contains two main binding domains (HiaBD1, HiaBD2) that interact with the same, as-yet-unidentified host receptor; mediates strong epithelial adhesion[2][6][7]. - **Hsf:** Large trimeric autotransporter in encapsulated (type b) strains; extended architecture allowing protrusion beyond the capsule; possesses multiple binding domains (HsfBD1, HsfBD2) homologous to those of Hia and required for binding to host cells[2][6]. - **Hap:** Self-associating and serine protease autotransporter; also implicated in adhesion and aggregation[3][6]. Collectively, these adhesins are considered key virulence factors and attractive vaccine or therapeutic targets for inhibiting H. influenzae colonization and infection[2][6]. However, the term "Haemophilus influenzae adhesins" describes a class rather than a single canonical molecule, and more specific nomenclature (e.g., "Haemophilus influenzae protein E") should be used in structured datasets[1][2][6].

Other names

H. influenzae adhesinsProtein E (PE)HiaHsfHap

For potential therapeutics, the main mechanism is inhibition of bacterial adhesion by blocking specific binding domains or eliciting an immune response (e.g., neutralizing antibodies targeting adhesive epitopes)[1][2].