Surface-adhesin protein E (PE)

Nontypeable Haemophilus influenzae Protein E (PE) is a highly conserved 16-kDa surface-exposed lipoprotein that functions as a multifunctional adhesin, critical for the colonization and persistence of the bacterium in the human respiratory tract [1, 11]. It facilitates bacterial adherence to host epithelial cells and extracellular matrix components, specifically laminin and vitronectin [13]. Beyond its role in adhesion, PE is a key factor in immune evasion, as it binds host complement regulators like C4b-binding protein (C4BP) and vitronectin to inhibit complement-mediated killing [3, 13]. It also interacts with host plasminogen, which may further promote bacterial pathogenesis and subvert innate immune responses [13]. Given its near-universal presence in clinical isolates and its essential role in virulence, PE is a primary target for the development of vaccines intended to prevent acute otitis media in children and exacerbations of chronic obstructive pulmonary disease (COPD) in adults [5, 8]. Current clinical efforts utilize PE or PE-fusion proteins (such as PE-PilA) combined with potent adjuvants to elicit protective, bactericidal, and adhesion-blocking antibodies [1, 2].

Other names

Protein EPEhpeompE16-kDa surface lipoproteinSurface-adhesin protein E

Induction of bactericidal antibodies, inhibition of bacterial adhesion to host cells, and blockade of bacterial complement evasion mechanisms