Protein E (Haemophilus influenzae) (PE)

Protein E (PE) is a highly conserved, 16-kDa surface-exposed lipoprotein found in non-typeable Haemophilus influenzae (NTHi) (Ronander et al., 2009). It serves as a multifunctional adhesin that mediates bacterial attachment to host respiratory epithelial cells and extracellular matrix components (Singh et al., 2011). Beyond its role in adhesion, PE is critical for immune evasion; it binds to human vitronectin, a host complement regulator, which inhibits the formation of the complement membrane attack complex and protects the bacteria from serum-mediated killing (Hallström et al., 2009). Because PE is ubiquitous and highly conserved among clinical NTHi isolates, it is a primary target for vaccine development aimed at preventing infections such as acute otitis media in children and respiratory exacerbations in patients with chronic obstructive pulmonary disease (COPD) (Wilkinson et al., 2017). Experimental vaccines, such as the NTHi-MCAT candidate (GSK2831781A), incorporate PE to induce protective, bactericidal antibodies that interfere with bacterial colonization and survival (Van Natta et al., 2021).

Other names

PEhpe16-kDa lipoproteinHaemophilus influenzae Protein EProtein E (NTHi)

Induction of neutralizing and opsonophagocytic antibodies that block bacterial adhesion to host cells and inhibit vitronectin-mediated complement evasion, leading to enhanced bacterial clearance.