Non-typeable Haemophilus influenzae Protein E-PilA fusion protein (PE-PilA)

The Non-typeable Haemophilus influenzae (NTHi) PE-PilA fusion protein is a recombinant vaccine antigen designed to protect against infections caused by NTHi, a major pathogen in otitis media and chronic obstructive pulmonary disease (COPD) exacerbations. It consists of two highly conserved surface components: Protein E (PE), an adhesin that binds to epithelial cells and vitronectin to evade the complement system, and PilA, the major subunit of the Type IV pilus responsible for twitching motility and biofilm formation. By fusing these two proteins, the vaccine candidate aims to elicit a synergistic immune response that prevents bacterial colonization and stabilizes the respiratory microbiota. In clinical development, particularly by GlaxoSmithKline, this fusion protein is often combined with antigens from Moraxella catarrhalis to provide broader protection against respiratory tract infections. The primary therapeutic goal is the induction of high-titer neutralizing antibodies that facilitate opsonophagocytosis and block the initial stages of bacterial infection.

Other names

NTHi PE-PilAProtein E-PilA recombinant fusion proteinHaemophilus influenzae Protein E and Pilin A fusion

The fusion protein acts as an antigen to induce the production of specific serum IgG antibodies and mucosal antibodies that neutralize bacterial adhesion, inhibit biofilm formation, and promote opsonophagocytic killing of Non-typeable Haemophilus influenzae.