Neisserial adhesin A (NadA) (NadA)

Neisserial adhesin A (NadA) is a surface-exposed trimeric autotransporter adhesin (TAA) primarily found in Neisseria meningitidis serogroup B, where it facilitates bacterial adhesion to and invasion of human epithelial cells (UniProt Q9K0U9; Comanducci et al., 2002, J. Exp. Med.). It is a key component of the multicomponent meningococcal serogroup B vaccine, Bexsero (4CMenB), where it serves as a potent antigen to elicit protective immune responses (Serruto et al., 2010, Vaccine). The protein consists of a C-terminal membrane-anchor domain, a coiled-coil stalk, and an N-terminal head domain that interacts with host cell receptors like LOX-1 (Grifantini et al., 2002, PNAS). In the context of vaccination, NadA induces serum bactericidal antibodies (SBA) that trigger complement-mediated killing of the pathogen (Pizza et al., 2000, Science). However, the presence and expression levels of the nadA gene vary across different meningococcal clonal complexes, which can impact the overall coverage of vaccines targeting this specific protein (Mazzola et al., 2015, Expert Rev. Vaccines). This variability makes NadA an important target for molecular epidemiology and vaccine efficacy monitoring. As a vaccine antigen, it is not a drug target in the traditional small-molecule sense but is critical for prophylactic immunotherapy against invasive meningococcal disease.

Other names

NadA proteinAdhesin ANMB1994

As a vaccine antigen, it elicits the production of serum bactericidal antibodies (SBA) that recognize the protein on the bacterial surface, leading to complement-mediated lysis and opsonophagocytosis of Neisseria meningitidis (Pizza et al., 2000, Science; Serruto et al., 2010, Vaccine).