Factor H binding protein of Neisseria meningitidis (fHbp)

Factor H binding protein of Neisseria meningitidis (fHbp) is a surface-exposed lipoprotein and a major virulence factor that enables the bacterium to evade host immune responses by binding human complement factor H, thereby inhibiting complement activation on the bacterial surface[1][2][3][4][5]. fHbp is highly polymorphic with over 1000 known alleles and is present in almost all disease-causing N. meningitidis isolates[2][3][5]. It is the key antigen in two licensed vaccines (Bexsero and Trumenba) for the prevention of serogroup B meningococcal disease, where it induces protective, bactericidal antibodies[2][5]. The protein's expression varies between strains and impacts both the pathogen's virulence and the likelihood of vaccine-induced immunity protecting against different meningococcal strains[2][5]. The presence, sequence variant, and expression level of fHbp are important for predicting disease risk and vaccine efficacy[2][5].

Other names

Factor H-binding proteinfHbpNMB1870 (based on gene annotation)Neisserial adhesin A (only sometimes, but this more commonly refers to NspA which is distinct)

Vaccines using fHbp as antigen induce production of antibodies that bind to fHbp, blocking its interaction with human factor H, enabling complement-mediated lysis of Neisseria meningitidis Direct bactericidal activity by anti-fHbp monoclonal antibodies, interfering with complement evasion Prevention of meningococcal infection by immune recognition of surface-expressed fHbp