Mapping the Laminin Receptor Binding Domains of Neisseria meningitidis PorA and Haemophilus influenzae OmpP2

Abstract

Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae are major bacterial agents of meningitis. They each bind the 37/67-kDa laminin receptor (LamR) via the surface protein adhesins: meningococcal PilQ and PorA, H. influenzae OmpP2 and pneumococcal CbpA. We have previously reported that a surface-exposed loop of the R2 domain of CbpA mediates LamR-binding. Here we have identified the LamR-binding regions of PorA and OmpP2. Using truncated recombinant proteins we show that binding is dependent on amino acids 171–240 and 91–99 of PorA and OmpP2, respectively, which are predicted to localize to the fourth and second surface-exposed loops, respectively, of these proteins. Synthetic peptides corresponding to the loops bound LamR and could block LamR-binding to bacterial ligands in a dose dependant manner. Meningococci expressing PorA lacking the apex of loop 4 and H. influenzae expressing OmpP2 lacking the apex of loop 2 showed significantly reduced LamR binding. Since both loops are hyper-variable, our data may suggest a molecular basis for the range of LamR-binding capabilities previously reported among different meningococcal and H. influenzae strains.

Deciphering the complex three-way interaction between the non-integrin laminin receptor, galectin-3 andNeisseria meningitidis

“…Bacterial strains were grown in liquid culture, washed and labelled with digoxigenin (Roche) as described previously [51]. Labelled bacteria were added to ELISA plates for 2–4 h at room temperature.…”

Pathogens Penetrating the Central Nervous System: Infection Pathways and the Cellular and Molecular Mechanisms of Invasion

“…There has been significant research into the host-pathogen interactions that occur prior to bacterial invasion of brain microvascular endothelial cells (Table 1), including the identification of host receptors that mediate these interactions. E. coli, H. influenzae, N. meningitidis, and S. pneumoniae bind to HBMECs via the 37/67-kDa laminin receptor (149)(150)(151)(152). The 37-kDa laminin receptor is a precursor for the mature, 67-kDa laminin receptor, which binds laminin-1 within the basement membrane on the abluminal surface of eukaryotic cells (153).…”

Looking into laminin receptor: critical discussion regarding the non‐integrin 37/67‐kDalaminin receptor/RPSAprotein

“…(2) Bacterial, viral and parasite infection Several meningitis-causing bacteria have been implicated in using LAMR as a target of bacterial surface adhesins. Among them, Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae and E. coli have been investigated to determine the nature of the tropism (Chung et al, 2003;Kim et al, 2005b;Orihuela et al, 2009;Abouseada et al, 2012). The best-studied system is E. coli interaction via cytotoxic necrotizing factor 1 (CNF1) binding to LAMR (Chung et al, 2003;Kim et al, 2005b).…”