In vivo expression of Neisseria meningitidis proteins homologous to the Haemophilus influenzae Hap and Hia autotransporters

Abstract

The genome sequences of Neisseria meningitidis serogroup B strain MC58 and serogroup A strain Z2491 were systematically searched for open reading frames (ORFs) encoding autotransporters. Eight ORFs were identified, six of which were present in both genomes, whereas two were specific for MC58. Among the identified ORFs was the gene encoding the known autotransporter IgA1 protease. The deduced amino acid sequences of the other identified ORFs were homologous to known autotransporters and found to contain an N-terminal signal sequence and a C-terminal domain that could constitute a beta-barrel in the outer membrane. The ORFs NMB1985 and NMB0992, encoding homologs of the Hap (for Haemophilus adhesion and penetration protein) and Hia (for Haemophilus influenzae adherence protein) autotransporters of H. influenzae, were cloned from serogroup B strain H44/76 and expressed in Escherichia coli. Western blots revealed that all sera of patients (n=14) and healthy carriers (n=3) tested contained antibodies against at least one of the recombinant proteins. These results indicate that both genes are widely distributed among N. meningitidis isolates and expressed during colonization and infection.

Prevalence and Distribution of Adhesins in Invasive Non-Type b Encapsulated Haemophilus influenzae

“…As previously described for NTHi strains, hmw and hia are mutually exclusive in non-type b encapsulated strains, with hia being most common. Homologs of Hap and Hia have been recently described in Neisseria meningitidis, underscoring the potential importance of these proteins in colonization and disease (41). A homolog of hmw1/2, previously reported to be present only in NTHi, was found in 13.2% of the invasive non-type b encapsulated H. influenzae strains analyzed in this study.…”

Role of the Periplasmic Chaperones Skp, SurA, and DegQ in Outer Membrane Protein Biogenesis in Neisseria meningitidis

“…NhhA is a trimeric autotransporter (44) whose membrane- embedded translocator domain is formed by three monomers, each donating four ␤-strands to the 12-stranded ␤-barrel, resulting in a heat-and SDS-resistant molecule migrating at a much higher apparent molecular weight than expected from the predicted size of a monomer with a molecular weight of 60,000 (9,44). We anticipated that chaperones might be required for the biogenesis of such a complex molecule.…”

Two-Partner Secretion Systems of Neisseria meningitidis Associated with Invasive Clonal Complexes

“…The polyclonal rabbit antisera were raised at Eurogentec (Liège, Belgium). The human sera used for this study were from the collection of the NRLBM and were described previously (22).…”