Structural and antigenic analysis of meningococcal piliation

Abstract

Pilin with an M, of 16,500 was purified to homogeneity from Neisseria meningitidis SP3428. Procedures which provided useful separation during purification included high-pressure liquid chromatography with a TSK size exclusion column, Sephacryl S-200 column chromatography, ion-exchange chromatography with SP-Sephadex, and preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The amino acid composition of this pilin was similar to that previously reported for this species. The sequence of the N-terminal 51 amino acids was also determined. The protein lacked a modified phenylalanine at the amino terminus and displayed six residues which were different from Neisseria gonorrhoeae in that region of the molecule determined to be the lectin-binding domain. Monoclonal antibody raised to this pilin was employed, along with a monoclonal antibody to an epitope common to all gonococcal pilins, to analyze the intraand interstrain heterogeneity of meningococcal piliation. The results indicate that N. meningitidis displays considerable intraand interstrain heterogeneity with respect to both pilus subunit size and antigenicity. The Mr of subunits ranged from 13,000 to 20,000.

Structural and serological relatedness of Haemophilus influenzae type b pili

“…Our results support these observations; in 22 of the 25 adherent Hib a major OMP with an apparent molecular weight of 24,000 was found, whereas in the remaining three isolates (cultured from a patient and from two contacts of this patient) a protein of 24,500 molecular weight was present. These results are in striking contrast to observations made in other gram-negative bacteria, in which there is considerable intraand interstrain variation in pilin subunit size (8,15,28,38). Guerina et al (14) found varied degrees of cross-reactivity between pili purified from Hib strain AO-2 (M43) and the pili purified from three heterologous Hib isolates in an enzymelinked immunoassay.…”

High adhesiveness of encapsulated Neisseria meningitidis to epithelial cells is associated with the formation of bundles of pili

“…As in N. gonorrhoeae, the MC pilin is subject to antigenic variation (Olafson et aL, 1985). Comparison of three class I pilins revealed that they consist of a constant amino-terminal region, a central region which varies mostly by single amino acid changes, followed by a highly variable carboxy-terminal region that differs Fig.…”

Distribution of specific DNA sequences among pathogenic and commensal Neisseria species

“…In addition, gonococcal pili undergo phase and antigenic variation, which may play a role in evasion of the host immune response (22). Less is known about meningococcal pili; however, they share morphologic characteristics, antigenicity, and some amino acid sequence homology with gonococcal pili (12,29,32). Pili have also been observed on commensal Neisseria species (24,37), but the function of these pili and their relationship to pili found on pathogenic species are unclear.…”