Neisseria lactamica and Neisseria meningitidis share lipooligosaccharide epitopes but lack common capsular and class 1, 2, and 3 protein epitopes

Abstract

Neisseria lactamica, a common human pharyngeal commensal, contributes to acquired immunity to Neisseria meningitidis. To define the surface antigens shared between these two species, we used monoclonal antibodies (MAbs) to study 35 N. lactamica strains isolated in various parts of the world for cross-reactivity with meningococcal capsules, outer membrane proteins, and lipooligosaccharides (LOS). No N. lactamica strain reacted significantly with MAbs specific for capsular group A, B, C, Y, or W, and we were unable to extract capsular polysaccharide from them. Only 2 of 33 strains reacted weakly with MAbs against class 2 serotype proteins P2b and P2c. None reacted with MAbs specific for meningococcal class 1 protein P1.2 or P1.16 or class 2/3 serotype protein P2a or P15. Most N. lactamica strains (30 of 35) bound one or more of seven LOS-specific MAbs. Two LOS epitopes, defined by MAbs 06B4 and 3F11, that are commonly found on pathogenic Neisseria species were found on 25 of 35 N. lactamica. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting showed that the LOS of N. lactamica are composed of multiple components that are physically and antigenically similar to the LOS of pathogenic Neisseria species. Among four other commensal neisserial species, only Neisseria cinerea shared LOS epitopes defined by MAbs 06B4 and 3F11. Previous studies have shown that pharyngeal colonization with N. lactamica induces bactericidal antibodies against the meningococcus. We postulate that shared N. lactamica and meningococcal LOS epitopes may play an important role in the development of natural immunity to the meningococcus.

Serum antibodies to cross‐reactive Neisseria outer membrane antigens in healthy persons and patients with meningococcal disease

“…Nm disease was verified by positive blood culture, and was caused by B: 15:Pl. 16 Nm strains in 10 patients. and in 6 patients by serogroup B strains which were not analysed for serotype and subtype.…”

“…Reed Army Institute of Research, Washington D.C. Antibodies with specificities against the serotype 15 porin (3-1 -P 1 5), the class 1 protein (3-I -P I . 16), a common class 1 protein epitope (9-1-P1C), the H.8 antigen (2-1 -CA2), a common fimbrie epitope (2-2-Fc), and LPS immunotype 3,7,9 (9-1-L379) were used to characterize the Nm, Ng, and N 1 OM antigens on immunoblots.…”

“…Thus, bacteria of these species synthesize the H.8 lipoprotein antigen ( 1, 8, 15). Also, N 1 LPS may show cross-reactivity with Nm LPS (16). Commensal Neisseria spp.…”

Meningococcal lipopolysaccharides: virulence factor and potential vaccine component.

“…Also, (sub)sero-Immunotypes L8, L9, L10, and Lll are found within group types may change over a period of years (50,125). The A meningococci; of these, L1Oand Lll are prevalent and are number of studies concerning the distribution of the menin-uniquely associated with this serogroup (77,115,150).…”

Further antigenic similarities of Neisseria gonorrhoeae lipooligosaccharides and human glycosphingolipids

“…The lipooligosaccharides (LOS) of pathogenic and nonpathogenic Neisseria species are composed of multiple components that are different antigenically and chemically (5). A number of monoclonal antibodies (MAbs) that bind to epitopes in the LOS of Neisseria gonorrhoeae (17), Neisseria meningitidis (14,17), Neisseria lactamica (13), and Haemophilus influenzae (21,27) have been identified, and these epitopes are similar antigenically to epitopes on mammalian glycosphingolipids (GSL). One group of MAbs binds to lactoneo-series (Galt31-34GlcNAcI1--+3Gal-R) GSL (18).…”