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Cross-reacting serum opsonins in patients with meningococcal disease
H K Guttormsen1, R Bjerknes, A Naess
1Medical Department B, University of Bergen, Haukeland Hospital, Norway.
Abstract:
We have examined the opsonic activity of sera from patients with Neisseria meningitidis (B:15:P1.16) infections against different meningococcal strains, using flow cytometry and luminol-enhanced chemiluminescence. A marked increase in the phagocytosis of ethanol-fixed meningococcal strains of different serogroups, serotypes, and serosubtypes was demonstrated in the presence of convalescence sera compared with acute sera. Convalescence sera also caused a significant increase of leukocyte oxidative metabolism during phagocytosis, as measured by luminol-enhanced chemiluminescence. The sera contained a broad range of opsonins cross-reacting with serogroup A, B, C, W-135, and Y meningococci of different serotypes and serosubtypes, indicating that the cross-reacting opsonins recognized surface epitopes other than those determined by current serotyping schemes.
Insights
Convalescent sera from Neisseria meningitidis infections enhance bacterial phagocytosis and leukocyte response. These sera contain cross-reacting opsonins recognizing diverse meningococcal surface epitopes beyond current typing methods.
Area of Science:
- Immunology
- Microbiology
- Infectious Diseases
Background:
- Neisseria meningitidis causes severe infections.
- Understanding immune responses to N. meningitidis is crucial for vaccine development.
Purpose of the Study:
- To investigate the opsonic activity of sera from patients with N. meningitidis infections.
- To identify the range of meningococcal strains recognized by these sera.
Main Methods:
- Flow cytometry was used to measure phagocytosis.
- Luminol-enhanced chemiluminescence assessed leukocyte oxidative metabolism.
- Sera from patients with N. meningitidis (B:15:P1.16) infections were tested against various meningococcal strains.
Main Results:
- Convalescent sera significantly increased phagocytosis of diverse meningococcal strains compared to acute sera.
- Leukocyte oxidative metabolism was significantly enhanced by convalescent sera during phagocytosis.
- Opsonins in convalescent sera showed broad cross-reactivity against serogroups A, B, C, W-135, and Y.
Conclusions:
- Immune sera from N. meningitidis infections possess broad opsonic activity.
- Cross-reacting opsonins recognize conserved surface epitopes not defined by current serotyping.
- Findings suggest potential for broader vaccine targets against meningococcal disease.