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Opsonophagocytic Killing Assay to Assess Immunological Responses Against Bacterial Pathogens
08:47

Opsonophagocytic Killing Assay to Assess Immunological Responses Against Bacterial Pathogens

Published on: April 5, 2019

Serum opsonins to group B meningococci

H Sjursen1, R Bjerknes, A Halstensen

  • 1Medical Department, University of Bergen, Haukeland Hospital, Norway.

Acta Pathologica, Microbiologica, Et Immunologica Scandinavica. Section C, Immunology
|December 1, 1987
PubMed

Insights

Serum antibody levels and opsonic activity against serogroup B meningococci significantly increased in patients recovering from disease and in volunteers receiving a novel vaccine. These immune responses remained elevated six weeks post-illness or immunization, indicating vaccine efficacy.

Area of Science:

  • Immunology
  • Microbiology
  • Vaccinology

Background:

  • Neisseria meningitidis serogroup B causes significant morbidity and mortality.
  • Developing effective vaccines against serogroup B meningococcal disease remains a public health priority.
  • Understanding the immune response to serogroup B meningococcal infections and vaccines is crucial for disease prevention.

Purpose of the Study:

  • To investigate the production of serum opsonins and antibodies against serogroup B serotype 15 meningococci.
  • To compare immune responses in patients recovering from meningococcal disease with those in healthy volunteers immunized with a novel vaccine.

Main Methods:

  • Serum opsonic activity was assessed using a flow cytometric phagocytosis assay with fluorescein isothiocyanate-labeled Neisseria meningitidis.
  • Serum antibodies to outer membrane complexes were measured via enzyme-linked immunosorbent assay (ELISA).
  • Study involved 7 patients with serogroup B meningococcal disease and 7 immunized volunteers.

Main Results:

  • Significant increases in serum opsonic activity were observed in patients during convalescence and in immunized volunteers compared to pre-immunization.
  • Both patients and vaccinees showed marked increases in IgG, IgM, and IgA antibodies against the test strain.
  • A strong positive correlation (r = 0.883) was found between serum opsonic activity and IgG antibody levels.

Conclusions:

  • Convalescent sera from patients and sera from vaccinees demonstrated enhanced opsonic activity against serogroup B meningococci.
  • The vaccine effectively elicited robust and sustained antibody responses, including IgG, IgM, and IgA.
  • Elevated serum opsonic activity and IgG levels suggest a protective immune response following vaccination or natural infection.

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