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A reference procedure to study chemiluminescence induced in polymorphonuclear leukocytes by Neisseria meningitidis
H Fredlund1, P Olcén, D Danielsson
1Department of Clinical Microbiology and Immunology, Orebro Medical Center Hospital, Sweden.
Abstract:
Luminol-enhanced chemiluminescence (CL) was used to study the ability of various strains of Neisseria meningitidis (MC) to induce oxidative metabolism of polymorphonuclear leukocytes (PMNL); an indirect measure of phagocytic activity. To circumvent variations related to different PMNL donors, a MC serogroup X strain was used as a control for indexing the CL responses induced by other MC strains. This procedure, with pooled serum from healthy blood donors to standardize opsonising conditions, gave reproducible and comparable results, irrespective of PMNL donors. Under these conditions, there was a highly significant difference between pathogenic and non-pathogenic MC strains as regards their ability to induce CL responses (p less than 0.001). The results indicated that the differences were due partly to opsonizing antibodies, partly to other differences related to pathogenicity of tested MC strains. These differences in leukocyte/MC interaction were also confirmed by phagocytic-killing experiments. The index procedure of CL measurements may be a suitable method to study the appearance of natural immunity to MC disease, as well as the pathogenicity of particular MC strains.
Insights
Luminol-enhanced chemiluminescence effectively distinguishes pathogenic Neisseria meningitidis strains by measuring their impact on polymorphonuclear leukocytes. This method aids in understanding immunity and bacterial pathogenicity.
Area of Science:
- Immunology
- Microbiology
- Cellular Biology
Background:
- Neisseria meningitidis (MC) poses a significant public health threat.
- Assessing MC pathogenicity and host immune response is crucial for disease control.
- Polymorphonuclear leukocytes (PMNL) are key immune cells involved in combating bacterial infections.
Purpose of the Study:
- To evaluate the utility of luminol-enhanced chemiluminescence (CL) as a method to assess the interaction between Neisseria meningitidis strains and human polymorphonuclear leukocytes.
- To differentiate between pathogenic and non-pathogenic strains of Neisseria meningitidis based on their ability to stimulate PMNL oxidative metabolism.
- To explore the potential of this CL-based assay for studying natural immunity and MC strain pathogenicity.
Main Methods:
- Luminol-enhanced chemiluminescence (CL) was employed to measure oxidative metabolism in PMNL.
- Various Neisseria meningitidis (MC) strains were tested for their ability to induce CL responses.
- A standardized protocol using a control MC serogroup X strain and pooled human serum was implemented to ensure reproducible results.
- Phagocytic-killing experiments were conducted to corroborate CL findings.
Main Results:
- A highly significant difference (p < 0.001) was observed in CL responses induced by pathogenic versus non-pathogenic MC strains.
- The observed differences were attributed to both opsonizing antibodies and other pathogenicity-related factors of the MC strains.
- Phagocytic-killing assays confirmed the distinct leukocyte interactions observed through CL measurements.
- The indexing procedure using CL provided reproducible and comparable results across different PMNL donors.
Conclusions:
- Luminol-enhanced chemiluminescence is a viable and reproducible method for assessing PMNL oxidative metabolism induced by Neisseria meningitidis.
- This technique can effectively differentiate between pathogenic and non-pathogenic MC strains, offering insights into bacterial virulence factors.
- The CL assay shows promise for monitoring the development of natural immunity against MC and for evaluating the pathogenicity of specific MC strains.