Protection against group B meningococcal disease. II. Infection and resulting immunity in a guinea pig model
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Abstract:
A guinea pig subcutaneous chamber model was used to evaluate the specificity of the immune response resulting from Neisseria meningitidis infection. Small numbers of meningococci easily infected the chambers. The infections persisted for 6-8 days with relatively high levels of organisms (10(5)-10(6)/milliliter) in the chambers, and were then rapidly eliminated and no organisms could be cultured beyond day 14. Clearance of infection correlated with appearance of circulating antibody. Antibody against both the protein serotype antigen and the capsular polysaccharide were induced as a result of meningococcal infection. The group-specific polysaccharide response peaked 2-3 wk after the animals were inoculated, while the type-specific protein response peaked at 5-6 wk. The animals were quite resistant to reinfection with either the homologous serogroup or serotype.
Insights
Guinea pigs infected with Neisseria meningitidis developed specific antibodies, clearing the infection and gaining resistance to reinfection. This study highlights the immune system's targeted response to meningococcal antigens.
Area of Science:
- Immunology
- Microbiology
- Infectious Diseases
Background:
- Neisseria meningitidis is a significant cause of bacterial meningitis.
- Understanding the host immune response is crucial for developing effective vaccines and treatments.
- The guinea pig subcutaneous chamber model offers a controlled environment to study host-pathogen interactions.
Purpose of the Study:
- To evaluate the specificity of the immune response to Neisseria meningitidis infection.
- To investigate the kinetics of antibody production against different meningococcal antigens.
- To assess the development of resistance to reinfection following an initial Neisseria meningitidis challenge.
Main Methods:
- Utilized a guinea pig subcutaneous chamber model to establish Neisseria meningitidis infections.
- Monitored organism levels within the chambers over time (up to 14 days).
- Measured circulating antibody levels against capsular polysaccharide and protein serotype antigens.
- Assessed resistance to reinfection with homologous serogroup and serotype strains.
Main Results:
- Neisseria meningitidis readily infected the chambers, persisting for 6-8 days at high concentrations (10^5-10^6 organisms/mL).
- Infection clearance correlated with the appearance of circulating antibodies.
- Antibodies against both capsular polysaccharide and protein serotype antigens were induced.
- Group-specific polysaccharide antibody response peaked at 2-3 weeks, while type-specific protein antibody response peaked at 5-6 weeks.
- Animals demonstrated significant resistance to reinfection.
Conclusions:
- The guinea pig subcutaneous chamber model effectively simulates Neisseria meningitidis infection and allows for the study of immune responses.
- Meningococcal infection elicits a specific antibody response targeting both capsular polysaccharide and protein antigens.
- The development of circulating antibodies is critical for clearing Neisseria meningitidis infection.
- Acquired immunity confers resistance to homologous reinfection, suggesting potential for vaccine development.