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Protection against intranasal infection of mice with Bordetella pertussis
Abstract:
Mice have been infected by intranasal instillation of Bordetella pertussis and the infection monitored by determining numbers of bacteria isolated from the lungs. Outer membrane proteins, filamentous hemagglutinin, toxoided-lymphocytosis promoting factor and agglutinogens (fimbriae) actively protect mice against intranasal infection and antibodies of the antigens neutralize infectivity. The neutralization of infection by agglutinins is serospecific. In general, antigens that actively protect mice against intracerebral infections also protect against intranasal infections but some antigens, such as filamentous hemagglutinin and agglutinogens, protect only against intranasal infections. The intranasal protective potency of antigens can be enhanced by including low levels of active lymphocytosis promoting factor in the preparations. The relevance of the intranasal test to the potency testing of pertussis vaccines is discussed.
Insights
This study shows that specific Bordetella pertussis antigens, like outer membrane proteins and filamentous hemagglutinin, protect mice from intranasal infection. Antibody responses to these antigens are key for neutralizing pertussis infectivity.
Area of Science:
- Microbiology
- Immunology
- Vaccinology
Background:
- Bordetella pertussis causes whooping cough, a significant public health concern.
- Understanding protective antigens is crucial for developing effective pertussis vaccines.
Purpose of the Study:
- To evaluate the protective efficacy of various Bordetella pertussis antigens against intranasal infection in mice.
- To assess the role of antibodies in neutralizing pertussis infectivity.
- To determine the relevance of intranasal infection models for pertussis vaccine potency testing.
Main Methods:
- Mice were infected intranasally with Bordetella pertussis.
- Bacterial load in lungs was quantified to assess infection.
- Active protection by outer membrane proteins, filamentous hemagglutinin, toxoided-lymphocytosis promoting factor, and agglutinogens was evaluated.
- Antibody-mediated neutralization of infectivity was measured.
Main Results:
- Outer membrane proteins, filamentous hemagglutinin, toxoided-lymphocytosis promoting factor, and agglutinogens demonstrated active protection against intranasal infection.
- Antibodies against these antigens neutralized pertussis infectivity in a serospecific manner.
- Some antigens, like filamentous hemagglutinin and agglutinogens, provided protection specific to intranasal challenge.
- Inclusion of lymphocytosis promoting factor enhanced the intranasal protective potency of antigens.
Conclusions:
- Intranasal infection models are relevant for evaluating pertussis vaccine components.
- Specific antigens and their corresponding antibodies play a critical role in conferring protection against Bordetella pertussis.
- The findings support the development of improved pertussis vaccines targeting key protective antigens.