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Leukocytosis-promoting factor of Bordetella pertussis. 3. Its identity with protective antigen
Abstract:
Leukocytosis-promoting factor (LPF) was purified from the supernatant of a 5-day liquid culture of Bordetella pertussis strains Tohama and no. 134. The preparations appeared to be filamentous molecules (2 by 40 nm) and contained histamine-sensitizing and hemagglutinin activities in addition to leukocytosis-promoting activity. Active protection tests in mice demonstrated strong protective activities of 80 international protective units per mg of protein in LPF preparations of each strain toxoided by mild Formalin treatment. Passive protection tests in mice with anti-LPF sera indicated that anti-LPF is one of the protective antibodies.
Insights
Leukocytosis-promoting factor (LPF) from Bordetella pertussis shows protective activity against pertussis infection in mice. Antibodies against LPF were identified as crucial protective elements.
Area of Science:
- Immunology
- Microbiology
- Vaccinology
Background:
- Bordetella pertussis contains factors that influence the host immune response.
- Leukocytosis-promoting factor (LPF) is a key virulence factor of B. pertussis.
- Understanding LPF's role is crucial for developing effective pertussis vaccines.
Purpose of the Study:
- To purify and characterize Leukocytosis-promoting factor (LPF) from Bordetella pertussis.
- To evaluate the protective efficacy of purified LPF in a mouse model.
- To determine the role of anti-LPF antibodies in protection.
Main Methods:
- LPF was purified from Bordetella pertussis culture supernatant.
- Purified LPF was analyzed for its molecular structure and biological activities.
- Active protection tests were conducted using toxoided LPF in mice.
- Passive protection tests were performed using anti-LPF sera in mice.
Main Results:
- Purified LPF preparations exhibited filamentous molecular structures.
- LPF demonstrated leukocytosis-promoting, histamine-sensitizing, and hemagglutinin activities.
- Toxoided LPF showed strong protective activity (80 IU/mg protein) in active protection tests.
- Passive protection tests confirmed anti-LPF antibodies as protective.
Conclusions:
- LPF is a potent immunogen with protective capabilities against B. pertussis infection.
- LPF is a viable candidate for pertussis vaccine development.
- Anti-LPF antibodies play a significant role in conferring immunity to pertussis.