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Leukocytosis-promoting factor of Bordetella pertussis. II. Biological properties
Abstract:
The leukocytosis-promoting factor (LPF), purified from materials extracted from agar in which Bordetella pertussis was grown, caused leukocytosis and an increased sensitivity to histamine when as little as 0.04 mug of protein was given intravenously to mice. LPF was adsorbed onto erythrocytes, causing hemagglutination. As little as 0.03 mug of LPF protein agglutinated chicken erythrocytes in 0.05 ml of a 0.5% suspension. The physicochemical, biological, and immunological properties indicated that leukocytosis, increased sensitivity to histamine in mice, and agglutination of erythrocytes are functions of a single substance.
Insights
The leukocytosis-promoting factor (LPF) from Bordetella pertussis induces leukocytosis and histamine sensitivity in mice. This single substance also causes hemagglutination, demonstrating its multifaceted biological activity.
Area of Science:
- Microbiology
- Immunology
- Biochemistry
Background:
- Bordetella pertussis is known to produce various toxins and factors that influence the host immune response.
- Leukocytosis and altered histamine sensitivity are observed in pertussis infections, but the responsible factors were not fully characterized.
Purpose of the Study:
- To purify and characterize the factor responsible for leukocytosis and histamine sensitivity induced by Bordetella pertussis.
- To investigate the potential role of this factor in hemagglutination.
Main Methods:
- Purification of leukocytosis-promoting factor (LPF) from Bordetella pertussis culture extracts.
- Intravenous administration of purified LPF to mice to assess biological effects.
- In vitro hemagglutination assays using chicken erythrocytes and purified LPF.
Main Results:
- A single substance, LPF, was purified and found to induce leukocytosis and increased histamine sensitivity in mice at very low doses (0.04 mug).
- LPF demonstrated hemagglutination properties, agglutinating chicken erythrocytes at concentrations as low as 0.03 mug.
- Physicochemical, biological, and immunological analyses confirmed these diverse effects stem from a single molecule.
Conclusions:
- The leukocytosis-promoting factor (LPF) is a key virulence factor of Bordetella pertussis.
- LPF possesses multiple biological activities, including the induction of leukocytosis, enhanced histamine sensitivity, and hemagglutination.
- Understanding LPF's functions provides insights into pertussis pathogenesis and potential therapeutic targets.