Related Experiment Videos
Immunomodulation by Bordetella pertussis: antiviral effects
Abstract:
Treatment of mice by intraperitoneal inoculation of pertussis vaccine or lipopolysaccharide extracted from B. pertussis will effect resistance to rabies virus, encephalomyocarditis virus, Semliki Forest virus, and Herpes simplex virus. Our previous observations indicated that treatment of C3H/HeN (+/nu) and BDF1 mice with pertussis vaccine injected i.p. five days prior to a mouse adenovirus lethal dose i.p. challenge elicited resistance to clinical disease and death. Susceptibility returned to a portion of the test population 35 days after pertussis vaccine treatment. The pertussis vaccine induced resistance developed in athymic (nude) mice also; however, the population succumbed to infection 35 days later. Titration of pertussis vaccine with respect to induction of resistance indicated the median effective dose (ED50) was approximately 25 micrograms dry weight. This report describes the antiviral activity of acellular components extracted from pertussis vaccine. Extraction of B. pertussis cells with 1.0M NaCl and ammonium sulfate fractionation (20-40% saturation) of the extract resulted in an acellular preparation that induced resistance to lethal dose mouse adenovirus infection. The resistance inducing activity was retained after treatment of the extract with detergent (GAF Emulphogene BC 720) to remove lipopolysaccharide and adsorption to alum gel. Comparison of endotoxin content of pertussis vaccine acellular fractions, polysaccharide fraction and purified lipopolysaccharide suggested that endotoxin probably plays a role in the induction of resistance. The endotoxin content of a Emulphogene-treated preparation that protected 80% of a test population was 39 ng. The lipopolysaccharide extracted from Escherichia coli, Vibrio cholerae, Salmonella typhimurium, and Salmonella minnesota did not induce a resistant state seven days after administration; however, lipopolysaccharide extracted from B. pertussis induced a resistant state.(ABSTRACT TRUNCATED AT 250 WORDS)
Insights
Pertussis vaccine components, particularly endotoxin, induce resistance against viral infections like adenovirus in mice. This antiviral effect, observed even in athymic mice, suggests a role for endotoxin in innate immunity.
Area of Science:
- Immunology
- Virology
- Microbiology
Background:
- Pertussis vaccine and its components can confer resistance against various viral infections.
- Previous studies showed pertussis vaccine protects mice against adenovirus, with resistance waning after 35 days.
- This protection was observed in both normal and athymic (nude) mice.
Purpose of the Study:
- To investigate the antiviral activity of acellular components from pertussis vaccine.
- To determine if endotoxin plays a role in the resistance induced by pertussis vaccine.
- To compare the resistance-inducing properties of lipopolysaccharides from different bacterial species.
Main Methods:
- Mice were treated with pertussis vaccine or its acellular components.
- Resistance was assessed against lethal doses of mouse adenovirus.
- Acellular fractions were prepared using salt extraction and ammonium sulfate precipitation.
- Lipopolysaccharide (LPS) was removed using detergent treatment.
- Endotoxin content was quantified.
Main Results:
- Acellular pertussis vaccine components induced resistance to mouse adenovirus infection.
- Resistance was maintained after detergent treatment to remove LPS, but endotoxin was still present.
- The median effective dose (ED50) for resistance induction was approximately 25 micrograms.
- Lipopolysaccharides from E. coli, V. cholerae, S. typhimurium, and S. Minnesota did not induce resistance, but B. pertussis LPS did.
Conclusions:
- Endotoxin likely plays a significant role in the induction of antiviral resistance by pertussis vaccine components.
- Acellular preparations of pertussis vaccine retain significant antiviral activity.
- The findings contribute to understanding the mechanisms of innate immunity and vaccine-adjuvanted protection.