Immunomodulation by Bordetella pertussis: antiviral effects

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.