A pyrogen derived from human white cells which is active in mice

Area of Science:

• Immunology
• Biochemistry

Background:

• Endogenous pyrogens mediate fever and inflammation.
• Previous studies identified larger pyrogens from human white blood cells.

Purpose of the Study:

• To characterize a newly identified, smaller endogenous pyrogen.
• To investigate its biological activity and biochemical nature.

Main Methods:

• Incubation of human white blood cells with zymosan.
• Separation and purification of pyrogenic substances.
• Fever induction studies in mice and rabbits.
• Inhibition studies using cycloheximide and leucine aminopeptidase.

Main Results:

• A novel, low molecular weight endogenous pyrogen was isolated.
• This pyrogen induced fever specifically in mice, not rabbits.
• Its production was inhibited by cycloheximide, suggesting de novo synthesis.
• Inactivation by leucine aminopeptidase indicated a peptide structure.

Conclusions:

• A distinct, peptide-based endogenous pyrogen has been identified.
• This pyrogen exhibits species-specific fever-inducing activity.
• Further research into its role in inflammatory processes is warranted.