Properties of human urinary interleukin 1 activities

Area of Science:

• Immunology
• Molecular Biology

Background:

• Interleukin 1 (IL 1) is a key intercellular messenger with diverse biological effects.
• IL 1 is produced by various cell types and exhibits pleiotropic activities.

Purpose of the Study:

• To investigate the presence and characteristics of IL 1-like activity in human urine.
• To determine if urinary IL 1 peptides represent functional breakdown products of the native IL 1 molecule.

Main Methods:

• Analysis of low molecular weight peptides in normal human urine.
• Assay of thymocyte comitogenic and fibroblast proliferation activities.
• Separation of urinary fractions using anion exchange chromatography.

Main Results:

• Normal human urine contains 4 kd and 2 kd peptides with IL 1's thymocyte comitogenic activity.
• Only the 2 kd urinary fraction demonstrated fibroblast proliferation activity, similar to intact IL 1.
• Anion exchange chromatography separated the 2 kd fibroblast-stimulating activity from the 2 kd thymocyte-stimulating activity.

Conclusions:

• Urinary IL 1 peptides may be breakdown products of the native 15 kd IL 1.
• Distinct molecular portions of IL 1 are responsible for its different biological effects.
• Measuring urinary IL 1 activity could serve as a diagnostic or prognostic indicator for various diseases.