2',5'-Oligoadenylate synthetase activity in lymphocytes from normal mouse

Area of Science:

• Immunology
• Molecular Biology
• Biochemistry

Background:

• 2',5'-oligoadenylate synthetase is an enzyme discovered in interferon-treated cells.
• Its role in normal, untreated cells, particularly lymphocytes, is not well understood.

Purpose of the Study:

• To investigate the presence and activity of 2',5'-oligoadenylate synthetase in normal mouse lymphocytes.
• To determine the functional impact of the synthesized oligoadenylate on protein synthesis.
• To explore the enzyme's distribution in various mouse tissues.

Main Methods:

• Assay of 2',5'-oligoadenylate synthetase activity in mouse spleen lymphocyte extracts.
• Assessment of the synthesized oligoadenylate's effect on protein synthesis using rabbit reticulocyte lysates.
• Analysis of oligomer resistance to T2 ribonuclease digestion.
• Comparison of enzyme levels in lymphocytes versus interferon-treated L929 cells.
• In vitro stimulation of lymphocyte enzyme activity with interferon.
• Tissue distribution analysis of enzyme activity.

Main Results:

• 2',5'-oligoadenylate synthetase activity was detected in normal mouse spleen lymphocytes.
• Lymphocyte extracts containing oligoadenylate inhibited protein synthesis.
• Synthesized oligomers were primarily trimers and resistant to T2 ribonuclease.
• Lymphocyte enzyme levels were 20-30% of interferon-treated L929 cells but enhanced by in vitro interferon.
• The enzyme was found in lymphoid tissues but not brain or liver.

Conclusions:

• Normal lymphocytes possess functional 2',5'-oligoadenylate synthetase.
• This enzyme's activity in lymphocytes suggests a potential role in immune system regulation.
• Interferon can further enhance enzyme activity in lymphocytes.