Cloning, sequence, and expression of bovine interleukin 2

Area of Science:

• Immunology
• Molecular Biology
• Biochemistry

Background:

• Interleukin 2 (IL-2) is a critical cytokine for immune responses.
• IL-2 cDNA clones have been previously identified in human and murine species.
• Understanding species-specific IL-2 is vital for comparative immunology.

Purpose of the Study:

• To isolate and characterize the cDNA encoding bovine Interleukin 2 (IL-2).
• To determine the structural and sequence homology of bovine IL-2 with its human and murine counterparts.
• To assess the biological activity of synthesized bovine IL-2.

Main Methods:

• Screening a bovine lymph node cell cDNA library using a human IL-2 probe.
• Amino acid sequence alignment and comparison with human and murine IL-2.
• Synthesis of bovine IL-2 in an Escherichia coli expression system.

Main Results:

• Isolation of a cDNA clone for bovine IL-2.
• Bovine IL-2 comprises 155 amino acids (predicted MW 19,555), with mature form having 135 amino acids (predicted MW 15,452).
• Bovine IL-2 shares 65% amino acid homology with human IL-2 and 50% with murine IL-2, featuring a unique N-linked glycosylation site.

Conclusions:

• The study successfully isolated and characterized bovine IL-2 cDNA.
• Bovine IL-2 exhibits significant homology to human and murine IL-2 but possesses unique structural features.
• Biologically active bovine IL-2 can be produced using recombinant expression systems.