Molecular cloning and functional expression of equine interleukin-1 receptor antagonist.

The research paper aimed at molecular cloning and functional analysis of Equine Interleukin-1 receptor antagonist (IL-1ra). The goal was to understand its potential for cytokine therapy in managing acute and chronic inflammatory conditions in horses.

Molecular Cloning of Equine IL-1ra

• The equine IL-1ra was cloned at a molecular level to serve as a basis for cytokine-mediated therapy for managing inflammatory diseases in horses.
• cDNA clones of the entire coding sequence of Equine IL-1ra were isolated from equine peripheral blood mononuclear cells (PBMCs). This isolation was achieved by stimulating the PBMCs using Lipopolysaccharide (LPS).
• IL-1ra cDNA obtained from the study contained an open reading frame capable of coding 177 amino acid residues.

Comparative Analysis

• The amino acid sequence of the equine IL-1ra was compared with the sequences of IL-1ra from humans, mice, and rabbits.
• It was found that the equine IL-1ra shared 75.7% similarity with the human, 75.3% with the murine (mouse), and 76.3% with the rabbit IL-1ras.
• The researchers also identified an N-glycosylation site and five cysteine residues which are conserved in the human, murine, and rabbit IL-1ras also in the same positions in equine IL-1ra.

Functional Expression of the Equine IL-1ra

• The functional expression of the equine IL-1ra was studied as a recombinant fusion with Glutathione S-transferase (GST). This fusion protein was produced by the bacteria, Escherichia coli.
• This fusion protein was purified and was demonstrated to inhibit the cytostatic (stopping cell growth and division) or cytotoxic (cell-killing) activity of IL-1 on A375S2 cells.
• These findings suggest that the equine IL-1ra cloned in the study encodes for a biologically active IL-1ra, which has potential for therapeutic use.