Researchers Hannum and Arend successfully cloned Recombinant Rat IL-1RA CDNA from IgG-induced human monocytes. The length of the CDNA is 1.8kb, encoding 177 amino acids. The 5'UTR is short with 14 nucleotides, while the 3'UTR is long with 113 nucleotides. The AUUUA sequence in the 3'UTR plays a role in regulating the half-life of many cytokines and growth factors mRNA. The N-terminal 25 amino acids of Recombinant Rat IL-1RA are similar to a signal peptide. The mature form of IL-1Ra consists of 152 amino acids with a molecular weight of approximately 17115. Although it contains 4 Cys, it cannot form disulfide bonds.
Eisenber and Goto separately cloned IL-1Ra in mice and rabbits. They found that the precursor protein of IL-1Ra in mice and rats is 178 amino acids long, with a 26 amino acid signal peptide, and a mature protein of 152 amino acids. The precursor protein of rabbit IL-1Ra is 17 amino acids long, with a 34 amino acid signal peptide, and a mature protein of 143 amino acids. Rabbit IL-1Ra lacks 9 amino acids at the N-terminus compared to human and rat IL-1Ra, which prevents glycosylation, although Asn109 is a potential glycosylation site. Rabbit IL-1Ra shares 77% homology with humans, making Recombinant Rat IL-1RA a highly conserved molecule, similar to IL-1 and IL-1a.
1. In the immune system: Recombinant Rat IL-1RA can inhibit the proliferation of TH2 clones induced by IL-1, but has no effect on TH1 clones. It can reduce the expression of TNF mRNA induced by IL-2 in LAK cells and decrease their cell activity. Recombinant Rat IL-1RA also reduces the blastogenesis of human lymphocytes induced by ConA and DNA synthesis of human lymphocytes induced by PHA. IL-1Ra can inhibit the response of human B cells and IgG synthesis. However, when human IL-1Ra is administered to mice, it does not inhibit various antigen-specific immune responses.
2. In the nervous system:
(1) Recombinant Rat IL-1RA can block IL-1-induced fever and non-rapid eye movement sleep (NREMS). Studies have shown that IL-1Ra may not only block IL-1 receptor binding but also interfere with the interaction between IL-1 and its intracellular effectors.
(2) It can block the interaction between IL-1β and temperature-sensitive neurons.
(3) It reduces neuronal death and prevents IL-1-mediated peripheral nerve regeneration.
3. In diabetes: Recombinant Rat IL-1RA inhibits insulin production in rat pancreatic β cells and induces cytotoxicity. However, Recombinant Rat IL-1RA can prevent both of these effects. Studies have also found that IL-1Ra is more effective in inhibiting α cells than β cells, requiring more than 1000 times the concentration of IL-1Ra to inhibit the latter.
[1] Huang, S., & Qin, C. (Year). A new member of the interleukin-1 family - IL-1Ra.
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