Proinflammatory cytokines of the interleukin-36 (IL-36) family are involved in the pathogenesis of different skin diseases in human and mice. Administration of exogenous IL-36 receptor antagonist (IL-36RA) may be an approach to therapy of different dermatitises. For its full biological activity, IL-36RA requires cleavage of N-terminal methionine residue. We created three E. coli strains producing IL-36RA coexpressed with E. coli methionine aminopeptidase under control of different promoters. To test the biological activity of IL-36RA from different strains we transfected А549 cells with plasmid carrying the IL-36 receptor gene (IL1RL2). These cells respond to IL-36g treatment with production of IL-8, which can be quantified with ELISA. IL-36RA treatment disrupts IL-36 receptor activation by IL-36g and production of IL-8. Using this system, we proved that IL-36RA from all three producer strains is fully biologically active.