Can a functional assay on cytokine kinetics be used for the identification of a disease-related role for Single Nucleotide Polymorphisms (SNPs) in Ankolysing spondylitis?

Interleukin 1α (IL-1α) is a proinflammatory cytokine that belongs to the IL-1 family. It is produced mainly by macrophages at sites of infection and regarded as an essential regulator of acute inflammation. IL-1α is synthesized as a 33 kDa precursor peptide that is cleaved by a calpain-like protease to a nuclear -associated 16 kDa propiece and a secreted 17 kDa mature IL-1α peptide. However, the full understanding of its dual function is missing. Recently, SNPs in the gene for IL-1α was also associated with the risk of developing ankylosing spondylitis (AS), a subgroup of the spondyloarthropathies. These findings lead us to produce antibodies towards the N- and C-terminal region of IL-1α to investigate IL-1α kinetics in human macrophages. This would eventually be used to asses any correlation between a defect in the production of the cytokine and a disease related SNP found in the IL-1α gene in patients suffering from AS. In the present study we generated human macrophages (Mf) from blood monocytes, stimulated the cells with lipopolysaccharide (LPS) and analysed the production and localization of IL-1α by use of monoclonal antibodies (MAbs) generated against recombinant precursor IL-1α. We obtained a MAb specific for the N-terminal propiece and for the C-terminal mature form of IL-1α, respectively. Assays, including DNA sequencing, immunofluorescence microscopy, qPCR and FACS are now available for the analysis of IL-1α kinetics in blood samples from AS patients.